期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1972
卷号：69
期号：12
页码：3713-3717
DOI：10.1073/pnas.69.12.3713
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：New 5-hydroxy- and 5-chloro-6-alkyl-1,4-benzoquinones with one or two methyl groups on the nucleus were synthesized as potential antimetabolites of plastoquinones for biological research on photosynthetic and mammalian enzyme systems; the primary emphasis was on photosynthesis. 2,3-Dimethyl-5-hydroxy-6-phytyl-1,4-benzoquinone completely inhibited in chloroplasts the water-dependent electron transport, but photosystem I was insensitive to this analog. The data are consistent with the interpretation that this analog inhibits electron transport in the chain prior to the site of electron donation from the ascorbate-dichlorophenolindophenol couple. Concentrations of 70 {micro}M and 120 {micro}M of this analog caused about 50 and 100% inhibition, respectively, of cyclic photophosphorylation. 2,3-Dimethyl-5-hydroxy-6-phytyl-1,4-benzoquinone is a new type of inhibitor of photosynthetic electron transport that specifically inhibits the rate-limiting step between photosystems I and II. Structurally related analogs caused inhibitions in the range of 50-100% in chloroplasts. These analogs showed marginal inhibition in mitochondrial coenzyme Q10-oxidase systems from beef heart.
关键词：chloroplasts ; beef heart ; coenzyme Q ; electron transport
