Phytoalexins are antimicrobial substances, some of which are antioxidative as well. They are defined, not by their having any particular chemical structure or character, but by the fact that they are defensively synthesized de novo by plants that produce the compounds rapidly at sites of pathogen infection. In general phytoalexins are broad spectrum inhibitors; they are chemically diverse, and different chemical classes of compounds are characteristic of particular plant taxa. Phytoalexins tend to fall into several chemical classes, including terpenoids, glycosteroids and alkaloids, however the term applies to any phytochemicals that are induced by microbial infection.
Quercetin is a plant flavonol from the flavonoid group of polyphenols. It is found in many fruits, vegetables, leaves, seeds, and grains; capers, red onions, and kale are common foods containing appreciable amounts of it. It has a bitter flavor and is used as an ingredient in dietary supplements, beverages, and foods.
Naringenin is a flavorless, colorless flavanone, a type of flavonoid. It is the predominant flavanone in grapefruit, and is found in a variety of fruits and herbs.
Rutin, also called rutoside, quercetin-3-O-rutinoside and sophorin, is the glycoside combining the flavonol quercetin and the disaccharide rutinose. It is a flavonoid found in a wide variety of plants, including citrus.
Naringin is a flavanone-7-O-glycoside between the flavanone naringenin and the disaccharide neohesperidose. The flavonoid naringin occurs naturally in citrus fruits, especially in grapefruit, where naringin is responsible for the fruit's bitter taste. In commercial grapefruit juice production, the enzyme naringinase can be used to remove the bitterness created by naringin. In humans naringin is metabolized to the aglycone naringenin by naringinase present in the gut.
Hesperidin is a flavanone glycoside found in citrus fruits. Its aglycone form is called hesperetin. Its name is derived from the word "hesperidium", for fruit produced by citrus trees.
Chalcone synthase or naringenin-chalcone synthase (CHS) is an enzyme ubiquitous to higher plants and belongs to a family of polyketide synthase enzymes (PKS) known as type III PKS. Type III PKSs are associated with the production of chalcones, a class of organic compounds found mainly in plants as natural defense mechanisms and as synthetic intermediates. CHS was the first type III PKS to be discovered. It is the first committed enzyme in flavonoid biosynthesis. The enzyme catalyzes the conversion of 4-coumaroyl-CoA and malonyl-CoA to naringenin chalcone.
In enzymology, an isoflavone 7-O-methyltransferase is an enzyme that catalyzes the chemical reaction
Flavonoids are synthesized by the phenylpropanoid metabolic pathway in which the amino acid phenylalanine is used to produce 4-coumaroyl-CoA. This can be combined with malonyl-CoA to yield the true backbone of flavonoids, a group of compounds called chalcones, which contain two phenyl rings. Conjugate ring-closure of chalcones results in the familiar form of flavonoids, the three-ringed structure of a flavone. The metabolic pathway continues through a series of enzymatic modifications to yield flavanones → dihydroflavonols → anthocyanins. Along this pathway, many products can be formed, including the flavonols, flavan-3-ols, proanthocyanidins (tannins) and a host of other various polyphenolics.
Tricin is a chemical compound. It is an O-methylated flavone, a type of flavonoid. It can be found in rice bran and sugarcane.
The O-methylated flavonoids or methoxyflavonoids are flavonoids with methylations on hydroxyl groups. O-methylation has an effect on the solubility of flavonoids.
Cunninghamella elegans is a species of fungus in the genus Cunninghamella found in soil.
Chalconoids Greek: χαλκός khalkós, "copper", due to its color), also known as chalcones, are natural phenols related to chalcone. They form the central core for a variety of important biological compounds.
Momilactone-A synthase (EC 1.1.1.295, momilactone A synthase, OsMAS) is an enzyme with systematic name 3beta-hydroxy-9beta-pimara-7,15-diene-19,6beta-olide:NAD(P)+ oxidoreductase. This enzyme catalyses the following chemical reaction
Naringenin 7-O-methyltransferase is a methyltransferase isolated from rice, which catalyzes the biosynthesis of sakuranetin.
Narirutin is a flavanone-7-O-glycoside, consisting of the flavanone naringenin bonded with the disaccharide rutinose.
Pisatin (3-hydroxy-7-methoxy-4′,5′-methylenedioxy-chromanocoumarane) is the major phytoalexin made by the pea plant Pisum sativum. It was the first phytoalexin to be purified and chemically identified. The molecular formula is C17H14O6.
Cunninghamella echinulata is a fungal species in the genus Cunninghamella. It is an asexually reproducing fungus and a mesophile, preferring intermediate temperature ranges. C. echinulata is a common air contaminant, and is currently of interest to the biotechnology industry due to its ability to synthesize γ-linolenic acid as well as its capacity to bioconcentrate metals. This species is a soil saprotroph that forms rhizoids, preferring soils enriched in nitrogen, phosphorus and potassium. It has been reported occasionally an agent of mucormycosis following the inhalation of fungal spores. Czapek's agar is a suitable growth medium for the propagation of C. echinulata.
2-Methoxyestrone (2-ME1) is an endogenous, naturally occurring methoxylated catechol estrogen and metabolite of estrone that is formed by catechol O-methyltransferase via the intermediate 2-hydroxyestrone. Unlike estrone but similarly to 2-hydroxyestrone and 2-methoxyestradiol, 2-methoxyestrone has very low affinity for the estrogen receptor and lacks significant estrogenic activity.
4-Methoxyestradiol (4-ME2) is an endogenous, naturally occurring methoxylated catechol estrogen and metabolite of estradiol that is formed by catechol O-methyltransferase via the intermediate 4-hydroxyestradiol. It has estrogenic activity similarly to estrone and 4-hydroxyestrone.
