Botric acid, a new antibiotic.

glucose, 1.0 % peptone, 1.0 % corn steep liquor, 0.2 /00 KH2PO4 and 0.1 % MgSO4 (pH 6.5) for 66 hours at 26°C. Botric acid principally existed in the mycelia, the activity was bio-assayed using Candida albicans as a test organism on SABOURAUD'S glucose medium. The cultured broth (180 liters) was filtered, and the mycelial cake was extracted twice with each 20liters of acetone. The extract was concentrated in racuo to 6liters, and the residual solution was extracted with equal volume of butylacetate. The solvent layer was treated with charcoal, and concentrated. The oily residue was dissolved in 2liters of methanol and allowed to stand overnight at 5°C. Crude botric acid was precipitated (10.5 g), and crystallized from hot methanol. The potasium salt was prepared as follows: the antibiotic was suspended in water and adjusted to pH 8.0 with 1 N KOH, and then lyophilized. Botric acid is yellow crystal (plates) having a weakly acidic nature (pK'a 7.8 in 75% dimethylformamide), and decomposes at 214-216°C. [n]25D-294° (c 0.1, CHC13). Anal. Calcd. for C25H32O4 (M.w. 396.53): C 75.80, H 8.08, 0 16.15 Found: C 75.33, H 8.08 The molecular weight has been confirmed by the M+ ion at m/e 396 in the mass spectrum. The ultraviolet spectrum show a broad maximum at 328-.338 nm (E1%1cm , 1,410) in methanol and maxima at 235 mn (E1%1cm, 497) and 330 nm (E1%1cm 497) in 0.1 N NaOH. The infrared spectrum is given in Fig. 1. The NMR spectrum (60 MHz in CDCl3) is illustrated in Fig. 2. Botric acid is soluble in acetone, ethylacetate, chloroform, dimethylformamide, dimethylsulfoxide, and alkaline water, slightly soluble in lower alcohols, and insoluble in nhexane petroleum ether and water. The antibiotic gives positive reaction to LIEBERMANBURCHARD, SALKOWSKI, TOLLENS, MOLISCH and hydroxamic acid-FeCl3, negative reaction to EHRLICH, FeCl3, and 2,4-dinitrophenylhydrazine. It shows Rf values 0.76 with wet ethylacetate, 0.80 with MeOH-H2O (4:1) and 0.35 with CHCl3-MeOH (10:1) on thin-layer chromatography (Merck, Keselgel G) detected by spraying of 0.1 % aqueous potassium permanganate solution. Botric acid is principally active against