Terpenoid composition and class of Tertiary resins from India

Abstract

The terpenoid composition and class of Tertiary resins preserved within lignites of Cambay, Kutch and Cauvery Basins of India have been characterized using Pyrolysis-Gas Chromatography-Mass Spectrometry (Py-GC-MS) and Fourier Transform Infrared (FTIR) Spectroscopy. Major pyrolysis products include cadalene-based C(15)-bicyclic sesqwterpenoids with some C(30) and C(31) bicadinanes and bicadinenes typical of Class 11 or dammar resin. The occurrence of these terpenoids in Early Eocene sediments may extend the first appearance of Dipterocarpaceae angiosperms, the predominant source of this resin class, back to the Early Eocene epoch in India. The same terpenoid biomarkers have been detected in many SE Asian oils reflecting a close source relationship with these resins. Strong CH(3) (1377 cm(-1)) and other CH(x) (3000-2800 and 1460-1450 cm(-1)) aliphatic absorptions of much larger intensity than the aromatic C = C (560-1650 cm(-1)) absorption were detected in the Indian resins by FTIR Spectroscopy, confirming the quantitative significance of the terpenoid pyrolysates. (C) 2009