Abstract: Improved chemical process for preparing the compounds of formula (I), wherein: R1 represents (C9-C12)alkyl; M represents hydrogen, &agr;-D-mannopyranosyl or 6-O-acetyl-&agr;-D-mannopyranosyl and Y represents an amino group of formula —NR2-alk1-(NR3-alk2)p-(NR4-alk3)q-W. One aspect of the invention refers to the preparation of the intermediate compound of formula (III) (which corresponds to the above compound of formula (I) wherein R1 and M are as above defined and Y is hydroxy), by reacting a compound of formula (II) (which corresponds to the above compound of formula (I) wherein R1 and M are as above defined and Y is hydroxymethyl), with a (C1-C4)alkanol in the presence of a concentrated mineral acid, using the same alkanol as the reaction solvent and submitting the obtained ester compound to a reductive process by adding an alkali metal borohndride into the same reaction mixture.

Abstract: The present invention is directed to a chemical process for preparing antibiotic L 17392 (deglucoteicoplanin) and its salts with bases and acids by submitting a teicoplanin compound or a teicoplanin-like compound to controlled strong acid hydrolysis in the presence of an organic aprotic solvent, and a purification thereof.

Abstract: The present invention relates to a new one-pot process for preparing 2'-(diethylamino)rifamycin P and its 25-desacetyl derivative which consists in cyclizing 3-bromorifamycin S or its 25-desacetyl derivative, dissolved in dimethylformamide, with 1,1-diethylthiourea and reducing, without isolation, the obtained 1,2-quinonimine intermediate with a mild reducing agent.

Abstract: This invention concerns the recovery of glycopeptidic antibiotics from aqueous solutions resulting from fermentation broths or process streams. Examples of glycopeptidicantibiotics to which the process of this invention may be applied are the following: vancomycin, actaplanin, ristocetin, avoparcin, actinoidin, LL-AM-374, A 477, OA 7653, A 35512 B, A 515668, AAD 216, A 41030, A 47934, A-40926 (European Pat. Appln. No. 85112406.5), the individual factors, derivatives and pseudo-aglycones and aglycones thereof, teicoplanin and teicoplanin-like compounds.

Abstract: The object of this invention is to provide a method for selectively increasing the ratio of the single T-A2 major components in the T-A2 complex. More particularly, the object of this invention is a process for obtaining teicoplanin A.sub.2 selectively enriched in any of its major components, T-A2-1, T-A2-2, T-A2-3, T-A2-4 and T-A2-5 which consists in adding to the culture medium of Actinoplanes teichomyceticus nov. sp. ATCC 31121 or a mutant thereof which produces T-A2 complex through the same metabolic pathway, a selectively effective amount of an appropriate precursor.

Abstract: A process for preparing 6-APA and 7-ACA and derivatives therefore is disclosed wherein a penicillin or cephalosporin substrate is reacted with a molar excess of an oxalyl halide of the formula halCOCOhal whereby the COOM group of the substrate, wherein M represents hydrogen, metal or ammonium cations, is transformed into the group COOCOCOhal.

Abstract: High yields of phthalaldehydic acid from .alpha.,.alpha.,.alpha.,.alpha.',.alpha.'-pentachloro-o-xylene can be obtained in an excellent degree of purity if a mixture of said pentachloroxylene and phthalaldehydic acid in water is heated to a temperature between about 80.degree. and about 180.degree. C., and preferably at the boiling temperature of the reaction mixture. The mutual ratio of the reactants is not critical, and may vary within wide ranges, although it is usually preferred to have such a ratio between the said pentachloroxylene and phthalaldehydic acid that for each part by weight of the former at least 0.1 part by weight of the latter is present. Practically, there is no upper limit to the amount of phthalaldehydic acid which may be present, even to a large molecular excess.

Abstract: Cephalosporin C is recovered from its fermentation broth by in situ formation of N-(p-nitrobenzoyl)cephalosporin C which is extracted therefrom and converted to 7-amino-cephalosporanic acid.