Formal Synthesis of Leucascandrolide A

✍ Scribed by David R. Williams; Scott V. Plummer; Samarjit Patnaik

• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: English
• Weight: 139 KB
• Volume: 42
• Category: Article
• ISSN: 0044-8249
• DOI: 10.1002/anie.200351817

✦ Synopsis

Extracts from the calcareous sponge Leucascandra caveolata were collected from waters along the northeastern coast of New Caledonia by Pietra and co-workers, and yielded the novel marine macrolide leucascandrolide A (1). [1] The structure of 1 was elucidated by extensive 2D NMR experiments and analysis of Mosher ester derivatives, which revealed an 18-membered macrolide containing two bridging trisubstituted tetrahydropyran rings and an ester side chain with a Za,b-unsaturated oxazole. The natural product displayed significant in vitro cytotoxicity against both KB oral epidermoid carcinoma and P388 leukemia cell lines (IC 50 = 0.05 and 0.25 mg mL À1 , respectively), as well as antifungal activity against the pathogenic yeast Candida albicans. Attempts to isolate additional quantities of the natural product through subsequent harvesting of sponge samples proved unfruitful, which led to the suggestion that 1 may be derived from the [*] Prof.