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Fulltext Rapid detection of colistin-resistant Enterobacterales using the resazurin reduction-based assay

Karim MR, Zakaria Z, Hassan L, Ahmad NI, Faiz NM, Garba B

J Glob Antimicrob Resist, 2021 09;26:154-156.
PMID: 34118481 DOI: 10.1016/j.jgar.2021.05.012
Matched MeSH terms: Oxazines
Silver(I)-mediated base pairing in parallel-stranded DNA involving the luminescent cytosine analog 1,3-diaza-2-oxophenoxazine

Schönrath I, Tsvetkov VB, Zatsepin TS, Aralov AV, Müller J

J Biol Inorg Chem, 2019 08;24(5):693-702.
PMID: 31263954 DOI: 10.1007/s00775-019-01682-1

1,3-Diaza-2-oxophenoxazine (X) has been introduced as a ligand in silver(I)-mediated base pairing in a parallel DNA duplex. This fluorescent cytosine analog is capable of forming stabilizing X-Ag(I)-X and X-Ag(I)-C base pairs in DNA duplexes, as confirmed by temperature-dependent UV spectroscopy and luminescence spectroscopy. DFT calculations of the silver(I)-mediated base pairs suggest the presence of a synergistic hydrogen bond. Molecular dynamics (MD) simulations of entire DNA duplexes nicely underline the geometrical flexibility of these base pairs, with the synergistic hydrogen bond facing either the major or the minor groove. Upon silver(I) binding to the X:X or X:C base pairs, the luminescence emission maximum experiences a red shift from 448 to 460 nm upon excitation at 370 nm. Importantly, the luminescence of the 1,3-diaza-2-oxophenoxazine ligand is not quenched significantly upon binding a silver(I) ion. In fact, the luminescence intensity even increases upon formation of a X-Ag(I)-C base pair, which is expected to be beneficial for the development of biosensors. As a consequence, the silver(I)-mediated phenoxazinone base pairs represent the first strongly fluorescent metal-mediated base pairs.

Matched MeSH terms: Oxazines/chemistry*
Fulltext Intramolecular Dimerization Quenching of Delayed Emission in Asymmetric D-D'-A TADF Emitters

Woon KL, Yi CL, Pan KC, Etherington MK, Wu CC, Wong KT, et al.

J Phys Chem C Nanomater Interfaces, 2019 May 16;123(19):12400-12410.
PMID: 32952765 DOI: 10.1021/acs.jpcc.9b01900

Understanding the excited-state dynamics and conformational relaxation in thermally activated delayed fluorescence (TADF) molecules, including conformations that potentially support intramolecular through-space charge transfer, can open new avenues for TADF molecular design as well as elucidate complex photophysical pathways in structurally complex molecules. Emissive molecules comprising a donor (triphenylamine, TPA) and an acceptor (triphenyltriazine, TRZ) bridged by a second donor (9,9-dimethyl-9-10-dihydroacridin, DMAC, or phenoxazine, PXZ) are synthesized and characterized. In solution, the flexibility of the sp3-hybridized carbon atom in DMAC of DMAC-TPA-TRZ, compared to the rigid PXZ, allows significant conformational reorganization, giving rise to multiple charge-transfer excited states. As a result of such a reorganization, the TRZ and TPA moieties become cofacially aligned, driven by a strong dipole-dipole attraction between the TPA and TRZ units, forming a weakly charge-transfer dimer state, in stark contrast to the case of PXZ-TPA-TRZ where the rigid PXZ bridge only supports a single PXZ-TRZ charge transfer (CT) state. The low-energy TPA-TRZ dimer is found to have a high-energy dimer local triplet state, which quenches delayed emission because the resultant singlet CT local triplet energy gap is too large to mediate efficient reverse intersystem crossing. However, organic light-emitting diodes using PXZ-TPA-TRZ as an emitting dopant resulted in external quantum efficiency as high as 22%, more than two times higher than that of DMAC-TPA-TRZ-based device, showing the impact that such intramolecular reorganization and donor-acceptor dimerization have on TADF performance.

Matched MeSH terms: Oxazines
Fulltext Spectrophotometric determination of trace arsenic (III) ion based on complex formation with gallocyanine

Nor Azah Yusof, Zainab Omar

Pertanika Journal of Science & Technology, 2009;17(1):-.
MyJurnal

In this study, a simple, selective and sensitive method, for spectrophotometric determination of As(III) with gallocyanine as the sensitive reagent was developed. The wavelength of an analytical measurement, for the determination of As (III), using gallocyanine was at 630 nm with an optimum response at pH 2. The RSD for the reproducibility of 100 ppm As (III) was 2.3%. The LOD was 0.04 ppm with linear dynamic range in As(III) concentration of 0.2 - 1.5 ppm. The developed method has been validated against Atomic Absorption Spectrophotometry (AAS). The interference study of several metal ions was carried out and it revealed that that Mn (II) ion was interfered the most.

Matched MeSH terms: Oxazines
Fulltext Effect of early neonatal exposure to deltamethrin on the purkinje cell number in rat cerebellum

Asari MA, Abdullah MS, Abdullah S

Malays J Med Sci, 2008 Jul;15(3):14-21.
PMID: 22570585 MyJurnal

Deltamethrin is a widely used insecticide belonging to the class of pyrethroid. Although the neurotoxicity of pyrethroids including deltamethrin is well established, it is still unclear whether exposure to deltamethrin during neonatal period has any deleterious effect on the survival of the Purkinje cells in the cerebellum. In the study, we investigated the total number of Purkinje cells in experimental rats exposed to deltamethrin using a stereological method, the fractionator. Deltamethrin in a dose of 1 mg/kg/day (corresponds to 20% of LD(50) ) was administered through oral gavage to male pups from 2(nd) to 5(th) postnatal day (PND). At PND 21 the animals were sacrificed and their cerebelli were removed. The cerebelli were systematically sampled using the fractionator method and stained with cresyl fast violet. The number of the Purkinje cells was counted for each cerebellum. The results showed that there was no significant difference in the total number of Purkinje cells in the deltamethrin-treated group as compared to the control animals. This suggests that deltamethrin exposure at the current dosage during the neonatal period do not have any significant effect on the survival of the Purkinje cells in the cerebellum.

Matched MeSH terms: Oxazines
Ofloxacin, a new quinolone for the treatment of gonorrhea

Rajakumar MK, Ngeow YF, Khor BS, Lim KF

Sex Transm Dis, 1988 1 1;15(1):25-6.
PMID: 3162781

Forty-three patients with uncomplicated gonorrhea were treated with 400 mg of ofloxacin. All had cultures negative for Neisseria gonorrhoeae at follow-up within two weeks of treatment. Minimal side effects were reported. Ofloxacin appears to be satisfactory as a single-dose oral drug for the treatment of gonococcal urethritis, including those cases caused by penicillinase-producing strains of N. gonorrhoeae.

Matched MeSH terms: Oxazines/administration & dosage; Oxazines/therapeutic use*
Fulltext Comparative performance of two commercial neonicotinoid baits against filth flies under field conditions

Nurita AT, Abu Hassan A

Trop Biomed, 2010 Dec;27(3):559-65.
PMID: 21399598 MyJurnal

Two performance (efficacy and attractiveness) comparisons of neonicotinoid baits QuickBayt® (imidacloprid) and Agita® (thiamethoxam) against filth flies were conducted under field conditions to determine suitability for use outdoors. The first experiment compared bait performance and the second compared effects of different applications on QuickBayt® performance. Applications compared were: (i) scattered in petri dish (SPD); (ii) wet-down in petri dish (WPD); (iii) scattered on cardboard (SCB) and (iv) painted on cardboards (PCB). Efficacy and attractiveness were assessed based on knockdown percentage (KD%) and number of flies feeding on baits, respectively. The KD% of QuickBayt® (34% ± 3.0%) was not significantly higher than Agita® (29% ± 1.3%) (t-test, P>0.05). Agita® (101 ± 5.7 flies) was significantly more attractive to flies than QuickBayt® (76 ± 4.8 flies) and the sugar solution (49 ± 7.2) (one-way ANOVA, P<0.05). The PCB and SCB applications were significantly more attractive to filth flies than WPD and SPD (One-way ANOVA, P<0.05), however differences in KD% were not significantly different (One-way ANOVA, P>0.05). The two baits provided the same level of efficacy in a wide-open area against filth flies of various species. QuickBayt® was more versatile; efficacy was not significantly affected by different applications. Surface area and moisture affects attractiveness of the bait.

Matched MeSH terms: Oxazines/pharmacology*; Oxazines/chemistry
Crystallographic, vibrational and DFT studies of 1-(2-hydroxy-4,5-dimethylphenyl)ethanone

Chidan Kumar CS, Parlak C, Fun HK, Tursun M, Bilge M, Chandraju S, et al.

Spectrochim Acta A Mol Biomol Spectrosc, 2015 Oct 5;149:762-70.
PMID: 25989614 DOI: 10.1016/j.saa.2015.05.012

Molecular structure and properties of 1-(2-hydroxy-4,5-dimethylphenyl)ethanone were experimentally investigated by X-ray diffraction technique and vibrational spectroscopy. Experimental results on the molecular structure of the reported compound were supported with computational studies using the density functional theory (DFT), with the Becke-3-Lee-Yang-Parr (B3LYP) functional and the 6-311+G(3df,p) basis set. Potential energy distribution (PED) and potential energy surface (PES) analyses were performed to identify characteristic frequencies and reliable conformational analysis correspondingly. The compound crystallizes in monoclinic space group C2/c with the CO up-OH down conformation. There is a good agreement between the experimentally determined geometrical parameters and vibrational frequencies of the compound to those predicted theoretically.

Matched MeSH terms: Oxazines
Synthesis, NMR, FT-IR, X-ray structural characterization, DFT analysis and isomerism aspects of 5-(2,6-dichlorobenzylidene)pyrimidine-2,4,6(1H,3H,5H)-trione

Barakat A, Al-Najjar HJ, Al-Majid AM, Soliman SM, Mabkhot YN, Shaik MR, et al.

Spectrochim Acta A Mol Biomol Spectrosc, 2015 Aug 5;147:107-16.
PMID: 25827772 DOI: 10.1016/j.saa.2015.03.016

The synthesis and spectral characterization of the 5-(2,6-dichlorobenzylidene)pyrimidine-2,4,6(1H,3H,5H)-trione;3 was reported. The solid state molecular structure of 3 was studied using X-ray crystallography. The relative stabilities of the seven possible isomers of 3 were calculated by DFT/B3LYP method using 6-311 G(d,p) basis set. The calculated total energies and thermodynamic parameters were used to predict the relative stabilities of these isomers. The effect of solvent polarity on the relative stability of these isomers was studied at the same level of theory using PCM. It was found that the keto form, (T0), is the most stable isomer both in the gaseous state and solution. In solution, the calculated total energies of all isomers are decreased indicating that all isomers are stabilized by the solvent effect. The vibrational spectra of the most stable isomer, 3(T0) are calculated using the same level of theory and the results are compared with the experimentally measured FTIR spectra. Good correlation was obtained between the experimental and calculated vibrational frequencies (R(2)=0.9992). The electronic spectra of 3(T0) in gas phase as well as in solutions were calculated using the TD-DFT method. All the predicted electronic transitions showed very little spectral shifts and increase in the intensity of absorption due to solvent effect. Also the (1)H- and (13)C-NMR chemical shifts of the stable isomer were calculated and the results were correlated with the experimental data. Good correlations between the experimental and calculated chemical shifts were obtained.

Matched MeSH terms: Oxazines
Fulltext The adsorption of reactive orange 16 and basic blue 3 from aqueous solution using quaternized blue swimmer crab carapace

Chuah, Y.J., Tan, Y.P., Abdullah, H.A.

Pertanika Journal of Science & Technology, 2018;26(4):2045-2062.
MyJurnal

The crab carapace is a waste which cannot be decomposed. This waste was used to
remove the Reactive Orange 16 (RO16) and Basic Blue 3 (BB3) from aqueous solution
at different operational parameters such as pH, mass load, the concentrations of dye and
the temperature. The crab collected was modified to obtain quaternized crab (QC) using
(3-chloro-2-hydroxypropyl) trimethylammonium chloride solution (C6H15Cl2NO, 65% w/w
in water). The pH of the dyes solution was varied from pH 4 to 10. The highest adsorption
percentage was achieved at pH 7 for both dyes. Increasing the QC mass for the adsorption
process had granted an increase of dyes removal percentage. The highest adsorption
percentage was achieved at 91.00% for RO16 and 29.40% for BB3 dyes with 7.5 g/L QC
used. However, the adsorption capacity of QC decreased with higher QC mass because the
dye molecules occupied on the surface and prevented other molecules to diffuse into the
QC. At higher concentration beyond 20 mg/L and 10 mg/L of RO16 and BB3, respectively,
the maximum adsorption was achieved at 2.5362 mg/g and 0.6812 mg/g. The adsorption of
both dyes by QC was best fitted using Langmuir isotherm model, explaining the adsorption
mainly occurred as a single layer on the surface of QC. Comparison to the results obtained
from the kinetic models, the adsorption was
chemisorption in nature. According to the
thermodynamic studies, the adsorption of
RO16 was an exothermic, while BB3 was
an endorthermic process.

Matched MeSH terms: Oxazines
Enhancing growth and lipid production of marine microalgae for biodiesel production via the use of different LED wavelengths

Teo CL, Atta M, Bukhari A, Taisir M, Yusuf AM, Idris A

Bioresour Technol, 2014 Jun;162:38-44.
PMID: 24736210 DOI: 10.1016/j.biortech.2014.03.113

Wavelength of light is a crucial factor which renders microalgae as the potential biodiesel. In this study, Tetraselmis sp. and Nannochloropsis sp. as famous targets were selected. The effect of different light wavelengths on growth rate and lipid production was studied. Microalgae were cultivated for 14 days as under blue, red, red-blue LED and white fluorescent light. The growth rate of microalgae was analyzed by spectrophotometer and cell counting while oil production under improved Nile red method. Optical density result showed the microalgae exhibited better growth curve under blue wavelength. Besides, Tetraselmis sp. and Nannochloropsis sp. under blue wavelength showed the higher growth rate (1.47 and 1.64 day(-1)) and oil production (102.954 and 702.366 a.u.). Gas chromatography analysis also showed that palmitic acid and stearic acid which were compulsory components for biodiesel contribute around 49-51% of total FAME from Nannochloropsis sp. and 81-83% of total FAME from Tetraselmis sp.

Matched MeSH terms: Oxazines/metabolism
Genetics and evidence for an esterase-associated mechanism of resistance to indoxacarb in a field population of diamondback moth (Lepidoptera: Plutellidae)

Sayyed AH, Wright DJ

Pest Manag Sci, 2006 Nov;62(11):1045-51.
PMID: 16886171

Bioassays (at generation G2) with a newly collected field population (designated CH3) of Plutella xylostella L. from farmers' fields in the Cameron Highlands, Malaysia, indicated resistance ratios of 813-, 79-, 171-, 498- and 1285-fold for indoxacarb, fipronil, spinosad, deltamethrin and Bacillus thuringiensis toxin Cry1Ac respectively compared with a laboratory susceptible population (Lab-UK). At G2 the field-derived population was divided into two subpopulations: one was selected (G2 to G7) with indoxacarb (indoxa-SEL), while the second was left unselected (UNSEL). A significant reduction in the resistance ratio for each compound was observed in UNSEL at G8. For indoxa-SEL, bioassays at G8 found that selection with indoxacarb gave a resistance ratio of 2594 compared with Lab-UK and of 90 compared with UNSEL. The toxicity of fipronil, spinosad and deltamethrin was not significantly different in indoxa-SEL at G8 compared with G2 but was significantly greater than UNSEL at G8. The toxicity of Cry1Ac was significantly reduced in indoxa-SEL at G8 compared with G2 but was also significantly greater than UNSEL at G8. This suggests that indoxacarb selection maintained resistance to these compounds in the indoxa-SEL population. Synergist studies indicated that resistance to indoxacarb in indoxa-SEL was esterase associated. Logit regression analysis of F1 reciprocal crosses between indoxa-SEL and Lab-UK indicated that resistance to indoxacarb was inherited as an autosomal, incompletely recessive (D(LC) = 0.35) trait. Tests of monogenic inheritance suggested that resistance to indoxacarb was controlled by a single locus.

Matched MeSH terms: Oxazines/metabolism*
Fulltext Bioactivity studies and adhesion of human osteoblast (hFOB) on silicon-biphasic calcium phosphate material

Ibrahim S, Sabudin S, Sahid S, Marzuke MA, Hussin ZH, Kader Bashah NS, et al.

Saudi J Biol Sci, 2016 Jan;23(1):S56-63.
PMID: 26858566 DOI: 10.1016/j.sjbs.2015.10.024

Surface reactivity of bioactive ceramics contributes in accelerating bone healing by anchoring osteoblast cells and the connection of the surrounding bone tissues. The presence of silicon (Si) in many biocompatible and bioactive materials has been shown to improve osteoblast cell adhesion, proliferation and bone regeneration due to its role in the mineralisation process around implants. In this study, the effects of Si-biphasic calcium phosphate (Si-BCP) on bioactivity and adhesion of human osteoblast (hFOB) as an in vitro model have been investigated. Si-BCP was synthesised using calcium hydroxide (Ca(OH)2) and phosphoric acid (H3PO4) via wet synthesis technique at Ca/P ratio 1.60 of material precursors. SiO2 at 3 wt% based on total precursors was added into apatite slurry before proceeding with the spray drying process. Apatite powder derived from the spray drying process was pressed into discs with Ø 10 mm. Finally, the discs were sintered at atmospheric condition to obtain biphasic hydroxyapatite (HA) and tricalcium phosphate (TCP) peaks simultaneously and examined by XRD, AFM and SEM for its bioactivity evaluation. In vitro cell viability of L929 fibroblast and adhesion of hFOB cell were investigated via AlamarBlue® (AB) assay and SEM respectively. All results were compared with BCP without Si substitution. Results showed that the presence of Si affected the material's surface and morphology, cell proliferation and cell adhesion. AFM and SEM of Si-BCP revealed a rougher surface compared to BCP. Bioactivity in simulated body fluid (SBF) was characterised by pH, weight gain and apatite mineralisation on the sample surface whereby the changes in surface morphology were evaluated using SEM. Immersion in SBF up to 21 days indicated significant changes in pH, weight gain and apatite formation. Cell viability has demonstrated no cytotoxic effect and denoted that Si-BCP promoted good initial cell adhesion and proliferation. These results suggest that Si-BCP's surface roughness (164 nm) was significantly higher than BCP (88 nm), thus enhancing the adhesion and proliferation of the osteoblast.

Matched MeSH terms: Oxazines
Fulltext Effect of Non-hydrogen Peroxide on Antibacterial Activity of Malaysian Meliponini Honey against Staphylococcus aureus

Jibril FI, Mohd Hilmi AB, Aliyu S

J Pharm Bioallied Sci, 2020 Nov;12(Suppl 2):S831-S835.
PMID: 33828385 DOI: 10.4103/jpbs.JPBS_280_19

Introduction: Stingless bee is an insect that belongs to the family Apidae. Its name is based on its disability of stinging. It has a high product of Meliponini honey and propolis by which are commonly referred to as stingless bee honey and stingless bee propolis. Meliponini honey is one of the crucial natural sources and has the potential to kill infectious microorganisms. Previous studies have proved that the antibacterial activity of natural honey was an effect of hydrogen peroxide, a substance contained in the honey. However, these claims were contradicting with too many studies.
Objective: Therefore, this study aimed to identify the antibacterial activity of Malaysian Meliponini honey which contained non-hydrogen peroxide against Staphylococcus aureus, an opportunistic microbial.
Materials and Methods: Meliponini honey was used as an antibacterial agent for the treatment of S. aureus in agar well diffusion assay. An amplex red hydrogen peroxide kit was used to identify the hydrogen peroxide in the honey sample. Meanwhile, non-hydrogen peroxide activity was performed by using honey-catalase treated.
Results: For the first time, we found that hydrogen peroxide was absent in all Meliponini honey samples. Meliponini honey has higher antibacterial activity (13.30 ± 0.56mm) compared to Apis honey (9.03 ± 0.22mm) in agar well diffusion assay.
Discussion: Non-hydrogen peroxide in Meliponini honey is a bioactive compound and beneficial to kill the microbial infection.
Conclusion: Antibacterial activity of Malaysian Meliponini honey is directly contributed by non-hydrogen peroxide.

Matched MeSH terms: Oxazines
Fulltext Cell proliferation assessment of human gingival fibroblasts treated with Clinacanthus nutans using alamarBlue assay

Kelvin Yong Pui Szi, Wan Afiqah Syahirah Wan Ghazali, Siti Fadilah Abdullah, Norzaliana Zawawi, Thirumulu Ponnuraj Kannan

Archives of Orofacial Sciences, 2018;13(2):1-6.
MyJurnal

Clinacanthus nutans (C. nutans), a well-known ethnopharmacological plant consumed for its medicinal purposes by Southeast Asian communities. C. nutans is said to possess antipyretic, inflammatory, antiedemic as well as analgesic properties and used traditionally in treating various skin ailments, Herpes infection, cancer and diabetes. The young leaves of this C. nutans are consumed in Malaysia for maintaining health. In this study, the proliferative activity of human gingival fibroblast cells (HGF-1, ATCC®CRL-2014™, USA) treated with the ethanol extract obtained from C. nutans leaves at three different concentrations (250, 125 and 62.5 µg/ml) was compared with the untreated cells using alamarBlue assay. The proliferative activity of HGF-1 using alamarBlue assay showed that the cells treated with 62.5 μg/ml of ethanolic extract of C. nutans leaves exhibited increased proliferation compared to the other groups and hence does not exhibit any cytotoxicity on HGF-1.

Matched MeSH terms: Oxazines
Enhanced Solubility and Bioavailability of Dolutegravir by Solid Dispersion Method: In Vitro and In Vivo Evaluation-a Potential Approach for HIV Therapy

Chaudhary S, Nair AB, Shah J, Gorain B, Jacob S, Shah H, et al.

AAPS PharmSciTech, 2021 Apr 09;22(3):127.
PMID: 33835317 DOI: 10.1208/s12249-021-01995-y

Being a candidate of BCS class II, dolutegravir (DTG), a recently approved antiretroviral drug, possesses solubility issues. The current research was aimed to improve the solubility of the DTG and thereby enhance its efficacy using the solid dispersion technique. In due course, the miscibility study of the drug was performed with different polymers, where Poloxamer 407 (P407) was found suitable to move forward. The solid dispersion of DTG and P407 was formulated using solvent evaporation technique with a 1:1 proportion of drug and polymer, where the solid-state characterization was performed using differential scanning calorimetry, Fourier transform infrared spectroscopy and X-ray diffraction. No physicochemical interaction was found between the DTG and P407 in the fabricated solid dispersion; however, crystalline state of the drug was changed to amorphous as evident from the X-ray diffractogram. A rapid release of DTG was observed from the solid dispersion (>95%), which is highly significant (p<0.05) as compared to pure drug (11.40%), physical mixture (20.07%) and marketed preparation of DTG (35.30%). The drug release from the formulated solid dispersion followed Weibull model kinetics. Finally, the rapid drug release from the solid dispersion formulation revealed increased Cmax (14.56 μg/mL) when compared to the physical mixture (4.12 μg/mL) and pure drug (3.45 μg/mL). This was further reflected by improved bioavailability of DTG (AUC: 105.99±10.07 μg/h/mL) in the experimental Wistar rats when compared to the AUC of animals administered with physical mixture (54.45±6.58 μg/h/mL) and pure drug (49.27±6.16 μg/h/mL). Therefore, it could be concluded that the dissolution profile and simultaneously the bioavailability of DTG could be enhanced by means of the solid dispersion platform using the hydrophilic polymer, P407, which could be projected towards improved efficacy of the drug in HIV/AIDS.

Matched MeSH terms: Oxazines/administration & dosage*; Oxazines/pharmacokinetics*; Oxazines/therapeutic use
Fulltext Biocompatibility assessment of fabricated melt-derived 45S5 bioactive glass on dental cells proliferation

Mohd Zain N.S., Tajudin S.S., Mohd Noor S.N.F., Mohamad H.

Journal of Biomedical and Clinical Sciences, 2016;1(1):26-32.
MyJurnal

Thisstudy aim tocharacterize melt-derivedbioactive glass and to determinethe bioactive glass (BG) suitability for dental usagethrough proliferative activity assessment of stem cells from human exfoliated deciduous teeth (SHED)when exposed to bioactive glass conditioned medium. Bioglass 45S5 in mole percentages (46.13% SiO2, 26.91% CaO, 24.35% Na2O and 2.60% P2O5)was synthesizedthrough melt-derived and characterized usingX-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR)to confirm and identify its properties.SHEDwere used to evaluate the biocompatibility of 45S5 by exposing the cells to various concentration of BG-conditioned medium (1-10 mg/ml) using alamarBlue assay. The BG produced has an amorphous structureas shown by XRD analysis. TheSi-O-Si bending, asymmetric Si-O stretching and asymmetricSi-O-Si stretchingbands were observed in the BG structure supporting the presenceof silicate network. For alamarBlue assay, SHED cultured in BG-conditioned medium showed high proliferation rate when subjected to minimal powder content in the DMEM cell culture medium.Hence, it can be concluded that SHED cultured in lower powder content of the BG-conditioned media showedhigh proliferative activity suggesting the potential of the BG for dental usage.

Matched MeSH terms: Oxazines
Investigating the Mechanistic and Structural Role of Lipid Hydrolysis in the Stabilization of Ammonia-Preserved Hevea Rubber Latex

Kumarn S, Churinthorn N, Nimpaiboon A, Sriring M, Ho CC, Takahara A, et al.

Langmuir, 2018 10 30;34(43):12730-12738.
PMID: 30335388 DOI: 10.1021/acs.langmuir.8b02321

The stabilization mechanism of natural rubber (NR) latex from Hevea brasiliensis was studied to investigate the components involved in base-catalyzed ester hydrolysis, namely, hydrolyzable lipids, ammonia, and the products responsible for the desired phenomenon observed in ammonia-preserved NR latex. Latex stability is generally thought to come from a rubber particle (RP) dispersion in the serum, which is encouraged by negatively charged species distributed on the RP surface. The mechanical stability time (MST) and zeta potential were measured to monitor field latices preserved in high (FNR-HA) and low ammonia (FNR-LA) contents as well as that with the ester-containing components removed (saponified NR) at different storage times. Amounts of carboxylates of free fatty acids (FFAs), which were released by the transformation and also hypothesized to be responsible for the like-charge repulsion of RPs, were measured as the higher fatty acid (HFA) number and corroborated by confocal laser scanning microscopy (CLSM) both qualitatively and quantitatively. The lipids and their FFA products interact differently with Nile red, which is a lipid-selective and polarity-sensitive fluorophore, and consequently re-emit characteristically. The results were confirmed by conventional ester content determination utilizing different solvent extraction systems to reveal that the lipids hydrolyzed to provide negatively charged fatty acid species were mainly the polar lipids (glycolipids and phospholipids) at the RP membrane but not those directly linked to the rubber molecule and, to a certain extent, those suspended in the serum. From new findings disclosed herein together with those already reported, a new model for the Hevea rubber particle in the latex form is proposed.

Matched MeSH terms: Oxazines
Fulltext Data on synthesis and characterization of new p-nitro stilbene Schiff bases derivatives as an electrochemical DNA potential spacer

Mohd Izham NZ, Yusoff HM, Ul Haq Bhat I, Endo T, Fukumura H, Kwon E, et al.

Data Brief, 2020 Jun;30:105568.
PMID: 32368595 DOI: 10.1016/j.dib.2020.105568

The structural investigation of synthesized compounds can be carried out by various spectroscopic techniques. It is an important prospect in order to elucidate the structure of the desired products before being further utilized. The preparation of new p-nitro stilbene Schiff base derivatives as an electrochemical DNA potential spacer was synthesized using (E)-4-(4-nitrostyryl)aniline from Heck reaction with aldehydes in ethanolic solution. The data presented here in this article contains FTIR, UV-Vis and 1H and 13C NMR of (E)-4-(4-nitrostyryl)aniline and nitrostyryl aniline derivatives.

Matched MeSH terms: Oxazines
Antibacterial and cytotoxic activity assessment of Channa striatus (Haruan) extract

Mat Zawawi NZ, Shaari R, Luqman Nordin M, Hayati Hamdan R, Peng TL, Zalati CWSCW

Vet World, 2020 Mar;13(3):508-514.
PMID: 32367957 DOI: 10.14202/vetworld.2020.508-514

Background and Aim: Channa striatus extract, a freshwater snakehead fish known as Haruan, is popular in Southeast Asia for consumption and as a traditional therapeutic remedy for wound healing. C. striatus is also used in osteoarthritic for its anti-inflammatory. The aim of this study was to determine the presence of antibacterial properties of C. striatus extract against oral bacteria and to investigate the cytotoxic activity against Vero cells.
Materials and Methods: The authors prepared C. striatus extract in chloroform-methanol solvents. Next, the authors took subgingival microbiological samples from 16 cats that had periodontal disease. The authors determined the antibacterial properties of C. striatus extract against the isolated bacteria using the disk diffusion method and a broth microdilution-based resazurin microtiter assay. Finally, the authors used the Vero cell line to evaluate the cytotoxic activity, and they assessed the cell availability using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.
Results: The results showed weak antibacterial activity of C. striatus extract against Pseudomonas spp. and Escherichia coli. In addition, the authors found that minimum inhibition concentration values ranged between 400 and 500 mg/mL, and minimum bactericidal concentration values ranged between 650 and 550 mg/mL. However, the cytotoxic results were promising, showing that C. striatus extract increased the cell viability and growth when it was at a higher concentration. The extract also promotes growth and cell proliferation.
Conclusion: These findings suggest that C. striatus extract promoted cell proliferation in vitro and could be a plausible therapeutic wound healing alternative for periodontal disease in cats.

Matched MeSH terms: Oxazines

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