Chemometrics-enhanced high performance liquid chromatography-diode array detection strategy for simultaneous determination of eight co-eluted compounds in ten kinds of Chinese teas using second-order calibration method based on alternating trilinear decomposition algorithm.

In this work, an attractive chemometrics-enhanced high performance liquid chromatography-diode array detection (HPLC-DAD) strategy was proposed for simultaneous and fast determination of eight co-eluted compounds including gallic acid, caffeine and six catechins in ten kinds of Chinese teas by using second-order calibration method based on alternating trilinear decomposition (ATLD) algorithm. This new strategy proved to be a useful tool for handling the co-eluted peaks, uncalibrated interferences and baseline drifts existing in the process of chromatographic separation, which benefited from the "second-order advantages", making the determination of gallic acid, caffeine and six catechins in tea infusions within 8 min under a simple mobile phase condition. The average recoveries of the analytes on two selected tea samples ranged from 91.7 to 103.1% with standard deviations (SD) ranged from 1.9 to 11.9%. Figures of merit including sensitivity (SEN), selectivity (SEL), root-mean-square error of prediction (RMSEP) and limit of detection (LOD) have been calculated to validate the accuracy of the proposed method. To further confirm the reliability of the method, a multiple reaction monitoring (MRM) method based on LC-MS/MS was employed for comparison and the obtained results of both methods were consistent with each other. Furthermore, as a universal strategy, this new proposed analytical method was applied for the determination of gallic acid, caffeine and catechins in several other kinds of Chinese teas, including different levels and varieties. Finally, based on the quantitative results, principal component analysis (PCA) was used to conduct a cluster analysis for these Chinese teas. The green tea, Oolong tea and Pu-erh raw tea samples were classified successfully. All results demonstrated that the proposed method is accurate, sensitive, fast, universal and ideal for the rapid, routine analysis and discrimination of gallic acid, caffeine and catechins in Chinese tea samples.

[Prevention of Inonotus obliquus polysaccharides for high power microwave radiation induced testicular injury in rats: an experimental research].

OBJECTIVE: To investigate the effect of Inonotus obliquus polysaccharides on testicular injury induced by exposure to high power microwave (HPM) in rats. METHODS: A total of 30 male Wistar rats were randomly divided into 5 groups, i.e., the normal control group, the microwave radiation model group, the treatment group, the new microwave radiation model group, and the prevention group, 6 in each group. All rats, except those in the normal control group, were exposed to microwave at an average power density of 200 mW/cm2 for 6 min. Rats in the control group and the model group were administered with normal saline by gastrogavage, once a day. Rats in the treatment group and the prevention group were given with Inonotus obliquus polysaccharides by gastrogavage, 2 mL each time (400 mg/kg body weight), once a day. All rats were sacrificed on the 11th day.The sperm density and the rate of sperm deformity were determined. Pathological changes of testis were observed by light microscope and transmission electron microscope. RESULTS: Short-term HPM irradiation could significantly reduce the sperm density and increase the sperm deformity rate (P < 0.05). Meanwhile, obvious pathological changes of testes occurred. Compared with the two model groups, the sperm density increased and the sperm deformity rate decreased in the treatment group and the prevention group (P < 0.05). Under the light microscope, injuries of spermatogenic cells and stromal cells, as well as vascular dilatation and congestion were obviously alleviated in the treatment group and the prevention group. Mitochondrial swelling and endoplasmic reticulum expansion shown by ultrastructural observation were also significantly alleviated. Of them, injuries of spermatogenic cells and inflammation response were milder in the treatment group than in the prevention group. CONCLUSIONS: Inonotus obliquus polysaccharides had significant protective effect on microwave radiation induced testicular injury. Better effect was obtained by therapeutic medication than preventive medication.

Simultaneous determination of eight flavonoids in propolis using chemometrics-assisted high performance liquid chromatography-diode array detection.

A fast analytical strategy of second-order calibration method based on the alternating trilinear decomposition algorithm (ATLD)-assisted high performance liquid chromatography coupled with a diode array detector (HPLC-DAD) was established for the simultaneous determination of eight flavonoids (rutin, quercetin, luteolin, kaempferol, isorhamnetin, apigenin, galangin and chrysin) in propolis capsules samples. The chromatographic separation was implemented on a Wondasil™ C18 column (250mm×4.6mm, 5µm) within 13min with a binary mobile phase composed of water with 1% formic acid and methanol at a flow rate of 1.0mLmin(-1) after flavonoids were only extracted with methanol by ultrasound extraction for 15min. The baseline problem was overcome by considering background drift as additional compositions or factors as well as the target analytes, and ATLD was employed to handle the overlapping peaks from analytes of interest or from analytes and co-eluting matrix compounds. The linearity was good with the correlation coefficients no less than 0.9947; the limit of detections (LODs) within the range of 3.39-33.05ngmL(-1) were low enough; the accuracy was confirmed by the recoveries ranged from 91.9% to 110.2% and the root-mean-square-error of predictions (RMSEPs) less than 1.1µg/mL. The results indicated that the chromatographic method with the aid of ATLD is efficient, sensitive and cost-effective and can realize the resolution and accurate quantification of flavonoids even in the presence of interferences, thus providing an alternative method for accurate quantification of analytes especially when the complete separation is not easily accomplished. The method was successfully applied to propolis capsules samples and the satisfactory results were obtained.

Simultaneous determination of phenolic antioxidants in edible vegetable oils by HPLC-FLD assisted with second-order calibration based on ATLD algorithm.

A novel strategy that combines the chemometrics method with high performance liquid chromatography with fluorescence detector (HPLC-FLD) was developed for the simultaneous determination of seven phenolic antioxidants in six kinds of oil samples. After a simple dilution step, oil samples can be directly injected into the detecting system and the data were measured in a short time with a chromatographic system operating in the gradient elution mode. Since the chromatographic and spectral peaks among interesting analytes and interferences were heavily overlapped, second-order calibration method based on alternating trilinear decomposition (ATLD) algorithm which fully exploiting the second-order advantage was adopted. Successful resolution was obtained in the presence of different matrix interferences in different oil samples, and the developed approach allows the quantification of the antioxidants at levels found in edible vegetable oils, without the necessity of applying either preconcentration or extraction steps, moreover, a column washing is also not required. Meanwhile, the effectiveness and reproducibility of the proposed method were also validated by some statistical parameters like root mean squared error of prediction (RMSEP), limits of detection (LOD) and relative standard deviation (RSD). Then the proposed method was compared with several commonly selected methods in sample preparation, elution time and LOD.

Fast analysis of synthetic antioxidants in edible vegetable oil using trilinear component modeling of liquid chromatography-diode array detection data.

A new chromatographic methodology is presented for fast quantitative analysis of ten synthetic phenolic antioxidants in five kinds of oil samples: propyl gallate (PG), 2,4,5-trihydroxybutyrophenone (THBP), tert-butylhydroquinone (TBHQ), nordihydroguaiaretic acid (NDGA), ethoxyquin (EQ), 3-tert-butyl-4- hydroxyanisole (BHA), octyl gallate (OG), 2,6-di-tert-butyl-4-hydroxymethyphenol (Ionox-100), dodecyl gallate (DG), 3,5-di-tert-butyl-4-hydroxytoluene (BHT). The second-order calibration, with second-order advantage, based on the alternating penalty trilinear decomposition (APTLD) algorithm has shown to be an excellent tool for modeling the three-way data, where overlapping peaks, uncalibrated inteferences, and baseline drift existed, making the fast determination and resolution of the phenolic antioxidants in oils possible. Such extraction procedure in which the antioxidants of interest would be seperated is unnecessary and the ten antioxidants can be eluted within 6 mins. For the validation of the method, linearity, root-mean-square error of prediction (RMSEP) and limit of detection (LOD) have been performed. The average recovery of antioxidants ranges from 94.9 to 106.1% and the ten analytes can be adequately determined with limits of detection of 0.18-5.72 µgm l(-1).

Abdominal acupuncture for insomnia in women: a randomized controlled clinical trial.

A randomized single-blind trial was conducted to evaluate the efficacy of short-term abdominal acupuncture as a novel treatment for insomnia in Chinese women. Forty-four patients between the ages of 22 and 56 were randomly assigned to an acupuncture (n = 23) and a medication group (n = 21). The acupuncture group received abdominal acupuncture once a day for the first three days and once every three days for the remaining 11 days. In addition, every subject in acupuncture group also received a placebo pill once daily. Abdominal acupuncture was administered according to a standardized protocol involving four master and four adjunctive acupoints: Zhongwan (CV 12), Xiawan (CV 10), Guanyuan (CV 4), and Qihai (CV 6); bilateral Shangqu (KI 17), Huaroumen (ST 24), Xiafengshidian, and Qipang. Subjects in the medication group were treated with sham acupuncture at the same time as the acupuncture group and received estazolam once a day. The outcome measure was the Leeds Sleep Evaluation Questionnaire (LSEQ), administered before and after the trial. Subjects who received abdominal acupuncture lowered their LSEQ scores by an average of 26.32 points (95% CI: 37.34, 15.30). After controlling for potential confounding factors, the effect of abdominal acupuncture in relieving insomnia was still statistically significant. Results indicate that short-term abdominal acupuncture is more effective than pharmacological treatment for relieving insomnia in adult women and has few adverse effects.