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Limonoid
Limonoids are phytochemicals of the triterpenoid class which are abundant in sweet or sour-scented citrus fruit and other plants of the families Cucurbitaceae, Rutaceae, and Meliaceae. Certain limonoids are antifeedants such as azadirachtin from the neem tree. Chemically, the limonoids consist of variations of the furanolactone core structure. The prototypical structure consists of four six-membered rings and a furan ring. Limonoids are classed as tetranortriterpenes. Citrus Citrus fruits contain the limonoids limonin, nomilin and nomilinic acid, while both neem seeds and leaves contain the limonoid azadirachtin, although higher concentrations are present in the former. Chisocheton erythrocarpus Eight previously unknown limonoids were identified via spectroscopy in the fruits of '' Chisocheton erythrocarpus'' gathered in Malaysia. These compounds were dubbed erythrocarpines after the species epithet. The same study tested several preparations of ''C. erythrocarpus'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neem
''Azadirachta indica'', commonly known as neem, margosa, nimtree or Indian lilac, is a tree in the mahogany family Meliaceae. It is one of the two species in the genus '' Azadirachta''. It is native to the Indian subcontinent and to parts of Southeast Asia, but is naturalized and grown around the world in tropical and subtropical areas. Its fruits and seeds are the source of neem oil. ''Nim'' is a Hindustani noun derived from Sanskrit ''nimba'' (). Description Margosa is a fast-growing tree that can reach a height of , and rarely . It is evergreen, shedding many of its leaves during the dry winter months. The branches are wide and spreading. The fairly dense crown is roundish and may reach a diameter of . The opposite, pinnate leaves are long, with 20 to 30 medium to dark green leaflets about long. The terminal leaflet often is missing. The petioles are short. White and fragrant flowers are arranged in more-or-less drooping axillary panicles which are up to long. The i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Azadirachtin
Azadirachtin, a chemical compound belonging to the limonoid group, is a secondary metabolite present in neem seeds. It is a highly oxidized tetranortriterpenoid which boasts a plethora of oxygen-bearing functional groups, including an enol ether, acetal, hemiacetal, tetra-substituted epoxide and a variety of carboxylic esters. Chemical synthesis Azadirachtin has a complex molecular structure; it presents both secondary and tertiary hydroxyl groups and a tetrahydrofuran ether in its molecular structure, alongside 16 stereogenic centres, 7 of which are tetrasubstituted. These characteristics explain the great difficulty encountered when trying to prepare this compound from simple precursors, using methods of synthetic organic chemistry. Hence, the first total synthesis was published over 22 years after the compound's discovery: this first synthesis was completed by the research group of Steven Ley at the University of Cambridge in 2007. The described synthesis was a relay appro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limonin
Limonin is a limonoid, and a bitter, white, crystalline substance found in citrus and other plants. It is also known as limonoate D-ring-lactone and limonoic acid di-delta-lactone. Chemically, it is a member of the class of compounds known as furanolactones. Sources Limonin is enriched in citrus fruits and is often found at higher concentrations in seeds, for example orange and lemon seeds. Presence in citrus products Limonin and other limonoid compounds contribute to the bitter taste of some citrus food products. Researchers have proposed removal of limonoids from orange juice and other products (known as "debittering") through the use of polymeric films. Research Limonin is under basic research Basic research, also called pure research, fundamental research, basic science, or pure science, is a type of scientific research with the aim of improving scientific theories for better understanding and prediction of natural or other phenome ... to assess its possible biolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetranortriterpenoid
The tetranortriterpenoid class of naturally occurring organic compounds, of which the most noted compound is azadirachtin, extracted from the neem tree (''Azadirachta indica'') that displays insecticidal properties. Azadirachtin mimics insect hormones called ecdysones that regulate the pupation of insects; application of azadirachtin interrupts the development and pupation of insects, eventually killing them. The name indicates that the basic skeleton of such compounds contains 26 carbon atoms (4 fewer than triterpenes). Azadirachtin is a tetranortriterpenoid and a limonoid Limonoids are phytochemicals of the triterpenoid class which are abundant in sweet or sour-scented citrus fruit and other plants of the families Cucurbitaceae, Rutaceae, and Meliaceae. Certain limonoids are antifeedants such as azadirachtin from .... References {{insecticides Plant toxin insecticides Triterpenes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chisocheton Erythrocarpus
''Chisocheton erythrocarpus'' is a tree in the family ''Meliaceae''. The specific epithet ' is from the Greek meaning 'red-fruited'. Description The tree grows up to tall with a trunk diameter of up to . The bark is dark grey to chocolate brown. The flowers are creamy-white. The fruits are round, yellow (blood-red when ripe), up to in diameter. Distribution and habitat ''Chisocheton erythrocarpus'' is found in Peninsular Malaysia, Borneo and the Philippines. The habitat is coastal forest. Phytochemicals Eight previously unknown limonoids were identified via spectroscopy in the fruits of ''C. erythrocarpus'' gathered in Malaysia. These compounds were dubbed erythrocarpines after the species epithet. The same study tested several preparations of ''C. erythrocarpus'' extract as larvicidal agent against ''Aedes aegypti ''Aedes aegypti'' ( or from Greek 'hateful' and from Latin, meaning 'of Egypt'), sometimes called the Egyptian mosquito, dengue mosquito or yellow fe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetranortriterpenoid
The tetranortriterpenoid class of naturally occurring organic compounds, of which the most noted compound is azadirachtin, extracted from the neem tree (''Azadirachta indica'') that displays insecticidal properties. Azadirachtin mimics insect hormones called ecdysones that regulate the pupation of insects; application of azadirachtin interrupts the development and pupation of insects, eventually killing them. The name indicates that the basic skeleton of such compounds contains 26 carbon atoms (4 fewer than triterpenes). Azadirachtin is a tetranortriterpenoid and a limonoid Limonoids are phytochemicals of the triterpenoid class which are abundant in sweet or sour-scented citrus fruit and other plants of the families Cucurbitaceae, Rutaceae, and Meliaceae. Certain limonoids are antifeedants such as azadirachtin from .... References {{insecticides Plant toxin insecticides Triterpenes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Citrus
''Citrus'' is a genus of flowering trees and shrubs in the family Rutaceae. Plants in the genus produce citrus fruits, including important crops such as oranges, mandarins, lemons, grapefruits, pomelos, and limes. ''Citrus'' is native to South Asia, East Asia, Southeast Asia, Melanesia, and Australia. Indigenous people in these areas have used and domesticated various species since ancient times. Its cultivation first spread into Micronesia and Polynesia through the Austronesian expansion (–1500 BCE). Later, it was spread to the Middle East and the Mediterranean () via the incense trade route, and from Europe to the Americas. Renowned for their highly fragrant aromas and complex flavor, citrus are among the most popular fruits in cultivation. With a propensity to hybridize between species, making their taxonomy complicated, there are numerous varieties encompassing a wide range of appearance and fruit flavors. Evolution Evolutionary history The large cit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antifeedant
Antifeedants are organic compounds produced by plants to repel herbivores through distaste or toxicity. These chemical compounds are typically classified as secondary metabolites in that they are not essential for the metabolism of the plant, but instead confer longevity. Antifeedants exhibit a wide range of activities and chemical structures as biopesticides. Examples include rosin, which inhibits attack on trees, and many alkaloids, which are highly toxic to specific insect species, such as quassinoids (extracts from ''Quassia'' trees) against the diamondback moth ('' Plutela xylostella''). ''Samadera indica'' also has quassinoids used for insect antifeedant uses. History "Plant-derived insecticides (e.g., rotenone, veratridines, pyrethrins, and nicotine) have been used for insect control since antiquity." The active ingredients in these plants have been purified and modified. For example, variations on pyrethrin have spawned a large number of synthetic insecticides calle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactones
Lactones are cyclic carboxylic esters. They are derived from the corresponding hydroxycarboxylic acids by esterification. They can be saturated or unsaturated. Lactones are formed by lactonization, the intramolecular esterification of the corresponding hydroxycarboxylic acids. Nomenclature Greek prefixes in alphabetical order indicate ring size. Lactones are usually named according to the precursor acid molecule (''aceto'' = 2 carbon atoms, ''propio'' = 3, ''butyro'' = 4, ''valero'' = 5, ''capro'' = 6, etc.), with a ''-lactone'' suffix and a Greek letter prefix that specifies the number of carbon atoms in the heterocycle — that is, the distance between the relevant -OH and the -COOH groups along said backbone. The first carbon atom after the carbon in the -COOH group on the parent compound is labelled α, the second will be labeled β, and so forth. Therefore, the prefixes also indicate the size of the lactone ring: α-lactone = 3-membered ring, β-lactone = 4-membered, γ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
