Sulfides in petroleum

Geochemistry of Sulfur in Petroleum Systems

“…This common structural feature was thought to reflect the site specificity of the biosynthetic pathway whereby sulfur is incorporated into the hydrocarbon framework. Continuing this view, Payzant et al (74) proposed that the bicyclicand tricyclicsulfides (I) and (XI) may be accessory pigments in photosynthesis because they have the carbon framework of carotenoids. However, these OSC have never been reported to occur in biota.…”

Aerobic microbial metabolism of some alkylthiophenes found in petroleum

“…Although hundreds of organic sulfur compounds have been identified in petroleum (Cyr et al 1986;Payzant et al 1986;Rail et al 1972;Sinninghe Damst6 et al 1986, fewer than twenty of these have been subjected to biodegradation studies (Fedorak 1990) because so few petroleumrelated organosulfur compounds are commercially available. Thus there is much to be learned about the fate of organosulfur compounds in petroleumcontaminated environments and about the biotransformations of these compounds in petroleum reservoirs.…”

A novel triterpenoid carbon skeleton in immature sulphur-rich sediments

“…The usual Raney nickel and nickel boride desulphurization techniques were, however, not effective on this sulphur compound, probably due to the severe steric protection of the methyl-groups and the cyclohexylrings. Desulphurization under "forcing conditions" (Raney nickel, cyclohexane, sealed tube, 200°C 3h; Payzant et al, 1986) yielded a mixture of unsaturated compounds. This mixture was first hydrogenated using standard techniques (H?, PtO,, ethyl acetate, room temperature; Sinninghe Damste et al, 1989), but these failed to hydrogenate the unsaturated compounds, probably due to steric hinderance of the cyclohexyl-rings.…”

“…Cyclic triterpenoids, derived from enzymatic cyclization reactions of squalene or its epoxide, are compounds which are often detected in a sulphurized form since they usually contain a number of double bonds suitable for S-incorporation. For example sulphurized hopane, sterane, oleanane, and gammacerane C skeletons are some of the compounds detected in S-rich sediments (e.g., Schmid, 1986;Sinninghe DamstC et al, 1989;Payzant et al, 1986;Kohnen et al, 1991;Adam et al, 1991). Since a number of these compounds are unique for certain organisms, they are very useful as biomarkers.…”