Abstract: Mycaminosyl tylonolide derivatives represented by the following general formula ##STR1## (wherein R.sup.1 denotes hydroxyl group, a lower alkanoyloxy group, benzoyloxy group, azido group, or amino group which mat optionally be substituted with a lower alkyl or a lower alkanoyl radical; R.sup.2 stands for hydrogen atom or hydroxyl group; R.sup.3 expresses hydrogen atom or formyl group; and means a double bond or a radical represented by ), and salts thereof.

Abstract: A rapid, accurate and simple method is disclosed for determining an index of freshness of fish and mollusks. The index of freshness is expressed as the ratio of the combined molar concentration of inosine and hypoxanthine to the total molar concentration of the decomposition products of adenosine triphosphate. Each concentration is determined electrochemically from the amount of hydrogen peroxide produced when a sample extract from fish or mollusks is subjected to the action of certain enzymes. The emzymes used for inosine and hypoxanthine concentration are nucleoside phosphorylase and xanthine oxidase and for the concentration of the decomposition products of adenosine triphosphate are alkaline phosphatase, adenylic acid kinase, AMP deaminase and adenosine deaminase in a crude extract obtained from calf intestine, nucleoside phosphorylase and xanthine oxidase. Sodium azide may be added to the sample extract to inhibit errors in measurement caused by the presence of catalase.

Abstract: Novel 3,5-di-tert-butyl-4-hydroxyphenyl-substituted heterocyclic compounds shown by the formula ##STR1## wherein .circle.Het -- represents a specific heterocyclic group and the salts thereof.The compounds have an anti-inflammatory, an anti-pyretic, an analgesic, an anti-arthritic, and an immunoregulatory activity. Hence, they are particularly useful as an antirheumatics.

Abstract: Novel 23-C-substituted mycaminosyl tylonolide of the general formula (I) ##STR1## wherein R.sup.1 represents a lower alkyl group, an aryl group, a lower alkenyl group or a lower alkynyl group, R.sup.2 represents a hydrogen atom or a hydroxyl group.These compounds have excellent antibacterial activities.

Abstract: Tylosin compounds of the formula ##STR1## wherein R.sub.1 represents a hydroxyl group; a halogen atom; ##STR2## group (wherein R.sub.5 is a hydrogen atom or a lower alkyl group which may be substituted by a hydroxyl group and R.sub.6 is a hydrogen atom, a lower alkyl group which may be substituted by a hydroxyl group, an aryl group, an aralkyl group, a cycloalkyl group having 3-10 carbon atoms, --CO(O).sub.m --R.sub.7 group (wherein m is 0 or 1 and R.sub.7 is a lower alkyl group, an aryl group, an aralkyl group, a furanyl group, or a pyridyl group), or --CH.sub.2 --R.sub.13 group (wherein R.sub.13 is a mono-, di-, or trifluoromethyl group)); --N(CH.sub.2).sub.n group (wherein n is an integer of 2-15) which may be substituted by an oxo group, a hydroxyl group, a lower alkyl group, or a hydroxy lower alkyl group; an imidazolyl group, a morpholino group, or a piperazino group each may be substituted by a lower alkyl group; or --OOCCH.sub.2 --R.sub.8 group (wherein R.sub.8 is ##STR3## group (wherein R.sub.

Abstract: New semi-synthetic antibiotics, 3"-epistreptomycin and 3"-epidihydrostreptomycin are now provided, which are useful as antibacterial agents. 3"-Epidihydrostreptomycin is produced by a process comprising hydrolyzing an appropriately N,O-protected 2",3"-N,O-carbonyl-3"-epidihydrostreptomycin which is prepared by skilled introduction of amino-protecting groups and hydroxyl-protecting groups of appropriately selected natures into dihydrostreptomycin and intermolecular condensation of a particular pair of amino-protecting and hydroxyl-protecting groups so introduced. 3"-Epistreptomycin is produced by a process comprising oxidizing the 3'-hydroxymethyl group of an appropriately N,O-protected 3"-epidihydrostreptomycin as prepared by skilled introduction of amino-protecting groups and hydroxyl-protecting groups of appropriately selected natures, and then removing the remaining protective groups from the resultant N,O-protected 3"-epistreptomycin obtained as the oxidation product.