Talaroclauxins A and B:Duclauxin-ergosterol and duclauxin-polyketide hybrid metabolites with complicated skeletons from Talaromyces stipitatus

Talaroclauxins A and B(1 and 2),two novel duclauxin hybrids,were obtained from Talaromyces stipitatus,along with three new(3-5)and one known analogue(6).Their structures were determined by NMR spectroscopy,HRESIMS,single-crystal X-ray diffraction,and quantum chemical calculations.Compound 1 is the first example of duclauxin-ergosterol hybrid featuring an unprecedented dodecacyclic ring system formed via a[4+2]cycloaddition,while compound 2,bearing an unusual 6/6/6/5/6/6/6/6 ring system,is a new member of the rare duclauxin-polyketide hybrid class of natural products.Plausible biosynthetic pathways for 1-6 are proposed.Compound 5 displayed moderate neuroprotective effects in glutamate sodium-induced SH-SY5Y cells.

真菌Talaromyces stipitatus中具有抗炎活性oligophenalenone二聚体

真菌Talaromyces stipitatus的发酵产物对脂多糖诱导的RAW264.7巨噬细胞系一氧化氮(NO)生成具有抑制作用。本实验以生物活性分析为导向,从真菌T.stipitatus发酵产物中分离得到6个具有抗炎活性的次生代谢产物,通过与文献比对核磁共振(nuclear magnetic resonance,NMR)和高分辨电喷雾电离质谱(high resolution electrospray ionization mass spectroscopy,HRESIMS)数据,鉴定为oligophenalenone二聚体,分别是bacillisporin A(1)、9a-epi-bacillisporin E(2)、bacillisporin F(3)、duclauxin(4)、bacillisporin B(5)和bacillisporin C(6)。化合物2—5在浓度30μmol·L-1时,显示出不同程度的NO生成抑制作用,且对巨噬细胞无细胞毒活性,抑制率均高于阳性对照药吲哚美辛(indomethacin,AG);2—4的半抑制浓度(IC50)分别为11.82±1.25、11.44±1.58和23.92±2.86μmol·L-1。首次从该种中分离得到5和6,并首次发现duclauxin及其同系物具有显著的体外抗炎活性,为抗炎活性研究提供了一类新的模式结构。