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B N Zhou

Publications and source records attributed to B N Zhou.

31 records · Page 2Linked to original sources

New triterpenoid saponins, asterbatanoside D and E, from Aster batangensis.

Two new triterpenoid saponins named asterbatanoside D and E have been isolated from Aster batangensis and their structures elucidated as 3-O-beta- D-glucopyranosyl-bayogenin-28-O-beta-D-glucopyranosyl-(1-->6)-beta -D- glucopyranoside and 3-O-6'-acetyl-beta-D-glucopyranosyl-bayogenin-28-O-beta-D- glucopyranosyl-(1-->6)-beta-D-glucopyranoside by means of MS, 1D and 2D NMR techniques (COSY, TOCSY, ROESY, HMQC, and HMBC), and chemical reactions.

Carbohydrate Conformation↗

Asteryunnanosides F and G: two new triterpenoid saponins from Aster yunnanensis.

Two new triterpenoid saponins, aster-yunnanosides F and G, were isolated from the roots of Aster-yunnanensis. Their structures were determined as oleanolic acid-28-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside and 3-O-beta-glucopyranosyloleanolic acid-28-O-beta-D-glucopyranosyl-(1-->6)-[alpha-L-rhamnopyranosyl-(1-->2) ]- beta-D-glucopyranoside by spectral data, especially 2D NMR analysis including COSY, HETCOR, HOHAHA, and ROESY techniques, and chemical transformation.

Carbohydrate Sequence↗

Yuanhuacin A is a selective antagonist of phorbol ester receptor in protein kinase C.

Protein kinase C with a molecular weight of 82 kD has been purified to electrophoresis homogeneous from rat brain through a series of chromatography columns including DE-52, Sepharose G-200 and phenyl-Sepharose. The enzyme possessed autophosphorylation activity. Yuanhuacin A inhibited the 3H-phorbol-12, 13-dibutyrate (3H-PdBu) binding of PKC with an IC50 value of 1.48 +/- 0.28 x 10(-8) mol/L when the concentration of 3H-PdBu was 1.5 x 10(-9) mol/L (Ki = 1.2 x 10(-8) mol/L). Yuanhuacin A inhibited the PdBu-stimulated PKC activity in the catalysis of the phosphorylation of Histone III-S with an IC50 of 2.82 +/- 0.37 x 10(-9) mol/L (PdBu = 10(-6) mol/L), while it had no effect on the basal and Ca(2+)-stimulated PKC activity in the same assay system. This result suggests that Yuanhuacin A is a selective antagonist of the phorbol ester receptor in protein kinase C.

Animals↗

The pregnane glycoside marsdekoiside A from Marsdenia koi.

A new pregnane glycoside, marsdekoiside A was isolated from the stems of Marsdenia koi (Asclepiadaceae) and its structure was elucidated from chemical and spectral data as 12-cinnamoyl-dihydrosarcostin-3-O-methyl-6-deoxy-beta-D-allopyr ano syl-(1----4)-O-beta-D-oleandropyranosyl-(1----4)-O-beta-D-++ +cymar opyranoside.

Carbohydrate Sequence↗

Studies on the antifertility components from Marsdenia koi.

By random screening test, Marsdenia koi was found to have antifertility activity on SD rat. From MeOH extracts of this plant two steroidal glycosides, marsdekoiside A and B, were isolated, and their structures were elucidated on the basis of spectral evidence and by comparison of the hydrolysis products with the authentic samples. Both are newly identified compounds, and marsdekoiside A has good antifertility activity.

Animals↗

Some progress on the chemistry of natural bioactive terpenoids from Chinese medicinal plants.

(1) Pseudolaric acids--Novel diterpenes, Pseudolaric acid A, B, C and D were isolated from Pseudolarix kaempferi Gorden (pinaceae). Their structures were assigned by spectroscopic data and chemical correlations. In the continuous studies, the absolute configurations, the conformations in the solutions, the fragmentation mechanisms of MS and assignments of all NMR spectral signals were also reported. They showed the antifungal and cytotoxic activities. (2)--Daphnane diterpenes--In the further studies on the plants of Thymelaeaceae, besides 10 known diterpenes, 16 new daphnane diterpenes were isolated from Daphne genkwa, D. tangutica, D. giraldii, Wikstroemie chamaedaphne. They showed the antifertilities activities. (3) Tripterygium diterpenes--14 new diterpenes were isolated from Triperygium wilfordii, T. regeli and T. hypoglaucum. Some of them showed the antitumour activities. The CD spectra showed that A/B ring of all compounds have trans configuration as same as tripdiolide and triptolide determined by X-ray diffraction. (4) Pregnane glycosides from Marsdenia koi--Two new pregnane glycosides marsdenikoiside A and marddenikoiside B which can terminate the early pregnancy were isolated from Marsdeia koi. Their structures were elucidated by hydrolysis and spectroscopic methods.

Contraceptive Agents↗