New flavonoids and methylchromone isolated from the aerial parts of Baeckea frutescens and their inhibitory activities against cyclooxygenases-1 and -2 / 中国天然药物

In the present study, we carried out a phytochemical investigation of the ethanol extract of the aerial parts of Baeckea frutescens, which resulted in the isolation of two new flavonoid glycosides, myricetin 3-O-(5″-O-galloyl)-α-L-arabinofuranoside (1), 6-methylquercetin 7-O-β-D-glucopyranoside (2), one new methylchromone glycoside, 7-O-(4', 6'-digalloyl)-β-D-glucopyranosyl-5-hydroxy-2-methylchromone (3), together with three known compounds (4-6). The structures of these isolated compounds were established on the basis of 1D and 2D NMR techniques and chemical methods. The anti-inflammatory activities of the compounds 1-6 were evaluated for their inhibitory effects against cyclooxygenases-1 and -2 in vitro. Compounds 1-6 showed potent COX-1 and COX-2 inhibiting activities in vitro with IC values ranging from 1.95 to 5.54 μmol·L and ranging from 1.01 to 2.27 μmol·L, respectively.

New flavonoids and methylchromone isolated from the aerial parts of Baeckea frutescens and their inhibitory activities against cyclooxygenases-1 and -2 / 中国天然药物

In the present study, we carried out a phytochemical investigation of the ethanol extract of the aerial parts of Baeckea frutescens, which resulted in the isolation of two new flavonoid glycosides, myricetin 3-O-(5″-O-galloyl)-α-L-arabinofuranoside (1), 6-methylquercetin 7-O-β-D-glucopyranoside (2), one new methylchromone glycoside, 7-O-(4', 6'-digalloyl)-β-D-glucopyranosyl-5-hydroxy-2-methylchromone (3), together with three known compounds (4-6). The structures of these isolated compounds were established on the basis of 1D and 2D NMR techniques and chemical methods. The anti-inflammatory activities of the compounds 1-6 were evaluated for their inhibitory effects against cyclooxygenases-1 and -2 in vitro. Compounds 1-6 showed potent COX-1 and COX-2 inhibiting activities in vitro with IC values ranging from 1.95 to 5.54 μmol·L and ranging from 1.01 to 2.27 μmol·L, respectively.

Detecting hexamethylene diamine in workplace air by high performance liquid chromatography / 中国职业医学

OBJECTIVE: To establish a method for detecting hexamethylene diamine in workplace air by high performance liquid chromatography( HPLC).METHODS: Hexamethylene diamine in the workplace air was collected by silica gel tube,and each was added with a concentration of 0.05 mol/L sodium bicarbonate solution,each with 0.60 mL of dansyl chloride solution( a mass concentration of 240.00 mg/L),and the volume was adjusted to 5.00 mL with acetonitrile,heating for 40.00 min in bath water,acetonitrile:water( 75:25,V/V) as the mobile phase,quantitated by the standard curve method,using HPLC for determinationstandard.RESULTS: The linear range of hexamethylene diamine was 0.040 0-6.000 0 mg/L,the correlation coefficient was 0.999 3,and the detection limit was 0.003 8 mg/L,and the minimum detection concentration was 0.002 5 mg/m~3( calculated by sample volume of 3.0 L); The within-run relative standard deviation( RSD) was 2.1%-3.0%,and the between-run RSD was 2.9%-3.6%.The average desorption efficiency of the method was 91.4%-94.1%.The sampling efficiency was 98.5%-99.6%.CONCLUSION: The method is simple,rapid,sensitive,accurate and suitable for the detecting hexamethylene diamine concentration in workplace air.

Determination of Cobalt by Spectrophotometry Using a New Reagent, 1-(6-bromo-2-benzothiazolyl)-3-(5-bromo-8-quinolyl)-triazene / 环境与健康杂志

Objective To synthesize a new reagent, 1-(6-bromo-2-benzothiazolyl)-3-(5-bromo-8-quinolyl)-triazene (BBTBQT) and apply to the determination of cobalt. Methods The reagent had been synthesized by diazotization and coupling reaction. After purification and characterization, BBTBQT was tested for its color reaction conditions with cobalt in the presence of cetylpyridinium bromide (CPB). Results In the presence of borax buffer solution at pH value of 9.0, the reagent reacted with cobalt to form a blue stable complex with a molar ratio of 2∶1; the complex had a maximum absorption at 640 nm. The apparent molar absorptivity of the complex is 1.55 ?105 L/(mol?cm). Beer’s law was obeyed in the range of 0-0.28 mg/L for cobalt. The method had been applied to determine cobalt in drainage sediment and vitamin B12 injection solution with a mean relative error of 1.9%-5.8% and a standard relative deviation of 1.7%-3.8%. Conclusion The present method is selective, sensitive, accurate, convenient and suitable for determination of trace cobalt in the samples.