Biosynthesis of Flavanon

Flavanones, a direct precursor to the most flavonoids, synthesized from the amino acid phenylalanine or tyrosine. The process begins with the enzyme phenylalanine / tyrosine ammonia lyase (PAL / TAL), change buillding block of amino acids into phenyl-propanoic acid. Biosynthetic pathway involving the enzyme flavanones, cytochrome-P450, cinnamate 4-hydroxylase (C4H), by adding 4'-hydroxyl group of the aromatic ring of phenylalanine. The next CoA esters synthesized from phenylpropanoic acids with the help of enzymes phenylpropanoyl-CoA ligases, such as 4 - coumaryl: CoA ligase (4CL). Type III polyketide synthase Chalcone synthase (CHS) then catalyzes the sequential condensation of three malonyl-CoA CoA-ester with 1 form chalcones. This is the step that produces flavonoid biosynthesi.

 First, there is an alternative pathway enzymes type III polyketide synthases that have high homology with CHS (> 70%) using the same precursor form stilbenes (using 3 units of malonyl-CoA), benzylacetolactone (only use 1 unit malonyl-CoA), and other aromatic molecules.

Flavanones final structure is formed only if diisomerisasi chalcones into (2S)-flavanone by Chalcone isomerase (CHI), this reaction occurs spontaneously at alkaline conditions. Once formed flavanones, a lot of compound enzymes could alter the functional group or alter the conformation of the 3-ring core fenilpropan produces up to 8000 different compounds structure.Functionalization can be hydroxylation, reduction, alkylation, oxidation, and glukosilasi, each alone or in combination. By nature, these enzymes exist in plants, but according to reports Ueda et al. that there is a type III polyketide synthases derived from microorganisms. This information is essential for the production of compounds flavanones in scale bioreactor.

The addition of consecutive carbon atoms of malonyl-CoA by CHS are shown in green, red, and blue. R group showed hydroxylation patterns on natural flavonoid unnatural although substitutions can occur in this position. Abbreviations: DFR dihydroflavanone reductase, reductase leucoanthocynanidin LAR, ANS anthocyanidin synthase, 3GT uridine, flavanone 3-glucoside transferase, FSI flanone synthase, CHR Chalcone reductase, IFS isoflavanone synthase, flavanone hydroxytransferase FHT, FLS flavonol synthase.

Flavonoids

Flavonoids (or bioflavonoids) (from the Latin word flavus meaning yellow, their colour in nature) are a class of plant secondary metabolites.
Flavonoids were referred to as Vitamin P (probably due to the effect they had on the permeability of vascular capillaries) from the mid-1930s to early 50s, but the term has since fallen out of use.

Flavonoids (or bioflavonoids) (from the Latin word flavus meaning yellow, their colour in nature) are a class of plant secondary metabolites.
Flavonoids were referred to as Vitamin P (probably due to the effect they had on the permeability of vascular capillaries) from the mid-1930s to early 50s, but the term has since fallen out of use.

Flavonoids (or bioflavonoids), also collectively known as Vitamin P and citrin, are a class of plant secondary metabolites. According to the IUPAC nomenclature, they can be classified into:

• ''flavonoids'', derived from 2-phenylchromen-4-one (2-phenyl-1,4-benzopyrone) structure (examples: quercetin, rutin).
• ''isoflavonoids'', derived from 3-phenylchromen-4-one (3-phenyl-1,4-benzopyrone) structure
• ''neoflavonoids'', derived from 4-phenylcoumarine (4-phenyl-1,2-benzopyrone) structure.

The three flavonoid classes above are all ketone-containing compounds, and as such, are flavonoids and flavonols. This class was the first to be termed "bioflavonoids." The terms flavonoid and bioflavonoid have also been more loosely used to describe non-ketone polyhydroxy polyphenol compounds which are more specifically termed flavanoids, flavan-3-ols, or catechins (although catechins are actually a subgroup of flavanoids).

Flavonoids are widely distributed in plants fulfilling many functions.

Flavonoids are the most important plant pigments for flower coloration producing yellow or red/blue pigmentation in petals designed to attract pollinator animals.

Flavonoids secreted by the root of their host plant help ''Rhizobia'' in the infection stage of their symbiotic relationship with legumes like peas, beans, clover, and soy. Rhizobia living in soil are able to sense the flavonoids and this triggers the secretion of Nod factors, which in turn are recognized by the host plant and can lead to root hair deformation and several cellular responses such as ion fluxes and the formation of a root nodule.

They also protect plants from attacks by microbes, fungi and insects.

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. Both sets of compounds have evidence of health-modulating effects in animals which eat them.

The widespread distribution of flavonoids, their variety and their relatively low toxicity compared to other active plant compounds (for instance alkaloids) mean that many animals, including humans, ingest significant quantities in their diet. Resulting from experimental evidence that they may modify allergens, viruses, and carcinogens, flavonoids have potential to be biological "response modifiers", such as anti-allergic, anti-inflammatory, anti-microbial and anti-cancer activities shown from in vitro studies.

Antioxidant activity in vitro

Flavonoids (both flavonols and flavanols) are most commonly known for their antioxidant activity in vitro.

Consumers and food manufacturers have become interested in flavonoids for their possible medicinal properties, especially their putative role in prevention of cancers and cardiovascular diseases. Although physiological evidence is not yet established, the beneficial effects of fruits, vegetables, and tea or even red wine have sometimes been attributed to flavonoid compounds rather than to known micronutrients, such as vitamins and dietary minerals.

Alternatively, research conducted at the Linus Pauling Institute and evaluated by the European Food Safety Authority indicates that, following dietary intake, flavonoids themselves are of little or no direct antioxidant value. As body conditions are unlike controlled test tube conditions, flavonoids and other polyphenols are poorly absorbed (less than 5%), with most of what is absorbed being quickly metabolized and excreted.

The increase in antioxidant capacity of blood seen after the consumption of flavonoid-rich foods is not caused directly by flavonoids themselves, but most likely is due to increased uric acid levels that result from metabolism of flavonoids. According to Frei, "we can now follow the activity of flavonoids in the body, and one thing that is clear is that the body sees them as foreign compounds and is trying to get rid of them."

Other potential health benefits

Cancer

Physiological processing of unwanted flavonoid compounds induces so-called Phase II enzymes that also help to eliminate mutagens and carcinogens, and therefore may be of value in cancer prevention. Flavonoids could also induce mechanisms that may kill cancer cells and inhibit tumor invasion.

Research also indicated that only small amounts of flavonoids may be needed for possible benefits. Taking large dietary supplements likely provides no extra benefit and may pose risks. However, certainty of neither a benefit nor a risk has been proven yet in large-scale human intervention trials.

Capillary stabilizing agents

Bioflavonoids like rutin, monoxerutin, diosmin, troxerutin and hidrosmin have potential vasoprotective proprieties still under experimental evaluation.

PROBLEM :
I'm looking for a flavonoid extraction and i dont find any exact one.
how to exact flavonoids, the process, and i heard something about i can extract it from the orange or any other fruit.