| abstract |
1. A PEPSIN INHIBITOR DESIGNATED PEPSTATN, EFFECTIVE N INHIBITING PEPSIN, BUT NOT EFFECTIVE IN INHIBITING TRYPSIN, PLASMIN AND PAPAIN, EFFECTIVE IN PROTECTIONS OF STOMACH ULCER OF PYLORUS LIGATED RATS, USEFUL FOR TREATMENT OF PEPTIC ULCER, SAID PEPSTATIN BEING A SUBSTANCE WHICH IS SOLUBLE IN METHANOL, ETHANOL, ACETIC ACID, PYRIDINE AND DIMETHYLSULFOXIDE, SLIGHTLY OR INSOLUBLE IN ETHYL ACETATE, ETHER, BENZENE, CHLOROFORM AND WATER, WHICH EXHIBITS NO ABSORPTION MAXIMUM OF ULTRAVIOLET LIGHT FROM 220 MU TO 350 MU, WHICH GIVES POSITIVE REACTIONS TO RYDON-SMITH AND PERMANGANATE AND NEGATIVE REACTIONS TO NINHYDRIN, SAKAGUCHI AND EHRLICH TESTS, WHICH CONTAINS CARBOXYL GROUP AND FORMS METAL SALTS AND ESTERS; FURTHER PROPERTIES OF SAID CRYSTALLINE PEPSTATIN BEING THAT IT HAS THE FORMULA C34H63N5O9, EXHIBITS (A)D20= -90* (C=0.288 IN METHANOL), MELTS AT 228-229* C. WITH DECOMPOSITION, EXHIBITS ADSORPTION BANDS IN THE INFRAED REGION OF THE SPECTRUM WHEN PELLETED IN POTASSIUM BROMIDE AT THE FOLLOWING WAVE NUMBERS IN CM.-1: 3320, 3090, 2955, 1635, 1545, 1470, 1450, 1420, 1390, 1370, 1300, 1220, 1178, 1070, 710, YIELDS L-ALANINE AND L-VALINE IN THE RATIO OF 1:2 RESPECTIVELY TOGETHER WITH ISO-VALERIC ACID AND ANOTHER AMINO ACID WHICH IS VERY WEAK IN NINHYDRIN REACTION, AND IS SHOWN TO HAVE THE FOLLOWING STRUCTURE BY ISOLATION OF 4 HYDROLYSIS PRODUCTS SHOWN IN SAID STRUCTURE, AND MASS SPECTROMETRY OF PERMETHYLATED PEPSTATIN METHYL ESTER: (H3C)2-CH-CH2-CO-NH-CH(-CH(-CH3)2)-CO-NH-CH(-CH(-CH3)2)- CO-NH-CH(-CH2-CH(-CH3)2)-CH(-OH)-CH2-CO-NH-CH(-CH3)-CO- NH-CH(-CH2-CH(-CH3)2)-CH(-OH)-CH2-COOH |