Chemical investigation of L. tongolensis afforded two new eremophilenolides, which were identified as 3β-(2?-methylbutanoyloxy)-8βH-eremophil-7(11)-en-12, 8α (14, 6α)-diolide (1) and 8βH-eremophil-3, 7(11)-dien-12, 8α (14, 6α)-diolide (2). Their structures were established by spectroscopic methods including 2D NMR experiments.
Two novel epimeric eremophilane sesquiterpenes, 7β-H-3α-angeloyl-9(10)-ene-11, 12-epoxy-8-oxoeremophilane (1) and 7β-H-3α-angeloyl-9(10)-ene-11, 12-epoxy-8-oxoeremophi- lane (2) were isolated from the methanol extract of the flower of Cacalia tangutica (Franch.) Hand-Mazz. Their structures were characterized by 1D-, 2D-NMR (1H-1H COSY, HMQC, HMBC, 1H-1H NOESY) and HRESI-MS techniques.
The chemical investigation of Ixeris polycephala afforded two new norsesquiterpenes,named as ixerols A and B (1-2). Their structures were established based on spectroscopic methods including 2D NMR experiments. The absolute structure of ixerol B was determined by its CD spectrum.
＜正＞The genus Ligularia （Compositae） was made up of approximately 100 species and has extensive distribution. M...
WU, Quan-Xiang SHI, Yan-Ping (State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000) (Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000)
A novel dimeric eremophilane, ligulolide B, was isolated from the alcoholic extract of the whole plant of Ligularia virgaurea spp. oligocephala. The structure was elucidated by various spectroscopic methods including intensive 2D NMR techniques (1H-1H COSY, gHMQC, gHMBC and 1H-1H NOESY) and HR-ESI-MS.
Two new sesquiterpene lactone glycosides were isolated from the whole plant of Sonchus transcaspicus. Their structures were elucidated as 1β-O-β-D-glucopyranosy-5α, 6β H-eudesma-3-en-12, 6α-olide and 1β-O-β-D-glucopyranosy-15-O-(p-hydroxylphenylacetate)-5α, 6β H-eudesma-3, 11(13)-dien-12, 6α-olide by spectral methods (HRMS, 1D and 2D NMR).
Two new butenolide derivatives, named as erigeracerin A and erigeracerin B, which are a pair of epimers, were isolated from Erigeron acer. Their structures were elucidated by spectroscopic analysis including 2D NMR and HR-ESI-MS .
The genus Gentiana (Gentianaceae) contains about 400 species, which distribute almost all over the world. Some species have been investigated on phytochemistry and they could be characterized by the presence of some secoiridoid glucosides (bitter principles), flavone-C-glucosides and xanthone aglycones and glucosides,[1] but nothing is known, up to now, about the chemical constitutents of Gentiana piasezkii Maxim. Members of the genus Gentiana have been used as traditional Chinese herbal medicines to treat hepatitis.[2] In order to find active compounds as lead molecule for medicine, we have studied on constituents of Gentiana piasezkii Maxim and found two new natural occurring,6'-O-(4-hydroxy-veratroyloxy)-arbutin (1) and luteolin 7-(3-hydroxy-4-methoxyl-cinnamoyl)-8-C-glucoside (2) from n-BuOH soluble fraction of an ethanolic extract of the whole plant. Their structures were elucidated by spectroscopic methods including 2D NMR techniques (1H-1H COSY, HMQC and HMBC). So we describe herein the structures of two new phenolic glucosides.……
