Hirofumi AkiyamaNaoya OkuEnjuro HarunariWatanalai PanbangredYasuhiro IgarashiToyama Prefectural UniversityMahidol University2020-01-272020-01-272020-01-01Journal of Antibiotics. Vol.73, No.1 (2020), 60-6518811469002188202-s2.0-85072167335https://repository.li.mahidol.ac.th/handle/20.500.14594/49686© 2019, The Author(s), under exclusive licence to the Japan Antibiotics Research Association. A norditerpenoid k4610422 (1), an inhibitor of testosterone-5α-reductase originally discovered from a mesophilic rare actinomycete of the genus Streptosporangium, was isolated from the culture extract of a thermophilic actinomycete Actinomadura sp. The complete 1H and 13C NMR assignment and absolute configuration of 1 were addressed by spectroscopic measurements including NOESY and CD spectra coupled with ECD calculation, which allowed to establish the (5 R,9 S,10 R,13 S)-configuration. Compound 1 was moderately cytotoxic against P388 murine leukemia cells with IC50 30 μM.Mahidol UniversityPharmacology, Toxicology and PharmaceuticsArticleSCOPUS10.1038/s41429-019-0231-7