Studies on lens-aldose-reductase inhibitor in medicinal plants. II. Active constituents of Monochasma savatierii Franch. et Maxim

The 70% acetone extract of Monochasma savatierii FRANCH. et MAXIM. showed very strong inhibition of rabbit lens aldose reductase (AR). From the active fraction, five iridoid glucosides along with the two phenolic glycosides, acteoside and dehydroacteoside, have been isolated. Among them, acteoside showed the highest activity, being about 2.5 times more potent than baicalein, a known natural inhibitor of AR (IC50 = 9.8 x 10(-7) M). Demethylmussaenoside and 7-O-acetyl-8-epi-loganic acid, which are iridoid glucosides, had weak inhibitory activity.     

Some cytotoxicological aspects of ethyl and fluoroethyl alkanesulfonates in Escherichia coli: role of fluorine substitution

Several fluoroethyl derivatives of alkanesulfonates and N-nitrosourea were tested for cytotoxicity and mutagenicity in E. coli K12 AB1157. Cytotoxicity was potentiated by fluorine substitution in the alkyl moiety of the ethylating agents. Mutagenicity was strongly suppressed by fluorine substitution in the alkanesulfonates, but not in the N-nitrosourea. The capacity to induce the SOS repair network was suppressed, as was mutagenicity, in alkanesulfonates, but not in N-nitrosourea. The potentiating effect of fluorine on the cytotoxicity of alkanesulfonates seems to be due to an as yet unknown killing mechanism. An appreciable suppressive effect on the mutagenicity and the SOS induction is worth notice for the biological role of fluorine substitution in alkylating agents.     

Studies on furan derivatives. II. Preparation of α-substituted β-2-(5-nitrofuryl)vinylamines

α-Subslituted β-2-(5-nitrofuryl)viriylamines were synthesized from α-ary]-β-2-(5-nitrofuryl)-aeryloyl azides and N-[α-substituled β-2-(5-nitrofuryl)vinyl] pyridinium bromides.     

Further studies on the pharmacological effect of the anti-inflammatory compound, bis[2-(E-2-octenoylamino)ethyl] disulfide

Further studies on the pharmacological effect of orally administered bis[2-(E-2-octenoyl-amino)ethyl] disulfide (compd. I-3) was examined by using several experimental models in vivo. Compound I-3 showed analgesic activity, inhibiting both acetic acid- and acetylcholine-induced writhings in mice. This compound also showed antipyretic activity against yeast-induced fever in rats, and significantly inhibited arachidonic acid-induced mortality in mice. However, it had no effect on serotonin-induced paw edema formation or platelet activating factor-acether-induced mortality in mice. The effects of compd. I-3 are suggested to be due to inhibition of prostaglandin biosynthesis.     

Synthesis of 4H-furo[3,2-b]indoles. II. Bromination,acylation and nitration of 4H- and 4-benzoylfuro[3,2-b]indoles

Monobromination and monoacylation at the 2-position of 4H-furo[3,2-b]indole ring (III) were facilitated by the benzoyl group in the 4-position; subsequent nitration attempts were unsuccessful.     

Synthesis of Furo[2,3-c]isoquinoline Derivatives

2-Methylfuro [2,3-c] isoquinolin-5(4H)one (X) and 1-phenylfuro[2,3-c] isoquinolin-5(4H)one (XI) were prepared from thermal cyelization via the Curtius rearrangement of 5-methyl-3-phenyl-2-furoyl azide (VI) and 3,4-diphenyl-2-furoyl azide (VII), respectively. Stability against acid, alkylation and conversion of the NHCO group to a C=N double bond of X and XI, which were synthesized, are described. Also, 5-substituted furo[2,3-c] isoquinolines (XVIIIa-c) and (XIXa-c) were prepared.     

Ion flotation—spectrophotometric determination of traces of chromium(VI)

Ion flotation is used to concentrate chromium(VI) in the range 3–70μg l^-1 from 14 samples. The chromium(III)—diphenylcarbazone complex formed by reaction with diphenylcarbazide is floated efficiently with sodium lauryl sulfate, and the subsided foam is measured spectrophotometrically after simple dilution. Continuous flotation methods at solution flow rates of 2, 3 and 4 l h^-1 are discussed.     

Screening of chemiluminescent systems for the determination of some biologically important organic compounds

Screening tests are described for the development of chemiluminescence systems (oxidizing systems) capable of detecting biological organic compounds. The light emission depends strongly on the oxidizing systems employed. Acidic permanganate system gives rise to light emission for many compounds, including catechols, catecholamines, triphenols and indoles. The following oxidizing systems led specifically to chemiluminescence for hydroquinone, adrenaline or phenylpyruvic acid: 10^?1 M thiosulphate with 10^?1 M sodium hydroxide and 10^?4 M Ag (I), 0.3 % hydrogen peroxide with 10^?3 M sodium hydroxide/50% acetonitrile and 10^?4 M Fe (II), and 0.3% hydrogen peroxide with 10^?2 M sodium hydroxide/10^?2 M didodecyldimethylammonium bromide and 10^?4 M Co(II), respectively.     

Isolation of inhibitors of adenylate cyclase from dan-shen, the root of Salvia miltiorrhiza

The effect of dan-shen extract, the root of Salvia miltiorrhiza, on adenylate cyclase was investigated in both rat brain and rat erythrocytes. The EtOAc fraction of the MeOH extract was proved to have significant inhibitory activity. Potent inhibitory principles in the EtOAc fraction were isolated and identified as 4 polyphenolic acids, rosemarinic acid, lithospermic acid, and their methyl ester derivatives.