RESUMEN
Three new pyrrole alkaloids albifipyrrols A-C (1-3), were isolated from the endophytic fungus Albifimbria viridis collected from the Chinese medicinal plant. Their structures were elucidated by extensive NMR and HRESIMS spectrometric analyses. All compounds were evaluated for immunosuppressive activity. Fortunately, compound 2 exhibits certain inhibition specifically against the LPS-induced proliferation of B lymphocyte cells with IC50 value 16.16 µM.
RESUMEN
BACKGROUND: Reproduction in most flowering plants may be limited because of the decreased visitation or activity of pollinators in fragmented habitats. Hedysarum scoparium Fisch. et Mey. is an arid region shrub with ecological importance. We explored the pollen limitation and seed set of Hedysarum scoparium in fragmented and restored environments, and examined whether pollen limitation is a significant limiting factor for seed set. We also compared floral traits and pollinator visitation between both habitats, and we determined the difference of floral traits and pollinators influenced reproductive success in Hedysarum scoparium. RESULTS: Our results indicated that supplementation with pollen significantly increased seed set per flower, which is pollen-limited in this species. Furthermore, there was greater seed set of the hand cross-pollination group in the restored habitat compared to the fragmented environment. More visits by Apis mellifera were recorded in the restored habitats, which may explain the difference in seed production between the fragmented and restored habitats. CONCLUSIONS: In this study, a positive association between pollinator visitation frequency and open flower number was observed. The findings of this study are important for experimentally quantifying the effects of floral traits and pollinators on plant reproductive success in different habitats.