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Pinoresinol
Pinoresinol is a tetrahydrofuran lignan found in ''Styrax sp.'', ''Forsythia suspensa, and in Forsythia koreana''. It is also found in the caterpillar of the cabbage butterfly, ''Pieris rapae'' where it serves as a defence against ants. In food, it is found in sesame seed, in ''Brassica'' vegetables and in olive oil. Pinoresinol has also been found to be toxic to larvae of the milkweed bug Oncopeltus fasciatus and of the haematophagous insect Rhodnius prolixus, which is a vector of chagas disease. Currently, pinoresinol is isolated from plants with low efficiency and low yield. Biosynthesis A first dirigent protein was discovered in '' Forsythia intermedia''. This protein has been found to direct the stereoselective biosynthesis of (+)-pinoresinol from coniferyl alcohol monomers. Recently, a second, enantiocomplementary dirigent protein was identified in ''Arabidopsis thaliana'', which directs enantioselective synthesis of (-)-pinoresinol. Pharmacology Pinoresinol inhib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dirigent Protein
Dirigent proteins are members of a class of proteins which dictate the stereochemistry of a compound synthesized by other enzymes. The first dirigent protein was discovered in ''Forsythia intermedia''. This protein has been found to direct the stereoselective biosynthesis of (+)-pinoresinol from coniferyl alcohol monomers: Lignan biosynthesis is catalysed by oxidative enzymes. In the test tube the reaction results in a heteregenous mixture of dimeric compounds. When a dirigent protein is present during the reaction, one stereoisomer of one compound is highly enriched. Dirigent proteins appear to possess no oxidative radical forming activity of their own; in the absence of oxidative enzyme, no reaction will occur. Recently, a second, enantiocomplementary dirigent protein was identified in ''Arabidopsis thaliana'', which directs enantioselective synthesis of (-)-pinoresinol. Activity In lignan biosynthesis, oxidative enzymes perform proton coupled electron transfer to remove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lignan
The lignans are a large group of low molecular weight polyphenols found in plants, particularly seeds, whole grains, and vegetables. The name derives from the Latin word for "wood". Lignans are precursors to phytoestrogens. They may play a role as antifeedants in the defense of seeds and plants against herbivores. Biosynthesis and metabolism Lignans and lignin differ in their molecular weight, the former being small and soluble in water, the latter being high polymers that are undigestable. Both are polyphenolic substances derived by oxidative coupling of monolignols. Thus, most lignans feature a C18 cores, resulting from the dimerization of C9 precursors. The coupling of the lignols occurs at C8. Eight classes of lignans are: "furofuran, furan, dibenzylbutane, dibenzylbutyrolactone, aryltetralin, arylnaphthalene, dibenzocyclooctadiene, and dibenzylbutyrolactol." Many lignans are metabolized by mammalian gut microflora, producing so-called enterolignans. Food sources Flax ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stereoselective Biosynthesis
In chemistry, stereoselectivity is the property of a chemical reaction in which a single reactant forms an unequal mixture of stereoisomers during a non- stereospecific creation of a new stereocenter or during a non-stereospecific transformation of a pre-existing one. The selectivity arises from differences in steric and electronic effects in the mechanistic pathways leading to the different products. Stereoselectivity can vary in degree but it can never be total since the activation energy difference between the two pathways is finite. Both products are at least possible and merely differ in amount. However, in favorable cases, the minor stereoisomer may not be detectable by the analytic methods used. An enantioselective reaction is one in which one enantiomer is formed in preference to the other, in a reaction that creates an optically active product from an achiral starting material, using either a chiral catalyst, an enzyme or a chiral reagent. The degree of selectivity is m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coniferyl Alcohol
Coniferyl alcohol is an organic compound with the formula HO(CH3O)C6H3CH=CHCH2OH. A colourless or white solid, it is one of the monolignols, produced via the phenylpropanoid biochemical pathway. When copolymerized with related aromatic compounds, coniferyl alcohol forms lignin or lignans. Coniferin is a glucoside of coniferyl alcohol. Coniferyl alcohol is an intermediate in biosynthesis of eugenol and of stilbenoids and coumarin. Gum benzoin contains significant amount of coniferyl alcohol and its esters. It is found in both gymnosperm and angiosperm plants. Sinapyl alcohol and paracoumaryl alcohol, the other two lignin monomers, are found in angiosperm plants and grasses. Occurrence Coniferyl alcohol is produced from coniferyl aldehyde by the action of dehydrogenase enzymes. It is a queen retinue pheromone (QRP), a type of honey bee pheromone found in the mandibular glands. In '' Forsythia intermedia'' a dirigent protein was found to direct the stereoselective biosy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forsythia Suspensa
''Forsythia suspensa'', commonly known as weeping forsythia or golden-bell, is a species of flowering plant in the family Oleaceae, it is native to China. Taxonomy The Latin epithet of ''suspensa'' is derived from ''suspensus'' meaning suspended. It was first described and published in Enum. Pl. Obs. Vol.1 on page 39 in 1804. Description ''Forsythia suspensa'' is a deciduous shrub that grows up to tall. Its flowers are golden-yellow and they bloom March to April. Leaves are green in color, broadly-ovate, and simple. It can be grown as a weeping shrub on stream banks and can be identified by its pale flowers. Garden cultivars can be found. It is a spring flowering shrub, with yellow flowers. It is grown and prized for its toughness. Before '' Forsythia × intermedia'' was known as a true wild Chinese species, ''F. suspensa'' was considered one of its parents. Distribution and habitat ''Forsythia suspensa'' is native to China. It is introduced in Japan, Spain, Bulgaria, Cze ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Phytochemicals In Food
While there is ample evidence to indicate the health benefits of diets rich in fruits, vegetables, legumes, whole grains and nuts, no specific food has been acknowledged by scientists and government regulatory authorities as providing a health benefit. Current medical research is focused on whether health effects could be due to specific essential nutrients or to phytochemicals which are not defined as essential. The following is a list of phytochemicals present in commonly consumed foods. Terpenoids (isoprenoids) Carotenoids (tetraterpenoids) ''Carotenes'' orange pigments * α-Carotene – to vitamin A . * β-Carotene – to vitamin A . * γ-Carotene - to vitamin A, * δ-Carotene * ε-carotene * Lycopene . * Neurosporene * Phytofluene . * Phytoene . ''Xanthophylls'' yellow pigments * Canthaxanthin . * β-Cryptoxanthin to vitamin A . * Zeaxanthin . * Astaxanthin . * Lutein . * Rubixanthin . Triterpenoid * Saponins . * Oleanolic acid . * Ursolic acid . * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sesame
Sesame ( or ; ''Sesamum indicum'') is a flowering plant in the genus ''Sesamum'', also called benne. Numerous wild relatives occur in Africa and a smaller number in India. It is widely naturalized in tropical regions around the world and is cultivated for its edible seeds, which grow in pods. World production in 2018 was , with Sudan, Myanmar, and India as the largest producers. Sesame seed is one of the oldest oilseed crops known, domesticated well over 3,000 years ago. ''Sesamum'' has many other species, most being wild and native to sub-Saharan Africa. ''S. indicum,'' the cultivated type, originated in India. It tolerates drought conditions well, growing where other crops fail. Sesame has one of the highest oil contents of any seed. With a rich, nutty flavor, it is a common ingredient in cuisines around the world. Like other foods, it can trigger allergic reactions in some people. Etymology The word "sesame" is from Latin ''sesamum'' and Greek σήσαμον : ''sēsamon' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brassica
''Brassica'' () is a genus of plants in the cabbage and mustard family ( Brassicaceae). The members of the genus are informally known as cruciferous vegetables, cabbages, or mustard plants. Crops from this genus are sometimes called ''cole crops''derived from the Latin ''caulis'', denoting the stem or stalk of a plant. The genus ''Brassica'' is known for its important agricultural and horticultural crops and also includes a number of weeds, both of wild taxa and escapees from cultivation. ''Brassica'' species and varieties commonly used for food include bok choy, broccoli, cauliflower, cabbage, choy sum, kohlrabi, napa cabbage, rutabaga, turnip and some seeds used in the production of canola oil and the condiment mustard. Over 30 wild species and hybrids are in cultivation, plus numerous cultivars and hybrids of cultivated origin. Most are seasonal plants ( annuals or biennials), but some are small shrubs. ''Brassica'' plants have been the subject of much scientific i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olive Oil
Olive oil is a liquid fat obtained from olives (the fruit of ''Olea europaea''; family Oleaceae), a traditional tree crop of the Mediterranean Basin, produced by pressing whole olives and extracting the oil. It is commonly used in cooking: for frying foods or as a salad dressing. It can be found in some cosmetics, pharmaceuticals, soaps, and fuels for traditional oil lamps. It also has additional uses in some religions. The olive is one of three core food plants in Mediterranean cuisine; the other two are wheat and grapes. Olive trees have been grown around the Mediterranean since the 8th millennium BC. In 2019–2020, world production of olive oil was . Spain was the largest producer followed by Italy, Tunisia, Greece, Turkey and Morocco. San Marino has by far the largest per capita consumption of olive oil worldwide. The composition of olive oil varies with the cultivar, altitude, time of harvest, and extraction process. It consists mainly of oleic acid (up to 83%), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pieris Rapae
''Pieris rapae'' is a small- to medium-sized butterfly species of the whites-and-yellows family Pieridae. It is known in Europe as the small white, in North America as the cabbage white or cabbage butterfly, on several continents as the small cabbage white, and in New Zealand as the white butterfly. The butterfly is recognizable by its white color with small black dots on its wings, and it can be distinguished from '' P. brassicae'' by its larger size and the black band at the tip of its forewings. The caterpillar of this species, often referred to as the "imported cabbageworm", is a pest to crucifer crops such as cabbage, kale, bok choy and broccoli. ''Pieris rapae'' is widespread in Europe and Asia; it is believed to have originated in the Eastern Mediterranean region of Europe, and to have spread across Eurasia thanks to the diversification of brassicaceous crops and the development of human trade routes. Over the past two centuries, it spread to North Africa, North Americ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forsythia Intermedia
''Forsythia'' , is a genus of flowering plants in the olive family Oleaceae. There are about 11 species, mostly native to eastern Asia, but one native to southeastern Europe. ''Forsythia'' – also one of the plant's common names – is named after William Forsyth.Flora of China''Forsythia''/ref>Flora Europaea''Forsythia''/ref>St Andrews Botanic Garden Description ''Forsythia'' are deciduous shrubs typically growing to a height of and, rarely, up to with rough grey-brown bark. The leaves are borne oppositely and are usually simple, though sometimes trifoliate with a basal pair of small leaflets; they range between in length and, rarely, up to , with a margin that is serrated or entire (smooth). Twigs may be hollow or chambered, depending on the species. The flowers are produced in the early spring before the leaves, bright yellow with a deeply four-lobed flower, the petals joined only at the base. These become pendent in rainy weather thus shielding the reproducti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Styrax
''Styrax'' (common names storax or snowbell) is a genus of about 130 species of large shrubs or small trees in the family Styracaceae, mostly native to warm temperate to tropical regions of the Northern Hemisphere, with the majority in eastern and southeastern Asia, but also crossing the equator in South America.Fritsch ''et al.'' (2001) The resin obtained from the tree is called benzoin or storax (not to be confused with the ''Liquidambar'' storax balsam). The genus ''Pamphilia'', sometimes regarded as distinct, is now included within ''Styrax'' based on analysis of morphological and DNA sequence data. The spicebush (''Lindera benzoin'') is a different plant, in the family Lauraceae. Styrax trees grow to 2–14 m tall, and have alternate, deciduous or evergreen simple ovate leaves 1–18 cm long and 2–10 cm broad. The flowers are pendulous, with a white 5–10-lobed corolla, produced 3–30 together on open or dense panicles 5–25 cm long. The fruit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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