High-performance size-exclusion chromatography studies on the formation and distribution of polar compounds in camellia seed oil during heating

Camellia seed oil （CSO） is rich in oleic acid and has a high number of active components, which give the oil high nutritional value and a variety of biological activity. The aim of the present study was to determine the changes in the content and distribution of total polar compounds （TPC） in CSO during heating. TPC were isolated by means of preparative flash chromatography and further analyzed by high-performance size-exclusion chromatography （HPSEC） The TPC content of CSO increased from 4.74% to 25.29%, showing a significantly lower formation rate as compared to that of extra virgin olive oil （EVOO） and soybean oil （SBO） during heating. Furthermore, heating also resulted in significant differences （P〈0.05） in the distribution of TPC among these oils. Though the content of oxidized triacyl- glycerol dimers, oxidized triacylglycerol oligomers, and oxidized triacylglycerol monomers significantly increased in all these oils, their increased percentages were much less in CSO than those in EVOO, indicating that CSO has a greater ability to resist oxidation. This work may be useful for the food oil industry and consumers in helping to choose the correct oil and to decide on the useful lifetime of the oil.

Preliminary Findings on Anticancer and Lymphocyte Stimulated Activities of Bioactive Compounds Extracted from Vietnam Carica papaya Leaves

In this study, the target bioactive compounds （e.g., alkaloids, flavonoids, saponins and other polar compounds） in Vietnamese Caricapapaya leaves were extracted. The cytotoxic activities of the papaya leaves extracts on the selected tumor cell lines, such as lung cancer cell line LU-1, carcinoma cell line KB, breast cancer cells MCF7 and leukemia cell line HL-60, were examined. Preliminary findings showed a high inhibitive activity of papaya leave extracts against the four tested tumor cell lines at the concentration of 100 μg/mL. Out of the bioactive compounds in papaya leaves extract, alkaloids showed the highest inhibitive activity （105.95% on MCF7 and 91.86% on LU-1）, followed by polar compounds （62.88% on LU-1 and 21.80% on KB）, and saponins （59.74% on MCF7 and 25.25% on LU-1）. Flavonoids has the lowest inhibitive activity on cell lines （e.g., 45.51% on MCF7 and 20.32% on LU-1）. Taken together, the results suggest that alkaloids have a relatively high inhibitive activity on the selected tumor cell lines and their stimulated concentration at 50% （IC50） values for on MCF7 and KB were 24.67 μg/mL and 33.56 μg/mL, respectively. However, the result pointed out the immunostimulatory ability of only polar compounds and saponins which could stimulate the growth of in vitro lymphocytes but not flavonoids and alkaloids. The SC50 （stimulated concentration at 50%） values of polar compounds and saponins were 287.87μg/mL and 192.99 μg/mL, respectively.

Low polar volatile constituents from Isodon excisa by GC-MS

An attempt had been made to isolate and identify the low polar volatile constituents from Isodon excisa. The dried plants were heat extracted with ethanol and then extracted with petroleum ether. The constituents were isolated and analyzed by GC-MS and then we retrieved them on NIST08 mass spectrometry database to determine their structures. Finally, successful results were achieved, 111 compounds were obtained and identified. 105 of them were reported for the first time in lsodon excisa and 22 of them were first found in natural products. Thus, the main constituents of it were found to be Sitosterol （33.28%）, 3-Amino-4-pyrazolecarbonitrile （9.55%）

Preliminary Studies on Composition, Quality and Oxidative Stability of Commercial Avocado Oil Produced in Chile

Avocado oil is a relatively new oil in the market and is highly appreciated by the consumers because of its fine aroma, pleasant taste and health benefits. A study on the characterization of commercial avocado oils produced in Chile was conducted in order to discuss their quality parameters. The study was applied to two marketed avocado oils. The main analytical parameters evaluated to the oils were： fatty acid composition, total chlorophylls, total carotenoids, tocopherols, acid value, peroxide value, total phenolic compounds, polar compounds, oil stability, UV absorption and 3.5-stigmastadiene content. The fatty acid compositions of the studied oils were according with oil composition of pulp pure of avocado fruit. The analysis of tocopherols by high performance liquid chromatography （HPLC） revealed significant differences between the avocado oils studied. Total phenolic compounds, oil stability, UV Absorption characteristics, peroxide value, acid value, tocopherols content, total chlorophylls, total carotenoids and polar compounds were also significantly different between the commercial studied oils. All the above results show a different quality between both commercial avocado oils, showing that the sample C has worse values for the parameters of quality as those required by legislation in many countries. Also, 3.5-stigmastadiene content shows high concentration for one of the commercial avocado oil evaluated which demonstrates the presence of refined oil or that the oil has been submitted to high temperatures. On the other hand it is remarkable that despite the fact that there are many differences in quality parameters, both oils are labeled and marketed as extra virgin quality oils, demonstrating the need to regulate the classification of appreciated oils by the consumers.

Rapid Analysis of Polar Components in Ophiocordyceps sinensis by Conventional Liquid Chromatography System

Objective To develop a rapid high-performance liquid chromatography coupled with diode array detection （HPLC-DAD） method for the simultaneous determination of six polar compounds in Ophiocordyceps sinensis. Methods A poroshell SB Aq column （50 mm × 4.6 mm, 2.7 μm） and gradient elution were used; The detection wavelength of compounds was set at 260 nm. The chromatographic peaks of the six investigated compounds in sample were identified by comparing their retention times with reference compounds. Results All calibration curves showed good linearity （r〉 0.999） within the tested ranges. The intra- and inter-day precisions of the six analytes were less than 0.8% and 2.1%, respectively, and the recoveries of the six analytes were between 95% and 103%. The validated method was successfully applied to the determination of six polar compounds in O. sinensis samples. Conclusion The poroshell SB Aq column is suitable for the rapid analysis of polar components in Chinese materia medica on conventional HPLC system and the developed HPLC method is also helpful to the quality control of O. sinensis.

Online Postcolumn Indirect Detection for Determination of Ibandronate in Pharmaceutical Tablets by HPLC/DAD

Ibandronate sodium monohydrate is a highly polar aliphatic compound that belongs to the bisphosphonate class,a widely used bone resorption inhibitor.The aliphatic nature of ibandronate precludes direct photometric detection and its high polar-ity urged analysts to use ion-pairing agents in the mobile phase to promote retention in reversed-phase columns.In this work,a reversed-phase method for determination of ibandronate sodium monohydrate in pharmaceutical tablets is introduced by employing an online postcolumn ligand exchange reaction to enable photometric detection.The method offers for the first time the ability to separate the drug from its well-known impurities on conventional reversed-phase columns.The detection reac-tion depends on the ability of ibandronate and its degradation products to displace salicylate in the iron(III)salicylate complex,forming various colorless iron(III)complexes and showing a negative chromatographic signal for ibandronate and its degra-dants atλ_(max)=525 nm.The chromatographic separation was achieved using a Hypersil BDS C_(8) column(5μm particle size,150 mm×4.6 mm i.d.)and a mobile phase consisting of a mixture of aqueous formate buffer pH 3(pH 3,5 mM)and methanol in a ratio of 80:20%(v/v),delivered at a flow rate of 0.8 mL/min.The postcolumn iron(III)salicylate reagent was prepared at 250μM in aqueous formate buffer,delivered using a syringe pump at a flow rate of 0.5 mL/min.The proposed method was validated as per the guidelines of the International Conference on Harmonization Q2(R1)and was found linear over the range 40-120μg/mL(r=0.9995)with a limit of detection of 3.19μg/mL.Compared to currently reported methods,the proposed method is considerably simpler,faster,cheaper,and adequately sensitive and makes use of the most popular LC detectors.