Two new alkaloids chaetoglobosins V (1) and W (2), together with the six known congeners 3-8, were isolated through bioassay-guided fractionations from the EtOAc extract of a solid culture of Chaetomium globosum IFB-E041. The structures were elucidated by spectroscopic methods including mainly 1D and 2D NMR techniques. Chaetoglobosin W (2) was unique in its possession of an oxolane ring formed via an oxygen bridge between C-3 and C-6. The isolated fungal metabolites exhibited moderate cytotoxic activities against four human cancer cell lines (KB, K562, MCF-7, and HepG2) with their IC(50) values in a range of 18-30 µg/mL.
This article draws upon responses given by volunteers who work in the Beijing LGBT Centre regarding perceptions of sexual identity, and how Chinese culture affects hidden or open sexual identities of Chinese lesbian and gay people in this region. The insights gained from those working carefully to create social change offers an important and original contribution to the field of gay and lesbian studies in China. The findings indicate the volunteers at the Beijing LGBT Centre are frustrated by the lack of acceptance of non-heterosexual relationships among Chinese culture and society, and by the disregard of lesbian gay and bisexual (LGB) people by the Chinese government. The findings also illustrate stigmatization of homosexuality in China is enacted in structural terms (such as in the lack of policy, legislation and positive endorsement by governmental and socio-political organizations), public expression (such as negative attitudes, beliefs or reactions towards LGB people) and internalized repression (through fear of stigmatization, and subsequent abuse due to negative societal attitudes and discrimination). Influenced by the Chinese tradition of conforming to group values, the findings from this study show that volunteers at the Beijing LGBT Centre believe LGB people in China are generally hesitant to disclose their sexual identities, and reject the idea that there had been a collective shift in Chinese culture regarding increased acceptance of LGB people. It also finds volunteers at the LGBT Centre in Beijing blame Chinese culture for its lack of acceptance of non-heterosexual relationships, and state stigmatization of homosexuality in China is due to deep-rooted cultural homophobia.
(1)H-NMR guided fractionation of the EtOAc extract from the culture of Myrothecium gramminum (strain no. 3.1968) led to the isolation of eight cytotoxic trichothecene macrolides ( 1 - 8), all being substantially inhibitory against HepG2 (human hepatocellular carcinoma) and KB (human nasopharynyeal epidermoid tumor) cell lines with IC (50) values ranging from 2.2 to 12.2 mug/mL. Their inactivity to or weaker action on Vero cells (IC (50) values > 20 microg/mL, originated from the African green monkey kidney) highlighted preliminarily the nature of the selective cytotoxicity of the fungal metabolites against the test cancer cell lines. In addition, verrucarin A ( 1) and roridin A ( 5) were found to be potent inhibitors of the radial growth of Echinochloa crusgalli with corresponding IC (50) values of (7.96 +/- 0.31) x 10 ( - 6) and (9.18 +/- 0.44) x 10 ( - 6) M, respectively, which were more potent than that of the positive control (2,4-dichlorophenoxyacetic acid) [(9.40 +/- 0.04) x 10 ( - 5) M].
(-)-Alternarlactam [(-)-1], a new promising cytotoxin against two human cancer cell lines, was isolated from an endophyte culture and synthesized (along with (+)-1) from readily available starting materials. The absolute configuration, chirality-activity relevance and self-aggregation of (-)-1 were assigned by a combination of synthetic, spectroscopic and computational approaches. The full characterization of the new fungal cytotoxin may provide valuable information in the discovery of new antitumor agents.
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