: γ-Hydroxybutenolides (γ-HB) is an important structural core found in many bioactive marine natural products (MNPS). The γ-HB core containing NPS served as an inspiration to medicinal chemists to undertake designing of the new synthetic strategies to construct γ-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. γ-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 A2 (cladocorans A and B), BACE inhibitors (ianthellidone G), etc. Moreover, the γ-HB moiety was explored as antifouling 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 γ-HB skeleton as a core unit. Furthermore, the synthesis of selective γ-HB containing bioactive MNPS like manoalide, secomanoalide, cacospongionolides, luffarielloide and dysidiolide were highlighted in the article.

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Marine fungi Aspergillus flavipes and A. terreus were investigated for secondary metabolites using electrospray ionization‐quadrupole time‐of‐flight mass spectrometry (ESI‐QTOF MS) analysis. The ESI‐MS analysis showed that A. flavipes showed molecular ion peaks for compounds, terrein (1), butyrolactone I (2), butyrolactone I‐carboxylic acid (3), butyrolactone III (4), while, A. terreus had additional presence of new compound aspernolide Q (5) with absence of compound (3). By using tandem mass spectrometry data, the prominent fragment ions helped in the establishing the structure of compounds (2‐5). Further, chemical transformation of butyrolactone I to butyrolactone III and aspernolide Q were carried out followed by NMR analysis which strongly suggested their structures. The evaluation of salt stress experiment of A. terreus culture medium affected the production of major bioactive metabolites, terrein and butyrolactone I (2). The HPLC analysis showed that culture produces high amount of terrein at 35 ‰, while, maximum production of butyrolactone I was observed in fresh water i. e. 0‰. The study highlighted an importance of salinity in producing these metabolites where, terrein and butyrolactone I could be produced in equal ratio at 18‰. Importantly, we have demonstrated that using this fungal strain and by growing in medium at specific salinity could be way forward for commercial production of these bioactive compounds.