Results
Secoemestrin C suppresses the proliferation of Con A-stimulated splenocytes
A total of 5.2 g of secoemestrin C was isolated from Aspergillus nidulans, which had been growing on rice culture medium (40 kg). The structure of the compound was elucidated by NMR and HR-ESI-MS (Fig. 1A, Supplemental Table 1 and Supplemental Fig. 1). The purity of the secoemestrin C was ≥99.0%, as determined via high performance liquid chromatography with a UV detector. To investigate whether secoemestrin C has the potential to suppress immunological reactions, a Con A-induced splenocyte proliferation assay was carried out in the presence of secoemestrin C. Mouse splenocytes strongly proliferated in response to the Con A stimulation in vitro (Fig. 1B, C). However, secoemestrin C treatment potently inhibited this Con A-stimulated splenocyte proliferation (Figure 1B, C).