Isolation and identification of two pairs of cytotoxic diterpene tautomers and their tautomerization mechanisms.

ABSTRACT: Discovering anticancer drugs that do not have adverse side effects has been a developing research field worldwide in recent decades. In this work, four previously undescribed cytotoxic diterpenoids were isolated from the aerial parts of Isodon excisoides. Interestingly, these four diterpenoids were two pairs of tautomers that were first reported in plants. Their structures were further elucidated using various spectroscopic methods. The tautomerization phenomenon and mechanism for these two pairs of tautomers were emphatically described. The theoretical simulation results indicated that the diterpene tautomerization is greatly related to certain factors, including the existence of a transition state, the change of bond length and the level of conversion energy; the tautomerization for the

SUBMITTER: Dai LP 

PROVIDER: S-EPMC6989466 | biostudies-literature | 2020 Jan

REPOSITORIES: biostudies-literature