DESCRIPTIONS OF ANTIBIOTICS 



2G.3 



Toxicity: Helixin B toxic to tomato and cowpea 

 cuttings at 7.5 to 15 /ug per ml. Not toxic to whole 

 tomato plants at 90 /ig per ml when used as a water- 

 ing solution. No phytotoxic effects at 3 mg per 

 ml, applied as a spray on young bean, corn, cow- 

 pea, tomato, and wheat plants. Inhil)ition of seed 

 germination at 25 to 100 ^g per ml (2). 



Utilization : Plant diseases caused hy fungi. 



References: 



1. Leben, C. et al. Alycologia H: 159-109, 



1952. 



2. Leben, C. and Keitt. (1. W. Phytopa- 



thology 42: 168-170. 1952. 



3. Smeby, R. R. et al. Phytopathology 12: 



506-511, 1952. 



4. Leben, C. et al. Phytopathology 43: 391- 



394, 1953. 



F]iiteroni> ciii 



Produced by: Sireptoniyces alhireticuli (1, 3). 

 This culture also produces eurocidin, carl)omyciii, 

 and tertiomycin A (5). 



Method of extraction: Extracted from culture- 

 broth with ethyl acetate at pH 2.0. Back-extracted 

 into Na-iCOs . Re-extracted into ethyl acetate at 

 acid pH (acidified with H.>S04). Recrystallized 

 from ethanol (2). 



Chemical and physical properties: Acidic sub- 

 stance. Pale yellow crystals. Decomposes at 160- 

 162°C. Soluble in methanol, ethanol, ethyl acetate, 

 butyl acetate, and dioxane. Sparingly soluble in 

 water, acetone, and chloroform. Insoluble in 

 benzene, ether, and petroleum ether. Ultraviolet 

 absorption spectrum maximum at 300 to 320 mn 

 (ethanol). Optically inactive in methanol. Con- 

 tains carbonyl and C — OCHa groups. C = 38.21%; 

 H = 4.62%", N = 14.32%. CMsO-,^, . Releases 

 CO2 on addition of sodium bicarbonate (2-4). 



Biological activity: Active on gram-negative 

 bacteria, including E. ccAi. Proteus, Serratia, Sal. 

 typhi, Shigella, V. cholerae, and Pseudonionas. Less 

 active on gram-positive bacteria, including Staph, 

 aureus, B. subtilis, Ps. aeruginosa, and myco- 

 bacteria. Active on certain viru.ses. Not active on 

 fungi. More active at acid than alkaline pH (2-4). 



Toxicity: LD50 (mice) 135 to 138 mg per kg 

 intravenously (2, 4). 



References: 



1. Nakazawa, K. J. Agr. Chem. Soc. Japan 



29: 647-649, 1955. 



2. Nakazawa, K. J. Agr. Chem. Soc. Jajjan 



29:659-661, 1955. 



3. Shibata, M. Japanese Patent 4994, 1956. 



4. Shibata, iVI. Japanese Patent 4995, 1956. 



5. Miyake, A. et al. J. Antibiotics (Japan) 

 12A: 59-64, 1959. 



El ythroniycin 



Produced by: Streptomyces erythrcus (13). 



Synonym: Erythromycin A. 



Method of extraction: I. Broth-filtrate extracted 

 with amyl acetate or methyl isobutyl ketone at 

 pH 9.4. Back-extracted into water at pH 5.1. 

 Aciueous extract adjusted to pH 8.0, concentrated, 

 and readjusted to pH 9.5 to 11.0 to precipitate 

 erythromycin. Recrystallized from acetone -water 

 or petroleum ether (9, 13). II. Broth-filtrate de- 

 fatted with petroleum ether, adjusted to pH 8.5, 

 and extracted with ethyl acetate or butanol. Ex- 

 tracts evaporated to dryness in vacuo. Solid tritu- 

 rated with petroleum ether. Precipitated from 

 ethanol on addition of water and cooling. Re- 

 crystallized from ethanol and aqueous acetone to 

 give the "erythromycin acid addition salt." Also 

 isolated by absorption on acid-treated charcoal 

 and l)utanol elution. "Acid addition salt" sus- 

 pended in water, pH adjusted to 6.3, and washed 

 with CHCI3 . Aqueous layer extracted with amyl 

 acetate at pH 9.8. Extracts evaporated off in 

 vacuo. Residue recrystallized from aqueous etha- 

 nol (13). III. Crude powders, containing two or 

 more components of the complex, yield, on dis- 

 solving in nitromethane, warming, decolorizing, 

 and cooling, essentially pure erythromycin, leav- 

 ing the other components in the mother liquor. 

 Recrystallized from the same solvent and aqueous 

 acetone (37). IV. Crude erythromycin salt solu- 

 tion adjusted to pH 8.0 to 8.5, heated to 35-45°C, 

 stirred with acetone, ethanol, or isoi)ropanol and 

 a water-soluble salting-out agent such as NaCl. 

 The whole adjusted to pH 10 to 10.8, and heated 

 to 35-45°C to bring erythromycin into the organic 

 phase. Water added to tiu-bidity at 45°C and the 

 whole cooled to 15°C to give crystals (38). 



Chemical and physical properties: Basic macro- 

 lide (1). Free base (hydrate or solvates from ace- 

 tone or chloroform): White needles of the hexag- 

 onal system or short rods; ni.]). 136-140°C or 

 134-136°C (15). If slow heating is continued, re- 

 solidifies, then melts again at 190-193°C (15). Very 

 soluble in alcohols, acetone, chloroform, aceto- 

 nitrile, and ethyl acetate. Moderately soluble in 

 ether, ethylene dichloride, and amyl acetate. Sol- 

 uble to 2 mg per ml in water (1, 13). Ultraviolet 

 absorj)tion spectrum maximum at 278 niyu (e = 27) 

 (15), 280 mfj. (e = 50, broad peak, pH 6.3) (1), or 

 288 to 289 niM (£'1™ 0.395) (13). Infrared spectrum 

 given in references 13 and 15. [afp = —78° (c = 

 1.99 i)er cent in ethanol) (1, 38). Separation from 



