The fungal strain of Alternaria sp. hh930 was isolated from fresh stems of Isodon sculponeatus that were collected from Weishan County, Dali City, Yunnan Province, People's Republic of China, in September 2014. The fungal strain was cultured on slants of potato dextrose agar at 28 ℃ for 7 days. Agar plugs were cut into small pieces (about 0.5 × 0.5 × 0.5 cm³) under aseptic conditions, and 10 pieces were used to inoculate three Erlenmeyer flasks (250 mL), each containing 50 mL of media (0.4% glucose, 1% malt extract, and 0.4% yeast extract); the final pH of the media was adjusted to 7.0, and the flasks were sterilized by autoclave. Three flasks of the inoculated media were incubated at 28 ℃ on a rotary shaker at 170 rpm for 5 days to prepare the seed culture. Spore inoculum was prepared in sterile, distilled H₂O to give a final spore/cell suspension of 1 × 10⁶/mL. Fermentation was carried out on solid rice medium in 30 Fernbach flasks (500 mL, 90 mL distilled water was added to 80g rice and kept overnight before autoclaving). Each flask was inoculated with 5.0 mL of the spore inoculum and incubated for 40 days at 28 ℃ in a static incubator.