Combined molecular mechanics (MM2) and molecular orbital (AM1) study of periplanone-A and analogues. Evaluation of biological activity from electronic properties and geometries. Part 2

Kazuko Shimazaki, Masataka Mori, Kentaro Okada, Tatsuji Chuman, Shigefumi Kuwahara, Takeshi Kitahara, Kenji Mori, Hitoshi Goto, Eiji Osawa, Kazuhisa Sakakibara, Minoru Hirota

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)

Abstract

Combined molecular mechanics (MM) and semiempirical molecular orbital (MO) calculations have been applied to periplanone-A (1), the epoxy epimer (2) and a structurally-related analogue (3). Conformational properties of these compounds have been obtained by the use of MM2 with an additional set of force-field parameters in conjunction with an automatic conformation generating program. The global minimum 1A has the same type of ring conformation as that found in periplanone-B (4). The remarkable contrast between 1 and 4 is the presence in 1 of significant amounts of conformers having different ring conformations such as 1B. In both 2 and 3, which are far less biologically active than 1, 1A ring type conformers exist only in low populations. The conformer distribution of 2 obtained by MM2 well explains the highly complex NMR (2D-NOESY) spectrum. The MM-predicted geometries of the stable conformers of 3 show good agreement with that observed in dynamic NMR spectroscopy. When the 1B ring type conformers are taken into account, the accuracy of the previously proposed index for the evaluation of the pheromone activity of analogues, effective frontier parameter EF(N)(S), is improved.

Original languageEnglish
Pages (from-to)1167-1173
Number of pages7
JournalJournal of the Chemical Society, Perkin Transactions 2
Issue number6
Publication statusPublished - 1993 Dec 1
Externally publishedYes

ASJC Scopus subject areas

  • Chemistry(all)

Fingerprint

Dive into the research topics of 'Combined molecular mechanics (MM2) and molecular orbital (AM1) study of periplanone-A and analogues. Evaluation of biological activity from electronic properties and geometries. Part 2'. Together they form a unique fingerprint.

Cite this