DNA
Deoxyribonucleic acid (DNA)- A nucleic acid that carries the genetic
information in the cell and is capable of self-replication and
synthesis of RNA. DNA consists of two long chains of nucleotides
twisted into a double helix and joined by hydrogen bonds between
the complementary bases adenine and thymine or cytosine and guanine.
The sequence of nucleotides determines individual hereditary characteristics.
DNA is composed of two long polymer strands of the sugar 2-deoxyribose,
phosphate, and purine and pyrimidine bases. The backbone of each
strand is composed of alternating 2-deoxyribose and phosphate
linked together through phosphodiester bonds. A DNA strand has
directionality; each phosphate is linked to the 3' position of
the preceding deoxyribose and to the 5' position of the following
deoxyribose.
The Four bases Found in DNA
Adenine - A purine base, C5H5N5, that is the constituent involved
in base pairing with thymine in DNA and with uracil in RNA
Thymine - Thiamine plays a role in promoting growth & repair
of body tissues.
Guanine - A purine base, C5H5ON5, that is an essential constituent
of both RNA and DNA.
Cytosine - A pyrimidine base, C4H5N3O, that is the constituent
of DNA and RNA involved in base pairing with guanine.
Each 2-deoxyribose is linked to one of the four bases via a covalent
glycosidic bond, forming a nucleotide. The sequence of these four
bases allows DNA to carry genetic information. Bases can form
hydrogen bonds with each other. Adenine forms two bonds with thiamine,
and cytosine forms three bonds with guanine. These two sets of
base pairs have the same geometry, allowing DNA to maintain the
same structure regardless of the specific sequence of base pairs.
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RNA
Ribonucleic Acid (RNA) - One of the two main types of nucleic
acid (the other being DNA), which functions in cellular protein
synthesis in all living cells and replaces DNA as the carrier
of genetic information in some viruses. Like DNA, it consists
of strands of repeating nucleotides joined in chainlike fashion,
but the strands are single (except in certain viruses), and it
has the nucleotide uracil (U) where DNA has thymine (T). Messenger
RNA (mRNA), a single strand copied from a DNA strand that acts
as its template, carries the message of the genetic code from
DNA (in chromosomes) to the site of protein synthesis (on ribosomes).
Ribosomal RNA (rRNA), part of the building blocks of ribosomes,
participates in protein synthesis. Transfer RNA (tRNA), the smallest
type, has fewer than 100 nucleotide units (mRNA and rRNA contain
thousands). Each nucleotide triplet on mRNA specifies which amino
acid comes next on the protein being synthesized, and a tRNA molecule
with that triplet's complement on its protruding end brings the
specified amino acid to the site of synthesis to be linked into
the protein.
Ribonucleic acid (RNA) is a biologically important type of molecule
that consists of a long chain of nucleotide units. Each nucleotide
consists of a nitrogenous base, a ribose sugar, and a phosphate.
RNA is very similar to DNA, but differs in a few important structural
details: in the cell, RNA is usually single-stranded, while DNA
is usually double-stranded; RNA nucleotides contain ribose while
DNA contains deoxyribose (a type of ribose that lacks one oxygen
atom); and RNA has the base uracil rather than thymine that is
present in DNA.
RNA is transcribed from DNA by enzymes called RNA polymerases
and is generally further processed by other enzymes. RNA is central
to protein synthesis. Here, a type of RNA called messenger RNA
carries information from DNA to structures called ribosomes. These
ribosomes are made from proteins and ribosomal RNAs, which come
together to form a molecular machine that can read messenger RNAs
and translate the information they carry into proteins. There
are many RNAs with other roles in particular regulating which
genes are expressed, but also as the genomes of most viruses.
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Nucleic
Acids
Any of a group of organic substances found in the chromosomes
of living cells and viruses that play a central role in the storage
and replication of hereditary information and in the expression
of this information through protein synthesis. In most organisms,
nucleic acids occur in combination with proteins; the combined
substances are called nucleoproteins. Nucleic acid molecules are
complex chains of varying length. The two chief types of nucleic
acids are DNA (deoxyribonucleic acid), which carries the hereditary
information from generation to generation, and RNA (ribonucleic
acid), which delivers the instructions coded in this information
to the cell's protein manufacturing sites.
A substance that he called nuclein (now known as DNA) was isolated
by 1869 by Friedrich Miescher, but it was only in the last half
of the 20th cent. that that research revealed its significance
as the material of which the gene is composed, and thus its function
as the chemical bearer of hereditary characteristics. RNA was
first made by laboratory synthesis in 1955. In 1965 the nucleotide
sequence of tRNA was determined, and in 1967 the synthesis of
biologically active DNA was achieved. The amount of RNA varies
from cell to cell, but the amount of DNA is normally constant
for all typical cells of a given species of plant or animal, no
matter what the size or function of that cell.
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Flavonoids
Flavonoids (or bioflavonoids), also collectively known as Vitamin
P and citrin are polyphenolic compounds that are ubiquitous in
nature and are categorized, according to chemical structure, into
flavonols, flavones, flavanones, isoflavones, catechins, anthocyanidins
and chalcones. Over 4,000 flavonoids have been identified, many
of which occur in fruits, vegetables and beverages (tea, coffee,
beer, wine and fruit drinks). The flavonoids have aroused considerable
interest recently because of their potential beneficial effects
on human health-they have been reported to have antiviral, anti-allergic,
antiplatelet, anti-inflammatory, antitumor and antioxidant activities.
Some of the flavonoids have pharmacological actions, but they
are not known to be dietary essentials, although claims have been
made (they were at one time classified as vitamin P), and are
sometimes called bioflavonoids. They may make a contribution to
the total antioxidant intake, and some are phytoestrogens.
Flavonoids (both flavonols and flavanols) are most commonly known
for their antioxidant activity.
Flavonoids (specifically flavanoids such as the catechins) are
"the most common group of polyphenolic compounds in the human
diet and are found ubiquitously in plants". Flavonols, the original
bioflavonoids such as quercetin, are also found ubiquitously,
but in lesser quantities.
Benefits of Flavniods
Flavonoids are widely disbursed throughout plants and are what
give the flowers and fruits of many plants their vibrant colors.
They also play a role in protecting the plants from microbe and
insect attacks. More importantly, the consumption of foods containing
flavonoids has been linked to numerous health benefits. Though
research shows flavonoids alone provide minimal antioxidant benefit
due to slow absorption by the body, there is indication that they
biologically trigger the production of natural enzymes that fight
disease.
Recent research indicates that flavonoids can be nutritionally
helpful by triggering enzymes that reduce the risk of certain
cancers, heart disease, and age-related degenerative diseases.
Some research also indicates flavonoids may help prevent tooth
decay and reduce the occurrence of common ailments such as the
flu.
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Phenolic
Acids
Phenolic acids are plant metabolites widely spread throughout
the plant kingdom. Recent interest in phenolic acids stems from
their potential protective role, through ingestion of fruits and
vegetables, against oxidative damage diseases (coronary heart
disease, stroke, and cancers). Phenolic compounds are essential
for the growth and reproduction of plants, and are produced as
a response for defending injured plants against pathogens. The
importance of antioxidant activities of phenolic compounds and
their possible usage in processed foods as a natural antioxidant
have reached a new high in recent years.
Phenolics in Plants Phenolic acid compounds seem to be universally
distributed in plants. They have been the subject of a great number
of chemical, biological, agricultural, and medical studies. Phenolic
acids form a diverse group that includes the widely distributed
hydroxybenzoic and hydroxycinnamic acids.
Hydroxycinnamic acid compounds occur most frequently as simple
esters with hydroxy carboxylic acids or glucose. Hydroxybenzoic
acid compounds are present mainly in the form of glucosides.
Phenolics in Plants
Phenolic acid compounds seem to be universally distributed in
plants. They have been the subject of a great number of chemical,
biological, agricultural, and medical studies. Phenolic acids
form a diverse group that includes the widely distributed hydroxybenzoic
and hydroxycinnamic acids. Hydroxycinnamic acid compounds occur
most frequently as simple esters with hydroxy carboxylic acids
or glucose. Hydroxybenzoic acid compounds are present mainly in
the form of glucosides.
Chemistry of Phenolics
Plant phenolic compounds are diverse in structure but are characterised
by hydroxylated aromatic rings (e.g. flavan-3-ols). They are categorised
as secondary metabolites, and their function in plants is often
poorly understood. Many plant phenolic compounds are polymerised
into larger molecules such as the proanthocyanidins (PA; condensed
tannins) and lignins.
Furthermore, phenolic acids may occur in food plants as esters
or glycosides conjugated with other natural compounds such as
flavonoids, alcohols, hydroxyfatty acids, sterols, and glucosides.
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Terpenes
Terpenes are a large and varied class of hydrocarbons, produced
primarily by a wide variety of plants, particularly conifers,
though also by some insects such as termites or swallowtail butterflies,
which emit terpenes from their osmeterium. They are the major
components of resin, and of turpentine produced from resin. The
name "terpene" is derived from the word "turpentine". In addition
to their roles as end-products in many organisms, terpenes are
major biosynthetic building blocks within nearly every living
creature. Steroids, for example, are derivatives of the triterpene
squalene.
Terpenes (pinene, nerol, citral, menthol, d-limonene and others)
are widespread in nature, mainly in plants as constituents of
essential oils.
Terpenes, which are GRAS (Generally Recognized As Safe) have
been found to inhibit the growth of cancerous cells, decrease
tumor size, decrease cholesterol levels and decrease microorganism
concentration in vitro.
Terpenes i.e. geraniol, tocotrienol, perillyl alcohol, b-ionone
and d-limonene suppress hepatic HMG-COA reductase activity, a
rate limiting step in cholesterol synthesis, and modestly lower
cholesterol levels in animals . D-limonene and geraniol reduced
mammary tumors or suppressed the growth of transplanted tumors.
Terpenes (citral, geraniol, eugenol, menthol, cinnamic aldehyde)
have also been found to inhibit the in-vitro growth of bacteria
and fungi and some internal and external parasites.
There may be different modes of action of terpenes against bacteria.
They could:
(1) Interfere with the phospholipid bilayer of the cell membrane
(2) Impair a variety of enzyme systems (HMG-reductase) and
(3) Destroy or inactivate genetic material.
Uses of Terpenes
1. Terpene mixture or liposome-terpene combination to the diet
or to the drinking water will improve animal health, body weight
and efficiency of feed conversion because of the reduced microbial
load (Performance Improvement).
2. Terpene mixture or a liposome:terpene combination to the diet
or to the drinking water will reduce the microbial load, not only
in feed and water, but also in the intestine. Pathogenic bacteria
like salmonella, E. coli and listeria will be decreased, thereby
reducing the chance of contamination and the risk of pathogenic
microorganisms in the final edible product (Feed Withdrawal).
3. Terpene mixture or a liposome:terpene combination will reduce
the bacterial contamination in the scalder and chiller water,
therefore decreasing bacterial contamination of carcasses (Processing
Plant).
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Nucleosides
Nucleosides are glycosylamines consisting of a nucleobase (often
referred to simply base) bound to a ribose or deoxyribose sugar.
Examples of these include cytidine, uridine, adenosine, guanosine,
thymidine and inosine.
Nucleosides can be phosphorylated by specific kinases in the cell
on the sugar's primary alcohol group (-CH2-OH), producing nucleotides,
which are the molecular building blocks of DNA and RNA.
Nucleosides can be produced by de novo synthesis pathways, particularly
in the liver, but they are more abundantly supplied via ingestion
and digestion of nucleic acids in the diet, whereby nucleotidases
break down nucleotides (such as the thymine nucleotide) into nucleosides
(such as thymidine) and phosphate. The nucleosides, in turn, are
subsequently broken down:
in the lumen of the digestive system by nucleosidases into nucleobases
and ribose or deoxyribose.
inside the cell into nitrogenous bases, and ribose-1-phosphate
or deoxyribose-1-phosphate.
In medicine several nucleoside analogues are used as antiviral
or anticancer agents. The viral polymerase incorporates these
compounds with non-canonical bases. These compounds are activated
in the cells by being converted into nucleotides, they are administered
as nucleosides since charged nucleotides cannot easily cross cell
membranes.
In molecular biology several analogues of the sugar back bone
exist. Due to the low stability of RNA, which is prone to hydrolysis,
several more stable alternative nucleoside/nucleotide analogues
are used which correctly bind to RNA. This is achieved by using
a different backbone sugar. These analogues include LNA, morpholino,
PNA.
In sequencing dideoxynucleotides are used. These nucleotides possess
the non-canon sugar dideoxyribose, which lacks 3' hydroxyl group
(which accepts the phosphate) and therefore cannot bond with the
next base, terminating the chain as DNA polymerases mistake it
for a regular deoxyribonucleotide.
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Guanine
Guanine is one of the five main nucleobases found in the nucleic
acids DNA and RNA, the others being adenine, cytosine, thymine,
and uracil. In DNA, guanine is paired with cytosine. With the
formula C5H5N5O, guanine is a derivative of purine, consisting
of a fused pyrimidine-imidazole ring system with conjugated double
bonds. Being unsaturated, the bicyclic molecule is planar. The
guanine nucleoside is called guanosine.
Guanine is also the name of a white amorphous substance found
in the scales of certain fishes, the guano of sea-birds, and the
liver and pancreas of mammals.
Basic Principles
Guanine, along with adenine and cytosine, is present in both DNA
and RNA, whereas thymine is usually seen only in DNA, and uracil
only in RNA. Guanine has two tautomeric forms, the major keto
form (see figures) and rare enol form. It binds to cytosine through
three hydrogen bonds. In cytosine, the amino group acts as the
hydrogen donor and the C-2 carbonyl and the N-3 amine as the hydrogen-bond
acceptors. Guanine has a group at C-6 that acts as the hydrogen
acceptor, while the group at N-1 and the amino group at C-2 act
as the hydrogen donors.
The first isolation of guanine was reported in 1844 from the excreta
of sea birds, known as guano, which was used as a source of fertilizer.
About fifty years later, Fischer determined the structure and
also showed that uric acid can be converted to guanine. Facial
treatments using the droppings, or guano, from Japanese nightingales
is currently in favor in New York, reportedly because the guanine
in the droppings produces a clear, "bright" skin tone that some
people find desirable to attain.
Guanine can be hydrolyzed with strong acid to glycine, ammonia,
carbon dioxide, and carbon monoxide. Guanine is first deaminated
to xanthine. Guanine oxidizes more readily than adenine, the other
purine-derivative base in DNA. Its high melting point of 350°C
reflects the intermolecular hydrogen bonding between the oxo and
amino groups in the molecules in the crystal. Because of this
intermolecular bonding, guanine is relatively insoluble in water,
but it is soluble in dilute acids and bases.
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Auxins
The term auxin is derived from the Greek word auxein which means
to grow. Compounds are generally considered auxins if they can
be characterized by their ability to induce cell elongation in
stems and otherwise resemble indoleacetic acid (the first auxin
isolated) in physiological activity. Auxins usually affect other
processes in addition to cell elongation of stem cells but this
characteristic is considered critical of all auxins and thus "helps"
define the hormone
Molecular Mechanisms
Auxins directly stimulate or inhibit the expression of specific
genes. Auxin induces transcription by targeting for degradation
members of the Aux/IAA family of transcriptional repressor proteins,
The degradation of the Aux/IAAs leads to the derepression of Auxin
Respose Factors ARF-mediated transcription. Aux/IAAs are targeted
for degradation by ubiquitination, catalysed by an SCF-type ubiquitin-protein
ligase.
In 2005, it was demonstrated that the F-box protein TIR1, which
is part of the ubiquitin ligase complex SCFTIR1, is an auxin receptor.
Upon binding of auxin, TIR1 recruits specific transcriptional
repressors (the Aux/IAA repressors) for ubiquitination by the
SCF complex. This marking process leads to the degradation of
the repressors by the proteasome, alleviating repression and leading
to expression of specific genes in response to auxins (reviewed
in.
Another protein called ABP1 (Auxin Binding Protein 1) is a putative
receptor, but its role is unclear. Electrophysiological experiments
with protoplasts and anti-ABP1 antibodies suggest that ABP1 may
have a function at the plasma membrane.
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Fructose
Fructose (also levulose) is a simple monosaccharide found in many
foods. It is a white solid that dissolves readily in water. Honey,
tree fruits, berries, melons, and some root vegetables, contain
significant amounts of the fructose derivative sucrose (table
sugar). Sucrose is a disaccharide derived from the condensation
of glucose and fructose.
Fructose is a natural simple sugar found in fruits, honey, and
vegetables. In its pure form, fructose has been used as a sweetener
since the mid 1850s and has advantages for certain groups, including
people with diabetes and those trying to control their weight.
Of course, fructose has been consumed for centuries in foods we
still eat. It is known as a simple sugar because it is a single
sweetening molecule. Fructose is also known as a monosaccharide.
High fructose corn syrup (HFCS) is also a sweetener and is used
to sweeten foods and beverages. However, HFCS is not the same
as fructose. HFCS is a mixture of fructose and glucose, made by
an enzymatic process from glucose syrup from corn. The most common
forms are HFCS-42 and HFCS-55, which contain 42% fructose (and
58% glucose) or 55% (and 45% glucose). Table sugar (sucrose) has
50% fructose (and 50% glucose) and so is very similar to HFCS.
Misinformation about fructose recently appeared in the media.
This misinformation alleges obesity and negative health consequences
from the consumption of HFCS and fructose. Many incorrectly use
the terms fructose and HFCS interchangeably, confusing the
public as well as health and nutrition professionals. It is important
to be aware of the differences between these sweeteners.
Fructose is a natural sweetener that provides people with many
different benefit. To get the many benefits of this sweetener,
consume this product in small amounts because larger amounts can
cause health problems.
Benefits of Fructose
Sweetness
When using fructose, you will find that it is far sweeter than
sucrose. If you want to enhance your spicy food or add more flavor
to your fruity drinks, adding fructose is the way to go. Fructose
can come in many forms such as fruit, vegetables and in honey.
Long Storage Capacity
One of the best benefits of fructose is that it can be stored
for long periods of time, in some cases up to six months. Using
fructose allows your food to maintain its flavor, freshness and
taste much longer than using sucrose.
Smells Extremely Good
When using fructose in your baked foods, you may find that it
helps give your food that soft brown color and that delicious
smell that brings everyone to the dinner table.
Low Glycemic Index
Because of its low glycemic index number, fructose will not affect
your personal glucose level and will help you maintain a healthy
weight. With natural fructose, you have a sweetener that is used
more slowly and gives you more energy than regular sugar, which
allows you to burn calories.
Conclusion
Although some imply that HFCS and fructose are the same, they
are different sweeteners.
Consuming HFCS has essentially the same results as consuming
table sugar (sucrose).
Fructose helps to reduce calories in foods and drinks when used
in appropriate product formulations.
Obesity and diabetes are unlikely to be caused by one particular
food or food ingredient.
Fructose does not cause surges and dips in blood glucose levels
so it may be helpful to people with diabetes to reduce
post-prandial glycemia and to help limit calories
in foods requiring bulk sweeteners.
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Glucose
Glucose (Glc), a monosaccharide (or simple sugar) also known as
grape sugar, blood sugar, or corn sugar, is a very important carbohydrate
in biology. The living cell uses it as a source of energy and
metabolic intermediate. Glucose is one of the main products of
photosynthesis and starts cellular respiration in both prokaryotes
(bacteria and archaea) and eukaryotes (animals, plants, fungi,
and protists). The name "glucose" comes from the Greek word glukus,
meaning "sweet", and the suffix "-ose," which denotes a sugar.
Two stereoisomers of the aldohexose sugars are known as glucose,
only one of which (D-glucose) is biologically active. This form
(D-glucose) is often referred to as dextrose monohydrate, or,
especially in the food industry, simply dextrose (from dextrorotatory
glucose). This article deals with the D-form of glucose. The mirror-image
of the molecule, L-glucose, cannot be metabolized by cells in
the biochemical process known as glycolysis.
Our body's primary source of energy takes the form of glucose.
This type of sugar comes from digesting carbohydrates into a chemical
that we can easily convert to energy. When glucose levels in the
bloodstream aren't properly regulated, one can develop a serious
condition, such as diabetes.
Vegetables, and processed sweets qualify as carbohydrates. Our
digestive system, using bile and enzymes, breaks down the starch
and sugar in these foods into glucose. This functional form of
energy then gets absorbed through the small intestine into the
bloodstream. There, a chemical known as insulin, excreted by the
pancreas, meets the glucose. Together, they can enter cells in
muscles and the brain, allowing glucose to power activities like
lifting a book or remembering a phone number.
Since it is such a vital form of energy, and interacts with both
the digestive and endocrine system, keeping glucose within a normal
range is extremely important to health. Our body has adapted to
maintain this ideal level by storing extra glucose in the liver
as glycogen, so it can be reabsorbed when our levels drop. We
can also speed or slow the release of insulin. However, at any
step in the process, problems can arise in keeping the right amount
of glucose circulating in the blood.
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Brassins
Brassins is a a new family of plant hormones from rape pollen.
They are specific translocatable organic compounds isolated from
a plant and have induced measurable growth control when applied
in minute amounts to another plant.
Brassinosteroids (BR) are a group of steroidal plant hormones.
Brassinolide was the first of these steroid compounds discovered
in 1973, when it was shown that pollen from Brassica napus could
promote stem elongation and cell divisions and that the biologically
active molecule was a steroid that the authors called Brassins.
The yield of Brassinosteriods from 230 kg of Brassica napus pollen
was only 10 mg. Since their discovery, over 70 BR compounds have
been isolated from plants.
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Gibberellins
Gibberellins are defined as a class of related plant hormones
that stimulate growth in the stem and leaves, trigger the germination
of the seed and breaking of bud dormancy, and stimulate fruit
development with auxin.
Unlike the classification of auxins which are classified on the
basis of function, gibberellins are classified on the basis of
structure as well as function. All gibberellins are derived from
the ent-gibberellane skeleton. The structure of this skeleton
derivative along with the structure of a few of the active gibberellins
are shown above. The gibberellins are named GA1....GAn in order
of discovery. Gibberellic acid, which was the first gibberellin
to be structurally characterised , is GA3. There are currently
136 GAs identified from plants, fungi and bacteria.
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Kinins
Kinins are proteins in the blood that affect certain muscle contractions
and blood pressure (especially low blood pressure). Kinins are
among the naturally occurring agents involved in inflammatory
reactions. All the processes of kinin generation appear to be
accentuated: the expression of prekininogen mRNA; the production
of kinin precursors (kinonogens) by the liver; the activation
of the generating enzymes, the kallikreins; and the local production
of kinins in inflammatory exudates. The kinins generated locally
contribute to the acute and possibly the chronic phase of the
inflammatory reaction by producing vasodilation, local oedema
and pain. Kinins may also modulate migration of white blood and
tissue cells that take part to the inflammatory process.
Defects of the kinin-kallikrein system or simply kinin system
in diseases are not generally recognized. The system is the subject
of much research due to its relationship to the inflammation and
blood pressure systems. It is known that kinins are inflammatory
mediators that cause dilation of blood vessels and increased vascular
permeability. Kinins are small peptides produced from kininogen
by kallikrein and are broken down by kininases. They act on phospholipase
and increase arachidonic acid release and thus prostaglandin (PGE2)
production.
Benefits of Kinins
Increase blood flow throughout the body.
Make it easier for fluids to pass through small blood vessels
(capillaries).
Stimulate pain receptors.
Are part of a complex system that helps repair damaged tissue
in the body.
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Vernine
Vernine is an alkaloid extracted from the shoots of the vetch,
red clover, etc., as a white crystalline substance. Alkaloid is
Basic organic compounds of plant origin, containing combined nitrogen.
Alkaloids are amines, so their names usually end in "ine" (e.g.,
caffeine, nicotine, morphine, quinine). Most have complex chemical
structures of multiple ring systems. They have diverse, important
physiological effects on humans and other animals.
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Saponins
Saponins is a phytonutrients found in grape skins, lower cholesterol
and fight inflammation.
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Xanthine
Xanthine is a substance found in caffeine, theobromine, and theophylline
and encountered in tea, coffee, and the colas. Chemically, xanthine
is a purine.
Xanthine is a nitrogenous compound closely allied to uric acid,
that occurs in extract of meat and in tea. It forms a colourless
powder slightly soluble in water, and yields alloxan and urea
on oxidation.
The name "xanthine" was taken from the Greek "xanqos" meaning
yellow + quinine since it forms yellow salts and its solution
forms a blue fluorescence as does quinine.
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Hypoxanthine
Hypoxanthine is a naturally occurring purine derivative. It is
occasionally found as a constituent of nucleic acids where it
is present in the anticodon of tRNA in the form of its nucleoside
inosine. It is also known as 6-Hydroxypurine. Hypoxanthine is
a necessary additive in certain cell, bacteria and parasite cultures
as a substrate and nitrogen source. For example it is commonly
a required reagent in malaria parasite cultures since Plasmodium
falciparum requires a source of hypoxanthine for nucleic acid
synthesis and energy metabolism.
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Nuclein
Any of the substances present in the nucleus of a cell, consisting
chiefly of proteins, phosphoric acids, and nucleic acids. Nucleic
Acid is any of a group of complex compounds found in all living
cells and viruses, composed of purines, pyrimidines, carbohydrates,
and phosphoric acid. Nucleic acids in the form of DNA and RNA
control cellular function and heredity.
Nuclien is the term used by Friedrich Miescher to describe the
nuclear material he discovered in 1869, which today is known as
DNA.
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Amines
Amines are organic compounds and functional groups that contain
a basic nitrogen atom with a lone pair. The lone pair of electrons
on the amine nitrogen enables amines to participate in a large
variety of reactions as a base or a nucleophile. Amines play prominent
roles in biochemical systems; they are widely distributed in nature
in the form of amino acids, alkaloids, and vitamins. Many complex
amines have pronounced physiological activity, for example, epinephrine
(adrenalin), thiamin or vitamin B1, and Novocaine. The odor of
decaying fish is due to simple amines produced by bacterial action.
Amines are used to manufacture many medicinal chemicals, such
as sulfa drugs and anesthetics. The important synthetic fiber
nylon is an amine derivative.
Compounds with the nitrogen atom attached to a carbonyl of the
structure R-C(=O)NR2 are called amides and have different chemical
properties from amines.
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Lecithin
Chemically lecithin is phosphatidyl choline; a phospholipid containing
choline. Commercial lecithin, prepared from soya bean, peanut,
and maize, is a mixture of phospholipids in which phosphatidyl
choline predominates. Used in food processing as an emulsifier,
e.g. in salad dressing, processed cheese, and chocolate, and as
an anti-spattering agent in frying oils. Is plentiful in the diet
and not a dietary essential.
Lecithin is a compound consisting of two fatty acid chains, a
phosphate group, and a base (choline), present in egg yolk and
soya beans. It is also called phosphatidyl-choline. Lecithin usually
contains a high proportion of linoleic acid. It is often added
to processed foods as an emulsifying agent, binding food components
together and making them more soluble. In the body, lecithin is
a component of cell membranes, including the myelin sheath around
nerves, and it is involved in fat metabolism. It has been claimed
that lecithin helps cholesterol bind to the high density lipoproteins
that remove the cholesterol from tissues. The involvement of lecithin
in fat mobilization has led to it being sold as a slimming aid,
but there is no evidence that it helps weight reduction. On the
contrary it is probably just as fattening as other vegetable oils.
Some coaches prescribe lecithin in post-competition diets because
they believe it accelerates recovery.
Benefits of Lecithin
Acts as an emulsifier and helps the body in the absorption of
fats.
A possible resource for lowering blood cholesterol because of
its reputation as a source of polyunsaturated fats.
Has a possible benefit to brain function, and supporters claim
that it may help prevent Alzheimer's disease.
Can be used to help lower cholesterol and deter memory loss.
Helps the liver metabolize fat and form lipoproteins.
Choline in lecithin may have the ability to penetrate the blood-brain
barrier and impact the production of acetylcholine, a
neurotransmitter that facilitates brain function.
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Xanthophylls
Yellow pigment in plants that, like chlorophyll, is responsible
for the production of carbohydrates by photosynthesis. Yellow-orange
hydroxylated carotene derivatives; occur in all green leaves together
with the chlorophyll and carotene, also present in egg yolk, Cape
gooseberry, rose hips, etc. Most have no vitamin A activity. Include
flavoxanthin, lutein, cryptoxanthin, which is converted into vitamin
A, rubixanthin, rhodoxanthin, and canthaxanthin.
The group of xanthophylls includes lutein, zeaxanthin, neoxanthin,
violaxanthin, and ?- and ?-cryptoxanthin. The latter compound
is the only known xanthophyll to contain a beta-ionone ring, and
thus ?-cryptoxanthin is the only xanthophyll which is known to
possess pro-vitamin A activity (and then only in plant-eating
species which possess the enzyme to make retinal from carotenoids).
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Crocetin
Crocetin is a natural carotenoid dicarboxylic acid that is found
in the crocus flower. It forms brick red crystals with a melting
point of 285 °C. The chemical structure of crocetin is the central
core of crocin, the compound responsible for the color of saffron.
Crocetin has long been used as a traditional ancient medicine
against different human diseases including cancer.
A recent study involving 14 individuals indicated that oral administration
of crocetin may decrease the effects of physical fatigue in healthy
men.
A stabilized crocetin-containing colorant which has as an effective
component a crocetin included by cyclodextrin. This colorant is
imparted with resistance against light and various chemicals to
crocetin, which is a hydrolysate of crocin, the main component
of the carotenoid gardenia yellow pigment. The colorant may be
added to various food products for use of crocetin as a stable
coloring matter.
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Zeaxanthin
Zeaxanthin is a yellow-colored plant pigment. It has strong antioxidant
properties and is one of two yellow carotenoids found in the retina.
It is abundant in spinach, collard greens, kale and corn. It acts
to filter and shield harmful blue light from the eye and protects
against age-related cataracts and macular degeneration, the leading
cause of blindness in people over 65. Macular degeneration is
a disease that destroys the central portion of the retina, the
light-gathering cells at the back of the eye. As the disease progresses,
the center of the field of vision begins to blur, making it difficult
to read, drive, and recognize faces. Zeaxanthin and Lutein can
restore macular pigment density, which declines with age.
The name is derived from Zea mays (common yellow maize corn) in
which zeaxanthin provides the primary yellow pigment, plus the
Greek word for yellow.
Zeaxanthin and Lutein are carotenoids found in highest concentration
in the macular region of the eyes (the back of the eye where the
retina is located), where they are believed to help filter out
damaging blue light and prevent free radical damage to the delicate
structures in the back of the eye.
Benefits of Zeaxanthin
Prevents age-related macular degeneration (ARMD)
May help prevent glaucoma and cataracts
Supports normal eye health
Antioxidant
Theory
Because antioxidants can provide increased protection against
the oxidizing ultraviolet radiation of the sun, anybody that spends
time outdoors exposed to the sun should be concerned with the
potential for ultraviolet radiation to damage eye health and impact
vision. Lutein and zeaxanthin are the only carotenoids that become
concentrated in the retinal region of the eye known as the macula.
High dietary intake of lutein-rich fruits and vegetables has been
associated with a significant reduction in macular degeneration
the leading cause of blindness in Americans over the age of
65.
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Lycopene
Lycopene is a pigment that gives vegetables and fruits, such as
tomatoes, pink grapefruit and watermelon, their red color. It
also appears to have strong antioxidant capabilities. Several
studies suggest that consumption of foods rich in lycopene is
associated with a lower risk of prostate cancer and cardiovascular
disease.
However lycopene has a greater property than food colouring. It
is a strong antioxidant, which can help to combat degenerative
diseases such as heart disease. It was found that increased concentration
of lycopene gave an increased protective effect, so the most concentrated
food sources, like tomato puree and ketchup, are better protectors
against these diseases. However the human body cannot produce
this molecule and needs to obtain it from tomatoes in our diet.
High lycopene foods like soup are the most effective against degenerative
diseases. There have been many recent studies into lycopene so
that it can be used to its fullest potential in fighting these
diseases.
It helps prevent degenerative diseases by donating its electrons
to oxygen free radicals thus quenching and neutralising them before
they can damage cells. Free radicals are molecules that have at
least one unpaired electron. By donating an electron lycopene
can stabilise the free molecule.
Benefits of Lycopene
It could reduce the risk of a heart attack.
Lycopene can be used as an anti-carcinogen, greatly reducing
the risk of some cancers.
Lycopene may be the most powerful carotenoid quencher of singlet
oxygen.
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Hexodecanal
In
enzymology, a hexadecanol dehydrogenase (EC 1.1.1.164) is an enzyme
that catalyzes the chemical reaction
hexadecanol + NAD+ \rightleftharpoons hexadecanal + NADH + H+
Thus, the two substrates of this enzyme are hexadecanol and NAD+,
whereas its 3 products are hexadecanal, NADH, and H+.
This enzyme belongs to the family of oxidoreductases, specifically
those acting on the CH-OH group of donor with NAD+ or NADP+ as
acceptor. The systematic name of this enzyme class is hexadecanol:
NAD+ oxidoreductase.
Oxidoreductases are a class of enzymes that catalyze oxidoreduction
reactions.
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Alpha-Amino-butyric-Acid
Alpha-Amino-butyric-Acid or Aminobutyric acid (ABA), when introduced
onto Arabidopis plants, has the ability to induce resistance to
certain pathogens. ABA protects these plants against pathogens
through activation of natural defense mechanisms of the plant,
such as callose deposition, the hypersensitive response (HR),
and the formation of trailing necroses. The induced resistance
is often associated with a process called priming, which is an
increased capacity to mobilize cellular defense responses. The
process of priming also occurred in grapevine plants (Vitis vinifera)
in order to build resistance against downy mildew.
Alpha-Amino-butyric-Acid is an isomer of the amino acid aminobutyric
acid with chemical formula C4H9NO2. There is also gamma-aminobutyric
acid (GABA) and beta-aminobutyric acid.
It is a key intermediate in the biosynthesis of ophthalmic acid
or ophthalmate, which was first isolated from calf lens.
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Monoglycerides
Monoacylglycerols are found in very low amounts in cell extracts but are intermediates in the degradation of triacylglycerols or diacylglycerols (lipolysis). When diacylglycerols are hydrolyzed by lingual and pancreatic lipases, sn-2-monoacylglycerols are formed but an important proportion is isomerized in the duodenum in sn-1 and sn-3-monoacylglycerols which again can be hydrolyzed (the sn-2 position is lipase resistant). This physiological mechanism is based on the acyl migration from the sn-2 position to the sn-1 or 3 position, migration which is also commonly observed experimentally during purification and in acidic medium. The use of borate ions, added in solvents or on silica gel plates, tends to prevent such artifact.
The abiotic synthesis of Monoacylglycerols has been shown to be
possible in the laboratory under simulated hydrothermal conditions
(Rushdi AI et al., Orig Life Evol Biosph 2006, 36, 93). These
results indicate that condensation reactions under these primitive
physical conditions may be the source of compounds for abiotic
membranes which are candidates for micelle/vesicle formation at
the beginning of life.
Monoacylglycerols are the most polar components of simple lipids (they have only one hydrocarbon chain and 2 alcohol groups) and, thus, need care to prevent their loss in hydrophilic solutions and on chromatographic columns. Furthermore, they have detergent properties, hence they easily form micelles in water solutions.
Monoacylglycerols with saturated or unsaturated fatty acids are by far the most commonly used food surfactants. Surfactants are used in the food industry to prepare food products and increase their shelf life. They give to emulsions their stability and the required viscosity. The first use of monoacylglycerols on an industrial scale was, more than 50 years ago, for making margarine where they emulsify the water phase in oil and fat phase.
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Diglycerides
These lipids (known also as diglycerides) are fatty acid diesters
of glycerol and occur in two isomeric forms. Diglycerides are
surface active molecules that both attract and repel water at
the same time. These hydrophilic and hydrophobic properties make
them excellent emulsifying agents because they are soluble in
fats and water. While substances like oil and water naturally
separate, the addition of an emulsifier can help disperse the
molecules evenly.
A diglyceride, or a diacylglycerol (DAG), is a glyceride consisting of two fatty acid chains covalently bonded to a glycerol molecule through ester linkages. One example, shown on the right, is 1-palmitoyl-2-oleoyl-glycerol, which contains side-chains derived from palmitic acid and oleic acid. Diacylglycerols can also have many different combinations of fatty acids attached at both the C-1 and C-2 positions.
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Triglycerides
Triglyceride(more properly known as Triacylglycerol.ogg triacylglycerol,
TAG or triacylglyceride) is a glyceride in which the glycerol
is esterified with three fatty acids. It is the main constituent
of vegetable oil and animal fats.
Triglycerides are formed from a single molecule of glycerol, combined with three fatty acids on each of the OH groups, and make up most of fats digested by humans. Ester bonds form between each fatty acid and the glycerol molecule. This is where the enzyme pancreatic lipase acts, hydrolysing the bond and "releasing" the fatty acid. In triglyceride form, lipids cannot be absorbed by the duodenum. Fatty acids, monoglycerides (one glycerol, one fatty acid) and some diglycerides are absorbed by the duodenum, once the triglycerides have been broken down.
Triglycerides, as major components of very low density lipoprotein (VLDL) and chylomicrons, play an important role in metabolism as energy sources and transporters of dietary fat. They contain more than twice as much energy (9 kcal/g) as carbohydrates and proteins. In the intestine, triglycerides are split into monoacylglycerol and free fatty acids in a process called lipolysis, with the secretion of lipases and bile, which are subsequently moved to absorptive enterocytes, cells lining the intestines. The triglycerides are rebuilt in the enterocytes from their fragments and packaged together with cholesterol and proteins to form chylomicrons. These are excreted from the cells and collected by the lymph system and transported to the large vessels near the heart before being mixed into the blood. Various tissues can capture the chylomicrons, releasing the triglycerides to be used as a source of energy. Fat and liver cells can synthesize and store triglycerides. When the body requires fatty acids as an energy source, the hormone glucagon signals the breakdown of the triglycerides by hormone-sensitive lipase to release free fatty acids. As the brain cannot utilize fatty acids as an energy source (unless converted to a ketone), the glycerol component of triglycerides can be converted into glucose, via gluconeogenesis, for brain fuel when it is broken down. Fat cells may also be broken down for that reason, if the brain's needs ever outweigh the body's.
Triglycerides cannot pass through cell membranes freely. Special enzymes on the walls of blood vessels called lipoprotein lipases must break down triglycerides into free fatty acids and glycerol. Fatty acids can then be taken up by cells via the fatty acid transporter (FAT).
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Pentosans
A group of polysaccharides found with cellulose in many woody plants and yielding pentoses on hydrolysis.
Pentose a class of monosaccharides having five carbon atoms per
molecule and including ribose and several other sugars.
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