Cytotoxic Polyketide Metabolites from a Marine Mesophotic Zone Chalinidae Sponge-Associated Fungus Pleosporales sp. NBUF144

Two new polyketide natural products, globosuxanthone F (1), and 2′-hydroxy bisdechlorogeodin (2), were isolated from the fungus Pleosporales sp. NBUF144, which was derived from a 62 m deep Chalinidae family sponge together with four known metabolites, 3,4-dihydroglobosuxanthone A (3), 8-hydroxy-3-methylxanthone-1-carboxylate (4), crosphaeropsone C (5), and 4-megastigmen-3,9-dione (6). The structures of these compounds were elucidated on the basis of extensive spectroscopic analysis, including 1D and 2D NMR and high-resolution electrospray ionization mass spectra (HRESIMS) data. The absolute configuration of 1 was further established by single-crystal X-ray diffraction studies. Compounds 1–5 were evaluated for cytotoxicity towards CCRF-CEM human acute lymphatic leukemia cells, and it was found that 1 had an IC₅₀ value of 0.46 µM.     

曙暮光对小豆始花期及叶片生理参数的影响

试验以中晚熟品种‘冀红4号’为材料,在开花前进行遮光处理,研究曙暮光对小豆始花期及叶片生理参数产生的影响。结果表明:曙暮光全遮处理下开花促进率为18.9%,遮去曙光处理的开花促进率为16.2%,遮去暮光处理的开花促进率为13.5%;曙暮光处理的植株始花节位较对照降低了1~2个节位,且始花数显著增加;曙暮光全遮和遮去暮光处理下植株的叶绿素含量显著高于遮去曙光处理和对照植株,且曙暮光全遮和遮去暮光后植株叶片中叶绿素a与叶绿素b的比值变小;遮光后植株叶片可溶性蛋白含量变化不稳定,处理间差异不明显;遮去曙光处理和遮去暮光处理对植株叶片游离氨基酸总量影响显著。