Diterpenóides com esqueleto cleistantano de Vellozia aff. carunculares martius ex seubert (Velloziaceae)

Abstract

Recebido em 24/8/00; aceito em 29/11/00 CLEISTANTHANE DITERPENOIDS FROM VELLOZIA AFF. CARUNCULARES MARTIUS EX SEUBERT (VELLOZIACEAE). From the hexane extract of leaves, stem and roots, of Vellozia aff. carunculares, fourteen cleistanthane diterpenoids were detected by HRGC-MS, through the analysis of their fragmentation patterns. Comparison of their MS spectra with those of authentic standards previously isolated from other species of the family Velloziaceae allowed the identification, with a high degree of confidence, of eigth known cleistanthane diterpenoids. Of these, four were isolated and identified from their MS, IR and 1 H and 13 C NMR spectra, as the known cleistantha-8,11,13-trien-7-one, cleistantha-8,11,13-trien-3,7-dione, cleistantha-1,8,11,13-tetraen-3,7-dione and the first reported 6-α-hydroxycleistantha-8,11,13-trien-7-one. The triterpenoid β-amyrin was also isolated.

Electrospray ionization tandem mass spectrometry analysis of isopimarane diterpenes from Velloziaceae

“…Despite this apparent weakness, many Velloziaceae species present the striking feature of being desiccation tolerant resurrection plants, such as the species of the Vellozia genus and the African Xerophyta and Talbotia . This feature, along with chemical composition, contributes to the surprising longevity of these plants . Previous phytochemical studies of Vellozia demonstrated the isolation of different molecular skeletons of diterpenes such as clerodane, cleisthantane, isopimarane, strobane, kaurane, halimane and labdane .…”

“…Previous phytochemical studies of Vellozia demonstrated the isolation of different molecular skeletons of diterpenes such as clerodane, cleisthantane, isopimarane, strobane, kaurane, halimane and labdane . Over a period of approximately 25 years, Pinto and co‐workers reported the isolation of around 190 diterpenes, 52 triterpenes, 5 flavonoids and 3 sterols from several studies of Brazilian Velloziaceae …”