Investigation an a fossil Sequoia bark from Turkey

A fossil bark from a complete Sequoia trunk recovered near Istanbul (Turkey ) was investigated to assess the degree of degradation of some of its compo nents with respect to a modern Sequoia. Polyoses were studied by cation exc hange technique while terpenes with GC/MS analyses of the dichloromethane e xtracts. Exchange measurements have shown the loss of nearly all carboxyl e ster groups of the fossil bark like in most fossil woods. The moist environ ment is considered the major cause of the hydrolysis of original carboxyl e sters to free carboxyl groups. Trifluoroacetic lignins have shown the occur rence of carboxyl groups attributable to the non-polyose fraction of bark i n amounts nearly equivalent to those of polyoses. This acidity occurs in fo rms of free carboxyls and carboxyl esters, analogously to the acidity suppl ied by polyoses. Terpene content, both as amount and component number, is l ower in the fossil bark than in the reference one. Identified components of fossil bark were some monoterpenes and sesquiterpenes in traces, the diter penes abietatriene, simonellite and dehydroferruginol as well as vanillin a nd beta-sitosterol. Reference bark revealed the presence of abietatriene, s imonellite, the phenol-diterpenes sugiol, dehydroferruginol and perhaps met hylferruginol in addition to beta-sitosterol. While the structure of mass s pectra of unidentified components has pointed to the presence of other phen ol-diterpenes, no evidence of fats or long-chain alcohols was found.