Acyclic branched or unbranched hydrocarbons having two carbon-carbon double bonds.

Evidence of a cyclooxygenase-related prostaglandin synthesis in coral. The allene oxide pathway is not involved in prostaglandin biosynthesis. (1/176)

Certain corals are rich natural sources of prostaglandins, the metabolic origin of which has remained undefined. By analogy with the lipoxygenase/allene oxide synthase pathway to jasmonic acid in plants, the presence of (8R)-lipoxygenase and allene oxide synthase in the coral Plexaura homomalla suggested a potential metabolic route to prostaglandins (Brash, A. R., Baertshi, S. W., Ingram, C.D., and Harris, T. M. (1987) J. Biol. Chem. 262, 15829-15839). Other evidence, from the Arctic coral Gersemia fruticosa, has indicated a cyclooxygenase intermediate in the biosynthesis (Varvas, K., Koljak, R., Jarving, I., Pehk, T., and Samel, N. (1994) Tetrahedron Lett. 35, 8267-8270). In the present study, active preparations of G. fruticosa have been used to identify both types of arachidonic acid metabolism and specific inhibitors were used to establish the enzyme type involved in the prostaglandin biosynthesis. The synthesis of prostaglandins and (11R)-hydroxyeicosatetraenoic acid was inhibited by mammalian cyclooxygenase inhibitors (indomethacin, aspirin, and tolfenamic acid), while the formation of the products of the 8-lipoxygenase/allene oxide pathway was not affected or was increased. The specific cyclooxygenase-2 inhibitor, nimesulide, did not inhibit the synthesis of prostaglandins in coral. We conclude that coral uses two parallel routes for the initial oxidation of polyenoic acids: the cyclooxygenase route, which leads to optically active prostaglandins, and the lipoxygenase/allene oxide synthase metabolism, the role of which remains to be established. An enzyme related to mammalian cyclooxygenases is the key to prostaglandin synthesis in coral. Based on our inhibitor data, the catalytic site of this evolutionary early cyclooxygenase appears to differ significantly from both known mammalian cyclooxygenases.  (+info)

Biosynthesis of depudecin, a metabolite of Nimbya scirpicola. (2/176)

Feeding experiments of labeled acetates to Nimbya scirpicola proved the carbon origin of the straight-chain polyketide, depudecin. Differential hydrogen exchange of the 2H label originating from 2H labeled acetate along the polyketide chain occurred. In particular, the deuterium of an epoxide methine at C-3 was lost to a substantial extent in the formation of depudecin.  (+info)

Female Attacus atlas respond to pheromones of Antheraea polyphemus: a comparative electrophysiological and biochemical study. (3/176)

Female Attacus atlas respond electrophysiologically to both of the Antheraea polyphemus pheromone components (E,Z)-6,11-hexadecadienyl acetate and (E,Z)-6,11-hexadecadienal. Moreover, they possess a pheromone-binding protein (PBP) and general odorant-binding proteins (GOBPs), as well as a pheromone-degrading sensillar esterase and aldehyde oxidase enzymes. They show no electroantennogram responses to their own gland extract. In contrast, female A. polyphemus do not respond to their own or to A. atlas pheromone. Male A. atlas do not detect any of the A. polyphemus compounds but only the conspecific female gland extracts. Both male A. atlas and female A. polyphemus possess PBP and GOBP but lack the pheromone-degrading esterases of male Antheraea. The results indicate that the two species use quite distinct classes of chemicals as pheromones. In spite of this, the N-terminal amino acid sequences of the PBPs show homology of 68%.  (+info)

Using electroactive substrates to pattern the attachment of two different cell populations. (4/176)

This report describes the development of an electroactive mask that permits the patterning of two different cell populations to a single substrate. This mask is based on a self-assembled monolayer of alkanethiolates on gold that could be switched from a state that prevents the attachment of cells to a state that promotes the integrin-mediated attachment of cells. Monolayers were patterned into regions having this electroactive monolayer and a second set of regions that were adhesive. After Swiss 3T3 fibroblasts had attached to the adhesive regions of this substrate, the second set of regions was activated electrically to permit the attachment of a second population of fibroblast cells. This method provides a general strategy for patterning the attachment of multiple cell types and will be important for studying heterotypic cell-cell interactions.  (+info)

Activation and inhibition of the transduction process in silkmoth olfactory receptor neurons. (5/176)

Electrophysiological responses of olfactory receptor neurons in both male and female silkmoths (Bombyx mori) were investigated. In both sexes, the G-protein activator sodium fluoride and 1,2-dioctanoyl-sn-glycerol, a membrane-permeable analog of the protein kinase C activator diacylglycerol, elicited nerve impulse responses similar to those elicited by weak continuous stimulation with odorants. Therefore, G(q)-proteins and diacylglycerol-activated ion channels seem to be involved in the transduction process in both pheromone-sensitive neurons in males and general odorant-sensitive neurons in females. Decyl-thio-trifluoro-propanone is known to inhibit electrophysiological responses of male moths to pheromones, but has no effect in females. Application of this inhibitor reduced the frequency, but not the amplitude of elementary receptor potentials. It had no inhibitory effect on nerve impulse responses elicited by sodium fluoride or 1,2-dioctanoyl-sn-glycerol. This supports the idea that decyl-thio-trifluoro-propanone acts on a prior step of the transduction cascade, e.g. on the pheromone receptor molecules. General odorants, such as (+/-)-linalool and 1-heptanol, excite olfactory receptor neurons in females, but inhibit the pheromone-sensitive neurons in males. Both (+/-)-linalool and 1-heptanol inhibited the responses of male neurons elicited by sodium fluoride or 1,2-dioctanoyl-sn-glycerol. (+/-)-Linalool reduced the amplitude of elementary receptor potentials. In contrast to decyl-thio-trifluoro-propanone, (+/-)-linalool and 1-heptanol seem to interfere with later processes of the transduction cascade, possibly the opening of ion channels.  (+info)

A novel push-pull Diels-Alder diene: reactions of 4-alkoxy- or 4-phenylsulfenyl-5-chalcogene-substituted 1-phenylpenta-2,4-dien-1-one with electron-deficient dienophiles. (6/176)

5-(phenylselenenyl)- and 5-(phenylsulfenyl)-4-ethoxy-1-phenyl-2,4-pentadien-1-ones (2) and (3) underwent [4+2] cycloaddition with N-methyl and N-phenylmaleimides and successive isomerization to give the 7-benzoyl-3a,4,5,7a-tetrahydro-1H-isoindole-1,3(2H)-diones 5, 8 and 9 in good yields. The 4-ethoxy group on the 2,4-pentadien-1-one was found to be effective to facilitate the cycloaddition with dienophiles. We also performed other [4+2] cycloadditions of 2,4-pentadien-1-ones with DMAD or naphthoquinone.  (+info)

Adaptation in pheromone-sensitive trichoid sensilla of the hawkmoth Manduca sexta. (7/176)

In extracellular tip recordings from long trichoid sensilla of male Manduca sexta moths, we studied dose-response relationships in response to bombykal stimuli of two different durations in the adapted and the non-adapted state. Bombykal-responsive cells could be distinguished from non-bombykal-sensitive cells in each trichoid sensillum because the bombykal-responsive cell always generated the action potentials of larger initial amplitude. The bombykal cell, which was recorded at a defined location within a distal flagellar annulus, can resolve at least four log(10)-units of pheromone concentrations but is apparently unable to encode all stimulus durations tested. Parameters of the amplitude-modulated sensillar potential and the frequency-modulated action potential responses were examined in different states of adaptation. Evidence is presented for the existence of several mechanisms of adaptation, which affect distinct steps of the transduction cascade. After adapting pheromone stimuli, the sensillar potential rises to a lower amplitude and declines faster compared with the non-adapted response. In addition, the frequency of the adapted action potential response is reduced. Only the time of rise of the sensillar potential is differentially affected by adapting pheromone stimuli of different duration. The time of rise does not increase after short, but only after long, adapting stimuli. Both short and long adapting stimuli shift the dose-response curves of the sensillar potential amplitude, as well as the initial slope of its rising phase, to higher stimulus concentrations by approximately one log(10)-unit. The shift in the dose-response curve of the action potential response is larger than for the sensillar potential response, suggesting that an additional adaptation mechanism acts at the level of action potential generation. Furthermore, a faster decline of the sensillar potential after short and long adapting stimuli suggests that the resting potential of the olfactory receptor neuron is stabilized.  (+info)

Synthesis and characterization of hexadecadienyl compounds with a conjugated diene system, sex pheromone of the persimmon fruit moth and related compounds. (8/176)

Hexadecadien-1-ol and the derivatives (acetate and aldehyde) with a conjugated diene system have recently been identified from a pheromone gland extract of the persimmon fruit moth (Stathmopoda masinissa), a pest insect of persimmon fruits distributed in East Asia. The alcohol and acetate showed their base peaks at m/z 79 in a GC-MS analysis by electron impact ionization, but the aldehyde produced a unique base peak at m/z 84, suggesting a 4,6-diene structure. To confirm this inference, four geometrical isomers of each 4,6-hexadecadienyl compound were synthesized by two different routes in which one of two double bonds was furnished in a highly stereoselective manner. Separation of the two isomers synthesized together by each route was facilely accomplished by preparative HPLC. Their mass spectra coincided well with those of natural components, indicating that they were available for use as authentic standards for determining the configuration of the natural pheromone. Furthermore, other hexadecadienyl compounds, including the conjugated diene system between the 3- and 10-positions, were synthesized to accumulate the spectral data of pheromone candidates. 5,7-Hexadecadienal interestingly showed the base peak at m/z 80; meanwhile, the base peaks of its alcohol and acetate were detected at m/z 79 like the corresponding 4,6-dienes. The base peaks of all 6,8-, 7,9-, and 8,10-dienes universally appeared at m/z 67 like 9,11-, 10,12-, and 13,15-dienes, the spectra of which have already been published. Although 3,5-hexadecadienal was not prepared, base peaks at m/z 67 and 79 were recorded for the alcohol and acetate, respectively.  (+info)

Alkadienes are organic compounds that contain two carbon-carbon double bonds in their molecular structure. The term "alka" refers to the presence of hydrocarbons, while "diene" indicates the presence of two double bonds. These compounds can be classified as either conjugated or non-conjugated dienes based on the arrangement of the double bonds.

Conjugated dienes have their double bonds adjacent to each other, separated by a single bond, while non-conjugated dienes have at least one methylene group (-CH2-) separating the double bonds. The presence and positioning of these double bonds can significantly affect the chemical and physical properties of alkadienes, including their reactivity, stability, and spectral characteristics.

Alkadienes are important intermediates in various chemical reactions and have applications in the production of polymers, pharmaceuticals, and other industrial products. However, they can also be produced naturally by some plants and microorganisms as part of their metabolic processes.

Friedrich, E. C.; Niyati-Shirkhodaee, F. (1991). "Regioselectivity and Solvent Effects in Cyclopropanation of Alkadienes". J. ...
"Cyclopentadiene Dimerization Kinetics in the Presence of C5 Alkenes and Alkadienes". Industrial & Engineering Chemistry ...
doi:10.1021/jp076572o v t e (Alkadienes, All stub articles, Hydrocarbon stubs). ...
The A race produces alkadienes and alkatrienes (derivatives of fatty acids) wherein n is an odd number 23 through 31. The B ... see vegetable oil refining). Botryococcenes are preferred over alkadienes and alkatrienes for hydrocracking as botryococcenes ... The vast majority of these hydrocarbons are botryocuccus oils: botryococcenes, alkadienes and alkatrienes. Transesterification ...
The book also described 16 original methods of industrial synthesis and polymerization of dialkenes (alkadienes). In 1910s, ...
163-193, ISBN 978-0-12-800780-8, retrieved 2022-11-17 "3.4: Alkenes, Cycloalkenes, and Alkadienes". Chemistry LibreTexts. 2014- ...
Alkadienes, Hemiterpenes, IARC Group 2B carcinogens, Monomers, Conjugated dienes). ...
Alkadienes, Hazardous air pollutants, Monomers, IARC Group 1 carcinogens, U.S. Synthetic Rubber Program, Commodity chemicals, ...
... alkadienes MeSH D02.455.326.271.665.146.240 - butadienes MeSH D02.455.326.271.665.146.280 - chloroprene MeSH D02.455.326.271. ...
Alkadienes, Conjugated dienes, All stub articles, Hydrocarbon stubs). ...
5 alkadienes, 5 alkynes and several alkanes and arenes in proportions. Ethene, acetylene and benzene were a major part at ...
Alkadienes, All stub articles, Organic compound stubs). ...
Friedrich, E. C.; Niyati-Shirkhodaee, F. (1991). "Regioselectivity and Solvent Effects in Cyclopropanation of Alkadienes". J. ...
Soják, L.; Královicová, E.; Ostrovský, I.; Leclercq, P.A., Retention behaviour of conjegated and isolated n-alkadienes. ...
Aromatics, alkanes, carboxylic acids, alkenes, alkadienes, and small quantities of gaseous products are produced by pyrolysis [ ...
Alkadienes_and_Approaches_to_Organic_Synthesis : property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+,,c__ ...
Alkadienes. Acyclic branched or unbranched hydrocarbons having two carbon-carbon double bonds.. ... PheromoneSalamandraAnisolesCalciumAxonsDEETVomeronasal OrganPatch-Clamp TechniquesInsect RepellentsDendritesAlkadienesNecturus ... PheromoneAnisolesCalciumDEETInsect RepellentsAlkadienesCyclic Nucleotide-Gated Cation ChannelsIon ChannelsAldehydesCyclohexenes ...
Profundizar en los temas de investigación en los que Química e Ingeniería Química está activo. Estas etiquetas de temas provienen de las obras de los integrantes de esta organización. Juntos, forma una huella digital única ...
hydrocarbons (alkenes, alkadienes).. Steel cylindrical body has a loading chamber for fuel, the door is equipped with a seal. ...
Alkenes and Alkadienes. *Alkynes. *Environmental Chemistry. Appendix 1: Chapterwise Solved JEE Main 2019 Questions (16 Sets) ...
Part 4. Halogenated alkenes and alkadienes (C1 to C4). - summary - document - ...
AlkadienesAlkynesCatalysisCyclizationCycloheptanesCyclopentanesHydrocarbonsMethaneMolecular StructureRutheniumStereoisomerism ...
a) Alkadienes. b) Alkynes. c) Aromatic compounds. d) Olefins. Answer:. d) Olefins ...
And also we found in some case we can obtain the expected conjugated alkadienes in high product yield. For example in this ... Under these conditions we found we can obtain all expected conjugated alkadienes in high isometric purity which will be shown ... think that is just middle of 1970 I was thinking to find nice general synthetic method of all kind of the conjugated alkadienes ...
Alkadienes: Classification into cumulated, conjugated and isolated dienes - Thieles theory of partial valency - 1,4-addition ...
... and alkadienes. Multivariate analysis of variance revealed that CHC amounts were significantly different among all species and ... including abundant unsaturated alkadienes. For insects adapted to different host plants and climatic regimes, our results ...
Polyene macrolide antibiotic with unknown composition. It is obtained from Streptomyces aureofaciens. It is used as an antifungal agent, an antiprotozoal agent, and in the treatment of BENIGN PROSTATIC HYPERTROPHY ...
Chen CJ, Ding D, Lee CC, Kearns KN, Pomeraniec IJ, Cifarelli CP, Arsanious DE, Liscak R, Hanuska J, Williams BJ, Yusuf MB, Woo SY, Ironside N, Warnick RE, Trifiletti DM, Mathieu D, Mureb M, Benjamin C, Kondziolka D, Feliciano CE, Rodriguez-Mercado R, Cockroft KM, Simon S, Mackley HB, Zammar SG, Patel NT, Padmanaban V, Beatson N, Saylany A, Lee J, Sheehan JP. Embolization of Brain Arteriovenous Malformations With Versus Without Onyx Before Stereotactic Radiosurgery. Neurosurgery. 2021 01 13; 88(2):366-374 ...
Chapter 3- Alkenes, Alkynes and Alkadienes. Chapter 4- Stereochemistry. Chapter 5- Alkyl halides and Grignard Reagent. ...
Thermal Conductivity and Thermal Diffusivity of Twenty-Nine Liquids: Alkenes, Cyclic (Alkanes, Alkenes, Alkadienes, Aromatics ...
Aromaticity Organic Reactions Quantitative Analysis Alkanes Alkenes Alkynes Cycloalkanes Alkadienes Aromatic Hydrocarbons ...
Enveloped viruses encased within a lipid bilayer membrane are highly contagious and can cause many infectious diseases like influenza and COVID-19, thus calling for effective prevention and inactivation strategies. Here, we develop a diatomic iron nanozyme with lipoxidase-like (LOX-like) activity fo …
... alkenes and alkadienes as determined by gas chromatography-mass spectrometry. ...
Alkadienes Preferred Term Term UI T001398. Date01/01/1999. LexicalTag NON. ThesaurusID NLM (1974). ... Alkadienes Preferred Concept UI. M0000709. Registry Number. 0. Scope Note. Acyclic branched or unbranched hydrocarbons having ... Alkadienes. Tree Number(s). D02.455.326.271.665.146. Unique ID. D000466. RDF Unique Identifier. http://id.nlm.nih.gov/mesh/ ...
Alkadienes Preferred Term Term UI T001398. Date01/01/1999. LexicalTag NON. ThesaurusID NLM (1974). ... Alkadienes Preferred Concept UI. M0000709. Registry Number. 0. Scope Note. Acyclic branched or unbranched hydrocarbons having ... Alkadienes. Tree Number(s). D02.455.326.271.665.146. Unique ID. D000466. RDF Unique Identifier. http://id.nlm.nih.gov/mesh/ ...
Alkadienes (1974). Catechols (1966-1974). Public MeSH Note:. 91; was see under CATECHOLS 1975-90. ...
10 Conjugation in Alkadienes and Allylic Systems. 11 Arenes and Aromaticity. 12 Reactions of Arenes: Electrophilic Aromatic ...
1-(Z)-Alkoxy-4-(E)-methoxybutadiene derivatives have been reacted with ethylgyoxylate and diethyl ketomalonate under thermal or hyperbaric conditions. They provide, with a total regioselectivity and fair to total endoselectivities, the expected dihydropyranic cycloadducts. Three of those pseudo-glycals have been converted in a few classical steps (deprotection, reduction, and dihydroxylation) into (racemic) allose, mannose, and gullose derivatives. The order of these three steps has a direct influence on the efficiency of the transformation and determines the stereochemistry of the final sugar.
Eg: Alkenes, alkadienes and their derivatives.. ⇒ Can take place through the formation of either free radicals or ionic species ...
Conjugation in Alkadienes and Allylic Systems. *Arenes and Aromaticity. *Electrophilic and Nucleophilic Aromatic Substitution ...
N0000179032 alginic acid N0000007227 alglucerase N0000179765 aliskiren N0000006664 alitretinoin N0000166372 Alkadienes ...
Alkenes were the least prevalent, with alkadienes dominating the chromatographic landscape in the longer chain lengths. Sexual ...
... alkadienes, aromatic compounds and carboxylic acids. Regarding the direct use of vegetables oils as fuel for combustion engines ...
2-alkadienes does not occur at 400 degrees, but requires temperatures which are high enough to break the hydrocarbon otherwise ...
Zhou C, Farooq A, Yang L and Mebel A (2022) Combustion chemistry of alkenes and alkadienes, Progress in Energy and Combustion ...
What are alkadienes. *Alla månader i ordning. *Valuta exchange göteborg. *Halvt basbelopp 2021 ...
... aljr aljso aljt alju aljuba aljubas aljvays aljve aljy alk alka alkaa alkab alkabir alkacid alkadienals alkadiene alkadienes ...
Alkadienes Alkalies Alkaline Ceramidase Alkaline Phosphatase Alkaloids Alkalosis Alkalosis, Respiratory Alkanes ...
Syndrome Aliivibrio Aliivibrio fischeri Aliivibrio Infections Aliivibrio salmonicida Alisma Alismataceae Alismatidae Alkadienes ...
  • The adult beetles had a complex mixture of hydrocarbons on their cuticular surface consisting of alkanes, methylalkanes, alkenes and alkadienes as determined by gas chromatography-mass spectrometry. (usda.gov)
  • Eg: Alkenes, alkadienes and their derivatives. (myrank.co.in)
  • The pyrolysis and the emulsification, however, produce heavy carbon deposits, incomplete combustion, an increase of lubricating oil viscosity and undesirable side products such as alkanes, alkenes, alkadienes, aromatic compounds and carboxylic acids. (ijert.org)
  • Part 2C: alkadienes and alkynes. (ihsesdu.com)
  • Rearrangement of 1-alkynes into 1, 2-alkadienes does not occur at 400 degrees, but requires temperatures which are high enough to break the hydrocarbon otherwise into smaller molecules (Hurd and Christ, ibid. (nih.gov)