Advanced Materials Research Vols. 554-556

Abstract: AIM: To establish the CoMFA models of the ent-kauranoids and give the theoretical basis to guide the design of the new drug. METHODS and RESULTS: The advanced 3D-QSAR method CoMFA ( comparative molecular field analysis) was used to study the ent-kauranoids on cytotoxicity in vitro agsinst k562 cells and leaded to one CoMFA models of these data. The Crossvalidated coefficient q² of one model reached 0.561, the non-crossvalidated coefficient r² was up to 0.999, standard deviation was 0.029. CONCLUSION: In the series of ent-kauranoids the CoMFA models reveal the relationship between their bioactivities and structures, these results are helpful to the further design work to find new natural drugs and lead compound with higher bioactivity.

Abstract: In this paper, the status and research progress of curcumin prodrugs were reviewed, involving polyethylene glycol(PEG) loading prodrug, cholesterol loading prodrug, surfactant like amphiphilic loading prodrug, curcumin-amino acid bioconjugates, which provided basis for the further development of curcumin.

Abstract: Tetronic acid, namely 4-hydroxy-2(5H)-furanone, was prepared from ethyl acetoacetate by bromination at γ position followed by hydrolysis and cyclization in aqueous NaOH solution. Using ethyl α-alkylacetoacetate afforded by alkylation of ethyl acetoacetate as starting material, four α-alkyltetronic acids were synthesized. Optimization of the reaction conditions led to total yield of more than 64%.

Abstract: Hypocrellins, natural photosensitizers including hypocrellin A (HA) and hypocrellin B (HB), have been used as a traditional Chinese herbal medicine to cure various skin diseases. Hypocrellins have excellent antiviral activity, which can inhibit the growth of human immunodeficiency virus. They also exhibit significant light-induced antitumor property. In this article, the progress on of free radicals research and conformational research Hypocrollins is introduced.

Abstract: A rapid method based on high performance liquid chromatography-tandem mass spectrometry (HPLC/MS/MS) with accelerated solvent extraction (ASE) or solid phase extraction (SPE) was developed for quantitative determination of perfluorooctane sulfonate (PFOS) in the coatings of nonstick pot, food packaging materials, waterborne coatings containing fluoride and fire-fighting foams. The linear calibration curve was obtained in the range of 0.002 - 0.1 μg/mL with a linear correlation coefficient (R2) of 0.998 or 0.999. The recovery for PFOS was in the range of 93.4 - 103% with relative standard deviation of 0.48 - 3.59%. The detection limit for PFOS was 0.4 μg/m2 with a signal-to-noise ratio of 10 for the coatings of nonstick pot and the food packaging materials, and 0.0002% for waterborne coatings containing fluoride and fire-fighting foams, both of which meet the restriction requirement for PFOS content in these chemical materials and consumer products in the EU directives.

Abstract: A new flow injection chemiluminescence (CL) method for the determination of Enoxacin（ENX）was described. The method was based on the weak CL reaction of Ce(Ⅳ)-SO₃^2- sensitized by Pr³⁺- ENX. The relative CL intensity was linear with the concentration of ENX in the range of 3×10^-8 g•mL-1~5.0×10^-7 g•mL-1. The detection limit is 1.0×10^-8 g•mL^-1 .The r^{Superscript text}elative standard deviation (RSD) for the determination of 4.0×10^-7 g•mL-1 ENX is 3.5% (n=11). The method has been successfully applied to the analysis of ENX in tablet

Abstract: Sargassum kjellmanianumianum was collected in Yangma Island of Yantai, Long Island and Qingdao, respectively. Chemical components analysis was conducted. The results show that proteins, carbohydrates and mineral elements are the main nutrition composition of the S.kjellmanianumianum in the three areas. Among them the crude protein content is in scope for 11.70% to 15.09%. The total sugar content is not high, occupying only 16.47% to 26.42% of the dry weight. The content of the mineral element of K, Na, Ca, Mg, Fe is very high. Fatty acids of C16 and C18 are predominant fatty acids, accounting for about half of the total fatty acids. Amino acid content ranges from 13.08% to 15.19%, and the content of the aspartic acid, glutamic acid, valine and alanine is rich, and each is higher than 1%. There are a variety of essential nutrients of human body in the Sargassum kjellmanianumianum, which are valuable to be researched and exploited.

Abstract: Inder order to determine Benzopyrene (BaP) in Mainstream and Sidestream Smoke, a Solid phase extraction (SPE) cartridge was used to isolate the BaP fraction from the total particulate matter of mainstream cigarette smoke and sidestream cigarette smoke and the BaP were measured by RP-HPLC with ultraviolet detection. The result showed that the recovery rate of BaP extracted is 94.5%, compared with the relative standard of 6.95%. The yields of BaP in mainstream smoke for Virginia cigarette are higher than those for blended cigarettes. The yields of BaP in sidestream smoke are much higher than those in mainstream smoke. The proposed method involves an solid phase extract and HPLC-UV analysis procedure. With this method, the BaP yields in mainstream and sidestream cigarette smoke can be measured fast, easily and precisely using readily available apparatus and instruments.

Abstract: Chitosan is a natural basic polysaccharide, currently which have no a very effective way to determine its content. In this paper, we used mixed acid and ultrasound-assisted with chitosan which hydrolyzed into glucosamine, under alkaline condition acetyl acetone may react with paradimethylaminobenzaldehyde acid alcohol solution to form red compound, which was measured at 525nm by spectrophotometry. More appropriate technological conditions have been determined. The results showed that the optimal conditions for quantity of chitosan was 2mg, 0.168mol/L hydrochloric acid was 0.8ml, 75% sulfuric acid was 3.5ml, in boiling water bath for 30min, supersonic for 60min at 50 °C, the average recovery was 96.9±3.24%, the content of chitosan was 87.89±1.02%, the production rate of chitosan was 84.79±0.99%. The results show that the mentioned method is easy and effective for the quantitative analysis of chitosan by spectrophotometry.

Abstract: In this article, acrylic fiber which was from factory production lines was chosen as samples. The method consisted of extraction of Diethyl Formamide (DMF) via using solid-liquid extraction technique and Gas Chromatograph (GC) analysis. DMF in acrylic fiber were extracted by distilled water, separated though DB-17 capillary column and detected by Flame Ionization Detector (FID). By means of external standard method quantitative analysis was accurately investigated. Detection limit was 3 ppm and recovery rate of DMF was in the range of 94% and 98%. These results showed that this test method was of high precision and sensitivity, which achieved the enterprise production requirements.