Revised structure of zeorin and its correlation with leucotylin

✍ Scribed by Itiro Yosioka; Tsutomu Nakanishi; Hiroshi Yamauchi; Isao Kitagawa

• Publisher: Elsevier Science
• Year: 1971
• Tongue: French
• Weight: 211 KB
• Volume: 12
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)96654-7

✦ Synopsis

Based on the chemical study 1) and X-ray analysie 2) , the a~ructure(1) was eatabliahed for leucotylin, a lichen triterpenoid iaolated from Parmelia leucotyliza Nyl. In addition, the chemical correlation between leucotylin and seorin, a co-existing triterpenoid in the same lichen, has led us to propoaele3) the structure(II*) 4) for the latter, poseesaing an isomeric isopropanol side chain configuration at C-21. Besidea, the proposal has been extended to hopane aa III* having C-21&l contrary to then believed structure(II1, with C-21Sll)5).

6)

However, aa mentioned in the preceding paper , the structure of zeorin has been established as II with C-21SH configuration as 8ame aa leucotylin(1) and consequently it follows that hopane should be expressed as III, which coincidem with the confirmation recently made X-ray crystallographically by Koyama and Nekai 7) . The conclusion is also in agreement with the chemical evidence supporting 8) C-2lSH of hopane presented by Ageta and Shiojima .