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Paper chromatography is very helpful in the identification and comparison of antibiotics, but very few results from the application of this technique have been published so far. The awakening of interest in the search for antibiotics which are active against fungi pathogenic to plants and animals makes the investigator aware of the scant information that is available to help characterize such agents. A knowledge of the Rf values of the known antifungal agents would help advance the search for such therapeutic materials. Often these values, in conjunction with the biological inhibitory activities, are the only criteria by which one can determine whether the unknown agent appears to be a new material. When the Rf data are obtained for shake cultures, one can eliminate many previously described antibiotic-producing organisms from further study, thus allowing more research to be applied to antibiotics which are new and different. The studies reported in this paper should serve as a guide to the identification of some of the known antifungal antibiotics.

Publisher Summary This chapter discusses the principles of paper chromatography of antibiotics. It includes all steps of analysis beginning with the preparation of samples and papers, development techniques, detection methods, and means of documentation. Paper chromatography of the best-known groups of antibiotics is also presented in the chapter. General theoretical aspects of paper chromatography are not dealt with except for those that directly emerged from studies of antibiotics. The chapter concludes with a discussion of paper chromatographic classification and systematic analysis of antibiotics.

A simple quantitative chromatographic method is described for the separation of epitetracycline and tetracycline in pharmaceutical preparations. The method is applicable qualitatively to human serum and quantitatively to the biological determination of tetracycline in urine. Whatman's modified cellulose phosphate cation-exchange paper is developed by the descending technique using 0·1 per cent w/v ammonium chloride solution. The spots are located as yellow fluorescent spots under ultra-violet light and ammonia vapour, eluted in 10 per cent w/v ammonium chloride, and the extinction determined at 356 mμ. The method is not suitable for the separation of chlortetracycline or oxytetracycline from tetracycline.

(1955). A New Method for Determination of Bacterial Sensitivity to Chemotherapeutic Agents by Means of Paper Strips. Scandinavian Journal of Clinical and Laboratory Investigation: Vol. 7, No. 3, pp. 259-263.

(1960). The Paper Disc Method for Determination of Bacterial Sensitivity to Antibiotics Studies on the Accuracy of the Technique. Scandinavian Journal of Clinical and Laboratory Investigation: Vol. 12, No. 4, pp. 408-413.

SummaryA procedure has been developed whereby paper chromatograms of antiviral agents can be developed by applying them to virus infected, agar overlay, chick embryo cell tissue cultures. Plaque-free zones are produced, thus indicating the area on paper chromatogram where the active material can be located. Using antiviral substances antibiotic W-112 and isatin-monothiosemicarbazone, W. Nile and vaccinia viruses, and 4 chromato-graphic solvent systems, it was possible to localize the biological activity of these antiviral agents. As little as 1 μg of antibiotic W-112 produced large plaque-free zones when paper chromatogram was applied to the overlay culture 1 hr after virus infection. When 100 μg of same material was used, large plaque-free areas resulted even when the paper was applied 46 hr after virus infection. Isatin-monothiosemicarbazone at 50 μg level not only produced a plaque-free zone but also produced a yellow spot on paper chromatogram that coincided exactly with the zone of antiviral activity.

Antibiotic discs were prepared, using several several batches of papers meeting Food and Drug Administration specifications. The analysis of 1,152 zones of inhibition produced showed no performance differences among these batches. Other discs were prepared using papers of different grades. These produced large differences in performance. It is obvious, therefore, that the use of a specified disc paper is necessary for standardizing the performances of the products of various manufacturers and that reproducible results can be attained with the grade of paper specified.

The test paper here described makes it relatively easy to choose the antibiotic best suited for treatment of a given bacterial infection. Each type of test paper bears both a culture medium and an antibiotic and is supplied, dry and sterile, in a transparent envelope. For a given test, the paper is wetted and inoculated and the envelope with its contents is incubated. It is not necessary to wait for the appearance of visible colonies because the metabolic activity of the bacteria is detected by an indicator (triphenyltetrazolium chloride) which is colorless until reduced to a bright red dye by bacterial enzymes. The reliability of the new test was established by a comparative study with other methods in 100 clinical cases. The test paper is easily stored, and the entire unit can be incinerated after use. It is therefore useful in general office practice and should help to make sure that each patient receives the most effective antibiotic.

MANNOSIDOSTREPTOMYCIN in some streptomycin preparations is conveniently detected by the paper chromatographic procedure of Winston and Eigen1. In the presence of high concentrations of salts such as in ion-exchange column eluates, or in fermentation broths, this procedure is not applicable: attempts to desalt such solutions, by mixed-bed ion-exchange, electrolytic de-ionization or solvent extraction, have proved unsuccessful. We have found it possible to separate streptomycin, mannosidostreptomycin and allied substances by paper electrophoresis, having developed (independently) a technique similar to that used for new antibiotic broths by Hosoya et al. 2, and King and Doery3.

An attempt to establish a systematic chromatographic analysis of antibiotics has been made. Sixty-two known antibiotics were distributed into five classes and into fourteen subclasses, according to their RF values in four principal solvent systems. Principles of the classification of antibiotics are given. For more detailed comparison and characterization of antibiotics further additional solvent systems were used. Additional solvent systems A, B, C, and D were used for class I, systems E, F, G, and H for classes II and III, systems I, J, K, and L were used for classes IV and V.

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