Objective:To determine the chemical composition of essential oils and lipid constituents of Ballola andreuzziana(B.andreuzziana),Teucrium zanonii(T.zanonii) and Verbena tenuisecta(V. tenuisecta) growing in Libya,and t...Objective:To determine the chemical composition of essential oils and lipid constituents of Ballola andreuzziana(B.andreuzziana),Teucrium zanonii(T.zanonii) and Verbena tenuisecta(V. tenuisecta) growing in Libya,and to test the antibacterial activity of different extracts of Teucrium zanonii.Methods:The volatile oils of all plants were extracted by hydrodistillation method and analyzed by GC/MS method.The lipid constituents of plants were obtained by extraction with petroleum ether and fractionated into fatty alcohols,fatty acids and unsapoinfiable matters. Antibacterial activity of T.zanonii extracts and antioxidant activity of different extracts of T. zanonii were also studied.Results:The volate oil of B.andreuzziana was found to consists of 20 compounds in which caryophyllin is the main one(63.1%),the volatile oil of T.zanonii consists of 74 compounds in which germacrene-D was the main compound,while the volatile oil of V. tenuisecta consists of 13 compounds with l-octen-3- ol as a major constituent(52.87%).The study of antimicrobial activity of different extracts of V.tenuisecta showed that,both methanol and butanol extracts exhibited the highest activity against Mycobacterium phlei(M.pblei) and Candida albicans(C.albicans) respectively,while petroleum ether,fatty alcohols and unsaponifiable fractions had no antimicrobial activity against all the tested microorganisms. Investigation of the antioxidant activity of different extracts of T.zanonii using DPPH method proved that,the ethyl acetate and butanol fractions showed the highest activity where the inhibition percentage(1%) are 93.6 and 92.1 respectively.Conclusions:This is the first report about the volatile oils of these plants where T.zanonii have the highest content and the highest number of the identified compounds.The study of antioxidant T.zanonii extracts proved that,the ethyl acetate,butanol and aqueous extracts have the highest antioxidant activity.Methanol and butanol extracts of V.tenuisecta exhibited the highest activity against M.phlei and C.albicans respectively.展开更多
The kinetics of the periodate oxidation of chromium(III)-complex, [CrIII(NTA)(Ala)(H2O)]-(NTA = Nitrilotriacetate and Ala = ß-alanine) to Cr(VI) have been carried out for the temperature range 15°C - 35&...The kinetics of the periodate oxidation of chromium(III)-complex, [CrIII(NTA)(Ala)(H2O)]-(NTA = Nitrilotriacetate and Ala = ß-alanine) to Cr(VI) have been carried out for the temperature range 15°C - 35°C under pseudo-first order conditions, >>?[complex]. Reaction obeyed first order dependence with respect to and [Cr(III)], and the rate of reaction increases with increasing of pH for the range 3.40 - 4.45. Experimentally, the mechanism of this reaction is found to be consistent with the rate law in which the hydroxo species, [CrIII(NTA)(Ala)(OH)]2- is considerably much more reactive than their conjugate acid. ΔH* and ΔS* have been calculated. It is proposed that electron transfer occurs through an inner-sphere mechanism via coordination of to chromium(III).展开更多
文摘Objective:To determine the chemical composition of essential oils and lipid constituents of Ballola andreuzziana(B.andreuzziana),Teucrium zanonii(T.zanonii) and Verbena tenuisecta(V. tenuisecta) growing in Libya,and to test the antibacterial activity of different extracts of Teucrium zanonii.Methods:The volatile oils of all plants were extracted by hydrodistillation method and analyzed by GC/MS method.The lipid constituents of plants were obtained by extraction with petroleum ether and fractionated into fatty alcohols,fatty acids and unsapoinfiable matters. Antibacterial activity of T.zanonii extracts and antioxidant activity of different extracts of T. zanonii were also studied.Results:The volate oil of B.andreuzziana was found to consists of 20 compounds in which caryophyllin is the main one(63.1%),the volatile oil of T.zanonii consists of 74 compounds in which germacrene-D was the main compound,while the volatile oil of V. tenuisecta consists of 13 compounds with l-octen-3- ol as a major constituent(52.87%).The study of antimicrobial activity of different extracts of V.tenuisecta showed that,both methanol and butanol extracts exhibited the highest activity against Mycobacterium phlei(M.pblei) and Candida albicans(C.albicans) respectively,while petroleum ether,fatty alcohols and unsaponifiable fractions had no antimicrobial activity against all the tested microorganisms. Investigation of the antioxidant activity of different extracts of T.zanonii using DPPH method proved that,the ethyl acetate and butanol fractions showed the highest activity where the inhibition percentage(1%) are 93.6 and 92.1 respectively.Conclusions:This is the first report about the volatile oils of these plants where T.zanonii have the highest content and the highest number of the identified compounds.The study of antioxidant T.zanonii extracts proved that,the ethyl acetate,butanol and aqueous extracts have the highest antioxidant activity.Methanol and butanol extracts of V.tenuisecta exhibited the highest activity against M.phlei and C.albicans respectively.
文摘The kinetics of the periodate oxidation of chromium(III)-complex, [CrIII(NTA)(Ala)(H2O)]-(NTA = Nitrilotriacetate and Ala = ß-alanine) to Cr(VI) have been carried out for the temperature range 15°C - 35°C under pseudo-first order conditions, >>?[complex]. Reaction obeyed first order dependence with respect to and [Cr(III)], and the rate of reaction increases with increasing of pH for the range 3.40 - 4.45. Experimentally, the mechanism of this reaction is found to be consistent with the rate law in which the hydroxo species, [CrIII(NTA)(Ala)(OH)]2- is considerably much more reactive than their conjugate acid. ΔH* and ΔS* have been calculated. It is proposed that electron transfer occurs through an inner-sphere mechanism via coordination of to chromium(III).