Studies with some medicinal plant derived organic molecules of biological relevance (original) (raw)

Background: For millennia, medicinal plants have been a valuable source of therapeutic agents, and still many of today's drugs are plant-derived natural products or their derivatives. However, since natural product-based drug discovery is associated with some intrinsic difficulties, pharmaceutical industry has shifted its main focus toward synthetic compound libraries and highthroughput screening (HTS) for discovery of new drug leads. The obtained results, however, did not meet the expectations as evident in a declining number of new drugs reaching the market. This circumstance revitalized the interest in natural product-based drug discovery, despite its high complexity, which in turn necessitates broad interdisciplinary research approaches. Natural products usually refer to chemical substances produced by a living organism or found in nature possessing distinctive biological and pharmacological effects, which have played a crucial role in modern drug development and still constitute a prolific source of novel lead compounds, or pharmacophores, for ongoing drug discovery programs. Natural products are classified based upon their origins, biological functions and structures, encompassing a wide variety of chemical compound classes that include alkaloids, antibiotics, terpenoids, flavonoids, xanthonoids, phenolics, carbohydrates, lipids, proteins and amino acids, and nucleic acids. This huge diversity in chemical structures of natural products is an outcome of biosynthetic processes that have been modulated over the millennia through genetic effects. With the advent of modern techniques, particularly the rapid improvements in spectroscopic as well as accompanying advances in high-throughput screening techniques, it has become possible to have an enormous repository of bioactive natural compounds, thus opening up exciting new opportunities in the field of new drug development to the pharmaceutical industry. Medicinal chemistry of such bioactive compounds encompasses a vast area that includes their isolation and characterization from natural sources, structure modification for optimization of their activity and other physical properties, and also total and semi-synthesis for a thorough scrutiny of structure-activity relationships. Despite substantial progresses in the fields of chemistry and biology, natural products chemistry still remains a central division of chemical and biological research with no boundaries.