Abstract: A novel antibiotic substance SF-1540 and a process for preparing the same which comprises culturing a substance SF-1540-producing microorganism belonging to the genus Streptomyces in a medium and isolating and recovering the substance SF-1540 from a cultured broth; a novel derivative of the substance SF-1540 and a process for preparing the same which comprises treating said antibiotic substance SF-1540 with methanol to form the corresponding antibiotic substance SF-1540 derivative.

Abstract: D-glucaro-1,5-lactam and its pharmaceutically acceptable salts are useful as an agent of protecting against renal failure or damage induced by administration of aminoglycosidic antibiotics.

Abstract: Novel antibiotics derivatives 7-(5-acylamido-5-carboxyvaleramido)-3-(.alpha.-methoxy-p-acyloxycinnamoylo xymethyl)-7-methoxy-3-cephem-4-carboxylic acids and the salts thereof which are useful as antibiotics and intermediates for the preparation of cephamycin derivatives, a process for preparing the same, and a process for recovering the cephamycin derivatives effectively and stably from the fermentation broth in the form of an N-acyl derivative.

Abstract: A new antibiotic designated as SF-1623 substance exhibiting a useful antibacterial activity against gram-negative bacteria is now produced by cultivating a new strain ATCC 21999 of the known species Streptomyces chartreusis. The SF-1623 substance in the form of its an alkali metal salt may be recovered from the culture when the cultivation is effected under aerobic conditions in the presence of an alkali metal thiosulfate.

Abstract: A new derivative of the macrolide antibiotic SF-837 substance is manufactured by treating a 9,2'-diacyl- or 9-acyl-SF-837 composition with dimethylsulfoxide and acetic anhydride, and, subsequently, with an alcohol or water-containing solvent to yield the novel compound, 9-Acyl-3"-thiomethoxymethyl-SF-837 composition. In addition to high therapeutic effectiveness and low acute toxicity, this novel compound of the present invention has the great advantages that it does not have the bitter taste originally accompanying the parent compounds, and the further advantage that it is suitable for pediatric and veterinary use.

Abstract: A new antibiotic designated as SF-1623 substance exhibiting a useful antibacterial activity against gram-negative bacteria is now produced by cultivating a new strain ATCC 21999 of the known species Streptomyces chartreusis. The SF-1623 substance in the form of its an alkali metal salt may be recovered from the culture when the cultivation is effected under aerobic conditions in the presence of an alkali metal thiosulfate.

Abstract: Novel 7-(5-amino-5-carboxyvaleramido)-7-methoxy-3-hydroxymethyl-3-cephem-4-carbo xylic acid derivatives. Such derivatives are prepared by subjecting cephamycin type compounds to the action of esterase enzyme of mold fungi.

Abstract: A 9-O-alkanoyl-3"-O-alkanoyloxymethyl-SF-837 substance is now synthetized, which is a new compound useful in that this new 9-O-alkanoyl-3"-O-alkanoyloxymethyl derivative of the SF-837 substance exhibits an antibacterial activity comparable to that of the parent SF-837 substance but is advantageously free from the unpleasant bitter taste inherent to the SF-837 substance and is hence adapted for oral administration. A process of producing the 9-O-alkanoyl-3"-O-alkanoyloxymethyl-SF-837 substance is also provided, which comprises hydrolysing partially and selectively a 9,2'-di-O-alkanoyl-3"-O-alkanoyloxymethyl-SF-837 substance in an aqueous alkanol or aqueous acetone. The 9,2'-di-O-alkanoyl-3"-O-alkanopyloxymethyl-SF-837 substance may be prepared by reacting a 9,2'-di-alkanoyl- or O-mono-O-alkanoyl-3"-O-thiomethoxymethyl-SF-837 substance with an alkanoic anhydride which is exemplified by acetic anhydride or propionic anhydride in the specification.

Abstract: D-Gluconic-.delta.-lactam is obtained by oxidizing nojirimycin with glucose-oxidizing enzymes or by the action of microorganisms capable of producing glucose-oxidizing enzymes.

Abstract: A BN-109 substance producing strain of the genus Bacillus is cultivated under an aerobic condition to produce and accumulate BN-109 substance in a culture medium. The BN-109 substance is isolated from the culture broth and purified, and proved to be a novel antibiotic. The BN-109 is effective in the treatment and prevention of swine scours.