Four new triterpenoids from the leaves of Psidium guajava

Abstract

Four new triterpenoids, psiguanins A–D (1–4), along with 13 known ones (5–17), were isolated from the leaves of Psidium guajava. The structures of new compounds were determined as 2α,3β-dihydroxy-taraxer-20-en-28-oic acid (1), 2α,3β,12α,13β-tetrahydroxy-urs-28-oic acid (2), 2α,3β,12β,13β-tetrahydroxy-urs-28-oic acid (3), and 2α,3β,12β,13α-tetrahydroxy-urs-28-oic acid (4), respectively, on the basis of comprehensive spectroscopic methods and molecular modeling calculation. Among them, compound 4 was characterized as an unusual ursane-type triterpenoid with cis-fused C/D ring system.

Keywords:

• Psidium guajava
• Myrtaceae
• triterpenoid

Acknowledgements

Financial support of this research was provided by the Program for Changjiang Scholars and Innovative Research Team in University (No. IRT0965), the National Natural Science Foundation of China (No. 81172946), the Research Team Program of Natural Science Foundation of Guangdong Province (No. 8351063201000003), the Science and Technology Development Fund of Macao Special Administrative Region (No. 013/2008/A1), and the Fundamental Research Funds for the Central Universities (No. 21611405).

Notes

^1. These authors contributed equally to this work.