Characterization of Proanthocyanidin Oligomers of Ephedra sinica.
Characterization of Proanthocyanidin Oligomers of Ephedra sinica.
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DOI：
10.3390/molecules22081308
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发表时间：
2017-08-06
期刊：
影响因子：
--
通讯作者：
Tanaka T
中科院分区：
文献类型：
--
作者：
Orejola J;Matsuo Y;Saito Y;Tanaka T
麻黄是一种重要的中药植物，其主要成分为原花青素低聚物的复杂混合物；然而，只有少量的成分被化学表征。本研究采用吸附-排粒径色谱法分离出分子量较大的低聚物，这是原花青素组分的主体。在巯基乙醇或间苯三酚存在下的酸催化降解导致18个片段的分离，通过实验和tddft计算的ECD光谱对其结构进行了鉴定。结果表明(−)-没食子儿茶素是主要的延伸单元，而儿茶素、a型没食子儿茶素-没食子儿茶素二聚体和a型没食子儿茶素同二聚体是末端单元。降解产物中，具有3,4-顺式构型的没食子儿茶素硫醚、具有a -键和b -键的prodelphinidin三聚体和具有α-取代a -键的prodelphiinidin二聚体为新化合物。此外，还分离到了a型prodelphinidin二聚体的间苯三酚加合物、表没食子儿茶素的双连接间苯三酚加合物以及芳香环重排产生的具有黄烷-3-醇骨架的独特产物。
Ephedra sinica, an important plant in Chinese traditional medicine, contains a complex mixture of proanthocyanidin oligomers as major constituents; however, only the minor components have been chemically characterized. In this study, oligomers with relatively large molecular weights, which form the main body of the proanthocyanidin fractions, were separated by adsorption and size-exclusion chromatography. Acid-catalyzed degradation in the presence of mercaptoethanol or phloroglucinol led to the isolation of 18 fragments, the structures of which were elucidated from their experimental and TDDFT-calculated ECD spectra. The results indicated that (−)-epigallocatechin was the main extension unit, while catechin, the A-type epigallocatechin–gallocatechin dimer, and the A-type epigallocatechin homodimer, were identified as the terminal units. Among the degradation products, thioethers of gallocatechin with 3,4-cis configurations, a B-type prodelphinidin dimer, a prodelphinidin trimer with both A- and B-type linkages, and a prodelphinidin dimer with an α-substituted A-type linkage were new compounds. In addition, a phloroglucinol adduct of an A-type prodelphinidin dimer, a doubly-linked phloroglucinol adduct of epigallocatechin, and a unique product with a flavan-3-ol skeleton generated by the rearrangement of the aromatic rings were also isolated.
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影响因子：
1.8
作者：
CRONJE, A;BURGER, JFW;FERREIRA, D
通讯作者：
FERREIRA, D
DOI：
10.1021/acs.joc.6b02161
发表时间：
2017-02-03
期刊：
The Journal of organic chemistry
影响因子：
--
作者：
Nam JW;Phansalkar RS;Lankin DC;McAlpine JB;Leme-Kraus AA;Vidal CM;Gan LS;Bedran-Russo A;Chen SN;Pauli GF
通讯作者：
Pauli GF
影响因子：
5.4
作者：
Alfonso Magos, Gil;Carlos Mateos, Juan;Guillermo Enriquez, Raul
通讯作者：
Guillermo Enriquez, Raul
影响因子：
1.8
作者：
HIKINO, H;TAKAHASHI, M;KONNO, C
通讯作者：
KONNO, C
影响因子：
2.1
作者：
BURGER, JFW;KOLODZIEJ, H;FERREIRA, D
通讯作者：
FERREIRA, D