Synthesis and analgesic and anti-inflammatory activities of 1,2-benzothiazine derivatives

Synthesis and pharmacological evaluation of pyrazolopyrimidopyrimidine derivatives: anti-inflammatory agents with gastroprotective effect in rats

We report the synthesis of new anti-inflammatory 1,7-dihydropyrazolo[3′,4′:4,5]pyrimido[1,6-a]pyrimidine 5 from aminocyanopyrazole. All compounds were characterized by physical, chemical and spectral studies. Preliminary pharmacological evaluation of the resulting products showed that compounds 5a, b, f (50–100 mg/kg, i.p) are active anti-inflammatory agents in carrageenan-induced rat paw oedema assay, and their effects are comparable to that of acetylsalicylic–lysine (300 mg/kg, i.p.), used as a reference drug. The nature of substituent (Y, R₃) had a pronounced effect on the anti-inflammatory activity. Studies of structure–activity relationships have led to selection of compound ethyl-3,5-dimethyl-7-imino-N¹-phenyl-1,7-dihydropyrazolo[3′,4′:4,5]pyrimido[1,6-a]pyrimidine-6-carboxylate, 5f which exhibited the most potent anti-inflammatory activity. In addition, the compounds 5a, b, f showed a significant gastroprotective effect against HCl/EtOH-induced gastric ulcer.

Synthesis and pharmacological profile of 6-methyl-3-isopropyl-2H-1,2-benzothiazin-4(3H)-one 1,1-dioxide derivatives: non-steroidal anti-inflammatory agents with reduced ulcerogenic effects in the rat

The new anti-inflammatory agents 6-methyl-3-isopropyl-2H-1,2-benzothiazin-4(3H)-one 1,1-dioxide 6a and its analogues 6b-f were synthesized from L-valine. All compounds were characterized by physical, chemical and spectral studies. Preliminary pharmacological evaluation of the resulting products showed that compounds 6a-f (5-20 mg/kg, i.p.) are active anti-inflammatory agents in carrageenan-induced rat paw oedema assay in albino rats, and their effects are comparable to that of piroxicam (5 mg/kg, i.p.), used as a reference drug. The nature of the substituents on the sulfonamide nitrogen and those on position three had a pronounced effect on the anti-inflammatory activity. Studies of structure-activity relationships have led to selection of compound 2,6-dimethyl-3-isopropyl-1,2-benzothiazin-3,4-diol 1,1-dioxide 6 f which exhibited the most potent activity (61.7% inhibition at 5 mg/kg, i.p. and ED(50)=4.5 mg/kg, i.p.). Comparison of the gastrointestinal safety of compounds 6a-f with that of piroxicam showed a far better tolerability for our products. This comparison was based on the ulcer index and the pH of gastric content.

Anti-inflammatory activity of methanol extract of Kalopanax pictus bark and its fractions

The methanol extract of Kalopanax pictus bark was evaluated on anti-inflammatory and anti-nociceptive activities in animal models. The extract produced a significant inhibition of vascular permeability at doses of 1 and 3 g/kg, p.o. in mice and of leucocyte emigration at doses of 0.15 and 0.3 g/rat, s.c., in CMC-pouch of rats. However, the extract (0.25 and 3 g/kg, p.o.) did not show anti-inflammatory activity in carrageenan induced edema of rats. The extract at a dose of 2.5 g/kg, p.o. inhibited writhing syndromes, whereas it did not exhibit anti-nociceptive in Randall-Selitto assay. The methanol extract was then partitioned with n-hexane, chloroform, ethyl acetate and butanol to give each soluble fraction and finally water soluble fraction. Among those fractions, the inhibitory effect on vascular permeability in mice was produced by ethyl acetate soluble fraction in this activity-guided fractionation. The methanol extract showed low acute toxicity in mice. These results suggest that the methanol extract of Kalopanax pictus bark has an anti-inflammatory activity which is distributed in the ethyl acetate fraction.