Ginkgonins A and B: Two new sesquiterpenoids from Streptomyces ginkgonis TH01

Two new sesquiterpenoids, ginkgonin A ( 1 ) and ginkgonin B ( 2 ), together with six known compounds ( 3 - 8 ), were isolated from the broth of Streptomyces ginkgonis TH01. Their structures were determined through comprehensive spectroscopic analysis, including HRESIMS and 1D/2D NMR (COSY, HSQC, HMBC, and NOESY). The absolute configurations were solved via electronic circular dichroism (ECD) calculations. Compounds 1 – 8 were evaluated for antimicrobial activity against Staphylococcus aureus , Bacillus subtilis , and Escherichia coli . Compounds 1 , 2 , 3 , 4 , and 7 exhibited moderate inhibitory effects against all tested strains, with MIC values ranging from 12.3 to 49.4 μg/mL. • Two previously unreported sesquiterpenoids, ginkgonin A and B, were isolated from Streptomyces ginkgonis . • Structures were elucidated by extensive NMR analysis and calculated ECD/ 13 C NMR data. • The strain was isolated from Lake Taihu sediment, an under-explored ecological niche. • Ginkgonins A and B showed moderate antibacterial activity against Staphylococcus aureus , Bacillus subtilis , and Escherichia coli (MIC values ranging from 12.3 to 49.4 μg/mL).