TRITERPENOID DIAGENESIS AND CUTICULAR PRESERVATION

Early diagenetic dehydration of various pentacyclic triterpenols and D elta(5)-sterols was observed in the cuticular membranes of mangrove le aves and seagrass rhizomes of live plants, leading to pentacyclic trit erpadienes with Delta(2) unsaturation and steradienes and steratrienes with Delta(3,5) unsaturation. In Rhizophora mangle leaf cuticle, beta -amyrin was largely confined to epicuticular wax, while taraxerol appe ared to be a cutin component. Protection of such triterpenols within r esistant cuticular membranes during diagenesis permitted the contribut ion of mangrove leaves to various sedimentary environments within Flor ida Bay to be evaluated. Evidence for the preservation of cuticles as amorphous material in sediments was obtained in the form of characteri stic triterpenoid fingerprints in pyrolysates.