The second edition of The Biomarker Guide is a fully updated and expanded version of this essential reference. Now in two volumes, it provides a comprehensive account of the role that biomarker technology plays both in petroleum exploration and in understanding Earth history and processes. Biomarkers and Isotopes in the Environment and Human History details the origins of biomarkers and introduces basic chemical principles relevant to their study. It discusses analytical techniques, and applications of biomarkers to environmental and archaeological problems. The Biomarker Guide is an invaluable resource for geologists, petroleum geochemists, biogeochemists, environmental scientists and archaeologists.

The Biomarker Guide

13C NMR spectra of pentacyclic triterpenoids--a compilation and some salient features

Anthocyanins and other flavonoids

Saponins, classification and occurrence in the plant kingdom

Medicinal plants have bioactive compounds which are used for curing of various human diseases and also play an important role in healing. Phytochemicals have two categories i.e., primary and secondary constituents. Primary constituents have chlorophyll, proteins sugar and amino acids. Secondary constituents contain terpenoids and alkaloids. Medicinal plants have antifungal, antibacterial and anti-inflammation activities. The present study involves ten different medicinal plants Acacia nilotica, Psidium gujauva, Luffa cylindrical, Morus alba, Morus nigra, Momordica charantia, Fagonia cretica, Punica granatum, Ficus palmate and Prunus persica locally available in Mardan region of Pakistan. The leaves of the selected medicinal plants were washed, air dried and then powdered. The aqueous extract of leaf samples were used for the phytochemical analysis to find out the phytochemical constituents in the plants. The main objective of the research work was to check the presence or absence of the phytochemical constituents in all the selected medicinal plants. The results of the phytochemical analysis of these medicinal plants showed that the terpenoids, phlobatannins, reducing sugar, flavonoids and alkaloids were found to be present in afore mentioned medicinal plants. The phytochemical analysis of the plants is very important commercially and has great interest in pharmaceutical companies for the production of the new drugs for curing of various diseases. It is expected that the important phytochemical properties recognized by our study in the indigenous medicinal plants of Mardan will be very useful in the curing of various diseases of this region.

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Phytochemical Analysis of Medicinal Plants Occurring in Local Area ofMardan

Novel migrated oleanane triterpenoid sapogenins from Mimusops elengi

Two new pentacyclic triterpene acids, mimusopic acid (3) and mimusopsic acid (5) possessing the novel migrated oleanane skeleton, mimusopane were isolated.

Novel Migrated Oleanane Triterpenoid Sapogenins from Mimusops elengi

Triterpenoids isolated and characterized from various sources are reviewed. The newer spectroscopic techniques used in their structure elucidation, the new skeleta characterized, their total chemical synthesis, and their biosynthesis are discussed. A compilation of the triterpenoids isolated during the period 1990-1994 along with their occurrence, physical data, spectroscopy and X-ray analysis used for their characterization, is included. The biological activities of the triterpenoids are also discussed. Copyright © 1997 Elsevier Science Ltd

http://www.if.ufrrj.br/biolig/art_citados/A%20D%20V%20A%20N%20C%20E%20S%20%20%20IN%20T%20R%20I%20T%20E%20R%20P%20E%20N%20O%20I%20D%20%20%20R%20E%20S%20E%20A%20R%20C%20H%20,%20%20%201990-1994.pdf

Review article number 118 advances in triterpenoid research, 1990-1994

Crossover events during recombination in meiosis are essential for generating genetic diversity as well as crucial to allow accurate chromosomal segregation between homologous chromosomes. Spatial control for the distribution of crossover events along the chromosomes is largely a tightly regulated process and involves many facets such as interference, repression as well as assurance, to make sure that not too many or too few crossovers are generated. Repression of crossover events at the centromeres is a highly conserved process across all species tested. Failure to inhibit such recombination events can result in chromosomal mis-segregation during meiosis resulting in aneuploid gametes that are responsible for infertility or developmental disorders such as Down's syndrome and other trisomies in humans. In the past few decades, studies to understand the molecular mechanisms behind this repression have shown the involvement of a multitude of factors ranging from the centromere-specific proteins such as the kinetochore to the flanking pericentric heterochromatin as well as DNA double-strand break repair pathways. In this chapter, we review the different mechanisms of pericentric repression mechanisms known till date as well as highlight the importance of understanding this regulation in the context of chromosomal segregation defects. We also discuss the clinical implications of dysregulation of this process, especially in human reproductive health and genetic diseases. 

Sucharita Sen

Papers

Novel migrated oleanane triterpenoid sapogenins from Mimusops elengi

Novel Migrated Oleanane Triterpenoid Sapogenins from Mimusops elengi

Review article number 118 advances in triterpenoid research, 1990-1994

Emerging mechanisms and roles of meiotic crossover repression at centromeres.