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51.
Beh HK Seow LJ Asmawi MZ Abdul Majid AM Murugaiyah V Ismail N Ismail Z 《Natural product research》2012,26(16):1492-1497
Morinda citrifolia L. has been used for the treatment of a wide variety of diseases, including cancer. This study was undertaken to evaluate the anti-angiogenic effect of M. citrifolia fruits and leaves. Anti-angiogenic activity was evaluated in?vivo using the chick chorioallantoic membrane assay. Bioactivity-guided fractionation and isolation were performed to identify the active constituent, and high-performance liquid chromatography analysis was then used to quantify the amount of this active constituent in the active extracts and fraction. The methanol extracts of fruits and leaves of M. citrifolia and the subsequent chloroform fraction of the fruit methanolic extract were found to have potential anti-angiogenic activity and were more potent compared to suramin. Scopoletin was identified as one of the chemical constituents that may be partly responsible for the anti-angiogenic activity of M. citrifolia fruits. The present findings further support the use of M. citrifolia in cancer or other pathological conditions related to angiogenesis. 相似文献
52.
Lactic acid produced by fermentation process mostly contains a number of aliphatic carboxylic acids as impurities. In this work, carboxylic acid impurities in lactic acid samples from a number of sources were determined at ppm levels. A simple HPLC method was developed that utilized a new generation polar embedded reverse phase, 20mM phosphate buffer at pH 2.20 (±0.05) and UV detection at 210 nm. The method enabled quantitative analysis of the above acids in lactic acid matrix. The experimental conditions for column temperature, mobile phase pH and flow rate were optimized. A detailed validation of the method was performed for linearity, precision, accuracy, selectivity, limit of detection (LOD), limit of quantitation (LOQ), ruggedness and repeatability and reproducibility (R&R). 相似文献
53.
Saleh MI Kusrini E Mohd Sarjidan MA Abd Majid WH 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,78(1):52-58
A mononuclear of [Eu(NO3)(Pic)(H2O)2(EO3)](Pic)·(0.73)H2O complex, where EO3=trietraethylene glycol and Pic=picrate anion, shows a red emission when used as an active layer in a single layer of ITO/EO3-Eu-Pic/Al configuration. The crystal structure of the complex consists of [Eu(NO3)(Pic)(H2O)2(EO3)]+ cation and [Pic]- anion. The Eu(III) ion is coordinated to the 10 oxygen atoms from one EO3 ligand, one Pic anion, one nitrate anion, and two water molecules. The complex is crystallized in triclinic with space group P-1. The hybrids in thin films I and II were prepared in the respective order solution concentrations of 15 and 20 mg/mL the emissive center. Comparing the photoluminescence (PL) and electroluminescence (EL) spectra, we can find that all emissions come from the characteristic transitions of the Eu(III) ion. The EL spectra of both thin films showed the occurrence of the most intense red-light emission around at 612 nm. Comparison of organic light-emitting device (OLED) current intensity characteristics as a function of voltage (I-V) show that the thin film I is better than those found for the thin film II. The thickness of the emitting layer is an important factor to control the current-voltage curve. The sharp and intense emission of the complex at low voltage indicates that the complex is a suitable and promising candidate for red-emitting materials. 相似文献
54.
I. M. Chung Mohd Ali A. Ahmad C. Y. Yu K. H. Ma J. G. Gwag Y. J. Park 《Chemistry of Natural Compounds》2005,41(6):650-653
One new compound 3,7,11,15,19-pentamethyl-9α,10α,11α,17α,18α-pentahydroxy-n-tetracosan-1-oxy-p-hydroxycaffeoate (oryzaterpenyl
caffeoate) (1), together with three known fatty acids linoleic acid, stearic acid and myristic acid were isolated and identified from the
rice grain of Oryza sativa. The structure of the new compound was elucidated by 1D and 2D NMR spectroscopic techniques (1H-1HCOSY, 1H-13C HETCOR) aided by EI-MS, and IR spectra.
__________
Published in Khimiya Prirodnykh Soedinenii, No. 6, pp. 535–537, November–December, 2005. 相似文献
55.
Huda Abdullah Wan Nasarudin Wan Jalal Mohd Syafiq Zulfakar 《Journal of Sol-Gel Science and Technology》2014,69(2):429-440
The need for miniaturization and weight reduction of GPS patch antennas has prompted the search for new microwave dielectric materials. In this study, a sol–gel method was used to prepare Zn(1?x)MgxAl2O4 thin films and fabricate GPS patch antennas at a low annealing temperature (700 °C). X-ray diffraction (XRD) patterns, field emission scanning electron microscopy images, Fourier transform infrared spectra, and optical band gap analyses confirmed the nanostructure of (Mg/Zn)Al2O4. The XRD patterns displayed the characteristic peaks of (Mg/Zn)Al2O4 with a face-centered cubic structure. Mg addition decreased the crystallite size, surface morphology, and lattice parameters of the resultant films, evidently affecting their density and dielectric constant (? r ). Based on the material investigated and microwave antenna theory, GPS patch antennas were fabricated using Zn(1?x)MgxAl2O4 and then studied using a PNA series network analyzer. The fabricated patch antennas with different ? r ceramics decreased in size from 12.5 to 10.8 cm2. The patch antennas resonated at a frequency of 1.570 GHz and provided a return loss bandwidth between ?16.6 and ?20.0 dB; their bandwidth also improved from 90 to 255 MHz. The GPS patch antenna fabricated from Zn0.70Mg0.30Al2O4 showed an excellent combination of return loss (?20.0 dB), small size (10.8 cm2), and wide bandwidth (255 MHz). Therefore, addition of Mg improves antenna performance and decreases the dimensions of the device. 相似文献
56.
Abdul Rohman Mohd AlIkhsan B. Ghazali Anjar Windarsih Irnawati Sugeng Riyanto Farahwahida Mohd Yusof Shuhaimi Mustafa 《Molecules (Basel, Switzerland)》2020,25(22)
Currently, the authentication analysis of edible fats and oils is an emerging issue not only by producers but also by food industries, regulators, and consumers. The adulteration of high quality and expensive edible fats and oils as well as food products containing fats and oils with lower ones are typically motivated by economic reasons. Some analytical methods have been used for authentication analysis of food products, but some of them are complex in sampling preparation and involving sophisticated instruments. Therefore, simple and reliable methods are proposed and developed for these authentication purposes. This review highlighted the comprehensive reports on the application of infrared spectroscopy combined with chemometrics for authentication of fats and oils. New findings of this review included (1) FTIR spectroscopy combined with chemometrics, which has been used to authenticate fats and oils; (2) due to as fingerprint analytical tools, FTIR spectra have emerged as the most reported analytical techniques applied for authentication analysis of fats and oils; (3) the use of chemometrics as analytical data treatment is a must to extract the information from FTIR spectra to be understandable data. Next, the combination of FTIR spectroscopy with chemometrics must be proposed, developed, and standardized for authentication and assuring the quality of fats and oils. 相似文献
57.
Hammond C Lopez-Sanchez JA Ab Rahim MH Dimitratos N Jenkins RL Carley AF He Q Kiely CJ Knight DW Hutchings GJ 《Dalton transactions (Cambridge, England : 2003)》2011,40(15):3927-3937
The reaction of glycerol with urea to form glycerol carbonate is mostly reported in the patent literature and to date there have been very few fundamental studies of the reaction mechanism. Furthermore, most previous studies have involved homogeneous catalysts whereas the identification of heterogeneous catalysts for this reaction would be highly beneficial. This is a very attractive reaction that utilises two inexpensive and readily available raw materials in a chemical cycle that overall, results in the chemical fixation of CO(2). This reaction also provides a route to up-grade waste glycerol produced in large quantities during the production of biodiesel. Previous reports are largely based on the utilisation of high concentrations of metal sulfates or oxides, which suffer from low intrinsic activity and selectivity. We have identified heterogeneous catalysts based on gallium, zinc, and gold supported on a range of oxides and the zeolite ZSM-5, which facilitate this reaction. The addition of each component to ZSM-5 leads to an increase in the reaction yield towards glycerol carbonate, but supported gold catalysts display the highest activity. For gold-based catalysts, MgO is the support of choice. Catalysts have been characterised by XRD, TEM, STEM and XPS, and the reaction has been studied with time-on-line analysis of products via a combination of FT-IR spectroscopy, HPLC, (13)C NMR and GC-MS analysis to evaluate the reaction pathway. Our proposed mechanism suggests that glycerol carbonate forms via the cyclization of a 2,3-dihydroxypropyl carbamate and that a subsequent reaction of glycerol carbonate with urea yields the carbamate of glycerol carbonate. Stability and reactivity studies indicate that consecutive reactions of glycerol carbonate can limit the selectivity achieved and reaction conditions can be selected to avoid this. The effect of the catalyst in the proposed mechanism is discussed. 相似文献
58.
Andleeb Z. Naqvi Gamal A. Al-dahbali Mohd. Akram Kabir-ud-Din 《Journal of solution chemistry》2013,42(1):172-189
In the present work, the behavior of mixed drug–surfactant systems has been studied by surface tension measurements. The drug used in this work is adiphenine hydrochloride (ADP) and the surfactants are of m-s-m type geminis, i.e., alkanediyl-α,ω-bis(dimethylalkylammonium bromide), with m = (14, 16), s = (4, 5, 6), and conventional alkyltrimethylammonium bromides (CTAB, TTAB). The excess surface concentration (Γ max ) increases and the minimum head group area at the air/water interface (A min) decreases with increasing concentration of surfactant in the drug solution. Both the critical micelle concentration (cmc) and ideal cmc (cmc*) values decrease with mole fraction of surfactants. Also, the cmc values are lower than cmc*, indicating attractive interactions are present in the mixed micelles. The mole fractions of surfactant in the micelles $ \left( {X_{1}^{m} } \right) $ and monolayers $ \left( {X_{1}^{\sigma } } \right) $ , as well as the respective interaction parameters ( $ \beta^{m} $ , $ \beta^{\sigma } $ ), indicate that monolayer formation is easier than micelle formation due to the rigid hydrophobic part of the drug. 相似文献
59.
Mat Rasol Awang Hassan Hamdani Mutaat Mohd. Shukri Mahmud Wan Badrin Wan Husain Tajuddin Osman Khomsaton Abu Bakar Asmahwati Kassim Zal U''yun Wan Mahmud Ishak ManafTamikazu Kume Shoji Hashimoto 《Radiation Physics and Chemistry》1993,42(4-6):611-616
In solid state fermentation, Pleurotus sajor-caju has been found to be able to degrade at least 30% oil palm empty Fruit Bunch (EFB) fibre leaving 70 % useful materials. Conditions under which fermentation carried out were investigated. It was found that, in the temperature range between 25– 28 °C, relative ph between 6–8, moisture between 60–70 % and medium composition of CaCO3: rice bran 2 %: 5 % were the optimum conditions. The results showed in fermented products that, there were substantial reduction in cellulosic component such as Crude Fiber (CF, 18 %); Acid Detergent Fibre (ADF, 45 %), Neutral Detergent Fibre (NDF, 61 %) and Acid Detergent Lignin (ADL, 14 %). However, Crude Protein (CP, 10%) increased resulted from single cell protein enrichment of mycelial microbial mass. The mass reductions of substrate in fermentation process corresponds to the CO2 released during fermentation. Hence, attributable to the decreased in content of CF, ADF, NDF, and ADL. The digestibility study has also been carried out to determine the useful level of this product to ruminant. Aflatoxin content was detected low in both the initial substrates and products. Based on nutritional value and low content of aflatoxin, the product is useful as a source of roughage to ruminant. 相似文献
60.
The effect of cationic micelles of cetyltrimethyl ammonium bromide (CTAB) on the observed pseudo-first-order rate constant for the interaction of nickel dipeptide complex [Ni(II)-Gly-Gly]+ with ninhydrin has been studied spectrophotometrically. At constant temperature and pH, increase in the [CTAB] from 0.0 to 60.0 × 10?3 mol dm?3 caused nearly three-fold increase of the rate constant. The micellar catalysis is explained in terms of the pseudophase model. From the observed kinetic data, binding constants of micelle–[Ni(II)-Gly-Gly]+ (K S), and micelle–ninhydrin (K N) are evaluated, respectively, to be 5.3 mol?1 dm3 and 84.0 mol?1 dm3. The role of added inorganic (NaCl, NaBr, Na2SO4) and organic salts (NaBenz, NaSal) on the reaction rate has also been examined. 相似文献