Displaying publications 1 - 20 of 154 in total

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  1. Distribution of oil and grease and petroleum hydrocarbons in the Straits of Johor, peninsular Malaysia
    Abdullah AR, Woon WC, Bakar RA
    Bull Environ Contam Toxicol, 1996 Jul;57(1):155-62.
    PMID: 8661474
    Matched MeSH terms: Spectrophotometry, Ultraviolet
  2. Synthesis, X-ray, NMR, FT-IR, UV/vis, DFT and TD-DFT studies of N-(4-chlorobutanoyl)-N'-(2-, 3- and 4-methylphenyl)thiourea derivatives
    Abosadiya HM, Anouar el H, Hasbullah SA, Yamin BM
    Spectrochim Acta A Mol Biomol Spectrosc, 2015 Jun 5;144:115-24.
    PMID: 25748989 DOI: 10.1016/j.saa.2015.01.092
    A new isomers of thiourea derivatives, namely N-(4-chlorobutanoyl)-N'-(2-methylphenyl)-thiourea (1a), N-(4-chlorobutanoyl)-N'-(3-methylphenyl)thiourea (1b) and N-(4-chlorobutanoyl)-N'-(4-methylphenyl)thiourea (1c) have been synthesized by refluxing mixture of equimolar amounts of 4-chlorobutanoylisothiocyanate with 2, 3 or 4-toluidine, respectively. The three isomers were characterized by spectroscopic (UV/vis, FT-IR and NMR) and X-ray crystallography techniques. To investigate the isomerization effect on spectroscopic data, DFT and TD-DFT calculations have been carried out using five hybrid functionals (B3LYP, B3P86, CAM-B3LYP, M06-2X and PBE0) to predict UV/vis absorption bands (n→π∗ and π→π∗), (1)H and (13)C NMR chemical shifts, FT-IR vibration modes and X-ray parameters (bonds, bond angles and torsion angles) for 1a, 1b and 1c isomers. The results showed that the isomerization effect is significant on λ(MAX) absorption bands, while for IR and NMR the effect is negligible. In accordance with previous studies, B3LYP, B3P86 and PBE0 gave the most reliable to predict the excitation energies of thiourea derivatives.
    Matched MeSH terms: Spectrophotometry, Ultraviolet
  3. A screening method for cardiovascular active compounds in marine algae
    Agatonovic-Kustrin S, Kustrin E, Angove MJ, Morton DW
    J Chromatogr A, 2018 May 18;1550:57-62.
    PMID: 29615323 DOI: 10.1016/j.chroma.2018.03.054
    The interaction of bioactive compounds from ethanolic extracts of selected marine algae samples, separated on chromatographic plates, with nitric/nitrous acid was investigated. The nature of bioactive compounds in the marine algae extracts was characterised using UV absorption spectra before and after reaction with diluted nitric acid, and from the characteristic colour reaction after derivatization with anisaldehyde. It was found that diterpenes from Dictyota dichotoma, an edible brown algae, and sterols from green algae Caulerpa brachypus, bind nitric oxide and may act as a nitric oxide carrier. Although the carotenoid fucoxanthin, found in all brown marine algae also binds nitric oxide, the bonds between nitrogen and the fucoxanthin molecule are much stronger. Further studies are required to evaluate the effects of diterpenes from Dictyota dichotoma and sterols from green algae Caulerpa brachypus to see if they have beneficial cardiovascular effects. The method reported here should prove useful in screening large numbers of algae species for compounds with cardiovascular activity.
    Matched MeSH terms: Spectrophotometry, Ultraviolet
  4. Fulltext Synthesis, characterization, quantum chemical calculations and anticancer activity of a Schiff base NNOO chelate ligand and Pd(II) complex
    Ahmad N, Anouar EH, Tajuddin AM, Ramasamy K, Yamin BM, Bahron H
    PLoS One, 2020;15(4):e0231147.
    PMID: 32287324 DOI: 10.1371/journal.pone.0231147
    This paper reports the synthesis, characterization, anticancer screening and quantum chemical calculation of a tetradentate Schiff base 2,2'-((1E,1'E)-((2,2-dimethylpropane-1,3-diyl)bis- (azanylylidene))bis(methanylylidene))bis(4-fluorophenol) (L2F) and its Pd (II) complex (PdL2F). The compounds were characterized via UV-Visible, NMR, IR spectroscopy and single crystal x-ray diffraction. Density Functional Theory (DFT) and time-dependent DFT calculations in gas and solvent phases were carried out using B3LYP, B3P86, CAM-B3LYP and PBE0 hybrid functionals combined with LanL2DZ basis set. Complexation of L2F to form PdL2F was observed to cause a bathochromic shift of the maximum absorption bands of n-π* from 327 to 410 nm; an upfield shift for δ (HC = N) from 8.30 to 7.96 ppm and a decreased wavenumber for ν(C = N) from 1637 to 1616 cm-1. Overall, the UV-Vis, NMR and IR spectral data are relatively well reproduced through DFT and TD-DFT methods. L2F and PdL2F showed IC50 of 90.00 and 4.10 μg/mL, respectively, against human colorectal carcinoma (HCT116) cell lines, signifying increased anticancer activity upon complexation with Pd (II).
    Matched MeSH terms: Spectrophotometry, Ultraviolet
  5. Fulltext A Colorimetric pH Sensor Based on Clitoria sp and Brassica sp for Monitoring of Food Spoilage Using Chromametry
    Ahmad NA, Yook Heng L, Salam F, Mat Zaid MH, Abu Hanifah S
    Sensors (Basel), 2019 Nov 05;19(21).
    PMID: 31694284 DOI: 10.3390/s19214813
    A developed colorimetric pH sensor film based on edible materials for real-time monitoring of food freshness is described. The mixed natural dyes from edible plants Clitoria sp and Brassica sp were extracted and incorporated into ι-carrageenan film as a colorimetric pH sensor film for monitoring food spoilage and its freshness. The color changes of the developed colorimetric sensor film were measured with chromametry and UV-vis spectroscopy, respectively. Experimental results show that colorimetric pH sensor film demonstrated statistically significant differences (p < 0.05) between CIE-L*a*b* coordinates color system indicated that the developed colorimetric sensor film was able to give a gradual change in color over a wide pH range. The color of the colorimetric sensor film also changes discretely and linearly with factors that contribute to food spoilage using shrimp and durian samples. Moreover, the developed colorimetric pH sensor film has the potential to be used as a safe, non-destructive testing and also a flexibly visual method for direct assessment of food freshness indicator during storage.
    Matched MeSH terms: Spectrophotometry, Ultraviolet
  6. Fulltext Optimization and Validation of RP-HPLC-UV/Vis Method for Determination Phenolic Compounds in Several Personal Care Products
    Akkbik M, Assim ZB, Ahmad FB
    Int J Anal Chem, 2011;2011:858153.
    PMID: 21760792 DOI: 10.1155/2011/858153
    An HPLC method with ultraviolet-visible spectrophotometry detection has been optimized and validated for the simultaneous determination of phenolic compounds, such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) as antioxidants, and octyl methyl cinnamate (OMC) as UVB-filter in several personal care products. The dynamic range was between 1 to 250 mg/L with relative standard deviation less than 0.25% (n = 4). Limits of detection for BHA, BHT, and OMC were 0.196, 0.170, and 0.478 mg/L, respectively. While limits of quantification for BHA, BHT, and OMC were 0.593, 0.515, and 1.448 mg/L, respectively. The recovery for BHA, BHT, and OMC was ranged from 92.1-105.9%, 83.2-108.9%, and 87.3-103.7%, respectively. The concentration ranges of BHA, BHT, and OMC in 12 commercial personal care samples were 0.13-4.85, 0.16-2.30, and 0.12-65.5 mg/g, respectively. The concentrations of phenolic compounds in these personal care samples were below than maximum allowable concentration in personal care formulation, that is, 0.0004-10 mg/g, 0.002-5 mg/g, and up to 100 mg/g for BHA, BHT, and OMC, respectively.
    Matched MeSH terms: Spectrophotometry, Ultraviolet
  7. Simultaneous determination of atenolol, chlorthalidone and amiloride in pharmaceutical preparations by capillary zone electrophoresis with ultraviolet detection
    Al Azzam KM, Saad B, Aboul-Enein HY
    Biomed Chromatogr, 2010 Sep;24(9):977-81.
    PMID: 20066730 DOI: 10.1002/bmc.1395
    Capillary zone electrophoresis methods for the simultaneous determination of the beta-blocker drugs, atenolol, chlorthalidone and amiloride, in pharmaceutical formulations have been developed. The influences of several factors (buffer pH, concentration, applied voltage, capillary temperature and injection time) were studied. Using phenobarbital as internal standard, the analytes were all separated in less than 4 min. The separation was carried out in normal polarity mode at 25 degrees C, 25 kV and using hydrodynamic injection (10 s). The separation was effected in an uncoated fused-silica capillary (75 mum i.d. x 52 cm) and a background electrolyte of 25 mm H(3)PO(4) adjusted with 1 m NaOH solution (pH 9.0) and detection at 198 nm. The method was validated with respect to linearity, limit of detection and quantification, accuracy, precision and selectivity. Calibration curves were linear over the range 1-250 microg/mL for atenolol and chlorthalidone and from 2.5-250 microg/mL for amiloride. The relative standard deviations of intra- and inter-day migration times and corrected peak areas were less than 6.0%. The method showed good precision and accuracy and was successfully applied to the simultaneous determination of atenolol, chlorthalidone and amiloride in various pharmaceutical tablets formulations.
    Matched MeSH terms: Spectrophotometry, Ultraviolet/methods*
  8. Fulltext Synthesis and characterizations iron oxide carbon nanotubes nanocomposite by laser ablation for anti-microbial applications
    Al-Salih M, Samsudin S, Arshad SS
    J Genet Eng Biotechnol, 2021 May 18;19(1):76.
    PMID: 34003402 DOI: 10.1186/s43141-021-00161-y
    BACKGROUND: Environmental contamination by microbes is a major public health concern. A damp environment is one of the potential sources for microbe proliferation. Smart synthesis nanocatalytic coatings on surfaces, food, and material from different pathogen bacteria can inhibit using the Fe3O4/CNTs as anti-microbial growth can effectively curb this growing threat. In this present work, the anti-microbial efficacy of synthesis of a compound nanoparticle-containing iron oxide-multi-walled carbon nanotube was combined by laser ablation PLAL and explored the anti-bacterial action of colloidal solution of Fe3O4/CNTs NPs that was evaluated against bacteria which is classified as gram-negative (Escherichia coli (E. coli), Klebsiella pneumonia (K. pneumonia), and also that is identified as gram-positive (Streptococcus pyogenes (S .pyogenes) and Staphylococcus aureus (S. aureus) under visible light irradiation.

    RESULTS: Doping of a minute fraction of iron(III) salt (0.5 mol%) in a volatile solvent (ethanol) was carried out via the sol-gel technique. Fe3O4 was further calcined at various temperatures (in the range of 500-700 °C) to evaluate the thermal stability of the Fe3O4 nanoporous oxidizer nanoparticles. The physicochemical properties of the samples were characterized through X-ray diffraction (XRD), atomic force microscopy (AFM), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), and UV-Visible spectroscopy techniques. XRD results revealed that the nanoparticles framework of Fe3O4 was maintained well up to 650 °C by the Fe dopant. UV-Vis results suggested that absorption property of combination Fe3O4/CNTs nanopowder by PLAL was enhanced and the band gap is reduced into 2.0 eV.

    CONCLUSIONS: Density functional theory (DFT) studies emphasize the introduction of Fe+ and Fe2+ ions by replacing other ions in the CNT lattice, therefore creating oxygen vacancies. These further promoted anti-microbial efficiency. A significantly high bacterial inactivation that indicates results was evaluated and that the mean estimations of restraint were determined from triple assessment in every appraisal at 400 ml which represent the best anti-bacterial action against gram-positive and gram-negative microbes.

    Matched MeSH terms: Spectrophotometry, Ultraviolet
  9. An antimitotic and cytotoxic chalcone from Fissistigma lanuginosum
    Alias Y, Awang K, Hadi AH, Thoison O, Sévenet T, Païs M
    J Nat Prod, 1995 Aug;58(8):1160-6.
    PMID: 7595585
    Bioassay-guided fractionation of an ethyl acetate extract of Fissistigma lanuginosum led to the isolation of the known chalcone pedicin [1], which inhibited tubulin assembly into microtubules (IC50 value of 300 microM). From the same EtOAc fraction, two new condensed chalcones, fissistin [2] and isofissistin [3], which showed cytotoxicity against KB cells, were also obtained, together with the inactive dihydropedicin [4] and 6,7-dimethoxy-5,8-dihydroxyflavone [5]. In addition, the aminoquinones 6, 8, and 9 were isolated from the alkaloid extract. These compounds were artifacts, prepared by treatment of 1, 4, and 2, respectively, with NH4OH. The structures of the new compounds were elucidated by spectral methods, especially 2D nmr.
    Matched MeSH terms: Spectrophotometry, Ultraviolet
  10. Green-synthesised nanoparticles from Melia azedarach seeds and the cyclopoid crustacean Cyclops vernalis: an eco-friendly route to control the malaria vector Anopheles stephensi?
    Anbu P, Murugan K, Madhiyazhagan P, Dinesh D, Subramaniam J, Panneerselvam C, et al.
    Nat Prod Res, 2016 Sep;30(18):2077-84.
    PMID: 26679526 DOI: 10.1080/14786419.2015.1114935
    The impact of green-synthesised mosquitocidal nanoparticles on non-target aquatic predators is poorly studied. In this research, we proposed a single-step method to synthesise silver nanoparticles (Ag NP) using the seed extract of Melia azedarach. Ag NP were characterised using a variety of biophysical methods, including UV-vis spectrophotometry, scanning electron microscopy, energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. In laboratory assays on Anopheles stephensi, Ag NP showed LC50 ranging from 2.897 (I instar larvae) to 14.548 ppm (pupae). In the field, the application of Ag NP (10 × LC50) lead to complete elimination of larval populations after 72 h. The application of Ag NP in the aquatic environment did not show negative adverse effects on predatory efficiency of the mosquito natural enemy Cyclops vernalis. Overall, this study highlights the concrete possibility to employ M. azedarach-synthesised Ag NP on young instars of malaria vectors.
    Matched MeSH terms: Spectrophotometry, Ultraviolet
  11. Time-dependent density functional theory study of UV/vis spectra of natural styrylpyrones
    Anouar el H, Weber JF
    Spectrochim Acta A Mol Biomol Spectrosc, 2013 Nov;115:675-82.
    PMID: 23880409 DOI: 10.1016/j.saa.2013.06.114
    Natural styrylpyrones isolated from fungi are known for various biological activities including antioxidant activity by scavenging free radicals. UV/vis spectra play an important role in elucidating chemical structures of these compounds via identification of chromophore units. With the aim of predicting the UV/vis spectra of a series of natural styrylpyrones, we tested TD-DFT, CIS and ZINDO methods in gas and in PCM solvent. The results showed that the individual or combined B3P86 and B3LYP hybrid functionals are suitable to predict the maximum wavelength absorption bands (λmax) for styrylpyrones. The structure property relationship (SPR) study emphasized the role of (i) structural parameters (e.g., hydrogen bond and the length of conjugated double bonds) and (ii) electronic descriptors (e.g., ionization potential, electronic affinity, hardness and electrophilicity) in bathochromic and hypsochromic shifts of maximum wavelength absorption bands (λmax) of styrylpyrone derivatives.
    Matched MeSH terms: Spectrophotometry, Ultraviolet
  12. Characterization of hydroxypropylmethylcellulose films using microwave non-destructive testing technique
    Anuar NK, Wui WT, Ghodgaonkar DK, Taib MN
    J Pharm Biomed Anal, 2007 Jan 17;43(2):549-57.
    PMID: 16978823
    The applicability of microwave non-destructive testing (NDT) technique in characterization of matrix property of pharmaceutical films was investigated. Hydroxypropylmethylcellulose and loratadine were selected as model matrix polymer and drug, respectively. Both blank and drug loaded hydroxypropylmethylcellulose films were prepared using the solvent-evaporation method and were conditioned at the relative humidity of 25, 50 and 75% prior to physicochemical characterization using microwave NDT technique as well as ultraviolet spectrophotometry, differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR) techniques. The results indicated that blank hydroxypropylmethylcellulose film exhibited a greater propensity of polymer-polymer interaction at the O-H and C-H domains of the polymer chains upon conditioned at a lower level of relative humidity. In the case of loratadine loaded films, a greater propensity of polymer-polymer and/or drug-polymer interaction via the O-H moiety was mediated in samples conditioned at the lower level of relative humidity, and via the C-H moiety when 50% relative humidity was selected as the condition for sample storage. Apparently, the absorption and transmission characteristics of both blank and drug loaded films for microwave varied with the state of polymer-polymer and/or drug-polymer interaction involving the O-H and C-H moieties. The measurement of microwave NDT test at 8GHz was sensitive to the chemical environment involving O-H moiety while it was greatly governed by the C-H moiety in test conducted at a higher frequency band of microwave. Similar observation was obtained with respect to the profiles of microwave NDT measurements against the state of polymer-polymer and/or drug-polymer interaction of hydroxypropylmethylcellulose films containing chlorpheniramine maleate. The microwave NDT measurement is potentially suitable for use as an apparent indicator of the state of polymer-polymer and drug-polymer interaction of the matrix.
    Matched MeSH terms: Spectrophotometry, Ultraviolet
  13. Oleic acid-conjugated silver nanoparticles as efficient antiamoebic agent against Acanthamoeba castellanii
    Anwar A, Abdalla SAO, Aslam Z, Shah MR, Siddiqui R, Khan NA
    Parasitol Res, 2019 Jul;118(7):2295-2304.
    PMID: 31093751 DOI: 10.1007/s00436-019-06329-3
    Acanthamoeba castellanii belonging to the T4 genotype is an opportunistic pathogen which is associated with blinding eye keratitis and rare but fatal central nervous system infection. A. castellanii pose serious challenges in antimicrobial chemotherapy due to its ability to convert into resistant, hardy shell-protected cyst form that leads to infection recurrence. The fatty acid composition of A. castellanii trophozoites is known to be most abundant in oleic acid which chemically is an unsaturated cis-9-Octadecanoic acid and naturally found in animal and vegetable fats and oils. This study was designed to evaluate antiacanthamoebic effects of oleic acid against trophozoites, cysts as well as parasite-mediated host cell cytotoxicity. Moreover, oleic acid-conjugated silver nanoparticles (AgNPs) were also synthesized and tested against A. castellanii. Oleic acid-AgNPs were synthesized by chemical reduction method and characterized by ultraviolet-visible spectrophotometry, atomic force microscopy, dynamic light scattering analysis, and Fourier transform infrared spectroscopy. Viability, growth inhibition, encystation, and excystation assays were performed with 10 and 5 μM concentration of oleic acid alone and oleic acid-conjugated AgNPs. Bioassays revealed that oleic acid alone and oleic acid-conjugated AgNPs exhibited significant antiamoebic properties, whereas nanoparticle conjugation further enhanced the efficacy of oleic acid. Phenotype differentiation assays also showed significant inhibition of encystation and excystation at 5 μM. Furthermore, oleic acid and oleic acid-conjugated AgNPs also inhibited amoebae-mediated host cell cytotoxicity as determined by lactate dehydrogenase release. These findings for the first time suggest that oleic acid-conjugated AgNPs exhibit antiacanthamoebic activity that hold potential for therapeutic applications against A. castellanii.
    Matched MeSH terms: Spectrophotometry, Ultraviolet
  14. Metformin-coated silver nanoparticles exhibit anti-acanthamoebic activities against both trophozoite and cyst stages
    Anwar A, Soomaroo A, Anwar A, Siddiqui R, Khan NA
    Exp Parasitol, 2020 Aug;215:107915.
    PMID: 32461112 DOI: 10.1016/j.exppara.2020.107915
    Acanthamoeba castellanii is an opportunistic protozoan responsible for serious human infections including Acanthamoeba keratitis and granulomatous amoebic encephalitis. Despite advances in antimicrobial therapy and supportive care, infections due to Acanthamoeba are a major public concern. Current methods of treatment are not fully effective against both the trophozoite and cyst forms of A. castellanii and are often associated with severe adverse effects, host cell cytotoxicity and recurrence of infection. Therefore, there is an urgent need to develop new therapeutic approaches for the treatment and management of Acanthamoebic infections. Repurposing of clinically approved drugs is a viable avenue for exploration and is particularly useful for neglected and rare diseases where there is limited interest by pharmaceutical companies. Nanotechnology-based drug delivery systems offer promising approaches in the biomedical field, particularly in diagnosis and drug delivery. Herein, we conjugated an antihyperglycemic drug, metformin with silver nanoparticles and assessed its anti-acanthamoebic properties. Characterization by ultraviolet-visible spectrophotometry and atomic force microscopy showed successful formation of metformin-coated silver nanoparticles. Amoebicidal and amoebistatic assays revealed that metformin-coated silver nanoparticles reduced the viability and inhibited the growth of A. castellanii significantly more than metformin and silver nanoparticles alone at both 5 and 10 μM after 24 h incubation. Metformin-coated silver nanoparticles also blocked encystation and inhibited the excystation in Acanthamoeba after 72 h incubation. Overall, the conjugation of metformin with silver nanoparticles was found to enhance its antiamoebic effects against A. castellanii. Furthermore, the pretreatment of A. castellanii with metformin and metformin-coated silver nanoparticles for 2 h also reduced the amoebae-mediated host cell cytotoxicity after 24 h incubation from 73% to 10% at 10 μM, indicating that the drug-conjugated silver nanoparticles confer protection to human cells. These findings suggest that metformin-coated silver nanoparticles hold promise in the improved treatment and management of Acanthamoeba infections.
    Matched MeSH terms: Spectrophotometry, Ultraviolet
  15. Silver nanoparticle conjugation affects antiacanthamoebic activities of amphotericin B, nystatin, and fluconazole
    Anwar A, Siddiqui R, Hussain MA, Ahmed D, Shah MR, Khan NA
    Parasitol Res, 2018 Jan;117(1):265-271.
    PMID: 29218442 DOI: 10.1007/s00436-017-5701-x
    Infectious diseases are the leading cause of morbidity and mortality, killing more than 15 million people worldwide. This is despite our advances in antimicrobial chemotherapy and supportive care. Nanoparticles offer a promising technology to enhance drug efficacy and formation of effective vehicles for drug delivery. Here, we conjugated amphotericin B, nystatin (macrocyclic polyenes), and fluconazole (azole) with silver nanoparticles. Silver-conjugated drugs were synthesized successfully and characterized by ultraviolet-visible spectrophotometry, Fourier transform infrared spectroscopy, and atomic force microscopy. Conjugated and unconjugated drugs were tested against Acanthamoeba castellanii belonging to the T4 genotype using amoebicidal assay and host cell cytotoxicity assay. Viability assays revealed that silver nanoparticles conjugated with amphotericin B (Amp-AgNPs) and nystatin (Nys-AgNPs) exhibited significant antiamoebic properties compared with drugs alone or AgNPs alone (P 
    Matched MeSH terms: Spectrophotometry, Ultraviolet
  16. Fulltext Synthesis of 4-(dimethylamino)pyridine propylthioacetate coated gold nanoparticles and their antibacterial and photophysical activity
    Anwar A, Khalid S, Perveen S, Ahmed S, Siddiqui R, Khan NA, et al.
    J Nanobiotechnology, 2018 Jan 29;16(1):6.
    PMID: 29378569 DOI: 10.1186/s12951-017-0332-z
    BACKGROUND: Gold nanoparticles are useful candidate for drug delivery applications and are associated with enhancement in the bioavailability of coated drugs and/or therapeutic agent. Since, heterocyclic compounds are known to exhibit antimicrobial potential against variety of pathogens, we designed this study to evaluate the antibacterial effects of gold nanoparticles conjugation with new synthesized cationic ligand; 4-Dimethyl aminopyridinium propylthioacetate (DMAP-PTA) in comparison with pure compound and antibiotic drug Pefloxacin. Antibacterial activity of DMAP-PTA coated gold nanoparticles was investigated against a fecal strain of E. coli (ATCC 8739).

    RESULTS: A new dimethyl aminopyridine based stabilizing agent named as DMAP-PTA was synthesized and used for stabilization of gold nanoparticles. Gold nanoparticles coated with DMAP-PTA abbreviated as DMAP-PTA-AuNPs were thoroughly characterized by UV-visible, FT-IR spectroscopic methods and transmission electron microscope before biological assay. DMAP-PTA, DMAP-PTA-AuNPs and Pefloxacin were examined for their antibacterial potential against E. coli, and the minimum inhibitory concentration (MIC) was determined to be 300, 200 and 50 µg/mL respectively. Gold nanoparticles conjugation was found to significantly enhance the antibacterial activity of DMAP-PTA as compared to pure compound. Moreover, effects of DMAP-PTA-AuNPs on the antibacterial potential of Pefloxacin was also evaluated by combination therapy of 1:1 mixture of DMAP-PTA-AuNPs and Pefloxacin against E. coli in a wide range of concentrations from 5 to 300 µg/mL. The MIC of Pefloxacin + DMAP-PTA-AuNPs mixture was found to be 25 µg/mL as compared to Pefloxacin alone (50 µg/mL), which clearly indicates that DMAP-PTA-AuNPs increased the potency of Pefloxacin. AFM analysis was also carried out to show morphological changes occur in bacteria before and after treatment of test samples. Furthermore, DMAP-PTA-AuNPs showed high selectivity towards Pefloxacin in spectrophotometric drug recognition studies which offers tremendous potential for analytical applications.

    CONCLUSIONS: Gold nanoparticles conjugation was shown to enhance the antibacterial efficacy of DMAP-PTA ligand, while DMAP-PTA-AuNPs also induced synergistic effects on the potency of Pefloxacin against E. coli. DMAP-PTA-AuNPs were also developed as Pefloxacin probes in recognizing the drug in blood and water samples in the presence of other drugs.

    Matched MeSH terms: Spectrophotometry, Ultraviolet
  17. Two new naphthoquinone derivatives from the stem bark of Callicarpa maingayi
    Asiri SM, Shaari K, Abas F, Al-Mekhlafi NA, Lajis NH
    Nat Prod Commun, 2012 Oct;7(10):1333-6.
    PMID: 23157003
    Two new naphthoquinones designated as 3alpha-hydroxy-2-(2-hydroxypropan-2-yI)-9alpha-methoxy-2,3,3alpha,9alpha-tetra-hydronaphtho[2,3-b]furan-4,9-dione (callicarpa-quinone A, 1) and 5-hydroxy-2-(2-hydroxypropan-2-yl)naphtho[2,3-b]furan-4,9-dione (callicarpaquinone B, 2) were isolated from the chloroform fraction of Callicarpa maingayi. Three other known compounds, identified as avicequinone-C (3), wodeshiol (4) and paulownin (5), were reported for the first time from this species. The structure elucidation of compounds was established by comprehensive 1D and 2D NMR spectroscopic analyses as well as EIMS, UV and IR spectral data. Compounds 1 and 2 were tested in vitro for their cytotoxic activity against human breast cancer MCF-7cells. Compound 2 exhibited strong cytotoxic activity with an IC50 value of 1.9 +/- 0.2 microM, while 1 showed moderate activity with an IC50 value of 25.0 +/- 4.3 microM.
    Matched MeSH terms: Spectrophotometry, Ultraviolet
  18. New alkaloids from Phoebe scortechinii
    Awang K, Mukhtar MR, Mustafa MR, Litaudon M, Shaari K, Mohamad K, et al.
    Nat Prod Res, 2007 Jul 10;21(8):704-9.
    PMID: 17616898
    The leaves of the Phoebe scortechinii (Gamb.) Kochummen Comb. Nov. (Lauraceae), afforded one new proaporphine-tryptamine dimer; (-)-phoebescortechiniine (1), along with two known ones; phoebegrandine A and phoebegrandine B. The proaporphine, tetrahydropronuciferine (2), was isolated for the first time as a natural product. The alkaloids were elucidated primarily by means of high field NMR and HRMS.
    Matched MeSH terms: Spectrophotometry, Ultraviolet
  19. New alkaloids from Phoebe grandis (Nees) Merr
    Awang K, Mukhtar MR, Hadi AH, Litaudon M, Latip J, Abdullah NR
    Nat Prod Res, 2006 May 20;20(6):567-72.
    PMID: 16835089
    The alkaloidal extract of the leaves of Phoebe grandis (nees) merr. have provided two new minor alkaloids; phoebegrandine D (1), a proaporphine-tryptamine dimer, and phoebegrandine E (2), an indoloquinolizidine. This is the first report on the occurrence of an indoloquinolizidine in the Phoebe species. The crude extract also exhibited antiplasmodial activity (IC50<8 microg mL-1). The structures of the novel compounds were elucidated by spectroscopic methods, notably 2D NMR and HRMS.
    Matched MeSH terms: Spectrophotometry, Ultraviolet
  20. Fulltext Anti-angiogenesis effect of biogenic silver nanoparticles synthesized Using Saliva officinalis on chick chorioalantoic membrane (CAM)
    Baharara J, Namvar F, Mousavi M, Ramezani T, Mohamad R
    Molecules, 2014;19(9):13498-508.
    PMID: 25255752 DOI: 10.3390/molecules190913498
    Angiogenesis, which is required for physiological events, plays a crucial role in several pathological conditions, such as tumor growth and metastasis. The use of plant extracts is a cost effective and eco-friendly way to synthesize nanoparticles. In the present study, we investigated the anti-angiogenesis properties of silver nanoparticles synthesized using Saliva officinalis extract on chick chorioalantoic membrane. The production of nanoparticles was confirmed by the color change from yellow to brown observed after approximately 3 h at 37 °C. Then, the nanoparticles were characterized by UV-visible spectroscopy, FTIR, and TEM. The UV-visible spectroscopy results showed that the surface plasmon resonance band for AgNPs was around 430 nm. The intensity of the AgNP-specific absorption peak improved with an increase of 0.5 mL of extract into 10 mL of AgNO3 (2.5 mM). The FTIR results showed good interaction between the plant extracts and AgNPs. The TEM images of the samples revealed that the NPs varied in morphology and size from 1 to 40 nm; the average was recorded at 16.5 ± 1.2 nm. Forty Ross fertilized eggs were divided into four groups; the control and three experimental groups. On the 8th day, gelatin sponges containing albumin were placed on the chorioalantoic membrane and soaked with different concentrations of NPs. On the 12th day, all the cases were photographed using a photostereomicroscope. The number and the lengths of the vessels were measured using Image J software. The crown rump (CR) and weight of the embryo were also recorded. Then the hemoglobin content was measured using Drabkin's reagent kit for quantification of the blood vessel formation. According to the data analysis, the number and length of the blood vessels, as well as the CR and weight of the embryos reduced significantly compared to the control (p < 0.05), dose dependently. The total hemoglobin was quantified as an indicator of the blood vessel formation. The hemoglobin content in the treated samples with AgNPs decreased, which showed its inhibitory effect on angiogenesis.
    Matched MeSH terms: Spectrophotometry, Ultraviolet
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