ABSTRACT
The separately distilled flowers (F) and leaves' (L) essential oils of Inula britannica L. were investigated using capillary gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS). A total of 83 constituents, representing 96.91% (F) and 96.73% (L) of the total oils, were registered. The oils were rich in terpenoids (57.85% and 77.28%), of which sesquiterpenoids dominated. The main constituents of the essential oils were viridiflorol (7.17%-8.20%) and himachalol (3.45%-8.71%) followed by 6,10,14-trimethyl-2-pentadecanone (5.43%-2.95%), 13-tetradecanolide (3.93%-4.87%) and 3-methyl-4-propyl-2,5-furandione (4.06%-0.29%).
Subject(s)
Inula/chemistry , Oils, Volatile/analysis , Plant Oils/analysis , Benzocycloheptenes/analysis , Benzocycloheptenes/isolation & purification , Bulgaria , Flowers/chemistry , Gas Chromatography-Mass Spectrometry/methods , Oils, Volatile/chemistry , Plant Leaves/chemistry , Plant Oils/chemistry , Polycyclic Sesquiterpenes , Sesquiterpenes/analysis , Sesquiterpenes/isolation & purification , Terpenes/analysis , Terpenes/isolation & purificationABSTRACT
This paper presents a new method for spectrophotometirc detection of sulfide applying fungal peroxidase immobilized on sodium alginate. The sensing scheme was based on decrease of the absorbance of the orange compound, purpurogallin produced from pyrogallol and H2O2 as substrates, due to the inhibition of peroxidase by sulfide. Absorbance of purpurogallin was detected at 420nm by using a spectrophotometer. The proposed method could successfully detect the sulfide in the concentration range of 0.6-7.0µM with a detection limit of 0.4µM. The kinetic parameters of Michaelis-Menten with and without sulfide were also calculated. Possible inhibition mechanism of peroxidase by sulfide was deduced according to the variation of parameters and uncompetitive mechanism was observed with respect to hydrogen peroxide. The current method provides an easy to use method for sulfide detection in water samples.
Subject(s)
Benzocycloheptenes/analysis , Biosensing Techniques/methods , Peroxidases/antagonists & inhibitors , Spectrophotometry , Sulfides/analysis , Water Pollutants, Chemical/analysis , Benzocycloheptenes/chemistry , Enzyme Activation/drug effects , Enzyme Inhibitors/pharmacology , Hydrogen Peroxide/metabolism , Limit of Detection , Peroxidases/analysis , Pyrogallol/analysis , Pyrogallol/chemistry , Sulfides/pharmacology , Water/chemistryABSTRACT
A graphene oxide/hemoglobin (GO/Hb) composite hydrogel was prepared for catalyzing a peroxidatic reaction in organic solvents with high yields, exceptional activity and stability.
Subject(s)
Graphite/chemistry , Hemoglobins/metabolism , Hydrogels , Oxides/chemistry , Benzocycloheptenes/analysis , Benzocycloheptenes/metabolism , Catalysis , Enzymes, Immobilized/chemistry , Enzymes, Immobilized/metabolism , Hemoglobins/chemistry , Hydrogen Peroxide/metabolism , Microscopy, Electron, Scanning , Organic Chemicals , Oxidation-Reduction , Protein Stability , Pyrogallol/metabolism , Solvents/chemistryABSTRACT
The photostability of selected benzocycloheptane antihistaminic agents, namely, loratadine (I), pizotifen (II), ketotifen fumarate (III) and cyproheptatidine (IV), was investigated. Both I and II were photolabile while III and IV were photostable. To perform stability studies on the photolabile compounds (I and II), specific stability-indicating high performance liquid chromatographic (HPLC) methods were established. The accuracy, precision and reliability of the developed HPLC methods for the assay of I and II in their pharmaceutical dosage forms were reported. Assay results for both drugs were within R.S.D. values <2%. The stability-indicating power of the developed methods was validated through study of UV-degraded solutions of I and II contained in quartz cells. The photostability of both drugs was studied under UV-irradiation at 254 nm. The photodegradation kinetics of both drugs, studied in different solvents, are also reported. TLC fractionation of photodegraded solutions of both drugs, revealed two fluorescent photodegradates of drug I. The use of UV-absorbers (ascorbic acid and p-aminobenzoic acid (PABA)) enhanced the photostability of both drugs possibly through a spectral-overlay effect.
Subject(s)
Benzocycloheptenes/analysis , Benzocycloheptenes/chemistry , Histamine H1 Antagonists/analysis , Histamine H1 Antagonists/chemistry , Benzocycloheptenes/radiation effects , Drug Stability , Histamine H1 Antagonists/radiation effects , LightABSTRACT
OBJECTIVE: To study the chemical constituents of teapigment. METHOD: Some constituents were isolated by chromatographic methods and identified by chemical constituents and their structures were elucidated by spectral data. RESULT: From teapigment, two compounds have been isolated and identified as purpurogallin (I) and purpurogallin carboxylic acid (II). CONCLUSION: These compounds were main pigments obtained from teapigment for the first time, and likely to be active compounds of teapigment.
