Crude extracts of the marine sponge Chelonaplysilla sp. collected in Samoa, that were obtained from the NCI Open Repository (NCS 21903), inhibited Mycobacterium tuberculosis growth. Assay-guided fractionation of the extract led to the isolation and structural elucidation of the known diterpenoid macfarlandin D (1) and three new diterpenoids macfarlandins F (2), G (3), and H (4). Macfarlandin D (1) exhibited potent antimicrobial activity against M. tuberculosis with an MIC of 1.2 ± 0.4 µg mL-1. Macfarlandins F (2), G (3), and H (4) exhibited significantly weaker antitubercular activities, revealing SAR for the macfarlandin antitubercular pharmacophore. The structures of compounds 2, 3, and 4 were elucidated via detailed analysis of NMR and MS data.

中文翻译：

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从萨摩亚海洋海绵Chelonaplysilla sp中分离出的二萜。抑制结核分枝杆菌的生长。

海洋海绵Chelonaplysilla sp。的粗提取物。从NCI开放资料库（NCS 21903）获得的萨摩亚收集到的细菌抑制了结核分枝杆菌的生长。提取物的测定指导分馏导致已知二萜类麦克法兰蛋白D（1）和三个新的二萜类麦克法兰蛋白F（2），G（3）和H（4）的分离和结构解析。Macfarlandin D（1）表现出对结核分枝杆菌的有效抗菌活性，MIC为1.2±0.4 µg mL-1。Macfarlandins F（2），G（3）和H（4）表现出明显较弱的抗结核活性，从而揭示了Macfarlandin抗结核药效团的SAR。通过对NMR和MS数据进行详细分析，阐明了化合物2、3和4的结构。