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Ochnaflavone
Ochnaflavone, a secondary plant secondary metabolite of the Biflavonoid family, has been widely investigated in past decades due to its unique ability to mediate biological activities, such as inhibition of phospholipase A2 and lymphocyte proliferation. It was first isolated from '' Ochna squarrosa'' Linn, a member of Ochnaceae family, in 1973. Synthesis The first total synthesis of ochnaflavone derivatives was achieved by Kawano group in 1973, followed by the Heerden group for the first time reporting the total synthesis the ochnaflavone by constructing a diaryl ether intermediate and assemble the two flavone nuclei through ring cyclization. To date, the field of biochemistry of biflavonoids is still wide open. Little is known about Ochnaflavone of its natural occurrence and biosynthesis. Activity Although Ochnaflavone has not been fully studied in the past decades, its protective role in plants and human body already attract scientists’ much attention, such as anti-atherogen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biflavonoid
Biflavonoids are a type of flavonoids with the general formula scheme (C6-C3-C6)2. Examples * Amentoflavone (bis-apigenin coupled at 8 and 3' positions) * Lophirone L and lophirone M found in ''Lophira alata'' * Sulcatone A, a naturally occurring biflavonoid isolated from '' Ouratea sulcata''. Extracts of the leaves of this plant, used with and with other plant's extracts, are used in many African countries to treat some infections such as upper tract respiratory infections, dysenteria, diarrhoea and toothache. Positive antimicrobial activity has been shown in-vitro against '' Staphylococcus aureus'' and ''Bacillus subtilis''. ''Escherichia coli'' showed to be resistant in the same study. * Hinokiflavone, a cytotoxic biflavonoid from ''Toxicodendron succedaneum'', ''Juniperus sp.'', or '' Chamaecyparis obtusa'' (hinoki). * Leaflets of ''Cycas circinalis'' and '' C. revoluta'' contain biflavonoids such as (2''S'', 2′′''S'')-2,3,2′′,3′′-tetrahydro-4′,4′′′-di- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phospholipase A2
The enzyme phospholipase A2 (EC 3.1.1.4, PLA2, systematic name phosphatidylcholine 2-acylhydrolase) catalyse the cleavage of fatty acids in position 2 of phospholipids, hydrolyzing the bond between the second fatty acid “tail” and the glycerol molecule: :phosphatidylcholine + H2O = 1-acylglycerophosphocholine + a carboxylate This particular phospholipase specifically recognizes the ''sn''2 acyl bond of phospholipids and catalytically hydrolyzes the bond, releasing arachidonic acid and lysophosphatidic acid. Upon downstream modification by cyclooxygenases or lipoxygenases, arachidonic acid is modified into active compounds called eicosanoids. Eicosanoids include prostaglandins and leukotrienes, which are categorized as anti-inflammatory and inflammatory mediators. PLA2 enzymes are commonly found in mammalian tissues as well as arachnid, insect, and snake venom. Venom from bees is largely composed of melittin, which is a stimulant of PLA2. Due to the increased presenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ochna Squarrosa
''Ochna''Linnaeus C (1753) ''Sp. Pl.'' 1: 513. is a genus comprising 86 species of evergreen trees, shrubs and shrublets belonging to the flowering plant family ''Ochnaceae''. These species are native to tropical woodlands of Africa, the Mascarenes and Asia. Species of this genus are usually called ochnas, bird's-eye bushes or Mickey-mouse plants, a name derived from the shape of the drupelet fruit. The name of this genus comes from the Greek word ''Ochne'', used by Homer and meaning ''wild pear'', as the leaves are similar in appearance. Some species, including ''Ochna integerrima'' (yellow ''Mai'' flower) and '' O. serrulata'' (bird's eye plant), are cultivated as decorative plants. Distribution Species of this genus are found in the Old World Tropics, especially in Africa, Madagascar, the Mascarene Islands and Asia. Selected species *''Ochna afzelii'' *''Ochna andamanica'' *''Ochna angustata'' *''Ochna arborea'' *''Ochna awrrulata'' *''Ochna barbosae'' – sand plane, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ochnaceae
Ochnaceae is a family of flowering plants in the order Malpighiales.Vernon H. Heywood, Richard K. Brummitt, Ole Seberg, and Alastair Culham. ''Flowering Plant Families of the World''. Firefly Books: Ontario, Canada. (2007). . In the APG III system of classification of flowering plants, Ochnaceae is defined broadly, to include about 550 species,Maria do Carmo E. Amaral, and Volker Bittrich. 2014. "Ochnaceae". pages 253-268. In: Klaus Kubitzki (editor). 2014. ''The Families and Genera of Vascular Plants'' volume XI. Springer-Verlag: Berlin, Heidelberg, Germany. (print). (eBook). and encompasses what some taxonomists have treated as the separate families Medusagynaceae and Quiinaceae. In a phylogenetic study that was Academic publishing, published in 2014, Ochnaceae was recognized in the broad Sensu, sense,Julio V. Schneider, Pulcherie Bissiengou, Maria do Carmo E. Amaral, Ali Tahir, Michael F. Fay, Marco Thines, Marc S.M. Sosef, Georg Zizka, and Lars W. Chatrou. 2014. "Phyloge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synthesis Of Ochnaflavone
Synthesis or synthesize may refer to: Science Chemistry and biochemistry *Chemical synthesis, the execution of chemical reactions to form a more complex molecule from chemical precursors **Organic synthesis, the chemical synthesis of organic compounds ***Total synthesis, the complete organic synthesis of complex organic compounds, usually without the aid of biological processes ***Convergent synthesis or linear synthesis, a strategy to improve the efficiency of multi-step chemical syntheses **Dehydration synthesis, a chemical synthesis resulting in the loss of a water molecule *Biosynthesis, the creation of an organic compound in a living organism, usually aided by enzymes **Photosynthesis, a biochemical reaction using a carbon molecule to produce an organic molecule, using sunlight as a catalyst **Chemosynthesis, the synthesis of biological compounds into organic waste, using methane or an oxidized molecule as a catalyst **Amino acid synthesis, the synthesis of an amino acid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atherogenesis
Atherosclerosis is a pattern of the disease arteriosclerosis in which the wall of the artery develops abnormalities, called lesions. These lesions may lead to narrowing due to the buildup of atheromatous plaque. At onset there are usually no symptoms, but if they develop, symptoms generally begin around middle age. When severe, it can result in coronary artery disease, stroke, peripheral artery disease, or kidney problems, depending on which arteries are affected. The exact cause is not known and is proposed to be multifactorial. Risk factors include abnormal cholesterol levels, elevated levels of inflammatory markers, high blood pressure, diabetes, smoking, obesity, family history, genetic, and an unhealthy diet. Plaque is made up of fat, cholesterol, calcium, and other substances found in the blood. The narrowing of arteries limits the flow of oxygen-rich blood to parts of the body. Diagnosis is based upon a physical exam, electrocardiogram, and exercise stress test, among ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extracellular Signal-regulated Kinase
In molecular biology, extracellular signal-regulated kinases (ERKs) or classical MAP kinases are widely expressed protein kinase intracellular signalling molecules that are involved in functions including the regulation of meiosis, mitosis, and postmitotic functions in differentiated cells. Many different stimuli, including growth factors, cytokines, virus infection, ligands for heterotrimeric G protein-coupled receptors, transforming agents, and carcinogens, activate the ERK pathway. The term, "extracellular signal-regulated kinases", is sometimes used as a synonym for mitogen-activated protein kinase (MAPK), but has more recently been adopted for a specific subset of the mammalian MAPK family. In the MAPK/ERK pathway, Ras activates c-Raf, followed by mitogen-activated protein kinase kinase (abbreviated as MKK, MEK, or MAP2K) and then MAPK1/2 (below). Ras is typically activated by growth hormones through receptor tyrosine kinases and GRB2/ SOS, but may also receive other si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Matrix Metalloproteinase
Matrix metalloproteinases (MMPs), also known as matrix metallopeptidases or matrixins, are metalloproteinases that are calcium-dependent zinc-containing endopeptidases; other family members are adamalysins, serralysins, and astacins. The MMPs belong to a larger family of proteases known as the metzincin superfamily. Collectively, these enzymes are capable of degrading all kinds of extracellular matrix proteins, but also can process a number of bioactive molecules. They are known to be involved in the cleavage of cell surface receptors, the release of apoptotic ligands (such as the FAS ligand), and chemokine/cytokine inactivation. MMPs are also thought to play a major role in cell behaviors such as cell proliferation, migration (adhesion/dispersion), differentiation, angiogenesis, apoptosis, and host defense. They were first described in vertebrates (1962), including humans, but have since been found in invertebrates and plants. They are distinguished from other endopeptida ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inflammation
Inflammation (from la, wikt:en:inflammatio#Latin, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or Irritation, irritants, and is a protective response involving immune cells, blood vessels, and molecular mediators. The function of inflammation is to eliminate the initial cause of cell injury, clear out necrotic cells and tissues damaged from the original insult and the inflammatory process, and initiate tissue repair. The five cardinal signs are heat, pain, redness, swelling, and Functio laesa, loss of function (Latin ''calor'', ''dolor'', ''rubor'', ''tumor'', and ''functio laesa''). Inflammation is a generic response, and therefore it is considered as a mechanism of innate immune system, innate immunity, as compared to adaptive immune system, adaptive immunity, which is specific for each pathogen. Too little inflammation could lead to progressive tissue destruction by the harmful stimulus (e.g. b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phospholipase A2
The enzyme phospholipase A2 (EC 3.1.1.4, PLA2, systematic name phosphatidylcholine 2-acylhydrolase) catalyse the cleavage of fatty acids in position 2 of phospholipids, hydrolyzing the bond between the second fatty acid “tail” and the glycerol molecule: :phosphatidylcholine + H2O = 1-acylglycerophosphocholine + a carboxylate This particular phospholipase specifically recognizes the ''sn''2 acyl bond of phospholipids and catalytically hydrolyzes the bond, releasing arachidonic acid and lysophosphatidic acid. Upon downstream modification by cyclooxygenases or lipoxygenases, arachidonic acid is modified into active compounds called eicosanoids. Eicosanoids include prostaglandins and leukotrienes, which are categorized as anti-inflammatory and inflammatory mediators. PLA2 enzymes are commonly found in mammalian tissues as well as arachnid, insect, and snake venom. Venom from bees is largely composed of melittin, which is a stimulant of PLA2. Due to the increased presenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flavones
Flavones (from Latin ''flavus'' "yellow") are a class of flavonoids based on the backbone of 2-phenylchromen-4-one (2-phenyl-1-benzopyran-4-one) (as shown in the first image of this article). Flavones are common in foods, mainly from spices, and some yellow or orange fruits and vegetables. Common flavones include apigenin (4',5,7-trihydroxyflavone), luteolin (3',4',5,7-tetrahydroxyflavone), tangeritin (4',5,6,7,8-pentamethoxyflavone), chrysin (5,7-dihydroxyflavone), and 6-hydroxyflavone. Intake and elimination The estimated daily intake of flavones is about 2 mg per day. Following ingestion and metabolism, flavones, other polyphenols, and their metabolites are absorbed poorly in body organs and are rapidly excreted in the urine, indicating mechanisms influencing their presumed absence of metabolic roles in the body. Drug interactions Flavones have effects on CYP (P450) activity, which are enzymes that metabolize most drugs in the body. Biosynthesis The biosynthesis of f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
