Butyrolactone I

Butyrolactone I is a secondary metabolite from A. terreus that acts as an ATP-competitive inhibitor of cyclin-dependent kinase 1 (Cdk1; IC50 = 20 μg/ml in PC-14 cells).1 It induces dose-dependent G2/M arrest, inhibits DNA synthesis, and decreases Cdk1 protein expression in vitro.1 Butyrolactone I has antitumor effects in non-small cell lung, small cell lung, and prostate cancer cell lines (mean IC50 = 50 μg/ml).[1],[2] It inhibits in vitro Cdk1 phosphorylation of tau and in vivo phosphorylation of transcription factor E2F-1.[3],[4] Additionally, exogenous application of butyrolactone I to A. terreus cultures increases biogenesis of the secondary metabolites lovastatin and conidiation in a quorum-sensing manner.[5]

Reference:
[1]. Nishio, K., Arioka, H., Kurokawa, H., et al. Antitumor effects of butyrolactone I, a selective cdc2 kinase inhibitor, on human lung cancer cell lines. Anticancer Res. 16(6B), 3387-3395 (1996).
[2]. Suzuki, M., Hosaka, Y., Matsushima, H., et al. Butyrolactone I induces cyclin B1 and causes G2/M arrest and skipping of mitosis in human prostate cell lines. Cancer Lett. 138(1-2), 121-130 (1999).
[3]. Hosoi, T., Uchiyama, M., Okumura, E., et al. Evidence for cdk5 as a major activity phosphorylating tau protein in porcine brain extract. J. Biochem. 117(4), 741-749 (1995).
[4]. Kitagawa, M., Higashi, H., Suzuki-Takahashi, I., et al. Phosphorylation of E2F-1 by cyclin A-cdk2. Oncogene 10(2), 229-236 (1995).
[5]. Palonen, E.K., Raina, S., Brandt, A., et al. Transcriptomic complexity of Aspergillus terreus velvet gene family under the influence of butyrolactone I. Microorganisms 14;5(1), (2017).