Recent Developments Towards the Synthesis of Varitriol: An Antitumour Agent from Marine Derived Fungus Emericella Variecolor

Marine natural products are recognized as a fruitful source of drug development due to their rare structural entities and diverse biological activities, and consequently, publicized number of metabolites as new medicines. Although extensive progress has been made in identifying novel bioactive molecules from marine source, endeavors to explore these molecules for medicinal applications are much needed. Marine fungi are one of the important sources of natural products, exhibiting a wide range of biological activities. (+)-Varitriol, isolated from the marine fungus Emericella variecolor, has shown 100-fold increased potency over the mean toxicity towards variety of cancer cell lines. Hence (+)-varitriol, an antitumour marine natural product has been a fascinating target for total synthesis over the last decade. The intense search for developing new approaches coupled with its biological activity has resulted in a wealth of methods towards the syntheses of this molecule. But, unfortunately only limited analogues have been synthesized and evaluated for their biological activities. Thus, there are still demands to modify aromatic part as well as sugar moiety of varitriol, which could provide the opportunity for further SAR studies to discover potential lead anticancer agents. This review describes the different strategies developed for the syntheses of varitriol and its analogues in various laboratories around the world covering literature from 2002 till date. The construction of the challenging and fashionable furanoside ring as well as substituted styrene derivatives are crucial steps in most of the reported synthetic endeavors. Keywords: Antitumour agent, asymmetric synthesis, carbohydrate, marine fungi, natural product, varitriol.