Abstract

TRUNCATIN: A TRITERPENE DIMER ISOLATED FROM Maytenus truncata REISSEK (CELASTRACEAE)

Gloria Del Carmen Meléndez Salazar, Grasiely Faria de Sousa*, Lucienir Pains Duarte, Roqueline Rodrigues Silva, Sidney Augusto Vieira-Filho and Grácia Divina de Fátima Silva

ABSTRACT

Maytenus truncata Ressek is a medicinal plant naturally found in Cerrado biome of Brazil. The tea from its leaves is used to treat gastrointestinal disorders. Such as other species of the Celastraceae family, the aerial parts, and roots of Maytenus truncata are rich in pentacyclic triterpenes. Roots of M. truncata were subjected to chromatographic methods that culminated in the isolation of a dimer pentacyclic triterpene termed truncatin. The structure of truncatin was established based on FT-IR, 1D/2D NMR, including DEPT-135, HSQC, HMBC and COSY spectra, and mass spectrometry. The compound was characterized as containing a quinone methide friedelane-type unit linked to another unit constituted by a skeleton similar to those of lupane series. These two units are linked together through the respective ring A, by two ether linkages. This work presents for the first time, the skeleton lupane as a unit of a dimer of pentacyclic triterpenes.

Keywords: Maytenus truncata, Celastraceae, pentacyclic triterpene dimer, hetero Diels-Alder reaction, 1D/2D NMR.