Abstract
Bis [2- (E-2-alkenoylaminoethyl)] disulfides (I) and 2- (E-2-alkenoylamino) ethyl carbamoylmethyl sulfides (II) with various alkenyl chain lengths were synthesized and their inhibitory effects on gastric secretion in rats were compared. There was a relationship between the alkenyl chain length of a series of sulfide derivatives (II) and their biological activities (C10 and C11 alkenyl derivatives were the most effective compounds). On the other hand, variation of the alkenyl chain length did not affect the anti-ulcerogenic activity of the disulfide derivatives (I). The derivatives (II) showed stronger biological activity than (I) when the same alkenyl group was present in both.
The administration of 2- (E-2-decenoylamino) ethyl carbamoylmethyl sulfide (II-5) or 2- (E-2-undecenoylamino) ethyl carbamoylmethyl sulfide (II-6) at a dose of 20 mg/kg (i.p.) caused significant inhibition of various experimental ulcerations caused by stress, aspirin and HCl-ethanol. Oral administration of both acetamides (II-5, II-6) also caused 50-60% inhibition of ulceration in the water-immersion stress model at a dose of 20 mg/kg, although the activity was not as strong as that after i.p. injection. An improvement in anti-ulcerogenic activity was observed when acetamides were administered as a suspension in 10% HCO-60. Both acetamides (II-5, II-6) caused a dose-dependent decrease of the ulcer index of restrained and water-immersion stress-loaded rats in the dosage range from 0.5 mg/kg p.o. to 5 mg/kg p.o. The lethal dose 50% values (LD50) for both acetamides were over 8 g/kg (p.o. or i.p.).
