Chemical investigation of a previously unreported indigenous Australian Streptomyces strain MST-91080 has identified six novel analogues related to the oxazole-pendanted macrodiolide, conglobatin. Phylogenetic analysis of the 16S rRNA gene sequence identified MST-91080 as a species of Streptomyces, distinct from reported conglobatin producer, Streptomyces conglobatus ATCC 31005. Conglobatins B–E diverge from conglobatin through differing patterns of methylation on the macrodiolide skeleton. The altered methyl positions suggest a deviation from the published biosynthetic pathway, which proposed three successive methylmalonyl-CoA extender unit additions to the conglobatin monomer. Conglobatins B1, C1 and C2 exhibited more potent cytotoxic activity selectively against the NS-1 myeloma cell line (IC₅₀ 0.084, 1.05 and 0.45 µg ml⁻¹, respectively) compared with conglobatin (IC₅₀ 1.39 µg ml⁻¹).

对以前未报告的澳大利亚原住民链霉菌菌株MST-91080的化学研究已鉴定出六种与恶唑-彭丹化大环内酯类糖蛋白有关的新型类似物。对16S rRNA基因序列的系统发育分析确定MST-91080是链霉菌的一种，与报道的球蛋白生产者链球菌不同。ATCC31005。巨球蛋白B–E通过大环糖苷骨架上甲基化的不同模式而不同于巨球蛋白。改变的甲基位置表明与已公开的生物合成途径有所偏离，该途径提出了向连续球蛋白单体连续添加三个甲基丙二酰-CoA扩展剂单元。Conglobatins B1，C1和C2选择性地针对NS-1骨髓瘤细胞系（表现出IC更有效的细胞毒活性₅₀ 0.084，1.05和0.45微克毫升^-1与conglobatin相比分别）（IC ₅₀ 1.39微克毫升^-1）。