Synthesis, Antifungal Activity, and Structure−Activity Relationships of Coruscanone A Analogues
摘要:
Coruscanone A, a plant-derived cyclopentenedione derivative, showed potent in vitro antifungal activity against Candida albicans and Cryptococcus neoformans comparable to amphotericin B and fluconazole. A series of analogues have been synthesized by modification of the cyclopentenedione ring, the enolic methoxy functionality, and the side chain styryl moiety of this natural product lead. A structurally close 1,4-benzoquinone analogue was also prepared. All the compounds were examined for their in vitro activity against major opportunistic fungal pathogens including C. albicans, C. neoformans, and Aspergillus fumigatus and fluconazole-resistant C. albicans strains, with several analogues demonstrating potent antifungal activity. Structure-activity relationship studies indicate that the 2-methoxymethylenecyclopent-4-ene-1,3-dione structural moiety is the pharmacophore responsible for the antifungal activity of this class of compounds while the side chain styryl-like moiety plays an important complementary role, presumably contributing to target binding.
Efficient Control of π-Alkyne and Vinylidene Complex Pathways for the W(CO)<sub>5</sub>(L)-Catalyzed Synthesis of Two Types of Nitrogen-Containing Bicyclic Compounds
作者:Yuji Onizawa、Hiroyuki Kusama、Nobuharu Iwasawa
DOI:10.1021/ja0782605
日期:2008.1.1
2-azabicyclo[3.3.0]octanes were obtained in good yield via pi-alkyne complexes. On the other hand, treatment of the same substrates with a catalytic amount of W(CO)6 in the presence of n-Bu3N under the same reaction conditions gave 3-azabicyclo[3.3.0]octanes in good yield exclusively via vinylidenecomplexes. Thus, the pi-alkyne and vinylidenecomplex pathways are easily controlled by using a catalytic amount