90(P-14) 置換クエン酸天然物トラキスプ酸とビリジオファンジンAの全合成(ポスター発表の部)

概要

論文の詳細を見る
Trachyspic acid was isolated from the culture broth of Talaromyces trachyspermus SANK 12191 after screening for substances that exhibit heparanase inhibitory activity. Structurally, this compound is characterized by a novel spiroketal structure consisting of the 4-nonyl-3-furanone and the tetrahydrofuran containing a citric acid unit. The relative configuration was determined by our recent synthesis of racemic tracyspic acid; however, the absolute configuration has not been determined yet. We describe the first synthesis of (+)-trachyspic acid based on Cr(II)/Ni(II)-mediated Nozaki-Hiyama-Kishi reaction of the C1-C6 aldehyde 4 containing the citric acid moiety and the C7-C18 long chain triflate 5, thereby establishing its absolute configuration to be 3S,4S,6S. Viridiofungin A was isolated from a strain of Trichoderma viride Pers. together with viridiofundin B and C after screening for substances that exhibit cholesterol lowering activity. Although viridiofungins were found to be less active than zaragozic acids in inhibition of squalene synthase, they have newly attracted much attention as novel potent inhibitors of sphingolipid synthesis. These viridiofungins have unique structures consisting of a common citric acid moiety having C-16 long chain and an aromatic amino acid residue such as tyrosine, phenylalanine, and tryptophane. Recently, we have successfully determined the absolute configuration of viridiofungin A to be 3S,4S,2'S by the enantiocontrolled synthesis of viridiofungin A trimethyl ester. However, we could not achieve the synthesis of natural viridiofungin A from its trimethyl ester because saponification of the trimethyl ester caused decomposition possibly via retro-aldol process. We describe herein an alternative approach to viridiofungin A employing its tri-tert-butyl ester as a precursor, the key step of which is the olefin cross metathesis of citric acid core 20 and hexadec-15-en-8-one.
天然有機化合物討論会の論文
2004-10-01

90(P-14) 置換クエン酸天然物トラキスプ酸とビリジオファンジンAの全合成(ポスター発表の部)

スポンサーリンク

概要

著者

関連論文

スポンサーリンク