Enantioselective synthesis of (2S,3′R,7′Z)-N-(3′-hydroxy-7′-tetradecenoyl)-homoserine lactone
作者:Gullapalli Kumaraswamy、Neerasa Jayaprakash
DOI:10.1016/j.tetlet.2010.09.138
日期:2010.12
A concise enantioselective total synthesis of (2S,3′R,7′Z)-N-(3′-hydroxy-7′-tetradecenoyl)-homoserine lactone is described. Key feature of this protocol is a catalytic asymmetric hydrogenation and a prophenol–zinc-catalyzed diazo addition to imine reaction as genesis of chirality. Moreover, flexibility is built in the synthesis to generate enantioenriched analogsusingcatalytic amount of enantioenriched
Improved Synthesis of (3<i>E</i>,7<i>Z</i>)-3,7-Tetradecadienyl Acetate, the Major Sex Pheromone Constituent of the Potato Pest <i>Symmetrischema tangolias</i> (Gyen)
An efficient six-step synthesis of (3E,7Z)-3,7-tetradecadienyl acetate, the major component of the sexpheromone of the potato pest Symmetrischema tangolias (Gyen), is described, starting from the commercially available dihydropyran. The stereoselective formation of the 7Z double bond is accomplished by a Wittigreaction, while the 3E double bond is formed by a modified Knoevenagel condensation. The
This invention reverses male pattern baldness by shocking dormant hair follicles out of their androgen induced hibernation phase back to the active hair-growing anagenic phase. The invention integrates two functions: 1) It blocks synthesis of compounds holding the follicles in the telogenic/hibernating phase and 2) It stimulates synthesis of compounds animating the hair-growing/anagenic phase in the follicular activity cycle. One preferred embodiment comprises an enzyme inhibitor blocking the conversion of testosterone to dihydrotestosterone (DHT), a flavonoid simultaneously increasing synthesis of prostaglandins alternative to prostaglandin D2, and a selected cannabinoid compound stimulating restore the hair follicle to its normal growth cycle. This novel trimodal therapy restores the hair follicles to their normal cycling processes and maintains these restorative properties so long as this rebalance in maintained.
Kovalev, B. G.; Dzhumakulov, T.; Abduvakhabov, A. A., Doklady Chemistry, 1987, vol. 297, # 12, p. 544 - 548
作者:Kovalev, B. G.、Dzhumakulov, T.、Abduvakhabov, A. A.、Sadykov, A. S.
DOI:——
日期:——
Synthesis and Stereochemistry-Activity Relationship of <i>small</i> Bacteriocin, an Autoinducer of the Symbiotic Nitrogen-Fixing Bacterium <i>Rhizobium leguminosarum</i>
作者:Arata Yajima、Anton A. N. van Brussel、Jan Schripsema、Tomoo Nukada、Goro Yabuta
DOI:10.1021/ol8005198
日期:2008.5.1
The four stereoisomers of small bacteriocin, an autoinducer of the symbiotic nitrogen-fixing bacterium Rhizobium leguminosarum, were synthesized via a versatile methodology for 3'-hydroxyacyl homoserine lactones based on the Nagao asymmetric aldol reaction. The synthetic isomers were much less effective at inhibiting the growth of R. leguminosarum RBL5523 than the natural isomer, showing the importance of stereochemistry for activity.