- Control Mechanism for cis Double-Bond Formation by Polyunsaturated Fatty-Acid Synthases
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Polyunsaturated fatty acids (PUFAs) such as docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and arachidonic acid (ARA) are essential fatty acids for humans. Some microorganisms biosynthesize these PUFAs through PUFA synthases composed of four subunits with multiple catalytic domains. These PUFA synthases each create a specific PUFA without undesirable byproducts, even though the multiple catalytic domains in each large subunit are very similar. However, the detailed biosynthetic pathways and mechanisms for controlling final-product profiles are still obscure. In this study, the FabA-type dehydratase domain (DHFabA) in the C-subunit and the polyketide synthase-type dehydratase domain (DHPKS) in the B-subunit of ARA synthase were revealed to be essential for ARA biosynthesis by in vivo gene exchange assays. Furthermore, in vitro analysis with truncated recombinant enzymes and C4- to C8-acyl ACP substrates showed that ARA and EPA synthases utilized two types of DH domains, DHPKS and DHFabA, depending on the carbon-chain length, to introduce either saturation or cis double bonds to growing acyl chains.
- Hayashi, Shohei,Satoh, Yasuharu,Ogasawara, Yasushi,Maruyama, Chitose,Hamano, Yoshimitsu,Ujihara, Tetsuro,Dairi, Tohru
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- INHIBITORS OF YEAST FILAMENTOUS GROWTH AND METHOD OF THEIR MANUFACTURE
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The invention broadly relates to the use of α, β-unsaturated fatty acids to inhibit the filamentous growth of fungi and yeasts and to a method for producing same. In particular the invention relates to the use of optionally substituted C8 to C15 α, β-unsaturated fatty acids or salts, esters or amides thereof for inhibiting or retarding the yeast-to-mycelium transition of organisms having a dimorphic life cycle.
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Page/Page column 12-14
(2008/06/13)
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- Cross coupling reactions of organozinc iodides with solid-supported electrophiles: Synthesis of 4-substituted benzoic and 3-substituted (E)- and (Z)-propenoic acids and amides
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The solid-supported iodobenzoic acid derivatives 8-10 were coupled with a range of organozinc reagents 1-4 under palladium(o) catalysis. The coupled products released by acidic cleavage with TFA were obtained in high purities after recrystallization. Anal
- Oates, Leslie J.,Jackson, Richard F.W.,Block, Michael H.
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p. 140 - 144
(2007/10/03)
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- Palladium(0)-catalysed Transfer Hydrogenation of Alkynes to cis-Alkenes with HCO2H-NEt3
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Transfer hydrogenation of alkynes using HCO2H-NEt3 as a hydrogen donor in the presence of Pd0-catalyst proceeds highly stereoselectively to afford cis-alkenes in excellent yields, thus providing a practical method for conversion of alkynes to cis-alkenes.
- Tani, Kousuke,Ono, Naoya,Okamoto, Sentaro,Sato, Fumie
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p. 386 - 387
(2007/10/02)
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- Studies on the Metabolism of Unsaturated Fatty Acids. V. Isomerization of Thiol Esters of cis-2-Alkenoic Acids during Their Preparation and Alkaline Hydrolysis
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N-Acetylcysteamine and coenzyme A esters of cis-2-alkenoic acids have been found to undergo isomerization to the corresponding trans-isomers during their preparation by the mixed anhydride method and also during their alkaline hydrolysis.The isomerization might proceed by interaction of the free thiol group and the cis-double bond of 2-alkenoic thiol esters.The use of pyridine as a base and three or more equivalents of the mixed anhydride to the thiol compound prevented the formation of the trans-isomer.Addition of hydrogen peroxide during alkaline hydrolisys also prevented the isomerization completely.
- Mizugaki, Michinao,Ito, Yoko,Hoshino, Toshiaki,Shiraishi, Takayuki,Yamanaka, Hiroshi
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p. 206 - 213
(2007/10/02)
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