The unusual conformational preference of N1,N5,N10-tri-p-coumaroylspermidine E-Z isomers from the Japanese apricot tree, Prunus mume, for the (ZZZ)-form
Autor: | Katsumi Goto, Hiroshi Fukui, Miki Akamatsu, Shinnosuke Mori, Nobuhiro Hirai, Junko Tsukioka |
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Rok vydání: | 2019 |
Předmět: |
biology
010405 organic chemistry Hydrogen bond Chemistry Stereochemistry Ab initio Plant Science biology.organism_classification 01 natural sciences Biochemistry Fluorescence 0104 chemical sciences 010404 medicinal & biomolecular chemistry chemistry.chemical_compound Chlorogenic acid Intramolecular force Proton NMR Japanese Apricot Agronomy and Crop Science Two-dimensional nuclear magnetic resonance spectroscopy Biotechnology |
Zdroj: | Phytochemistry Letters. 31:131-139 |
ISSN: | 1874-3900 |
Popis: | The Japanese apricot tree, Prunus mume (Siebold) Siebold & Zucc. cv. Nanko, bears two types of flowers: those with anthers that fluoresce under UV irradiation, and those that do not. The chemical composition of both types of anthers has been investigated: the non-fluorescent anthers contained eight E-Z isomers of N1,N5,N10-tri-p-coumaroylspermidine as major constituents; whereas the fluorescent anthers contained only a limited amount of (ZZZ)-isomer, but relatively large amounts of fluorescent chlorogenic acid, implying the abnormal development of fluorescent anthers. Of these eight E-Z isomers, three were undescribed, and identified as the (ZEZ)-, (ZEE)-, and (EEZ)-forms. Their photoequilibrium ratios were found to be characteristic, wherein the (ZZZ)-isomer predominated over the (EEE). 1H NMR and NOESY experiments and ab initio molecular orbital calculations indicated that intramolecular T-shaped π/π, CH/π, and OH⋯O = C hydrogen bonding interactions impart an unusual degree of stability to the (ZZZ)-isomer that is sufficient to overcome various factors that favor the (EEE)-form. |
Databáze: | OpenAIRE |
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