Studies of Zoapatle I. The Extraction of Zoapatle (Montanoa tomentosa) and the Identification of 21-Normontanol as the Initial Decomposition Product of Zoapatanol

Abstract

HotH20 and hexane were found to be inappropriate to extract zoapatanol (1) from the leaves of Montanoa tomentosa ssp. tomentosa-, EtOH and EtOAc, on the other hand, were far more effective. A number of Montanoa species and subspecies were examined for the presence of zoapatanol (1). Zoapatanol is highly unstable either neat or in aqueous solution at elevated temperatures, and only samples dissolved in solvent and stored at -5 to -10°have extended half-lives. The initial decomposition product of zoapatanol (1) has been identified as 21normontanol (2) through high field proton nmr analysis.

Diterpenoids

“…The ent-labdane (14) was isolated29 from Gutierrezia grandis whilst the labdanes (1 5 ) and (1 6 ) were obtained30 from Baccharis scoparia and (1 7 ) came31 from Oxylobus arbutifolius. The structure of the lactone (18), phlogantholide A, which was obtained from the Indian medicinal plant Phlogacanthus thyrsi$orus, has been establ i ~h e d . ~~…”

HPLC Analysis ofMontanoaSpecies for Pharmacologically Active Constituents1

“…In spite of the many studies of M. tomentosa, surprisingly little use has been made of HPLC for a rapid analysis and directed isolation of Mon tanoa constituents. RP-HPLC has been used to detect zoapatanol (13) and to separate some oxepane diterpenoids (14) and kauranoic acid derivatives (9) from highly prepurified fractions, but no method for the analysis of the structurally disparate "active" principles from crude extracts has been reported.…”