Abstract: The present invention relates to a process for producing amino/guanidinothiosulfonic acid, which comprises treating a styrenedivinylbenzene copolymer sulfonate of amino/guanidinoethyl disulfoxide into contact with an alkali, selectively eluting amino/guanidinosulfinic acid, then reacting this product in a non-aqueous solvent in the presence of a base, and passing the reaction product through a weakly acidic cation exchange resin column; in accordance with the present invention, hypotaurine, thiotaurine and the like having a high purity can industrially be produced.

Abstract: The present invention relates to a process for producing amino/guanidinothiosulfonic acid, which comprises treating a styrenedivinylbenzene copolymer sulfonate of amino/guanidinoethyl disulfoxide into contact with an alkali, selectively eluting amino/guanidinosulfinic acid, then reacting this product in a non-aqueous solvent in the presence of a base, and passing the reaction product through a weakly acidic cation exchange resin column; in accordance with the present invention, hypotaurine, thiotaurine and the like having a high purity can industrially be produced.

Abstract: Taurine analogues are used for scavenging active oxygen compounds and preventing and minimizing damage to the skin from ultraviolet rays. The taurine analogues have the following formula: ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 are as defined in the specification.

Abstract: A lipid metabolism improving drug or pharmaceutical composition contains pantetheine-S-sulfonic acid as an active ingredient. When an effective dose of pantetheine-S-sulfonic acid or a pharmaceutically active, non-toxic salt thereof is administered to an animal, such as a human, in pure form or composition form, the lipid concentration in the plasma is lowered, lipid peroxide concentration in the serum and liver is lowered, B-lipo protein-cholesterol concentration in serum is decreased and HDL-cholesterol concentration is increased.

Abstract: Cimetidine, namely N-cyano-N'-methyl-N"-[2-((4-methyl-5-imidazolyl) methylthio) ethyl] guanidine which is useful as an antagonist of H.sub.2 -receptor is prepared by reacting 4-methyl-5-[(2-aminoethyl) thiomethyl] imidazole, which is obtained by the reaction of 4-methyl-5-hydroxymethylimidazole on 2-aminoethanethiolsulfuric acid, with O-alkyl-S-alkyl-cyanothioimidocarbonate to give N-cyano-N'-[2-((4-methyl-5-imidazolyl) methylthio) ethyl]-O-alkylisourea, which is reacted with monomethylamine. According to the present process, cimetidine can be prepared in good yield and desired purity with very reduced amount of methyl mercaptan released from the reaction.