304 



DESCRIPTIONS OF ANTIBIOTICS 



fiod l)y rechroniatographing on alumina from 

 chloroform, with chloroform or chloroform-ace- 

 tone as developer. Recrystallized from acetone 

 on addition of carbon tetrachloride in the cold. 

 Mitomycins A and B could also he separated by 

 countercurrent distribution (benzene-chloroform 

 and pH 7.2 phosphate buffer) (1). Mitomycin C 

 was also distinguished (4). The later workers used 

 a method of extraction essentially the same as 

 that given above except that "Fraction R" was 

 described as being left in the aqueous layer after 

 step I. This was extracted from the aqueous layer 

 with cyclohexanone, the extract concentrated, 

 and the substance precipitated with petroleum 

 ether. Chromatography gave active fractions de- 

 scribed as mitomycins A, B, and C(X), and frac- 

 tions X and Y (9). 



Chemical ami physical properties: Mitomycins 

 A and B: Basic substances. Plates or needles. 

 Solu])le in acetone, methanol, ethanol, chloro- 

 form, methyl ethyl ketone, jjyridine, methyl 

 Cellosolve, n-butanol, ethylene dichloride, water, 

 ethyl and n-butyl acetate, ether, and cyclohexa- 

 nol. Slightly soluble or insoluble in xylene, car- 

 bon disulfide, carbon tetrachloride, ligroin, pe- 

 troleum ether, and cyclohexane. Infrared spectra 

 given in reference 1. Positive 2,4-dinitrophenyl- 

 hydrazine and bromine tests. Negative Elson- 

 Morgan, biuret, and anthrone tests. Mitomycin A: 

 m.p. 159-161 °C (decomposition). Soluble in ben- 

 zene, toluene, trichloroethylene, and nitroben- 

 zene. Light -absorption maxima at 215 ni/i {E\\m 

 234), 316 to 318 m^ {E^^ra .122), and 530 m/x (E\\n^ 

 18.8) (in water) ; at 360 and 550 to 560 niyu (in 0.1 

 N NaOH); or at 235, 285, 335, and 430 m^ (in 0.1 

 A^ HCl). Red-violet color of mitomycin A fades 

 in Schiff's reagent, 0.1 A HCl, and 0.1 A NaOH; 

 changes to blue in concentrated H2SO4 and to 

 orange in concentrated HCl. Gives a green color 

 with Molisch reagent. C = 54.22%; H = 5.05%; 

 N = 11.68%. No CI or S. Mitomycin B: m.p. 182- 

 184°C (decomposition). Insoluble in benzene, 

 toluene, trichloroethylene, and nitrobenzene. 

 Light-absorption maxima at 220 ran {Ei'lm 117.5), 

 320 niM (ETl,n 55), and 550 m/x iEX\ru 9.9) (in water); 

 at 360 and 580 m^ (0.1 N NaOH) ; and at 232, 284, 

 335, and 430 to 440 m^ (0.1 A HCl). The violet 

 color of mitomycin B fades with Schiff's reagent 

 and 0.1 A' HCl; changes to blue with 0.1 A NaOH, 

 and from blue to green with concentrated H2SO4 . 

 Color changes from yellow to orange with concen- 

 trated HCl, and from green to brown with the 

 Molisch reagent (1). Mitomycin A -like: Red 

 crystals; m.p. 167-168°C. Light-absorption max- 

 ima at 216 niM {E^cm 485), 320 m^ {ETcm 255), and 



520 ni/x (fi'icni 40) ill methanol. Pure substance re- 

 tains 93 per cent of its activity after 3 hours at 

 100°C. Less pure preparations are more labile. 

 C = 51.46%; H = 5.64%; N = 9.00%; O = 

 33.90%. Degradation products include cinnamic 

 acid amide. Mitomycin C (X): Bluish violet crys- 

 tals. No melting point up to 360°C. Soluble in 

 water, methanol, acetone, butyl acetate, and cy- 

 clohexanone. Sparingly soluble in benzene, carbon 

 tetrachloride, and ether. Insoluble in petroleum 

 ether. Ultraviolet absorption spectrum maxima 

 at 216 niyu (^llm 742), 360 m^ (£'}lm 742), and 560 

 m/.i (-fi'itm 0.06). Infrared spectrum given in refer- 

 ence 9. Positive Fehling, hydroxylamine hydro- 

 chloride, biuret, Ehrlich, FeClj , nitrous acid, 

 and Liebermann tests. Questionable positives: 

 bromine, 2,4-dinitrophenylhydrazine, and Janov- 

 sky reactions. Negative Benedict, Tollen, fuchsin, 

 ninhj'drin, Millon, and Raymond tests. Data on 

 paper chromatographic behavior given in refer- 

 ence 9. Bluish violet at alkaline pH, red at weakly 

 acid pH, and yellow at acid pH. Color changes 

 are reversil)le. Most stable at pH 6 to 7; labile to 

 acid and alkali. Photo-labile. Prolonged boiling 

 destroys biological activity and toxicity. Easily 

 oxidized, but not easily reduced. C = 53.84%; 

 H = 5.14%; X = 15.49%. C54H6iNi;sOi, (tenta- 

 tive). Chroinophore of C: Isolation procedure 

 given in reference 9. Red-brown crystals; m.p. 

 65-70°C (not distinct). Soluble in water, metha- 

 nol, ethanol, acetone, cyclohexanone, and diox- 

 ane. Ultraviolet absorption spectrum maxima at 

 215 niM (^'Hm 630) and 320 m^ (£'rcm 295) with a 

 shoulder at 260 mn. Exhibits the same color 

 changes as mitomycin C. Biologically inactive. 

 Fraction R: Brownish red amorphous powder. 

 Soluble in acetone, Viutanol, methanol, dioxane, 

 and alkaline water. Insoluble or slightly soluble 

 in ethyl acetate, butyl acetate, chloroform, car- 

 bon tetrachloride, ether, benzene, and water, 

 intraviolet absorption spectrum maxima at 215 

 and 315 mfi. Does not change color with pH. 

 Fraction Y: Orange crystals. Browns at 180°C. 

 Carbonizes at 240°C. Soluble in chloroform, ace- 

 tone, benzene, ether, and acidic acjueous solu- 

 tion. Insoluble or slightly soluble in benzene, 

 ether, and neutral or alkaline water. LTtraviolet 

 absorption spectrum maxima at 207, 237, 286, and 

 345 m^i (9). Violet in alkaline solution; yellow in 

 acidic. Considered a partial degradation product 

 of mitom>cin H. 



Biological activity: Mitomycins A and B: Active 

 on gram -positive and gram-negative bacteria, 

 mycobacteria, and Nocardia asteroides. Not active 

 on fungi or yeasts. Mitomycin A is activ(> in a 



