中国化学快报(英文版)2024，Vol.35Issue(5) ：223-226.DOI:10.1016/j.cclet.2023.108863

Effective assignment of positional isomers in dimeric shikonin and its analogs by 1H NMR spectroscopy

Ling-Hao Zhao Hai-Wei Yan Jian-Shuang Jiang Xu Zhang Xiang Yuan Ya-Nan Yang Pei-Cheng Zhang
中国化学快报(英文版)2024，Vol.35Issue(5) ：223-226.DOI:10.1016/j.cclet.2023.108863
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  • 万方数据

Effective assignment of positional isomers in dimeric shikonin and its analogs by 1H NMR spectroscopy

Ling-Hao Zhao 1Hai-Wei Yan 1Jian-Shuang Jiang 1Xu Zhang 1Xiang Yuan 1Ya-Nan Yang 1Pei-Cheng Zhang1
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作者信息

  • 1. State Key Laboratory of Bioactive Substance and Function of Natural Medicines,Institute of Materia Medica,Chinese Academy of Medical Sciences and Peking Union Medical College,Beijing 100050,China
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Abstract

An approach for distinguishing two types of positional isomers of dimeric shikonin and its analogs was explored with 4JC,H long-range correlation by prolonging the acquisition time at 2,3Jc,H values of 2.0 and 8.0 Hz.Furthermore,the 1H(proton)nuclear magnetic resonance(NMR)pattern of phenolic hydroxyl protons was developed as a"diagnosis signal"to ascertain the relative location of each side chain in DMSO-d6 at sample concentrations of 0.022-0.034 mol/L.The chemical shift differences of 0.6 ppm be-tween OH-5'and OH-1 and between OH-8'and OH-4 are assigned to Type A and Type B,respectively.All reported ambiguous structures were corrected by this pattern.Additionally,the steric structures of isolated compounds were elucidated by quantum chemical calculations of electronic circular dichroism(ECD)spectra.

Key words

Arnebia euchroma/Dimeric hydroxyl naphthoquinones/Positional isomers/1H NMR spectroscopy/Chemical shift difference

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基金项目

Chinese Academy of Medical Sciences(CAMS)Innovation Fund for Medical Sciences(2021-I2M-1-028)

出版年

2024
中国化学快报(英文版)
中国化学会

中国化学快报(英文版)

CSTPCD
影响因子：0.771
ISSN：1001-8417
参考文献量21
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