Research School of Chemistry, The Australian National University , Canberra, ACT, 0200, Australia.
J Nat Prod. 2013 Nov 22;76(11):2054-9. doi: 10.1021/np400473u. Epub 2013 Oct 29.
The pestalotiopsones are fungal metabolites isolated from an endophytic fungus Pestalotiopsis sp. found in the mangrove Rhizophora mucronata, used in traditional Chinese medicine to treat symptoms of dysentery. The absolute configurations of pestalotiopsones D (4) and E (5) were elucidated through total synthesis of both the R and S enantiomers, allowing for the assignment of the stereochemistry of the natural compounds as the (+)-S enantiomers. The key steps include homologation of a substituted benzoic acid to the appropriate phenylacetate derivative using Birch reductive alkylation, an oxa-Michael cyclization induced by microwave irradiation to form the chromanone substructure, and an IBX-mediated dehydrogenation yielding the chromone skeleton. Assessment of the synthetic compounds against clinical pathogens was performed.
佩氏硫线菌素是从红树林内生真菌佩氏多毛孢（Pestalotiopsis sp.）中分离得到的真菌代谢产物，在中国传统医学中用于治疗痢疾症状。通过对 R 和 S 对映异构体的全合成，阐明了佩氏硫线菌素 D（4）和 E（5）的绝对构型，从而确定了天然化合物的立体化学构型为（+）-S 对映异构体。关键步骤包括使用 Birch 还原烷基化反应将取代苯甲酸同系化为适当的苯乙酸酯衍生物、微波诱导的氧杂-Michael 环化反应形成色满酮亚结构以及 IBX 介导的脱氢反应生成色酮骨架。对合成化合物针对临床病原体的评估进行了研究。
