Displaying publications 61 - 80 of 92 in total

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  1. Fulltext Optimizing Bi2O3 and TiO2 to achieve the maximum non-linear electrical property of ZnO low voltage varistor
    Abdollahi Y, Zakaria A, Aziz RS, Tamili SN, Matori KA, Shahrani NM, et al.
    Chem Cent J, 2013;7:137.
    PMID: 23938168 DOI: 10.1186/1752-153X-7-137
    In fabrication of ZnO-based low voltage varistor, Bi2O3 and TiO2 have been used as former and grain growth enhancer factors respectively. Therefore, the molar ratio of the factors is quit important in the fabrication. In this paper, modeling and optimization of Bi2O3 and TiO2 was carried out by response surface methodology to achieve maximized electrical properties. The fabrication was planned by central composite design using two variables and one response. To obtain actual responses, the design was performed in laboratory by the conventional methods of ceramics fabrication. The actual responses were fitted into a valid second order algebraic polynomial equation. Then the quadratic model was suggested by response surface methodology. The model was validated by analysis of variance which provided several evidences such as high F-value (153.6), very low P-value (<0.0001), adjusted R-squared (0.985) and predicted R-squared (0.947). Moreover, the lack of fit was not significant which means the model was significant.
  2. Fulltext Palladium(0) catalyzed Suzuki cross-coupling reaction of 2,5-dibromo-3-methylthiophene: selectivity, characterization, DFT studies and their biological evaluations
    Rizwan K, Zubair M, Rasool N, Mahmood T, Ayub K, Alitheen NB, et al.
    Chem Cent J, 2018 May 04;12(1):49.
    PMID: 29728881 DOI: 10.1186/s13065-018-0404-7
    Thiophene derivatives have shown versatile pharmacological activities. The Suzuki reaction proved a convenient method for C-C bond formations in organic molecules. In the present research work novel derivatives of 2,5-dibromo-3-methylthiophene (3a-k and 3l-p) has been synthesized, via Suzuki coupling reaction in low to moderate yields. A wide range of functional groups were well tolerated in reaction. Density functional theory investigations on all synthesized derivatives (3a-3p) were performed in order to explore the structural properties. The pharmaceutical potential of synthesized compounds was investigated through various bioassays (antioxidant, antibacterial, antiurease activities). The compounds 3l, 3g, 3j, showed excellent antioxidant activity (86.0, 82.0, 81.3%), respectively by scavenging DPPH. Synthesized compounds showed promising antibacterial activity against tested strains. 3b, 3k, 3a, 3d and 3j showed potential antiurease activity with 67.7, 64.2, 58.8, 54.7 and 52.1% inhibition at 50 µg/ml. Results indicated that synthesized molecules could be a potential source of pharmaceutical agents.
  3. Fulltext Phytochemical constituents, antioxidant activity, and antiproliferative properties of black, red, and brown rice bran
    Ghasemzadeh A, Karbalaii MT, Jaafar HZE, Rahmat A
    Chem Cent J, 2018 Feb 17;12(1):17.
    PMID: 29455357 DOI: 10.1186/s13065-018-0382-9
    BACKGROUND: In the recent years, the health benefits of the pigmented rice varieties have reported due to the presence of bioactive compounds. In this study, the phytochemical constituents (total phenolic, flavonoid and anthocyanin content) and individual phenolics and flavonoids of the extracts of sixteen genotypes of pigmented rice bran were evaluated using spectrophotometric and ultra-high performance liquid chromatography method. Antioxidative properties of the free and bound fractions were evaluated using nitric oxide and 1,1-diphenyl-2-picrylhydrazyl scavenging assays. Extracts were evaluated for antiproliferative activity against breast cancer cell lines (MCF-7 and MDA-MB-231) using the MTT assay.

    RESULTS: Signifficant diferences were observed in the concentrations of phytochemicals and biological activities among different pigmented rice brans. The highest phytochemical content was observed in black rice bran followed by red and brown rice bran. The concentration of free individual flavonoids and phenolic compounds were significantly higher than those of bound compounds except those of ferulic acid and p-coumaric acid. Highest antioxidant activities were observed in black rice bran, followed by red and brown rice bran extracts. Extracts of black rice bran exhibited potent antiproliferative activity, with half maximal inhibitory concentrations (IC50) of 148.6 and 119.2 mg/mL against MCF-7 and MDA-MB-231 cell lines, respectively, compared to the activity of the extracts of red rice bran (175.0 and 151.0 mg/mL, respectively) and brown rice bran (382.3 and 346.1 mg/mL, respectively).

    CONCLUSIONS: Black rice bran contains high levels of phytochemicals, and thus has potent pharmaceutical activity. This highlights opportunities for researcher to breed new genotypes of rice with higher nutritional values, which the food industry can use to develop new products that will compete in expanding functional food markets.

  4. Fulltext Potential of silver against human colon cancer: (synthesis, characterization and crystal structures of xylyl (Ortho, meta, &Para) linked bis-benzimidazolium salts and Ag(I)-NHC complexes: In vitro anticancer studies)
    Iqbal MA, Haque RA, Nasri SF, Majid AA, Ahamed MB, Farsi E, et al.
    Chem Cent J, 2013;7(1):27.
    PMID: 23391345 DOI: 10.1186/1752-153X-7-27
    Since the first successful synthesis of Ag(I)-N-heterocyclic carbene complex in 1993, this class of compounds has been extensively used for transmetallation reactions where the direct synthesis using other metal ions was either difficult or impossible. Initially, silver(I)-NHC complexes were tested for their catalytic potential but could not get fame because of lower potential compare to other competent compounds in this field; however, these compounds proved to have vital antimicrobial activities. These encouraging biomedical applications further convinced researchers to test these compounds against cancer. The current work has been carried out with this aim.
  5. Fulltext Preparation, optimization and swelling study of carboxymethyl sago starch (CMSS)-acid hydrogel
    Tuan Mohamood NFA, Zainuddin N, Ahmad Ayob M, Tan SW
    Chem Cent J, 2018 Dec 06;12(1):133.
    PMID: 30523481 DOI: 10.1186/s13065-018-0500-8
    In this study, sago starch was modified in order to enhance its physicochemical properties. Carboxymethylation was used to introduce a carboxymethyl group into a starch compound. The carboxymethyl sago starch (CMSS) was used to prepare smart hydrogel by adding acetic acid into the CMSS powder as the crosslinking agent. The degree of substitution of the CMSS obtained was 0.6410. The optimization was based on the gel content and degree of swelling of the hydrogel. In this research, four parameters were studied in order to optimize the formation of CMSS-acid hydrogel. The parameters were; CMSS concentration, acetic acid concentration, reaction time and reaction temperature. From the data analyzed, 76.69% of optimum gel content was obtained with 33.77 g/g of degree of swelling. Other than that, the swelling properties of CMSS-acid hydrogel in different media such as salt solution, different pH of phosphate buffer saline solution as well as acidic and alkaline solution were also investigated. The results showed that the CMSS-acid hydrogel swelled in both alkaline and salt solution, while in acidic or low pH solution, it tended to shrink and deswell. The production of the hydrogel as a smart material offers a lot of auspicious benefits in the future especially related to swelling behaviour and properties of the hydrogel in different types of media.
  6. Fulltext Promising upshot of silver nanoparticles primed from Gracilaria crassa against bacterial pathogens
    Lavakumar V, Masilamani K, Ravichandiran V, Venkateshan N, Saigopal DV, Ashok Kumar CK, et al.
    Chem Cent J, 2015;9:42.
    PMID: 26251669 DOI: 10.1186/s13065-015-0120-5
    The study on newer antimicrobial agent from metal based nano materials has augmented in recent years for the management of multidrug resistance microorganisms. In our present investigation, we synthesized silver nanoparticles (AgNP's) from red algae, Gracilaria crassa as beginning material which effectively condensed the silver ions to silver nanoparticles with less price tag and no risk.
  7. Fulltext Reaction of 2,6-dichloroquinone-4-chloroimide (Gibbs reagent) with permethrin - an optical sensor for rapid detection of permethrin in treated wood
    Arip MN, Heng LY, Ahmad M, Hasbullah SA
    Chem Cent J, 2013;7:122.
    PMID: 23867006 DOI: 10.1186/1752-153X-7-122
    A novel optical sensor for the rapid and direct determination of permethrin preservatives in treated wood was designed. The optical sensor was fabricated from the immobilisation of 2,6-dichloro-p-benzoquinone-4-chloroimide (Gibbs reagent) in nafion/sol-gel hybrid film and the mode of detection was based on absorption spectrophotometry. Physical entrapment was employed as a method of immobilisation.
  8. Fulltext Regioselective synthesis of 2-(bromomethyl)-5-aryl-thiophene derivatives via palladium (0) catalyzed suzuki cross-coupling reactions: as antithrombotic and haemolytically active molecules
    Rizwan K, Zubair M, Rasool N, Ali S, Zahoor AF, Rana UA, et al.
    Chem Cent J, 2014;8:74.
    PMID: 25685184 DOI: 10.1186/s13065-014-0074-z
    It is seen that the regioselective functionalizations of halogenated heterocycles play an important role in the synthesis of several types of organic compounds. In this domain, the Suzuki-Miyaura reaction has emerged as a convenient way to build carbon-carbon bonds in synthesizing organic compounds. Some of the most important applications of these reactions can be seen in the synthesis of natural products, and in designing targeted pharmaceutical compounds. Herein, we present the regioselective synthesis of the novel series of 2-(bromomethyl)-5-aryl-thiophenes 3a-i, via Suzuki cross-coupling reactions of various aryl boronic acids with 2-bromo-5-(bromomethyl)thiophene (2).
  9. Fulltext Release behavior and toxicity profiles towards A549 cell lines of ciprofloxacin from its layered zinc hydroxide intercalation compound
    Abdul Latip AF, Hussein MZ, Stanslas J, Wong CC, Adnan R
    Chem Cent J, 2013;7:119.
    PMID: 23849189 DOI: 10.1186/1752-153X-7-119
    Layered hydroxides salts (LHS), a layered inorganic compound is gaining attention in a wide range of applications, particularly due to its unique anion exchange properties. In this work, layered zinc hydroxide nitrate (LZH), a family member of LHS was intercalated with anionic ciprofloxacin (CFX), a broad spectrum antibiotic via ion exchange in a mixture solution of water:ethanol.
  10. Fulltext Retracted: Luciferase-transfected colon adenocarcinoma cell line (DLD-1) for use in Orthotopic Xenotransplantation studies
    Siddique MR, Shynder S, Ashraf MA, Yusoff I, Wajid A
    Chem Cent J, 2012 Jul 18;6(1):69.
    PMID: 22809083 DOI: 10.1186/1752-153X-6-69
    BACKGROUND: Renilla Luciferase reporter gene (rLuc) GL4.82 and GL4.13 promoter are key player in transfection, but precise knowledge of its targets in colon cancer remains limited. The aim of this study was to characterize the best transfection technique to produce a stable transfected colon DLD1 (colorectal adenocarcinoma cell line), therefore imaging based approaches were employed.

    RESULTS: DLD1 cells were transfected with a Plasmid (SV40-RLuc) carrying Renilla luciferase under the control of the SV-40 promoter, by using two different transfection techniques. Cells expressing the required DNA were isolated after antibiotic (Puramycin) selection. Clones of DLD-1/SV40-RLuc were produced using two different techniques (96 well plates and Petri dish) and their florescence intensity was recorded using IVIS machine (Calliper Life Sciences, Hopkinton, USA). Both techniques were characterized with the help of serial dilution technique. Results from this study substantiated that electroporation is the best. As expected, clones varied in their specific luciferase activity along with the dilutions. With the increase in cell concentration increase in intensity of florescence was recorded.

    CONCLUSIONS: Based on the results we are confident that this transfected cell line DLD-1/SV40-RLuc (colorectal adenocarcinoma cell line) is the best for further Orthotopic Xenotransplantation Studies and in-vivo experiments as well. Investigation shows that DLD1/SV-rLuc cells have gained little bit resistance against both drugs therefore further study is suggested to know the reasons.

  11. Fulltext Retraction: Luciferase-transfected colon adenocarcinoma cell line (DLD-1) for use in Orthotopic Xenotransplantation studies
    Siddique MR, Shynder S, Ashraf MA, Yusoff I, Wajid A
    Chem Cent J, 2012 10 22;6(1):121.
    PMID: 23088540 DOI: 10.1186/1752-153X-6-121
  12. Fulltext Reverse pharmacophore mapping and molecular docking studies for discovery of GTPase HRas as promising drug target for bis-pyrimidine derivatives
    Kumar S, Singh J, Narasimhan B, Shah SAA, Lim SM, Ramasamy K, et al.
    Chem Cent J, 2018 Oct 22;12(1):106.
    PMID: 30345469 DOI: 10.1186/s13065-018-0475-5
    BACKGROUND: Pyrimidine is an important pharmacophore in the field of medicinal chemistry and exhibit a broad spectrum of biological potentials. A study was carried out to identify the target protein of potent bis-pyrimidine derivatives using reverse docking program. PharmMapper, a robust online tool was used for identifying the target proteins based on reverse pharmacophore mapping. The murine macrophage (RAW 264.7) and human embryonic kidney (HEK-293) cancer cell line used for selectivity and safety study.

    METHODS: An open web server PharmMapper was used to identify the possible target of the developed compounds through reverse pharmacophore mapping. The results were analyzed and validated through docking with Schrodinger v9.6 using 10 protein GTPase HRas selected as possible target. The docking studies with Schrödinger validated the binding behavior of bis-pyrimidine compounds within GTP binding pocket. MTT and sulforhodamine assay were used as antiproliferative activity.

    RESULTS AND DISCUSSION: The protein was found one of the top scored targets of the compound 18, hence, the GTPase HRas protein was found crucial to be targeted for competing cancer. Toxicity study demonstrated the significant selectivity of most active compounds, 12, 16 and 18 showed negligible cell toxicity at their IC50 concentration.

    CONCLUSION: From the results, we may conclude that GTPase HRas as a possible target of studied bis-pyrimidine derivatives where the retrieved information may be quite useful for rational drug designing.

  13. Fulltext Selectively increasing of polyunsaturated (18:2) and monounsaturated (18:1) fatty acids in Jatropha curcas seed oil by crystallization using D-optimal design
    Salimon J, Abdullah BM, Salih N
    Chem Cent J, 2012;6(1):65.
    PMID: 22747574 DOI: 10.1186/1752-153X-6-65
  14. Fulltext Semi-empirical study of ortho-cresol photo degradation in manganese-doped zinc oxide nanoparticles suspensions
    Abdollahi Y, Zakaria A, Abdullah AH, Fard Masoumi HR, Jahangirian H, Shameli K, et al.
    Chem Cent J, 2012 Aug 21;6(1):88.
    PMID: 22909072 DOI: 10.1186/1752-153X-6-88
    The optimization processes of photo degradation are complicated and expensive when it is performed with traditional methods such as one variable at a time. In this research, the condition of ortho-cresol (o-cresol) photo degradation was optimized by using a semi empirical method. First of all, the experiments were designed with four effective factors including irradiation time, pH, photo catalyst's amount, o-cresol concentration and photo degradation % as response by response surface methodology (RSM). The RSM used central composite design (CCD) method consists of 30 runs to obtain the actual responses. The actual responses were fitted with the second order algebraic polynomial equation to select a model (suggested model). The suggested model was validated by a few numbers of excellent statistical evidences in analysis of variance (ANOVA). The used evidences include high F-value (143.12), very low P-value (<0.0001), non-significant lack of fit, the determination coefficient (R2 = 0.99) and the adequate precision (47.067). To visualize the optimum, the validated model simulated the condition of variables and response (photo degradation %) be using a few number of three dimensional plots (3D). To confirm the model, the optimums were performed in laboratory. The results of performed experiments were quite close to the predicted values. In conclusion, the study indicated that the model is successful to simulate the optimum condition of o-cresol photo degradation under visible-light irradiation by manganese doped ZnO nanoparticles.
  15. Fulltext Stirring time effect of silver nanoparticles prepared in glutathione mediated by green method
    Balavandy SK, Shameli K, Biak DR, Abidin ZZ
    Chem Cent J, 2014;8(1):11.
    PMID: 24524329 DOI: 10.1186/1752-153X-8-11
    This study aims to investigate the influence of different stirring time for synthesis of silver nanoparticles in glutathione (GSH) aqueous solution. The silver nanoparticles (Ag-NPs) were prepared by green synthesis method using GSH as reducing agent and stabilizer, under moderate temperature at different stirring times. Silver nitrate (AgNO3) was taken as the metal precursor while Ag-NPs were prepared in the over reaction time.
  16. Fulltext Structural and optical characterization of metal tungstates (MWO4; M=Ni, Ba, Bi) synthesized by a sucrose-templated method
    M Zawawi SM, Yahya R, Hassan A, Mahmud HN, Daud MN
    Chem Cent J, 2013;7(1):80.
    PMID: 23634962 DOI: 10.1186/1752-153X-7-80
    Metal tungstates have attracted much attention due to their interesting structural and photoluminescence properties. Depending on the size of the bivalent cation present, the metal tungstates will adopt structures with different phases. In this work, three different phases of metal tungstates MWO4 (M= Ba, Ni and Bi) were synthesized via the sucrose templated method.
  17. Fulltext Structural and spectral investigations of the recently synthesized chalcone (E)-3-mesityl-1-(naphthalen-2-yl) prop-2-en-1-one, a potential chemotherapeutic agent
    Barakat A, Al-Majid AM, Soliman SM, Mabkhot YN, Ali M, Ghabbour HA, et al.
    Chem Cent J, 2015;9:35.
    PMID: 26106444 DOI: 10.1186/s13065-015-0112-5
    Chalcones (1,3-diaryl-2-propen-1-ones, represent an important subgroup of the polyphenolic family, which have shown a wide spectrum of medical and industrial application. Due to their redundancy in plants and ease of preparation, this category of molecules has inspired considerable attention for potential therapeutic uses. They are also effective in vivo as anti-tumor promoting, cell proliferating inhibitors and chemo preventing agents.
  18. Fulltext Structure-dependent optoelectronic properties of perylene, di-indenoperylene (DIP) isolated molecule and DIP molecular crystal
    Mohamad M, Ahmed R, Shaari A, Goumri-Said S
    Chem Cent J, 2017 Dec 02;11(1):125.
    PMID: 29198000 DOI: 10.1186/s13065-017-0352-7
    Theoretical simulations were designed by first principles approach of density functional theory to investigate the structural and optoelectronic properties of different structural classes of perylene; isolated perylene, diindeno[1,2,3-cd:1',2',3'-lm]perylene (DIP) molecule and DIP molecular crystal. The presence of molecular interactions in DIP crystal proved its structure-dependent behaviours. The herringbone molecular arrangement of DIP crystal has influenced the electronic properties by triggering the intermolecular interactions that reduced the energy gaps between HOMO and LUMO of the crystal. Strong hybridization resulting from dense charges population near zero Fermi energy has pushed valence band maxima in the density of states of all perylene structures to higher energies. Under small energy input, charges are transferred continuously as observed in the spectra of conductivity and dielectric. The existence of strong absorption intensities are consistent with the former works and supported by the obtained polarized reflectivity and loss spectra.
  19. Fulltext Sustained release formulation of an anti-tuberculosis drug based on para-amino salicylic acid-zinc layered hydroxide nanocomposite
    Saifullah B, Hussein MZ, Hussein-Al-Ali SH, Arulselvan P, Fakurazi S
    Chem Cent J, 2013;7(1):72.
    PMID: 23601852 DOI: 10.1186/1752-153X-7-72
    Tuberculosis (TB), is caused by the bacteria, Mycobacterium tuberculosis and its a threat to humans since centuries. Depending on the type of TB, its treatment can last for 6-24 months which is a major cause for patients non-compliance and treatment failure. Many adverse effects are associated with the currently available TB medicines, and there has been no new anti-tuberculosis drug on the market for more than 50 year, as the drug development is very lengthy and budget consuming process.Development of the biocompatible nano drug delivery systems with the ability to minimize the side effects of the drugs, protection of the drug from enzymatic degradation. And most importantly the drug delivery systems which can deliver the drug at target site would increase the therapeutic efficacy. Nanovehicles with their tendency to release the drug in a sustained manner would result in the bioavalibilty of the drugs in the body for a longer period of time and this would reduce the dosing frequency in drug administration. The biocompatible nanovehicles with the properties like sustained release of drug of the target site, protection of the drug from physio-chemical degradation, reduction in dosing frequency, and prolong bioavailability of drug in the body would result in the shortening of the treatment duration. All of these factors would improve the patient compliance with chemotherapy of TB.
  20. Fulltext Synthesis and biological profile of substituted benzimidazoles
    Vashist N, Sambi SS, Narasimhan B, Kumar S, Lim SM, Shah SAA, et al.
    Chem Cent J, 2018 Dec 01;12(1):125.
    PMID: 30506405 DOI: 10.1186/s13065-018-0498-y
    BACKGROUND: A series of benzimidazole derivatives was developed and its chemical scaffolds were authenticated by NMR, IR, elemental analyses and physicochemical properties. The synthesized compounds were screened for their antimicrobial and antiproliferative activities.

    RESULTS AND DISCUSSION: The synthesized benzimidazole compounds were evaluated for their antimicrobial activity using the tube dilution method and were found to exhibit good antimicrobial potential against selected Gram negative and positive bacterial and fungal species. The compounds were also assessed for their anticancer activity exhibited using the SRB assay and were found to elicit antiproliferative activity against MCF7 breast cancer cell line, which was comparable to the standard drug.

    CONCLUSION: Antimicrobial screening results indicated that compounds 1, 2 and 19 to be promising antimicrobial agents against selected microbial species and comparable to standard drugs which included norfloxacin and fluconazole. The anticancer screening results revealed that compounds, 12, 21, 22 and 29 to show the highest activity against MCF7 and their IC50 values were more potent than 5-fluorouracil.

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