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51.
Structure-activity relationships of a new antifungal imidazole, AFK-108, and related compounds 总被引:1,自引:0,他引:1
Hori K Sakaguchi A Kudoh M Ishida K Aoyama Y Yoshida Y 《Chemical & pharmaceutical bulletin》2000,48(1):60-64
Fungicidal activity of widely used imidazole antifungal drugs in topical applications is not so strong in spite of their fungistatic activities against dermatophytes and pathogenic yeasts. In order to improve fungicidal activity of imidazole antifungal agents, a series of novel imidazole derivatives having a hydrophobic substituent derived from isoprenoid were synthesized. The efficacy of these compounds was evaluated with respect to direct cell-membrane damaging activity, ergosterol biosynthesis inhibition, minimum growth-inhibitory concentration (MIC) and therapeutic effect for experimental dermatophytosis of guinea pigs. Among the newly synthesized compounds, the geranyl derivative named AFK-108 (2a) showed the highest in vivo fungicidal activity with both cell membrane damaging activity and ergosterol biosynthesis inhibition in vitro. 相似文献
52.
Chesney A Bryce MR Yoshida S Perepichka IF 《Chemistry (Weinheim an der Bergstrasse, Germany)》2000,6(7):1153-1159
Two conceptually different routes to transient 1,2-diselones are reported: 1) via ring fragmentation of the 1,4,2-diselenazine system 6, and 2) by the tributylphosphane-induced depolymerisation of the shelf-stable organoselenium polymer 15. Evidence for the intermediacy of 1,2-diselone species 7 and 16 is provided in both cases by in situ trapping with dimethyl acetylenedicarboxylate (DMAD) to yield 1,4-diselenin derivatives. The route via 15 is especially expedient and trapping of 16 is efficient. Subsequent reactions of adduct 17 afford [1,2-ethanediylbis(diphenylphosphane)] [5,6-bis(methoxycarbonyl)-1,4-diselenin-2,3-dithiolato]nickel(IV) (20). Theoretical calculations at Hartree-Fock (HF) and Moller-Plesset electron-correlated levels (MP2) suggest that the cyclic 1,2-diselenete structure 7c is significantly more stable than the acyclic 1,2-diselone structure 7a. For the bicyclic system 16, the difference in energy between the cyclic and acyclic structures is considerably reduced due to the conformational rigidity imposed by the fused 1,3-dithiole ring. In contrast, the acyclic structures of the 1,2-dithione analogues 13a and 25a are computed to be more stable than their corresponding cyclic 1,2-dithiete structures 13c and 25c. 相似文献
53.
This review covers simple indole alkaloids, isoprenoid tryptamines, and bisindole alkaloids with a nonrearranged monoterpenoid unit. Newly isolated alkaloids, structure determinations, total syntheses and biological activities are reported. The literature from January to December 2000 is reviewed, and 182 references are cited. 相似文献
54.
Hydrogen evolution on a platinum electrode decays against Xpt with the deposition of Sn ad-atoms and Pb ad-atoms in the same way as it decays with that of Ge ad-atoms, in which all of these ad-atoms occupy two platinum sites. In general the decay depends on the number of sites occupied by an atom of the ad-atom species.The potential ranges for oxygen adsorption by Sn ad-atoms and Pb ad-atoms are 0.45 to 1.24 V and 0.48 to 0.77 V, respectively, but the oxygen adsorbed by the latter ad-atoms is very small in amount. 相似文献
55.
56.
[reaction: see text] We have developed an efficient copper-catalyzed allylation of carbonyl derivatives using allyl(2-pyridyl)silanes, in which the strong directing effect of the 2-pyridyl group was observed. A useful synthesis and allylation of substituted allyl(2-pyridyl)silanes is also described. 相似文献
57.
Hiroshi Suda Masatoahi Motoi Masatoshi Fujii Shigeyoshi Kanoh Hiroshi Yoshida 《Tetrahedron letters》1979,20(47):4565-4568
Enantioselective reductions of prociral ketones with chiral hydride reagent prepared from optically active 2,2′-diamino-6,6′-dimethylbiphenyl and lithium aluminum hydride were accomplished in O.Y. more than 50%. 相似文献
58.
Transport phenomenon of three sulfonated azo dyes, C.I. Acid Red 88, C.I. Direct Yellow 12, and C.I. Direct Blue 15 into water-swollen cellulose membranes has been analyzed on the basis of parallel transport theory by surface and pore diffusion. Langmuir equation was applied into the mass balance equation to estimate dye concentration in the pores. The results were compared with the results obtained by applying Freundlich equation in our previous papers. The surface diffusivity (D
s) and the pore diffusivity (D
p) for the parallel diffusion model obtained by applying Langmuir equation agreed with those obtained by applying Freudlich equation. The theoretical concentration profiles for parallel diffusion calculated usingD
s andD
p coincided accurately with the experimental data when we applied either Langmuir or Freundlich equations. 相似文献
59.
The structural change from the porphyrin free base to monoacid and diacid by successive protonation has been studied by the IR, visible and NMR spectroscopy. The results have indicated that the cation and anion of the porphyrin diacid are strongly associated through H-bonding. The far IR spectra show especially marked differences in the free base, monoacid, and diacid due to the changes of the inner core of the porphyrin ring. 相似文献
60.
Masahiro Yoshida 《Tetrahedron letters》2004,45(29):5573-5575
The direct coupling of propargylic alcohols with arylboronic acids has been achieved using palladium catalyst. Various propargylic alcohols and arylboronic acids can be coupled to afford the corresponding allenic and propargylic arenes, which are selectively produced depending on the substituent on the propargylic alcohol, respectively. 相似文献