Discovery Of Dehydrocurvularin And Its Analogs As ACLY Inhibitors And Its Metabolism In Vitro And In Vivo

Dehydrocurvularin,also known as DCV,is a natural polyketide with a 12-membered macrolide fused to resorcinol ring structurally.Isolated from a variety of fungi,DCV showed bioactivities such as phytotoxic,antimicrobial,anti-inflammatory and,especially,excellent anti-cancer activities as it exhibited selective cytotoxic activity in vitro against several malignant cells.Studies on DCV were carried out in this paper.The methods and results were as follows.(1)Guided by OSMAC strategy,one DCV high-producing strain,Aspergillus WG4,was focused on in order to find more curvularin-type metabolites.Curvularin,5-methoxycurvularin and curvulopyran were isolated from the co-cultivation of WG4 with Antrodiella semisupina.Compared with the secondary metabolites in PDB fermentation media,WG4 in rice media was found to produce more hydrophobic constituents.And the two structures,which were not curvularin analogues,were identified.(2)Preliminary studies of DCV metabolism were carried out,including the species difference in liver microsomal metabolism in vitro and the metabolites of DCV in rats.The results showed that DCV incubation with different liver microsomes were different in metabolic rates,but similar in metabolites according to the UPLC-MS results.DCV may be converted to epoxycurvularin,10,11-ortho-hydroxycurvularin and curvulopyran through epoxidation,hydrotion reaction as well as intramolecular dehydration.The blood concentration reached the peak 4h after single i.g.administration but eliminated quickly.And the DCV content in feces collected during 24 h was much higher than in urine,and the low total excretion accumulation indicated low bioavailability of this compound.(3)The structural modification of DCV was studied in order to identify its targets or improve its physicochemical properties.We confirmed that ACLY was one of the antineoplastic targets of DCV through chemo-proteomic technology after the synthesis of the DCV-yne probe.Besides,other structural modifications of DCV were also attempted,but the target compounds could not be obtained may due to the instability of the α,β unsaturated double bond under alkaline or high temperature conditions.The specific reasons and improvement synthetic route need to be further studied.