Chemical constituents of Taxus chinensis var. mairei cell cultures / 药学学报

The chemical constituents of Taxus chinensis var. mairei cell cultures were investigated by chromatographic methods, including silica gel column chromatography, Sephadex LH-20 and preparative HPLC. Thirteen compounds were isolated from the 80% ethanol extract of cultured cells and their structures were elucidated by spectral data and physicochemical properties, which were identified as 2α,4α,7β,9α,10β-pentaacetoxy-14β-hydroxytax-11-ene (1), 2α,4α,7β,9α,10β-pentaacetoxytax-11-ene (2), 1β-deoxybaccatin VI (3), 2α-acetoxytaxusin (4), taxuyunnanine C (5), yunnanxane (6), 2α,5α,10β-triacetoxy-14β-propionyloxy-4 (20), 11-taxadiene (7), 2α,5α,10β-triacetoxy-14β-isobutyryloxy-4 (20), 11-taxadiene (8), 2α,5α,10β-triacetoxy-14β-(2'-methyl)butyryloxy-4 (20), 11-taxadiene (9), 13-dehydroxylbaccatin III (10), 13-dehydroxy-10-deacetylbaccatin III (11), paclitaxel (12) and (13) β-sitosterol. Among them, compound 1 is a new compound, and compounds 2, 4, 10 and 11 are isolated from the cell culture of Taxus chinensis var. mairei for the first time.

The construction and expression of superantigen SEA and antimelanoma ScFv fusion gene / 生物工程学报

Two strategies, direct ligation after enzyme digestion and over-lap PCR technology, were adopted to construct a fusion gene which was composed of the antimelanoma single chain antibody gene and the staphylococcal enterotoxin A gene without N-terminal signal sequence. The fusion gene was subcloned into pET28-a vector and transformed into E. coli BL21(DE3). Ni-NTA system was selected to separate and purify the expresstd products. The inhibition ratio of the fusion protein was tested by MTT method. It is shown that the 6His-ScFv-SEA fusion protein can be expressed stably in E. coli BL21 (DE3). The quantity of the fusion protein was shown up to 30% of the total protein of the bacteria and mainly in inclusion body. By activation the effective cells, the fution protein can inhibit the melanoma cell whith expressed corresponding antigen.