Genome Mining of Monoterpenes from Ascidian-Derived fungus Diaporthe sp. SYSU-MS4722

Marine-derived fungi represent anunderexplored sourceofmonoterpenes, withonlysporadicreportsover thepast twodecades,makingtheir discovery particularlychallenging.Whole-genomesequencing of Diaporthesp. SYSU MS4722,anascidian-derivedfungusisolatedfromStyelaplicata, identified130 biosyntheticgeneclusters(BGCs),underscoringitsvastbiosyntheticpotential. However, previous studies demonstrated that Diaporthe sp. SYSU-MS4722 predominantlyproduces xanthone phomoxanthone A understandardlaboratory conditions, suggestingthatmanyBGCs remaincryptic.Notably, 16 of these BGCs encode terpene synthase genes, indicatingthepotentialformonoterpene biosynthesis. To activate these silent BGCs and discover monoterpenes, we deleted sthe polyketide synthase (PKS) gene phoE, responsible for phomoxanthoneAbiosynthesis, generating themutant strainDiaporthe sp. SYSU-MS4722 phoE, fromwhich threenewmonoterpenes, diaporterpenes D-F (1-3), three knownmonoterpenes (4-6), and twonewpolypropionate derivatives, diaporpolypropionateA (7) anddiaporpolypropionateB (8),were isolated.Compounds1,4, 7, and8wereevaluatedfor theircytotoxicityand anti-inflammatory effects inhumannon-small cell lungcancer A549cells. Compound 1 exhibitedcytotoxic activitywith an IC50 valueof 89.33 M. Compounds4and7demonstratedanti-inflammatoryactivity,asmeasuredby anELISAassayassessingthe inhibitionof IL-6secretion,withEC50 values of 41.85 Mand70.80 M,respectively.