浅蓝霉素H的发酵优化与浅蓝苷K的化学合成

Fermentation Optimization of the Caerulomycin H and the Synthesis of Cyanogriside K

浅蓝霉素H (2)及其4-基α-L-吡喃鼠李糖苷[即浅蓝苷K (1)]是从海洋来源的浅蓝异壁放线菌WH1-2216-6的发酵产物中分离获得的天然产物,浅蓝苷K(1)具有良好的肿瘤细胞增殖抑制活性,但其产率低,合成未见报道.因此,首先对浅蓝霉素H(2)的主产菌株浅蓝异壁放线菌WH1-2216-6突变株CRM05进行发酵优化,采用放线菌5号与玉米配制的固体培养基发酵培养CRM05菌株,将浅蓝霉素H (2)的产量提高到272 mg/L(提高了5倍),获得了足量的浅蓝霉素H(2).接着,通过脱肟、鼠李糖苷化、成肟及脱乙酰保护等6步反应,以25.6%的总收率从浅蓝霉素H(2)合成了浅蓝苷K (1).通过高分辨质谱、核磁共振和比旋光等数据确认了浅蓝苷K (1)的结构,与报道的天然产物为同一化合物.浅蓝苷K (1)具有较强的肿瘤细胞抗增殖活性,对肿瘤细胞株PATU8988T、786-O、5673、DU145、A-375、FaDu和SF126的半数抑制浓度(IC50)为1.07~1.78μmol/L.

Caerulomycin H(2) and its 4-yl α-L-rhamnopyranoside [cyanogriside K(1)] are two microbial natural products from marine-derived Actinoalloteichus cyanogriseus WH1-2216-6. Cyanogriside K(1) shows good antiproliferative activity against tumor cells, whereas the yield is very low and the synthesis has not been reported. Thus, enough caerulomycin H(2)was first obtained by optimazing the fermentation condition of the mutant strain CRM05 of A. cyanogriseus WH1-2216-6. The yield of caerulomycin H(2) reached 272 mg/L(increased by 5 times) in the optimal solid medium consisted of corn pellets(80g) and liqiud medium 5# for actinomycetes(100 mL). Then cyanogriside K(1) was synthesized with 25.6% total yield from caerulomycin H(2) by six steps reactions including deoximation, rhamnosylation, oximation and deacetylation. The structure of cyanogriside K(1) was identified by NMR, HRESIMS and specific rotation data. It is the same compound as the reported natural product. Furthermore, cyanogriside K(1) showed good bioactivity against the proliferation of the tumor cell lines PATU8988T, 786-O, 5673, DU145, A-375, FaDu and SF126, with the half maximal inhibitory concentration(IC50) values ranging from 1.07 μmol/L to 1.78 μmol/L.