secondary metabolites

Endophytes are microscopic creatures that live as parasites in living plant body without affecting their host plant. These organisms may be fungi, bacteria or any other microbes that lives in various parts of the host plants such as the stems, roots, or leaves and other sections. Endophytes coexist in symbiotic relationships with their host plants, frequently offering advantages including improved growth, tolerance to environmental stresses and better resistance to disease. They are the kind of microorganism which has the potential to biosynthesise medicinally active substances called secondary metabolites. The discovery of secondary metabolites in diverse sources resulted in the development of medications intended to cure illnesses in humans. Novel secondary metabolic products with significant pharmacological value will be introduced by routine screening of natural resources. Many important bioactive compounds have been effectively discovered from endophytic fungi having cytotoxic, antimicrobial, insecticidal, anticancer and antioxidant activities. In this review, we attempt to summarize the endophytes-host relationship and the mechanism by which they are capable to produce secondary metabolites as their host plant and their utilization in development of new drugs.

Weeds are considered troublesome and undesirable component leading to enormous reduction in crop yield, wastages of resources and human energy. An attempt has been made to evaluate the effect extracts of four obnoxious weeds, Argemone mexicana, Parthenium hysterophorus, Cyperus rotundus Lin., Verbesina encelioides on the mitotic activity of germination of mung beans. Metabolites were extracted in methanol, acetone , hexane and distilled water using soxhlet extraction and assayed for the presence of bioactive metabolites. Presence of terpenes, flavonoids and quinines were observed in the methanol extract of all the weeds and hexane extracts indicated the presence of glycosides and flavonoids. Based on percentage inhibition studies, it was found water extracts followed by acetone extracts for all the weeds were most potent as a growth inhibitor. Argemone Mexicana and Parthenium hysterophoresus were found to be most potent in inhibiting mitotic activity and growth although statistical significance (P