Y.-H. Pei

Norisoprenoids from Ulva lactuca

Five norisoprenoids were isolated from the green marine alga Ulva lactuca. Two new compounds were assigned to (3R,5R,6R,7E)3,5,6-trihydroxy-7-megastigmen-9-one (1) and (3S,5R,6S,7E)3,5,6-trihydroxy-7-megastigmen-9-one (2). The structures and absolute configurations of the five compounds were determined by analyses of NMR, MS and circular dichroism (CD).

Two diketopiperazines from marine fungus Gliocladium sp. YUP08

Two new diketopiperazines, PJ147 (1) and PJ157 (2), were isolated from the mycelium of a fungus, Gliocladium sp. YUP08, which was separated from sea mud collected in Rushan, Shandong, China. Their structures were elucidated by spectroscopical and chemical methods.

Chemical constituents of Stellera chamaejasme L.

A new biflavanone, 7-methoxyneochamaejasmin A, and a new chromone derivative, isomohsenone, were isolated from the roots of Stellera chamaejasme L. The structures of two compounds were determined by means of ESI-MS, 1H NMR and 13C NMR, especially 2D NMR spectral analyses.

Two new compounds from marine Streptomyces sp. FX-58

Two new compounds, 5-carboxymethyl-2-propylchromone (1) and 1,6-dihydroxy-8-propylanthraquinone (2), together with a known anthraquinone, 3,8-dihydroxy-1-propylanthraquinone-2-carboxylic acid (3), were isolated from the mycelium of an actinomycete, Streptomyces sp. FX-58, which was separated from a marine plant collected in Qingdao. Their structures were determined based on spectroscopic methods, especially 2D NMR spectral analysis.

Aldose Reductase Inhibitors from Stellera chamaejasme

Abstract Six biflavonoids (chamaejasmin, 7-methoxyneochamaejasmin, 7-methoxychamaejasmin, chamaejasmenin B, chamaechromone, wikstrol A) from Stellera chamaejasme. L. have been assayed to show good aldose reductase inhibiting activity. These compounds may be useful to improve diabetic complications such as neuropathy, cataract formation, neophropathy, and retinopathy.

Two novel trichothecenes from Myrothecium roridum

Two new trichothecenes, Roridin P and Isororidin P, and two known trichothecenes, Verrucarin A and Verrucarin J, were isolated from liquid cultures of Myrothecium roridum Tale ex Fr. The stereo-structures of Roridin P and Isororidin P were established on the basis of one- and two-dimensional nuclear magnetic resonance (NMR) spectral analyses. Roridin P and Isororidin P induced morphological changes in Pyricularia oryzae, with a minimum concentration (MMCC) value of 6.2 ± 1.1xa0μmol/L and 7.9 ± 1.5xa0μmol/L.

A new triterpene glycoside from Asterias rollentoni

A new triterpene glycoside, rollentoside A, has been isolated from Asterias rollentoni Bell and identified as 3β-O-{3-O-methyl-β-d-xylopyranosyl-(1 → 3)-O-β-d-glucopyranosyl-(1 → 4)-O-β-d-quinopyranosyl-(1 → 2)-O-β-d-xylopyranosyl}-16-β-acetoxy-23S-acetoxy-holost-7-ene (1), together with a new natural product, rollentoside B (2). The structures of compounds 1 and 2 were elucidated by extensive 1D and 2D NMR investigation (1H–1H COSY, TOCSY, HSQC, HMBC, NOESY).

Triterpenoid saponins from Platycodon grandiflurum

A new bisdesmosidic saponin, named deapio-platycoside E (1), together with two known triterpenoid saponins (2, 3) were isolated from the roots of Platycodon grandiflorum (Jacq.) A. D.C. Their structures were elucidated by spectroscopic and chemical methods.

Biflavonoids from Stellera chamaejasme

Five biflavonoids (wilstrol A, wikstrol B, neochamaejasmin A, neochamaejasmin B and chamajssmine) were isolated from the roots of Stellera chamaejasme L. These compounds play a very important role in the chemotaxonomy of Thymelaeaceae.

A new monoterpene from the bark of Eucommia ulmoides

A new monoterpene, eucommidiol ( 1 ), was isolated from the bark of Eucommia ulmoides Oliv. (Eucommiaceae), together with a known compound 1,4a,5,7a-tetrahydro-7-hydroxymethyl-cyclopenta[c]pyran-4-carboxylic methyl ester. The structure of 1 was characterized as 6,6a-di(hydroxymethyl)-3,3a,4,6a-tetrahydro-2H-cyclopenta[b]furan-2-one on the basis of chemical and spectral evidence including 2DNMR studies.