Chiaki Kuroda

Name:

Organization: Rikkyo University

Department: Department of Chemistry and Research Center for Smart Molecules

Title:

Chemicals
References

Intra-specific diversity of the chemical composition of Ligularia lamarum in the Hengduan Mountains, China: The structures of four new eremophilanes and a new seco-eremophilane

Co-reporter:Yoshinori Saito, Motoki Hidaka, Akané Fukuda, Yasuko Okamoto, ... Chiaki Kuroda

Phytochemistry Letters 2017 Volume 20(Volume 20) pp:

Publication Date(Web):1 June 2017

DOI:10.1016/j.phytol.2017.04.026

•Five new eremophilane-/seco-eremophilane-type sesquiterpenoids were isolated.•Furanoeremophilane composition in Ligularia lamarum was diverse.•Major components of a pair of two sympatrically collected samples were different.•One of five samples was a hybrid, but its chemical composition was of L. lamarum.Chemical compositions and internal transcribed spacer (ITS) sequences of five samples of Ligularia lamarum collected in Sichuan Province, China, were analyzed. Fourteen compounds, including four new eremophilanes and one new seco-eremophilane, were isolated and their structures were elucidated by spectroscopic methods. Intra-specific diversity in the chemical composition was found to be higher than previously known. The result of DNA analysis suggested that one of the samples was introgressed, although its chemical composition was typical of L. lamarum.Download high-res image (175KB)Download full-size image

Synthesis and NMR Spectroscopic Elucidation of Four Diastereoisomers of Oxygenated Bisabolane Side Chain

Co-reporter:Misaki Hirai;Rurina Miyazaki;Kana Mitsui;Kota Kiuchi;Hiroyuki Onuki;Hiroshi Hirota

Helvetica Chimica Acta 2015 Volume 98( Issue 8) pp:1035-1060

Publication Date(Web):

DOI:10.1002/hlca.201400395

Abstract

Four possible stereoisomers of a model compound of highly O-bearing bisabolane sesquiterpenes were synthesized and their NMR spectra were compared. Starting from isopulegol, allylic oxidation and Grignard reaction afforded a mixture of alcohols at C(8), which was separated. After metathesis reaction, both α- and β-epoxides were obtained via non-stereoselective epoxidation, while VO(OⁱPr)₃-catalyzed epoxidation afforded a single diastereoisomer selectively. NMR Spectra of twelve synthesized compounds, four stereoisomers of acetates, isobutyrates, and tiglates, were measured. A difference between C(8α)- and C(8β)-acyloxy isomers was observed in the δ-values of HC(8) in CDCl₃. Within the 8β-acyloxy compounds, the α- and the β-epoxides were distinguished by either the J-value of HC(8) or the chemical shift of CH₂(9). Within the 8α-acyloxy compounds, two epoxide isomers were distinguished by the J-value of HC(10) in C₆D₆ or in CD₃OD.

Corrigendum to “Chemical and genetic diversity of Ligularia virgaurea collected in northern Sichuan and adjacent areas of China. Isolation of thirteen new compounds” [Tetrahedron 68 (2012) 10011–10029]

Co-reporter:Yoshinori Saito, Yuriko Takashima, Aya Kamada, Yurika Suzuki, Midori Suenaga, Yasuko Okamoto, Yoichi Matsunaga, Ryo Hanai, Takayuki Kawahara, Xun Gong, Motoo Tori, Chiaki Kuroda

Tetrahedron 2014 70(5) pp: 1099

Publication Date(Web):

DOI:10.1016/j.tet.2013.12.038

Chemical and genetic similarity and diversity of Ligularia anoleuca and L. fischeri collected in the Hengduan Mountains of China

Co-reporter:Anna Shimizu, Yurika Suzuki, Ryo Hanai, Yasuko Okamoto, Motoo Tori, Xun Gong, Chiaki Kuroda

Phytochemistry 2014 Volume 102() pp:137-144

Publication Date(Web):June 2014

DOI:10.1016/j.phytochem.2014.03.019

•Seventeen furanoeremophilanes were isolated from L. anoleuca and L. fischeri.•The presence of three chemotypes was detected by LCMS analysis.•Differences in chemical composition of L. anoleuca and L. fischeri are small.•L. anoleuca and L. fischeri are indistinguishable in the neutral DNA sequences.The sesquiterpenoid composition in the root and the DNA sequences of evolutionarily neutral regions were studied in Ligularia anoleuca and Ligularia fischeri (Asteraceae) collected in the Sichuan Province of China. LC–MS analysis showed that L. anoleuca populations from different localities had different chemical compositions. However, the isolated compounds were similar to each other, indicating that the differences in chemical composition were not large. The DNA analysis suggested that the two species were indistinguishable. Seventeen furanoeremophilanes and an eremophilane acetal were isolated.Graphical abstractThe two title species were indistinguishable both in the root chemicals and in neutral DNA sequences examined.

Chemical and genetic diversity of Cremanthodium lineare

Co-reporter:Yoshinori Saito, Mayu Ichihara, Koji Takiguchi, Yui Tanio, Yasuko Okamoto, Ryo Hanai, Chiaki Kuroda, Takayuki Kawahara, Xun Gong, Motoo Tori

Phytochemistry 2013 Volume 96() pp:184-190

Publication Date(Web):December 2013

DOI:10.1016/j.phytochem.2013.08.009

•Sixteen compounds were isolated from six samples of Cermanthodium lineare.•Three samples produced furanoeremophilanes, and the other three contained eremophilan-8-ones.•The DNA sequences supported the existence of two chemotypes in C. lineare.•Eremophilane sesquiterpenoids from Cremanthodium species were previously unknown.Chemical constituents and evolutionally neutral DNA sequences of six samples of Cremanthodium lineare Maxim., collected in the Sichuan Province of China, were studied. Three samples produced furanoeremophilanes and the other three, eremophilan-8-ones. The chemotypes were found to be correlated with DNA sequence types, suggesting that the chemical diversity observed has a genetic origin. Production of furanoeremophilanes by a Cremanthodium species suggests an evolutionary relationship between Cremanthodium and Ligularia species, and possibly to related genera.Three of six samples of Cremanthodium lineare produced furanoeremophilanes, and the other three contained eremophilan-8-ones; two chemotypes were thus found. These are correlated with DNA sequence types.