Two new Diels-Alder-type adducts from the stem barks of Morus yunanensis.

Two new Diels-Alder adducts, yunanensins B and D (1 and 2), were isolated from the stem bark of Morus yunanensis. Their structures were determined by spectroscopic analysis. Compounds 1 and 2 showed moderate antioxidant effects on liver microsomal lipid peroxidation induced by Fe(2+)-Cys system, with inhibitory ratios of 57.

[Chemical constituents from Faeces bombycis].

Objective: To study the chemical constituents from Faeces bombycis.

Method: Isolation and purification were carried out on silic gel, Sephadex LH-20 and RP-18 column chromatography. The chemical structures of the constituents were elucidated on the basis of physicochemical properties and spectral data.

Three new compounds from the barks of Morus nigra.

Three new compounds including two flavonoids and a new 2-phenylbenzofuran, named morunigrols A-C (1-3), together with three known compounds albafuran A (4), albafuran B (5), and mulberrofuran L (6), have been isolated from the barks of Morus nigra. Their structures have been elucidated by spectroscopic methods.

[Study of anti-oxidant phenolic compounds from stem barks of Morus yunanensis].

Objective: To study anti-oxidant phenolic compounds from stem barks of Morus yunanensis.

Method: Isolation and purification were carried out by silica gel, Sephadex LH -20 and RP - 18 column chromatography. The chemical structures of constituents were elucidated on the basis of physicochemical properties and spectral data.

A new Diels-Alder type adduct and two new flavones from the stem bark of Morus yunanensis Koidz.

Fractionation of the ethanolic extract of the stem bark of Morus yunanensis resulted in the isolation of a new Diels-Alder type adduct and two new flavones, named yunanensin A (1), yunanensol A (2) and yunanensol B (3), respectively, together with a known flavone (4). Their structures were determined on the basis of spectroscopic analysis and chemical methods. Among them, compound 1 showed moderate antioxidant and significant cytotoxic activities, and compound 2 showed potent anti-inflammatory activity.

Diterpenoids from the roots of Suregada glomerulata.

Six new diterpenoids, 7beta,8alpha-dihydroxy-12-oxo- ent-abietan-16,14-olide ( 1), 3,4,18beta-cyclopropa-7beta,17-dihydroxy- ent-abieta-8(14),13(15)-dien-16,12-olide ( 2), 3alpha,7beta-dihydroxy- ent-abieta-8(14),13(15)-dien-16,12-olide ( 3), 3-oxo-8beta,14beta-epoxy- ent-abieta-11,13(15)-dien-16,12-olide ( 4), 17-hydroxy- ent-pimara-8(14),15-dien-3-one ( 5), and 3alpha,6beta-dihydroxy- ent-kaur-16-ene ( 6), and two known compounds, 7beta-hydroxy- ent-abieta-8(14),13(15)-dien-16,12-olide ( 7) and jolkinolide B, were isolated from roots of Suregada glomerulata. The structures of the new compounds were elucidated on the basis of 1D and 2D NMR and other spectroscopic studies. The structure of compound 1 was confirmed by X-ray crystallography.