γ-Hydroxybutenolide Containing Marine Natural Products and Their Synthesis: A Review

gamma-Hydroxybutenolides (gamma-HB) is an important structural core found in many bioactive marine natural products (MNPS). The gamma-HB core containing NPS served as an inspiration to medicinal chemists to undertake designing of the new synthetic strategies to construct gamma-HB core. Subsequently, it further results in the development of novel physiological and therapeutic agents. The most notable example includes manoalides, cacospongionolides, petrosaspongioide M and dysidiolide from marine sponges possessing anti-inflammatory properties. gamma-HB containing MNPS were known to possess various pharmacological properties such as antimicrobial (acantholide B), cytotoxic (acantholide A-E, spongianolide A), inhibitors of secretory phospholipase A(2) (cladocorans A and B), BACE inhibitors (ianthellidone G), etc. Moreover, the gamma-HB moiety was explored as anti-fouling agents as well. Owing to their numerous biological activities and attractive molecular structures, there are lots of advances in the synthetic methodology of these compounds. This review gives the account on isolation and biological studies of MNPS with gamma-HB skeleton as a core unit. Furthermore, the synthesis of selective gamma-HB containing bioactive MNPS like manoalide, secomanoalide, cacospongionolides, luffarielloide and dysidiolide were highlighted in the article.