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Osmeterium
The osmeterium is a defensive organ found in all papilionid larvae, in all stages. The organ is situated in the prothoracic segment and can be everted when the larva feels threatened. The everted organ resembles a fleshy forked tongue (not unlike a snake tongue), and this along with the large eye-like spots on the body might be used to startle birds and small reptiles. The osmeterial organ remains inside the body in the thoracic region in an inverted position and is everted when the larva is disturbed in any way emitting a foul, disagreeable odor which serves to repel ants, small spiders and mantids. To humans, this odour is rather strong but pleasant, usually smelling like a concentrated scent of the caterpillar’s food plant and pineapple. The constitution of the osmeterial secretion varies from species to species and contains monoterpene hydrocarbons, sesquiterpenic compounds or a mixture of aliphatic acids and esters The fine structure of the osmeterium of '' Papilio dem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Papilio Xuthus Larva 2011-07-01
''Papilio'' is a genus in the swallowtail butterfly family, Papilionidae, as well as the only representative of the tribe Papilionini. The word ''papilio'' is Latin for butterfly. It includes the common yellow swallowtail ('' Papilio machaon''), which is widespread in the Northern Hemisphere and the type species of the genus, as well as a number of other well-known North American species such as the western tiger swallowtail (''Papilio rutulus''). Familiar species elsewhere in the world include the Mormons (''Papilio polytes'', ''Papilio polymnestor'', ''Papilio memnon'', and ''Papilio deiphobus'') in Asia, the orchard and Ulysses swallowtails in Australia ('' Papilio aegeus'', ''Papilio ulysses'', respectively) and the citrus swallowtail of Africa ('' Papilio demodocus''). Older classifications of the swallowtails tended to use many rather small genera. More recent classifications have been more conservative, and as a result a number of former genera are now absorbed within ''P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microvilli
Microvilli (singular: microvillus) are microscopic cellular membrane protrusions that increase the surface area for diffusion and minimize any increase in volume, and are involved in a wide variety of functions, including absorption, secretion, cellular adhesion, and mechanotransduction. Structure Microvilli are covered in plasma membrane, which encloses cytoplasm and microfilaments. Though these are cellular extensions, there are little or no cellular organelles present in the microvilli. Each microvillus has a dense bundle of cross-linked actin filaments, which serves as its structural core. 20 to 30 tightly bundled actin filaments are cross-linked by bundling proteins fimbrin (or plastin-1), villin and espin to form the core of the microvilli. In the enterocyte microvillus, the structural core is attached to the plasma membrane along its length by lateral arms made of myosin 1a and Ca2+ binding protein calmodulin. Myosin 1a functions through a binding site for filamentous ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
β-phellandrene
Phellandrenes are a pair of organic compounds that have a similar molecular structure and similar chemical properties. α-Phellandrene and β-phellandrene are cyclic monoterpenes and are double-bond isomers. In α-phellandrene, both double bonds are endocyclic and in β-phellandrene, one of them is exocyclic. Both are insoluble in water, but miscible with ether. α-Phellandrene was named after ''Eucalyptus phellandra'', now called '' Eucalyptus radiata'', from which it can be isolated. It is also a constituent of the essential oil of '' Eucalyptus dives''. β-Phellandrene has been isolated from the oil of water fennel and Canada balsam oil. The phellandrenes are used in fragrances because of their pleasing aromas. The odor of β-phellandrene has been described as peppery-minty and slightly citrusy. The α-phellandrene isomer can form hazardous and explosive peroxides on contact with air at elevated temperatures. Biosynthesis The biosynthesis of phellandrene begins with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limonene
Limonene is a colorless liquid aliphatic hydrocarbon classified as a cyclic monoterpene, and is the major component in the oil of citrus fruit peels. The -isomer, occurring more commonly in nature as the fragrance of oranges, is a flavoring agent in food manufacturing. It is also used in chemical synthesis as a precursor to carvone and as a renewables-based solvent in cleaning products. The less common -isomer has a piny, turpentine-like odor, and is found in the edible parts of such plants as caraway, dill, and bergamot orange plants. Limonene takes its name from Italian ''limone'' ("lemon"). Limonene is a chiral molecule, and biological sources produce one enantiomer: the principal industrial source, citrus fruit, contains -limonene ((+)-limonene), which is the (''R'')-enantiomer. Racemic limonene is known as dipentene. -Limonene is obtained commercially from citrus fruits through two primary methods: centrifugal separation or steam distillation. Chemical reaction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myrcene
Myrcene, or β-myrcene, is a monoterpene. A colorless oil, it occurs widely in essential oils. It is produced mainly semi-synthetically from ''Myrcia'', from which it gets its name. It is an intermediate in the production of several fragrances. α-Myrcene is the name for the isomer 2-methyl-6-methylene-1,7-octadiene, which has not been found in nature. Production Myrcene is often produced commercially by the pyrolysis (400 °C) of β-pinene, which is obtained from turpentine. It is rarely obtained directly from plants. Plants biosynthesize myrcene via geranyl pyrophosphate (GPP), which isomerizes into linalyl pyrophosphate. The release of the pyrophosphate (OPP) and a proton completes the conversion. Occurrence It could in principle be extracted from any number of plants, such as verbena or wild thyme, the leaves of which contain up to 40% by weight of myrcene. Many other plants contain myrcene, sometimes in substantial amounts. Some of these include cannabis, hops, ''Hou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
α-pinene
α-Pinene is an organic compound of the terpene class, one of two isomers of pinene. It is an alkene and it contains a reactive four-membered ring. It is found in the oils of many species of many coniferous trees, notably the pine. It is also found in the essential oil of rosemary (''Rosmarinus officinalis'') and '' Satureja myrtifolia'' (also known as ''Zoufa'' in some regions). Both enantiomers are known in nature; (1''S'',5''S'')- or (−)-α-pinene is more common in European pines, whereas the (1''R'',5''R'')- or (+)-α-isomer is more common in North America. The racemic mixture is present in some oils such as eucalyptus oil and orange peel oil. Reactivity : Commercially important derivatives of alpha-pinene are linalool, geraniol, nerol, a- terpineol, and camphene. α-Pinene 1 is reactive owing to the presence of the four-membered ring adjacent to the alkene. The compound is prone to skeletal rearrangements such as the Wagner–Meerwein rearrangement. Aci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3-hydroxybutanoic Acid
β-Hydroxybutyric acid, also known as 3-hydroxybutyric acid or BHB, is an organic compound and a beta hydroxy acid with the chemical formula CH3CH(OH)CH2CO2H; its conjugate base is β-hydroxybutyrate, also known as 3-hydroxybutyrate. β-Hydroxybutyric acid is a chiral compound with two enantiomers: D-β-hydroxybutyric acid and L-β-hydroxybutyric acid. Its oxidized and polymeric derivatives occur widely in nature. In humans, D-β-hydroxybutyric acid is one of two primary endogenous agonists of hydroxycarboxylic acid receptor 2 (HCA2), a G protein-coupled receptor (GPCR). Biosynthesis In humans, can be synthesized in the liver via the metabolism of fatty acids (e.g., butyrate), , and ketogenic amino acids through a series of reactions that metabolize these compounds into acetoacetate, which is the first ketone body that is produced in the fasting state. The biosynthesis of from acetoacetate is catalyzed by the β-hydroxybutyrate dehydrogenase enzyme. Butyrate can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instar
An instar (, from the Latin '' Ä«nstar'', "form", "likeness") is a developmental stage of arthropods, such as insects, between each moult (''ecdysis''), until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or assume a new form. Differences between instars can often be seen in altered body proportions, colors, patterns, changes in the number of body segments or head width. After shedding their exoskeleton (moulting), the juvenile arthropods continue in their life cycle until they either pupate or moult again. The instar period of growth is fixed; however, in some insects, like the salvinia stem-borer moth, the number of instars depends on early larval nutrition. Some arthropods can continue to moult after sexual maturity, but the stages between these subsequent moults are generally not called instars. For most insect species, an ''instar'' is the developmental stage of the larval forms of holometabolous (complete metamorphism) or nymphal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Larva
A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. The larva's appearance is generally very different from the adult form (''e.g.'' caterpillars and butterflies) including different unique structures and organs that do not occur in the adult form. Their diet may also be considerably different. Larvae are frequently adapted to different environments than adults. For example, some larvae such as tadpoles live almost exclusively in aquatic environments, but can live outside water as adult frogs. By living in a distinct environment, larvae may be given shelter from predators and reduce competition for resources with the adult population. Animals in the larval stage will consume food to fuel their transition into the adult form. In some organisms like polychaetes and barnacles, adults are im ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Papilio Demodocus
''Papilio demodocus'', the citrus swallowtail or Christmas butterfly, is a swallowtail butterfly which commonly occurs over the entirety of sub-Saharan Africa, including Madagascar, besides the southern Arabian Peninsula. The caterpillars feed on various native plants of especially the family Rutaceae, but have also taken to the leaves of cultivated citrus trees. Life cycle Citrus swallowtails pass through approximately three generations per year. Eggs Female butterflies lay their eggs singly on citrus leaves. After about six days, the egg hatches into an immature larva. Immature larva The immature larvae are black, yellow, and white with spikes. Their coloration provides effective camouflage, as they resemble bird droppings. They grow to a length of 10 or 15 mm before changing into mature larvae. Mature larva Mature larvae are green with white or pink markings and eyespots. They grow to a maximum length of about 45 mm. Mature caterpillars lack the camouflage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2-methylbutyric Acid
2-Methylbutanoic acid, also known as 2-methylbutyric acid is a branched-chain alkyl carboxylic acid with the chemical formula CH3CH2CH(CH3)CO2H, classified as a short-chain fatty acid. It exists in two enantiomeric forms, (''R'')- and (''S'')-2-methylbutanoic acid. (''R'')-2-methylbutanoic acid occurs naturally in cocoa beans and (''S'')-2-methylbutanoic occurs in many fruits such as apples and apricots, as well as in the scent of the orchid '' Luisia curtisii''. History 2-Methylbutanoic acid is a minor constituent of ''Angelica archangelica'' and the perennial flowering plant valerian (''Valeriana officinalis''), where it co-occurs with valeric acid and isovaleric acid. The dried root of this plant has been used medicinally since antiquity. The chemical identity of all three compounds was first investigated in the 19th century by oxidation of the components of fusel alcohol, which includes the five-carbon amyl alcohols. Among the products isolated was a compound which gave ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isobutyric Acid
Isobutyric acid, also known as 2-methylpropanoic acid or isobutanoic acid, is a carboxylic acid with structural formula ( CH3)2CH COOH. It is an isomer of ''n''-butyric acid. It is classified as a short-chain fatty acid. Deprotonation or esterification gives derivatives called isobutyrates. Isobutyric acid is a colorless liquid with a somewhat unpleasant odor. It is soluble in water and organic solvents. It is found naturally in carobs (''Ceratonia siliqua''), in vanilla, and in the root of ''Arnica dulcis'', and as an ethyl ester in croton oil. Production Isobutyric acid is manufactured by the oxidation of isobutyraldehyde, which is a byproduct of the hydroformylation of propylene. It can also be prepared by the high pressure hydrocarboxylation (Koch reaction) from propylene: :CH3CH=CH2 + CO + H2O → (CH3)2CHCO2H Isobutyric acid can also be manufactured commercially using engineered bacteria with a sugar feedstock. Laboratory methods Many routes are known inclu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
