Humulus, or hop, is a small genus of flowering plants in the family Cannabaceae. The hop is native to temperate regions of the Northern Hemisphere. Hops are the female flowers of the hop species H. lupulus; as a main flavor and aroma ingredient in many beer styles, H. lupulus is widely cultivated for use by the brewing industry.
Safrole is an organic compound with the formula CH2O2C6H3CH2CH=CH2. It is a colorless oily liquid, although impure samples can appear yellow. A member of the phenylpropanoid family of natural products, it is found in sassafras plants, among others. Small amounts are found in a wide variety of plants, where it functions as a natural antifeedant. Ocotea pretiosa, which grows in Brazil, and Sassafras albidum, which grows in eastern North America, are the main natural sources of safrole. It has a characteristic "sweet-shop" aroma.
Cinnamic acid is an organic compound with the formula C6H5-CH=CH-COOH. It is a white crystalline compound that is slightly soluble in water, and freely soluble in many organic solvents. Classified as an unsaturated carboxylic acid, it occurs naturally in a number of plants. It exists as both a cis and a trans isomer, although the latter is more common.
Phytochemistry is the study of phytochemicals, which are chemicals derived from plants. Phytochemists strive to describe the structures of the large number of secondary metabolites found in plants, the functions of these compounds in human and plant biology, and the biosynthesis of these compounds. Plants synthesize phytochemicals for many reasons, including to protect themselves against insect attacks and plant diseases. The compounds found in plants are of many kinds, but most can be grouped into four major biosynthetic classes: alkaloids, phenylpropanoids, polyketides, and terpenoids.
Isoflavones are substituted derivatives of isoflavone, a type of naturally occurring isoflavonoids, many of which act as phytoestrogens in mammals. Isoflavones occur in many plant species, but are especially high in soybeans.
Apigenin (4′,5,7-trihydroxyflavone), found in many plants, is a natural product belonging to the flavone class that is the aglycone of several naturally occurring glycosides. It is a yellow crystalline solid that has been used to dye wool.
Kaempferol (3,4′,5,7-tetrahydroxyflavone) is a natural flavonol, a type of flavonoid, found in a variety of plants and plant-derived foods including kale, beans, tea, spinach, and broccoli. Kaempferol is a yellow crystalline solid with a melting point of 276–278 °C (529–532 °F). It is slightly soluble in water and highly soluble in hot ethanol, ethers, and DMSO. Kaempferol is named for 17th-century German naturalist Engelbert Kaempfer.
The phenylpropanoids are a diverse family of organic compounds that are biosynthesized by plants from the amino acids phenylalanine and tyrosine in the shikimic acid pathway. Their name is derived from the six-carbon, aromatic phenyl group and the three-carbon propene tail of coumaric acid, which is the central intermediate in phenylpropanoid biosynthesis. From 4-coumaroyl-CoA emanates the biosynthesis of myriad natural products including lignols, flavonoids, isoflavonoids, coumarins, aurones, stilbenes, catechin, and phenylpropanoids. The coumaroyl component is produced from cinnamic acid.
Daidzein is a naturally occurring compound found exclusively in soybeans and other legumes and structurally belongs to a class of compounds known as isoflavones. Daidzein and other isoflavones are produced in plants through the phenylpropanoid pathway of secondary metabolism and are used as signal carriers, and defense responses to pathogenic attacks. In humans, recent research has shown the viability of using daidzein in medicine for menopausal relief, osteoporosis, blood cholesterol, and lowering the risk of some hormone-related cancers, and heart disease. Despite the known health benefits, the use of both puerarin and daidzein is limited by their poor bioavailability and low water solubility.
Flavones are a class of flavonoids based on the backbone of 2-phenylchromen-4-one (2-phenyl-1-benzopyran-4-one).
Pinosylvin is an organic compound with the formula C6H5CH=CHC6H3(OH)2. A white solid, it is related to trans-stilbene, but with two hydroxy groups on one of the phenyl substituents. It is very soluble in many organic solvents, such as acetone.
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.
The enzyme phenylalanine ammonia lyase (EC 4.3.1.24) catalyzes the conversion of L-phenylalanine to ammonia and trans-cinnamic acid.:
Fisetin (7,3′,4′-flavon-3-ol) is a plant flavonol from the flavonoid group of polyphenols. It can be found in many plants, where it serves as a yellow/ochre colouring agent. It is also found in many fruits and vegetables, such as strawberries, apples, persimmons, onions and cucumbers. Its chemical formula was first described by Austrian chemist Josef Herzig in 1891.
An aurone is a heterocyclic chemical compound, which is a type of flavonoid. There are two isomers of the molecule, with (E)- and (Z)-configurations. The molecule contains a benzofuran element associated with a benzylidene linked in position 2. In aurone, a chalcone-like group is closed into a 5-membered ring instead of the 6-membered ring more typical of flavonoids.
Scopoletin is a coumarin found in the root of plants in the genus Scopolia such as Scopolia carniolica and Scopolia japonica, in chicory, in Artemisia scoparia, in the roots and leaves of stinging nettle, in the passion flower, in Brunfelsia, in Viburnum prunifolium, in Solanum nigrum, in Datura metel, in Mallotus resinosus, or and in Kleinhovia hospita. It can also be found in fenugreek, vinegar, some whiskies or in dandelion coffee. A similar coumarin is scoparone. Scopoletin is highly fluorescent when dissolved in DMSO or water and is regularly used as a fluorimetric assay for the detection of hydrogen peroxide in conjunction with horseradish peroxidase. When oxidized, its fluorescence is strongly suppressed.
Phenylpropenes broadly are compounds containing a phenyl ring bonded to propene, more specifically those with an allyl group bonded to a benzene ring, having the parent structure of allylbenzene. These comprise a class of phenylpropanoids, where there are typically other substituents bonded to the aromatic ring.
Chavibetol is an organic chemical compound of the phenylpropanoid class. It is one of the primary constituents of the essential oil from the leaves of the betel plant and catatia. It is an aromatic compound with a spicy odor.
trans-Propenylbenzene is an organic compound with the formula C6H5CH=CHCH3. It is the more stable of the two isomers of 1-propenylbenzene. Both isomers are colorless flammable liquids. It is formed by the isomerization of allylbenzene.
Δ-3-Tetrahydrocannabinol is a synthetic isomer of tetrahydrocannabinol, developed during the original research in the 1940s to develop synthetic routes to the natural products Δ8-THC and Δ9-THC found in the cannabis plant. While the normal trans configuration of THC is in this case flattened by the double bond, it still has two enantiomers as the 9-methyl group can exist in an (R) or (S) conformation. The (S) enantiomer has similar effects to Δ9-THC though with several times lower potency, while the (R) enantiomer is many times less active or inactive, depending on the assay used. It has been identified as a component of vaping liquid products.
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