Ansatrienin B

Ansatrienin B (Mycotrienin II) is an ansamycin antibiotic isolated from?Streptomyces. Ansatrienin B is active against fungi and yeasts, but inactive against bacteria.Ansatrienin B displays antitumor antibiotic activity and can be used as an ADC Toxin^[1][2]. In Vitro: Ansatrienin B exhibits antimicrobial activities of Penicillium chrysogenuin 1AM 7106, Mucor pusillus IAM 6122, Rhizopus delemar IAM 6015, Saccharornyces cerevisiae IFO 0304, Candida utilus IFO 0396 and Candida krusei IFO 0590 with MIC values of 12.5 μg/ml, 12.5 μg/ml, 12.5 μg/ml, 8.0 μg/ml, 4.0 μg/ml, 4.0 μg/ml, and 4.0 μg/ml, respectively^[1].
Ansatrienin B inhibits the release of ⁴⁵calcium into the culture medium by fetal rat long bones with an apparent halfmaximal inhibition (IC₅₀) value of 21 nM^[2].
Ansatrienin B inhibits the translationof the protein synthesis stage by specific inhibition of L-leucine incorporation (IC₅₀=58 nM) in A549 cells). At the same time,?it also inhibits TNF-α-induced expression of ICAM-1 with an IC₅₀ of 300 nM^[3].
In Vivo: Ansatrienin B (intraperitoneal injection; once daily; 6 days) is against P-388 -injected mouse tumor growth. The LD₅₀ value in mice of MTN-II is 80 mg/kg in CDF1 male mice^[2].