<span style="font-size:13.0pt;mso-bidi-font-size: 14.0pt;font-family:"Times New Roman","serif";mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:HI; mso-bidi-font-weight:bold" lang="EN-US">Total flavonoid content and essential oil composition of <i>Chaenomeles japonica</i> (Thunb.) Lindl. ex Spach from North of Iran

90-92<span style="font-size:9.0pt;font-family: " times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";mso-ansi-language:="" en-us;mso-fareast-language:en-us;mso-bidi-language:hi"="" lang="EN-US">Essential oil of the fruits of Chaenomeles japonica (Thunb.) Lindl. ex Spach was obtained by hydro distillation and analyzed by GC and GC-MS. Thirty five components representing 94.6 % of total were identified. The oil was rich in monoterpenes (88.3 %) and the main components were: carvacrol <span style="font-size:9.0pt; font-family:" times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";="" mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:hi"="" lang="EN-US">(62.6 %), limonene (8.0 %), p-cymene (4.9 %) and γ-terpinene (3.2 %). Quantitative assessment of flavonoids was conducted by aluminum chloride colorimetric method in terms of quercetin equivalent in various extracts of C. japonica fruits. After one week duration of extraction, the highest amount of flavonoid content (1.316<span style="font-size:9.0pt; font-family:" times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";="" mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:hi"="" lang="EN-US"> mg/g) was observed in chloroform extract.</span

Total flavonoid content and essential oil composition of Chaenomeles japonica (Thunb.) Lindl. ex Spach from North of Iran

Essential oil of the fruits of Chaenomeles japonica (Thunb.) Lindl. ex Spach was obtained by hydro distillation and analyzed by GC and GC-MS. Thirty five components representing 94.6 % of total were identified. The oil was rich in monoterpenes (88.3 %) and the main components were: carvacrol (62.6 %), limonene (8.0 %), p-cymene (4.9 %) and γ-terpinene (3.2 %). Quantitative assessment of flavonoids was conducted by aluminum chloride colorimetric method in terms of quercetin equivalent in various extracts of C. japonica fruits. After one week duration of extraction, the highest amount of flavonoid content (1.316 mg/g) was observed in chloroform extract

Kinetic Study of the Oxidation of Catechols in the Presence of N-Methylaniline

The reactions of electrochemically generated o-quinones from oxidation of catechol and 4-methylcatechol as Michael acceptors with N-methylaniline as nucleophile have been studied using cyclic voltammetry. Voltammetric responses show that oxidation of catechols is followed by Michael addition of N-methylaniline. The reaction products are believed to be diphenylamine derivatives of catechols that undergo electron transfer at more negative potentials than the catechols. The observed homogeneous rate constants for Michael addition were estimated by digital simulation and show that the reactivity of 4-methyluinone is considerably less than o-quinone. The oxidation potentials of the desired products drastically depend on the solution pH and their structures

Electrochemical Study of Esculetin Nitration by Digital Simulation of Cyclic Voltammograms

The reaction of electrochemically generated o-quinones from oxidation of esculetin as Michael acceptor with nitrite ion as nucleophile has been studied using cyclic voltammetry. The reaction mechanism is believed to be EC, including oxidation of catechol moiety of esculetin followed by Michael addition of nitrite ion. The observed homogeneous rate constants (obs) for reactions were estimated by comparing the experimental voltammetric responses with the digitally simulated results based on the proposed mechanism. Also the effects of pH and nucleophile concentration on voltammetric behavior and the rate constants of chemical reactions were described