Ultraviolet absorption spectra and stereochemical structure of plant growth substances of the cis cinnamic acid type and of stilboestrol
Ultraviolet absorption spectra and stereochemical structure of plant growth substances of the cis cinnamic acid type and of stilboestrol
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顺式肉桂酸型和己烯雌酚植物生长物质的紫外吸收光谱和立体化学结构
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发表时间：
1948
期刊：
影响因子：
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通讯作者：
R. Nivard
中科院分区：
文献类型：
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作者：
E. Havinga;R. Nivard
记录了顺式和反式肉桂酸、顺式和反式-1，2，3，4-四氢萘(1)乙酸以及顺式和反式-β-(1-萘基)丙烯酸的紫外吸收光谱。与反式异构体相比，顺式异构体均表现出较低的消光系数和最大吸收波长的移动。结果表明，在顺式化合物中，由于空间位阻的作用，阻碍了芳环体系与羧基的共轭，使分子不具有平面结构。所有这些顺式化合物都显示出显著的植物生长促进活性，而反式异构体则完全没有活性，这与关于它们的立体化学结构的结论是一致的。比较了己烯雌酚和p，p‘-二羟基二苯乙烯的紫外吸收光谱，得出了己烯雌酚分子不具有平面结构的结论，并怀疑根据其与天然雌激素的“形式”相似性来解释雌激素活性是否合理。
Ultraviolet absorption spectra are recorded of cis- and trans- cinnamic acid, of cis- and trans-1,2,3,4,-tetrahydronaphthylidene (1) acetic acid and of cis- and trans-β-(naphthyl-1) acrylic acid. The cis isomers all show a lower extinction coefficient and a shift of the maximum of absorption to shorter wave-length in comparison with the trans isomers. It is concluded that as a result of steric hindrance in the case of the cis compounds the conjugation between aromatic ring system and carboxyl group is hindered, the molecules not possessing a plane structure. The fact that all these cis compounds show marked activity as plant growth promoter, whilst the trans isomers are totally inactive, is in accordance with the conclusions about their stereochemical structure. Comparison of the ultraviolet absorption spectra of stilboestrol and of p,p′-dihydroxystilbene leads to the conclusion that the stilboestrol molecule does not have a plane structure and that it is doubtful whether the explanation of the oestrogenic activity based on its often suggested „formal” similarity to the natural oestrogenic hormones is justified.