Abstract: The invention relates to cobalamin derivatives having no or low binding affinity to the transport protein transcobalamin II (TCII) and retaining activity as a vitamin B12 substitute, optionally carrying a therapeutic and/or diagnostic agent, such as a radioactive metal. These compounds have a much reduced accumulation rate in blood and benign organs, such as kidney and liver, compared to the accumulation rate in neoplastic tissues, and are more rapidly eliminated from blood. The invention further relates to a method of diagnosis and a method of treatment of a neoplastic disease or an infection by microorganisms in a mammal by exposing the mammal to a period of a vitamin B12 free diet, and subsequently applying a cobalamin derivative of the invention carrying a diagnostic and/or therapeutic agent. By selecting cobalamin derivatives acting as vitamin B12 substitutes, the risk of the formation of resistant off-spring in neoplastic tissue is much reduced.

Abstract: The invention relates to cobalamin derivatives (a) having no binding affinity or low binding affinity to the transport protein transcobalamin II TCII) and (b) retaining activity as a vitamin B12 substitute, optionally carrying a therapeutic and/or diagnostic agent, such as a radioactive metal. These compounds have a much reduced accumulation rate in blood and benign organs, such as kidney and liver, compared to the accumulation rate in neoplastic tissues, and are more rapidly eliminated from blood. The invention further relates to a method of diagnosis and a method of treatment of a neoplastic disease or an infection by microorganisms in a mammal comprising (a) exposing the mammal to a period of a vitamin B12-free diet, and (b) subsequently applying a cobalamin derivative of the invention carrying a diagnostic and/or therapeutic agent. By selecting cobalamin derivatives acting as vitamin B12 substitutes, the risk of the formation of resistant offspring in neoplastic tissue is much reduced.

Abstract: New antibiotically active compounds having the basic structure of rifamycin S, namely 3-hydroxyrifamycin S (formula A: X=>C.dbd.O; R.sup.1 =OH; R.sup.2 =H), 3,31-dihydroxy-rifamycin S (formula A: X=>C.dbd.O; R.sup.1 =R.sup.2 =OH) and 1-desoxy-1-oxarifamycin S (formula A: X=--O--; R.sup.1 =R.sup.2 =H) ##STR1## are formed by cultivating, under aerobic conditions, a strain of Nocardia mediterranei which is derived from Streptomyces mediterranei ATCC 13 685 as the parent strain and is characterized by the ability to produce at least one of the mentioned compounds. The recombinant strain Nocardia mediterranei DSM 1415 has proved suitable. The mentioned rifamycin S analogues have analogous antibiotic properties to this but have a wider range of action, especially against gram-negative bacteria.

Abstract: New antibiotically active compounds having the basic structure of rifamycin S, namely 3-hydroxyrifamycin S (formula A: X=<C.dbd.O; R.sup.1 =OH; R.sup.2 =H), 3,31-dihydroxyrifamycin S (formula A: X=<C.dbd.O; R.sup.1 =R.sup.2 =OH) and 1-desoxy-1-oxarifamycin S (formula A: X=--O--; R.sup.1 =R.sup.2 =H) ##STR1## are formed by cultivating, under aerobic conditions, a strain of Nocardia mediterranei which is derived from Streptomyces mediterranei ATCC 13 685 as the parent strain and is characterized by the ability to produce at least one of the mentioned compounds. The recombinant strain Nocardia mediterranei DSM 1415 has proved suitable. The mentioned rifamycin S analogues have analogous antibiotic properties to this but have a wider range of action, especially against gram-negative bacteria.

Abstract: New antibiotically active compounds having the basic structure of rifamycin S, namely 3-hydroxyrifamycin S (formula A: X.dbd.>C.dbd.O; R.sup.1 .dbd.OH; R.sup.2 .dbd.H), 3,31-dihydroxyrifamycin S (formula A: X.dbd.>C.dbd.O; R.sup.1 .dbd.R.sup.2 .dbd.OH) and 1-desoxy-1-oxarifamycin S (formula A: X.dbd.--O--; R.sup.1 .dbd.R.sup.2 .dbd.H) ##STR1## are formed by cultivating, under aerobic conditions, a strain of Nocardia mediterranei which is derived from Streptomyces mediterranei ATCC 13 685 as the parent strain and is characterized by the ability to produce at least one of the mentioned compounds. The recombinant strain Nocardia mediterranei DSM 1415 has proved suitable. The mentioned rifamycin S analogues have analogous antibiotic properties to this but have a wider range of action, especially against gram-negative bacteria.

Abstract: The new antibiotic "Papulacandin" is obtained by the cultivation of the microorganism Papularia sphaerosperma (Pers.) Hohnel, especially of the strain NRRL 8086, under aerobic conditions in an aqueous nutrient medium. There can also be used mutants of said microorganisms. Papulacandin consists of various components A, B, C, D and E, the more important of which are A and B, whose structures have been elucidated to a great extent: they contain only carbon, hydrogen and oxygen. Papulacandin and its components have a strong anti-fungal action, for instance against Candida albicans, and can be used for combating infections caused by pathogenic fungi.

Abstract: Feeds and feed additives for domestic animals and productive animals, which feeds and feed additives contain 1 to 500 ppm of avilamycin.

Abstract: In compounds of formula ##SPC1##Wherein R represents a lower alkyl radical and R.sub.1 the acyl radical of a carboxylic acid the acylamino group is deacylated to the amino group when the compounds are treated with microorganisms possessing acylase activity or with extracts containing acylase or with the acylases themselves in aqueous medium. The isolation of the amino compounds so formed is carried out in known manner.