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1.
Biosci Biotechnol Biochem ; 85(6): 1390-1394, 2021 May 25.
Article in English | MEDLINE | ID: mdl-33720279

ABSTRACT

An enantioselective synthesis of (3S,3aS,7aR)-wine lactone, a major aroma component of white wine and citrus juices, was achieved starting from (S)-2-methyl-3-butenoic acid. An intramolecular Diels-Alder reaction was employed as a key step.


Subject(s)
Lactones/chemistry , Lactones/chemical synthesis , Wine/analysis , Chemistry Techniques, Synthetic , Stereoisomerism
2.
Front Microbiol ; 6: 962, 2015.
Article in English | MEDLINE | ID: mdl-26441896

ABSTRACT

Amebiasis is a common worldwide diarrheal disease, caused by the protozoan parasite, Entamoeba histolytica. Metronidazole has been a drug of choice against amebiasis for decades despite its known side effects and low efficacy against asymptomatic cyst carriers. E. histolytica is also capable of surviving sub-therapeutic levels of metronidazole in vitro. Novel drugs with different mode of action are therefore urgently needed. The sulfur assimilatory de novo L-cysteine biosynthetic pathway is essential for various cellular activities, including the proliferation and anti-oxidative defense of E. histolytica. Since the pathway, consisting of two reactions catalyzed by serine acetyltransferase (SAT) and cysteine synthase (CS, O-acetylserine sulfhydrylase), does not exist in humans, it is a rational drug target against amebiasis. To discover inhibitors against the CS of E. histolytica (EhCS), the compounds of Kitasato Natural Products Library were screened against two recombinant CS isozymes: EhCS1 and EhCS3. Nine compounds inhibited EhCS1 and EhCS3 with IC50 values of 0.31-490 µM. Of those, seven compounds share a naphthoquinone moiety, indicating the structural importance of the moiety for binding to the active site of EhCS1 and EhCS3. We further screened >9,000 microbial broths for CS inhibition and purified two compounds, xanthofulvin and exophillic acid from fungal broths. Xanthofulvin inhibited EhCS1 and EhCS3. Exophillic acid showed high selectivity against EhCS1, but exhibited no inhibition against EhCS3. In vitro anti-amebic activity of the 11 EhCS inhibitors was also examined. Deacetylkinamycin C and nanaomycin A showed more potent amebicidal activity with IC50 values of 18 and 0.8 µM, respectively, in the cysteine deprived conditions. The differential sensitivity of trophozoites against deacetylkinamycin C in the presence or absence of L-cysteine in the medium and the IC50 values against EhCS suggest the amebicidal effect of deacetylkinamycin C is due to CS inhibition.

3.
Bioorg Med Chem ; 16(2): 950-64, 2008 Jan 15.
Article in English | MEDLINE | ID: mdl-17950609

ABSTRACT

Conformationally restricted analogues of KRN7000, an alpha-d-galactosyl ceramide, were synthesized to examine their bioactivity for mouse natural killer (NK) T cells to produce cytokines. RCAI-8, 9, 51, and 52 are the analogues with a pyrrolidine ring, and RCAI-18, 19, 49, and 50 are those with an azetidine ring. RCAI-18 was shown to be a potent inducer of cytokine production by mouse NKT cells, while RCAI-51 was a moderately active inducer.


Subject(s)
Azetidines , Cytokines/biosynthesis , Galactosylceramides , Killer Cells, Natural/drug effects , Pyrrolidines , Animals , Azetidines/chemical synthesis , Azetidines/chemistry , Azetidines/pharmacology , Cytokines/analysis , Galactosylceramides/chemical synthesis , Galactosylceramides/chemistry , Galactosylceramides/pharmacology , Killer Cells, Natural/immunology , Mice , Molecular Structure , Pyrrolidines/chemical synthesis , Pyrrolidines/chemistry , Pyrrolidines/pharmacology
4.
Biosci Biotechnol Biochem ; 67(8): 1744-50, 2003 Aug.
Article in English | MEDLINE | ID: mdl-12951509

ABSTRACT

(4R,6S,7R)-7-Hydroxy-4,6-dimethyl-3-nonanone and (3R,5S,6R)-6-hydroxy-3,5-dimethyl-2-octanone, the pheromone components of the bostrychid beetle, Dinoderus bifoveolatus, as well as their (4R,6S,7S)- and (3R,5S,6S)-isomers were synthesized from (2R,4S,5R)- and (2R,4S,5S)-2,4-dimethyl-5-heptanolide, respectively.


Subject(s)
Coleoptera/chemistry , Ketones/chemical synthesis , Pheromones/chemical synthesis , Alkanes/chemical synthesis , Alkanes/chemistry , Animals , Ketones/chemistry , Lactones/chemistry , Molecular Structure , Octanes/chemical synthesis , Octanes/chemistry , Pheromones/chemistry , Stereoisomerism
5.
Biosci Biotechnol Biochem ; 66(7): 1531-7, 2002 Jul.
Article in English | MEDLINE | ID: mdl-12224637

ABSTRACT

The ceramide sex pheromone [(2S,2'R,3S,4R)-2-(2'-hydroxy-21-methyldocosanoylamino)-1,3,4-pentadecanetriol (1)] of the female hair crab (Erimacrus isenbeckii) was synthesized by starting from (S)-serine and 12-bromo-1-dodecanol.


Subject(s)
Brachyura/metabolism , Ceramides/chemical synthesis , Sex Attractants/chemical synthesis , Animals , Female , Indicators and Reagents , Magnetic Resonance Spectroscopy , Spectrometry, Mass, Fast Atom Bombardment , Spectroscopy, Fourier Transform Infrared
6.
Biosci Biotechnol Biochem ; 66(5): 1032-8, 2002 May.
Article in English | MEDLINE | ID: mdl-12092812

ABSTRACT

All of the four stereoisomers of 3,12-dimethylheptacosane were synthesized from the enantiomers of citronellal. (Z)-9-Pentacosene and (Z)-9-heptacosene were also synthesized. These hydrocarbons are the characteristic components of the cuticular hydrocarbons of the queen of the ant, Diacamma sp..


Subject(s)
Alkanes/chemical synthesis , Alkenes/chemical synthesis , Ants/chemistry , Alkanes/chemistry , Alkenes/chemistry , Animals , Magnetic Resonance Spectroscopy , Mass Spectrometry , Stereoisomerism
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