GC-MS Analysis Of Extract Research Articles

MDBT estimation ratio for transformation organic matter ratio in Bazhenov Formation of Western Siberia (Tomsk Oblast, Russia)

The Bazhenov Formation is the main source rock in the West Siberian Basin, because of high organic-rich Bazhenov black shales, with a total organic carbon (TOC) content of 10-15wt.% generally. Based on Rock-Eval pyrolysis data, the initial generative potential for a significant part of West Siberian Bazhenov Formation organic matter (OM) is from 10 to 60% expended. Most West Siberian oils are in the Bazhenov Formation due to very high oil potential (initial hydrogen index = 710mgHC/gTOC) and widespread regional distribution). Vitrinite reflectance (Ro) does not correctly indicate the transformation ratio (TR) of the OM in Bazhenov black shales. However, GC-MS analysis of extracts indicated a good correlation between some molecular maturity and Rock-Eval maturity parameters. Molecular maturity parameters based on naphthalenes and phenanthrenes are not applicable for Bazhenov Formation OM. While the parameters based on 4-methyldibenzothiophene and 1- methyldibenzothiophene ratio (4MDBT/1MDBT) is applicable in estimating the hydrocarbon potential of Bazhenov Formation black shales and, consequently, provides more reliable information about marine OM TR than does Ro. The 4MDBT/1MDBT ratio is more consistent and precise than pyrolysis data. Therefore, it is more applicable in the case of scarcity of core samples throughout the whole formation.

<i>In vitro</i> anti-oxidative activities of the various parts of <i>Parkia Biglobosa</i> and gc-ms analysis of extracts with high activity.

The anti-oxidative activities of sequentially extracted solvent fractions of different parts of P. biglobosa were evaluated in a series of in vitro assays. Our findings indicated that all extracts had electron donating and free radical scavenging activities. But the ethanol (EtOH) extracts from all the parts demonstrated more promising anti-oxidative effects in these experimental models. Apart from the aqueous extracts of the stem bark and leaves, all other extracts exhibited hydroxyl radical scavenging (HRS) activity but the ethyl acetate (EtOAc) extract of the stem bark and EtOH extracts of the root and leaves possessed more powerful HRS activity than other corresponding extracts in the parts. Further, nitric oxide (NO) inhibition activities were observed in all the extracts except the EtOAc extract of the stem bark which showed pro-oxidative activity. However, the EtOH extract of the stem bark and root as well as the EtOAc extract of the leaves displayed more potent anti-NO activity than other extracts in the parts. The GC-MS analysis of the EtOH extracts revealed that the most abundant phytochemicals are pyrogallol derivatives. Data from this study suggest that the EtOH extracts from different parts of P. biglobosa contained potent anti-oxidative agents and pyrogallol could be the main bioactive constituent.

Chemical investigation and antibacterial study of hexane extract of leaves of Finlaysonia obovata

Finlaysonia obovata, a latex – exuding mangrove plant (Fam. Periplocaceae), is found in the tidal flats in India, Burma, and Malay, the leaves of which are reported to be eaten as salad in the Moluccas. Mangrove latex-bearing plants were found to show antibacterial and antiviral activity [1]. Earlier we have studied the antibacterial activity, performed the GCMS analysis of extracts, studied the lipids of the leaf, and isolated a rare antibacterial triterpene from F. obovata [2, 3]. The present paper deals with the antibacterial screening of column fractions of an active hexane extract, and isolation and spectral characterization of stigmast-4-en-3β-ol from leaves of F. obovata. The antibacterial assay of the hexane extract of leaves of F. obovata was carried out against seven freshwater fish pathogenic bacteria (see Experimental) [3]. The hexane extract was found active against all except S. aureus and E. tarda. This extract was further taken up for fractionations and isolations of secondary metabolites. The results of anti-pathogenic screening of the active column fraction of the hexane extract [compound 2 is isolated] are presented in Table1. The column fraction (EtOAc:hexane-1:9) showed activity against S. aureus, which clearly proves the enrichment of the active components during

Identification of thiosteranes in contaminated marine sediments from the Mediterranean Sea by capillary GC‐MS and capillary GC‐AED*

AbstractA series of unknown cyclic compounds was detected in the capillary GC‐MS analyses of extracts of marine sediments from the Tunisian coast at the Mediterranean sea. Using capillary GC‐atomic emission detection (AED), sulphur was elucidated in their structure. This allowed identification of the solutes as the thiosteranes 5‐α‐cholestane‐3‐β‐thiol, 24‐methyl‐5‐α‐cholestane‐3‐β‐thiol, and 24‐ethyl‐5‐α‐cholestane‐3‐β‐thiol. These sulphur compounds are formed from Δ‐2 sterenes and probably originate from plankton. The presence of these thiols in coastal sediments varies considerably with the location of the sampling points, indicating that they are potential markers for environmental pollution. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 90–95, 2001

African elephant sesquiterpenes.

GC-MS analysis of extracts from temporal gland secretions of an African elephant has revealed the presence of several farnesol-related sesquiterpenes. Among these are (E)-2, 3-dihydrofarnesol (3), a bumblebee pheromone not seen before in mammals, and a rare component of a Greek tobacco, drimane-8alpha, 11-diol (4), never observed before in an animal.