Sun J.X.,Key Laboratory of Ethnic Medicine Resource Chemistry |
Yang H.Y.,Key Laboratory of Ethnic Medicine Resource Chemistry |
Zhou P.,Yunnan University of Traditional Chinese Medicine |
Zhang G.Q.,Key Laboratory of Ethnic Medicine Resource Chemistry |
And 2 more authors.
Advanced Materials Research | Year: 2013
The antioxidant activity of Polyrhachis vicina wine extract was investigated: The IC50 of scavenging effect on superoxide radical generated by Pyrogallol autoxidation was 0.37 mg/mL; the maximum scavenging rate was 81.4%. The IC50 of scavenging effect on hydroxyl free radical generated by Fenton reaction was 0.66 mg/mL; the maximum scavenging rate was 91.8%. The IC50 of DPPH scavenging effect was 0.48 mg/mL; the maximum scavenging rate was 91.4%. The results indicated that Polyrhachis vicina wine extract showed activity both in scavenging free radicals and antioxidation. © (2013) Trans Tech Publications, Switzerland. Source
Gao X.,Key Laboratory of Ethnic Medicine Resource Chemistry |
Li X.,Key Laboratory of Ethnic Medicine Resource Chemistry |
Li X.,Yunnan Academy of Tobacco Science |
Yang X.,Key Laboratory of Ethnic Medicine Resource Chemistry |
And 4 more authors.
Heterocycles | Year: 2012
Two new lignan derivatives, nicotnorlignan A and nicotlactone A (1, 2), together with two known lignan derivatives (3, 4) were isolated from the leaves of Nicotiana tabacum. Their structures were elucidated by spectroscopic methods, including extensive 1D- and 2D-NMR techniques. Compounds 1-4 were tested for their anti-HIV-1 activity and anti-tobacco mosaic virus activities. The results showed compound 2 has high anti-tobacco mosaic virus activities, and all other compounds have modest anti-HIV-1 activity and anti-tobacco mosaic virus activities. © 2012 The Japan Institute of Heterocyclic Chemistry. Source
Gao Y.-T.,Yunnan Nationalities University |
Gao Y.-T.,Key Laboratory of Ethnic Medicine Resource Chemistry |
Zhou X.-J.,Yunnan Nationalities University |
Zhou X.-J.,Key Laboratory of Ethnic Medicine Resource Chemistry |
And 6 more authors.
Yejin Fenxi/Metallurgical Analysis | Year: 2012
A novel inlaid carbon nanotubes-bismuth film glassy carbon electrode was prepared. The electrochemical behavior of Cd on the electrode was investigated by cyclic voltammetry. An inreversible oxidation peak of Cd on the electrode was observed, E pa=0.637 V(vs.SCE). High sensitive electrochemical response of Cd on this electrode was obtained. The influencing factors for differential potentiometric stripping analysis of Cd were tested. The optimum conditions were -1.1 V of deposition potential, 0.4 mg/L of Bi 3+ concentration, pH 4.6 HAc-NaAc buffer solution. The analytical reliability of this electrode was enhanced by in-situ plated bismuth film and standard addition method. The stripping peak height (dt/dE) is a linear function of Cd concentration over the range 0.1-2.0 μg/L in the optimum conditions, with the detection limit of 0.2 μg/L.The proposed method was application in the determination of Cd in practical samples, the result was in agreement with those provided by AAS, RSD and the recovery were 3.1%-7.2%, 92%-102%, respectively. Source
Gao Y.,Yunnan Nationalities University |
Gao Y.,Key Laboratory of Ethnic Medicine Resource Chemistry |
Wang Z.,Yunnan Nationalities University |
Wang Z.,Key Laboratory of Ethnic Medicine Resource Chemistry |
And 6 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2012
In order to obtain the optimal conditions of ultrasound-assisted aqueous two-phase extraction of polyphenols from mango seed kernel, a novel extraction method involving ultrasound-assisted extraction combined with propyl-alcohol ammonium sulfate aqueous two-phase separation was developed for the extraction of polyphenols from mango seed kernel. Response surface methodology, based on a five levels, four variables central composite designs was employed to study the effect of extraction conditions on the extraction yield of total polyphenols. An extraction yield of 6.67% was achieved under the optimal extraction conditions of 59.7% of propyl-alcohol volume fraction, 23.4% of ammonium sulfate investigated concentration, 27.0 min of extraction time and liquid/solid ratio of 23 mL/g at ultrasonic power of 400 W and temperature of 45°C, which was agreement well with the optimal prediction value (6.82%). Total polyphenols content in the extract of ultrasound-assisted aqueous two-phase extraction was higher than that of conventional ultrasound-assisted extraction. The research indicates that the method of combining aqueous two-phase separation with ultrasound-assisted extraction to improve the extraction of polyphenols is practicable. The research can provide a reference for full utilization of mango seed kernel and the extraction technique of polyphenols. Source