تفاعل #55227

معادلة التفاعل

coformycin

formycin A

→

formycin B

coformycin

ظروف التفاعل

الإجراء التجريبي

A culture broth filtrate (2000 ml, pH 7.4, containing 26 mg of coformycin, 120 mg of formycin A and an unknown amount of formycin B) obtained from the submerged cultivation of a coformycin-producing microorganism, Nocardia interforma (ATCC No. 21072) was passed through a column (28 mm diameter) of 110 ml of a strong cation-exchange resin consisting of a polystyrene sulfonic acid (available as "Amberlite" IR-120, a commercial product of Rohm & Haas Co., U.S.A.) which had been converted into the 50% NH4+ -form prepared as described in Example 1. Coformycin and formycin A in the culture filtrate were adsorbed on the resin, but formycin B was not adsorbed. The resin column was washed with 550 ml of water and then eluted with 1 N aqueous ammonia. The first running (70 ml) was discarded, and the eluate was recovered (250 ml) after its pH increased to 9.6 or more. The recovered eluate containing coformycin and formycin A was concentrated to dryness under reduced pressure to give 725 mg of a crude powder. This crude powder was dissolved in 4 ml of water and the resulting aqueous solution (pH 9.0) was subjected to a column chromatography with a column (15 mm diameter) of 40 ml of "Amberlite" CG-50 (I-type) of 50% the NH4+ -form. The development was done with water. The eluate was collected in 4 ml-fractions. Each fraction was analysed by silica gel thin-layer chromatography in the same manner as described in Example 1. Fraction Nos. 28-34 containing coformycin alone were combined and concentrated to dryness under reduced pressure to give 43 mg of a colorless powder. This powder was crystallised from 0.6 ml of warm water, affording 19 mg of colorless crystals of coformycin. mp. 182°-184° C. Yield 73%. Fraction Nos. 35-61 containing formycin A alone were combined and concentrated to dryness under reduced pressure to give 135 mg of a colorless powder. This powder was crystallised from 4 ml of warm water, affording 90 mg of colorless crystals of formycin A. mp. 141°-142° C. Yield 75%.

المصدر