Chemistry and antioxidant activity of essential oil and oleoresins of black caraway (Carum bulbocastanum) fruits: Part 69.

BACKGROUND: The present study describes the chemical analysis of the essential oil and oleoresins from caraway, which have been studied by using GC-MS. The paper also explains the importance of the extracted oil and oleoresins in the antioxidant activities of target plant species. RESULTS: GC-MS analysis of caraway essential oil showed 51 compounds representing about 96.6% of the total weight. The major components were dillapiole (44.6%), germacrene-beta (14.1%), nothoapiole (8.3%), and beta-selinene (6.8%), along with many other components in minor amounts. Major components in ethyl acetate and iso-octane oleoresins are dillapiole, nothoapiole and germacrene-beta, whereas in ethanol oleoresin contains dillapiole (25%), sitosterol (21.3%) stigmasterol (9.5%) and nothoapiole (8.1%). The antioxidant activity was evaluated by various antioxidant assays such as peroxide, thiobarbituric acid and p-anisidine values. These experiments were further supported by other complementary antioxidant assays such as ferric thiocyanate method in linoleic acid system, reducing power, and scavenging effects on 1,1'-diphenyl-2-picrylhydrazyl (DPPH). Both the caraway volatile oil and its oleoresins showed strong antioxidant activity in comparison with butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). CONCLUSION: This study provides additional information about the chemistry and antioxidant activity of caraway. Hence, caraway may be used as natural food preservatives.

Preparation, characterization and thermolysis of nitrate and perchlorate salts of 2,4,6-trimethylaniline.

Nitrate and perchlorate salts of 2,4,6-trimethylaniline have been prepared and characterized by X-ray crystallography and gravimetric analyses. Their thermal decomposition has been studied by TG, TG-DSC and ignition/explosion delays. It has been observed that proton transfer from substituted anilinium ion to nitrate and perchlorate ion regenerate amine, HNO(3) and HClO(4) in condensed phase at higher temperature, where oxidation-reduction between amine and acids leads to ignition and explosion. The kinetics of thermal decomposition was evaluated by applying model fitting as well as isoconversional methods. The values of calculated activation energy of nitrate and perchlorate salts are 77.9 and 118.2 kJ mol(-1) respectively. The possible pathways of thermolysis of these salts have also been proposed.

Preparation, crystal structure, and thermolysis of phenylenediammonium diperchlorate salts.

Three salts of phenylenediammonium diperchlorate have been prepared and characterized by X-ray crystallography. Their thermal decomposition has been studied by thermogravimetry (TG), differential thermal analysis (DTA), and explosion delay (DE) measurements. The kinetics of thermal decomposition was evaluated by model fitting and isoconversional methods using TG data. The oxidation-reduction reactions near the surface of thermolysing perchlorates may be responsible for the decomposition followed by explosion. The possible pathways of thermolysis have also been proposed.

Preparation, characterization and thermolysis of phenylenediammonium dinitrate salts.

Four phenylenediammonium dinitrate salts were prepared and characterized by elemental, Infrared spectroscopy (IR), Ultraviolet spectroscopy (UV) and gravimetric methods. These dinitrates find application in propellant, explosives and pyrotechnics. Their thermal decomposition has been studied using thermogravimetry (TG) and simultaneous thermogravimetry-differential scanning calorimetry (TG-DSC). Kinetics parameters were evaluated by model fitting and isoconversional methods. Their thermolytic pathways have also been suggested, which involves decomposition followed by ignition.