Displaying publications 21 - 40 of 10151 in total

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  1. Mishra RK, Ramasamy K, Ahmad NA, Eshak Z, Majeed AB
    J Mater Sci Mater Med, 2014 Apr;25(4):999-1012.
    PMID: 24398912 DOI: 10.1007/s10856-013-5132-x
    Stimuli responsive hydrogels have shown enormous potential as a carrier for targeted drug delivery. In this study we have developed novel pH responsive hydrogels for the delivery of 5-fluorouracil (5-FU) in order to alleviate its antitumor activity while reducing its toxicity. We used 2-(methacryloyloxyethyl) trimetylammonium chloride a positively charged monomer and methacrylic acid for fabricating the pH responsive hydrogels. The released 5-FU from all except hydrogel (GEL-5) remained biologically active against human colon cancer cell lines [HT29 (IC50 = 110-190 μg ml(-1)) and HCT116 (IC50 = 210-390 μg ml(-1))] but not human skin fibroblast cells [BJ (CRL2522); IC50 ≥ 1000 μg ml(-1)]. This implies that the copolymer hydrogels (1-4) were able to release 5-FU effectively to colon cancer cells but not normal human skin fibroblast cells. This is probably due to the shorter doubling time that results in reduced pH in colon cancer cells when compared to fibroblast cells. These pH sensitive hydrogels showed well defined cell apoptosis in HCT116 cells through series of events such as chromatin condensation, membrane blebbing, and formation of apoptotic bodies. No cell killing was observed in the case of blank hydrogels. The results showed the potential of these stimuli responsive polymer hydrogels as a carrier for colon cancer delivery.
    Matched MeSH terms: Biocompatible Materials/chemistry; Drug Carriers/chemistry; Methacrylates/chemistry*; Polymethacrylic Acids/chemistry*
  2. Chowchaikong N, Nilwarangkoon S, Laphookhieo S, Tanunyutthawongse C, Watanapokasin R
    Int J Oncol, 2018 Jun;52(6):2031-2040.
    PMID: 29620273 DOI: 10.3892/ijo.2018.4353
    Colorectal cancer, which is the third most common type of cancer diagnosed in both men and women, is the leading cause of cancer-related deaths worldwide. Cowanin is a pure compound extracted from Garcinia cowa Roxb., a tree species present in Thailand, Malaysia and Myanmar. The crude extract has been demonstrated to have antitumor activity, inflammation induction, antibacterial activity, anti-inflammatory activity and antimalarial activity. In the present study, the effects of cowanin on apoptosis induction and on the apoptosis-related and mitogen-activated protein kinase (MAPK) pathways were investigated in the LoVo human colorectal cancer cell line. The cytotoxicity of cowanin in LoVo cells was determined by MTT assay. Hoechst 33342 and JC‑1 staining were used to determine nuclear morphological changes and mitochondrial membrane potential, respectively. The expression levels of BCL2 apoptosis regulator (Bcl‑2) family, MAPK and AKT serine/threonine kinase 1 (Akt) pathway proteins following cowanin treatment were determined by western blot analysis. The results demonstrated that cowanin inhibited cell proliferation and induced cell death via the apoptosis pathway. Cowanin treatment increased BCL2 associated X (Bax) and decreased Bcl‑2 expression. In addition, cowanin activated caspase‑9, -7 and poly-ADP-ribose-polymerase expression. Furthermore, cowanin decreased the levels of phosphorylated extracellular signal-regulated kinase (p‑ERK), p‑Akt, p‑3‑phosphoinositide‑dependent protein kinase‑1, while it increased p‑p38 expression, thus resulting in the induction of apoptosis. In conclusion, cowanin inhibited cell proliferation and induced apoptosis of LoVo cells via the MAPK and Akt signaling pathways. Notably, inhibition of p38 by using a p38 inhibitor (SB203580) prevented the cowanin-induced apoptosis in LoVo cells. These results suggested that cowanin may be a potential candidate for the treatment of colorectal cancer and provided important information on the molecular mechanisms underlying its antitumor activity.
    Matched MeSH terms: Tannins/chemistry
  3. Ramli I, Kamarulzaman NH, Shaari K, Ee GC
    Nat Prod Res, 2004 Aug;18(4):289-94.
    PMID: 15214478
    Leaf extracts of Melicope lunu-ankenda were chemically studied and found to contain mixtures of hydrocarbons and squalene, fatty acids and esters. A geranylated coumaric acid was isolated as the major compound. The crude dichloromethane and methanol extracts of the leaves were found to be strongly larvicidal with LC50 values below 20 microg mL(-1). This is a first isolation of p-O-geranylcoumaric acid from this plant.
    Matched MeSH terms: Coumaric Acids/chemistry; Plant Extracts/chemistry
  4. Lai SL, Wong PF, Lim TK, Lin Q, Mustafa MR
    Phytomedicine, 2015 Jan 15;22(1):203-12.
    PMID: 25636890 DOI: 10.1016/j.phymed.2014.11.016
    Panduratin A (PA), a cyclohexanyl chalcone from Boesenbergia rotunda (L.) Mansf. was shown to possess anti-angiogenic effects in our previous study. In the present study, the molecular targets and anti-angiogenic mechanisms of PA on human umbilical vein endothelial cells (HUVECs) were identified using an iTRAQ-based quantitative proteomics approach. A total of 263 proteins were found to be differentially regulated in response to treatment with PA. Ingenuity Pathway Analysis revealed that cellular growth and proliferation, protein synthesis, RNA post-transcriptional modification, cellular assembly and organization and cell-to-cell signaling and interaction were the most significantly deregulated molecular and cellular functions in PA-treated HUVECs. PA inhibited the expressions of ARPC2 and CTNND1 that are associated with the formation of actin cytoskeleton, focal adhesion and cellular protrusions. In addition, PA down-regulated CD63, GRB-2, ICAM-2 and STAB-1 that are implicated in adhesion, migration and tube formation of endothelial cells. The differential expressions of three targets, namely, ARPC2, CDK4, and GRB-2 were validated by western blot analyses. Furthermore, PA inhibited G1-S progression, and resulted in G0/G1 arrest in HUVECs. The blockage in cell cycle progression was accompanied with the suppression of mTOR signaling. Treatment of HUVECs with PA resulted in decreased phosphorylation of ribosomal S6 and 4EBP1 proteins, the two downstream effectors of mTOR signaling. We further showed that PA is able to inhibit mTOR signaling induced by VEGF, a potent inducer of angiogenesis. Taken together, by integrating quantitative proteomic approach, we identified protein targets in which PA mediates its anti-angiogenic effects. The present study thus provides mechanistic evidence to the previously reported multifaceted anti-angiogenic effects of PA. Our study further identified mTOR signaling as an important target of PA, and therefore highlights the potential of PA for therapeutic intervention against angiogenesis-related pathogenesis, particularly, metastatic malignancy.
    Matched MeSH terms: Rhizome/chemistry; Zingiberaceae/chemistry
  5. Kausar S, Altaf AA, Hamayun M, Rasool N, Hadait M, Akhtar A, et al.
    Molecules, 2020 Jul 31;25(15).
    PMID: 32752133 DOI: 10.3390/molecules25153520
    Lignin depolymerization for the purpose of synthesizing aromatic molecules is a growing focus of research to find alternative energy sources. In current studies, the photocatalytic depolymerization of lignin has been investigated by two new iso-propylamine-based lead chloride perovskite nanomaterials (SK9 and SK10), synthesized by the facile hydrothermal method. Characterization was done by Powder X-Ray Diffraction (PXRD), Scanning Electron Microscopy (SEM), UV-Visible (UV-Vis), Photoluminescence (PL), and Fourier-Transform Infrared (FTIR) Spectroscopy and was used for the photocatalytic depolymerization of lignin under UV light. Lignin depolymerization was monitored by taking absorption spectra and catalytic paths studied by applying kinetic models. The %depolymerization was calculated for factors such as catalyst dose variation, initial concentration of lignin, and varying temperatures. Pseudo-second order was the best suited kinetic model, exhibiting a mechanism for lignin depolymerization that was chemically rate controlled. The activation energy (Ea) for the depolymerization reaction was found to be 15 kJ/mol, which is remarkably less than conventional depolymerization of the lignin, i.e., 59.75 kJ/mol, exhibiting significant catalytic efficiencies of synthesized perovskites. Products of lignin depolymerization obtained after photocatalytic activity at room temperature (20 °C) and at 90 °C were characterized by GC-MS analysis, indicating an increase in catalytic lignin depolymerization structural subunits into small monomeric functionalities at higher temperatures. Specifically, 2-methoxy-4-methylphenol (39%), benzene (17%), phenol (10%) and catechol (7%) were detected by GC-MS analysis of lignin depolymerization products.
    Matched MeSH terms: Lead/chemistry*; Lignin/chemistry*; Oxides/chemistry*; Propylamines/chemistry*; Titanium/chemistry*; Calcium Compounds/chemistry*
  6. Bringmann G, Dreyer M, Kopff H, Rischer H, Wohlfarth M, Hadi HA, et al.
    J Nat Prod, 2005 May;68(5):686-90.
    PMID: 15921410
    Three new fully dehydrogenated naphthylisoquinoline alkaloids, the 7,1'-coupled ent-dioncophylleine A (3a), the likewise 7,1'-coupled 5'-O-demethyl-ent-dioncophylleine A (4), and the 7,8'-linked dioncophylleine D (5), have been isolated from the leaves of the recently described Malaysian highland liana Ancistrocladusbenomensis. All of them lack an oxygen function at C-6; this so-called Dioncophyllaceae-type structural subclass had previously been found only in naphthylisoquinoline alkaloids from West and Central African plants. Moreover, compounds 3a and 4 are the first fully dehydrogenated, i.e., only axially chiral, naphthylisoquinoline alkaloids of this type that are optically active; compound 5, by contrast, is fully racemic, due to its configurationally unstable biaryl axis. The structural elucidation was achieved by spectroscopic and chiroptical methods. Biological activities of these alkaloids against different protozoan parasites are described.
    Matched MeSH terms: Alkaloids/chemistry*; Antimalarials/chemistry; Isoquinolines/chemistry; Naphthalenes/chemistry; Plants, Medicinal/chemistry*; Trypanocidal Agents/chemistry; Plant Leaves/chemistry
  7. Lau SE, Schwarzacher T, Othman RY, Harikrishna JA
    BMC Plant Biol, 2015;15:194.
    PMID: 26260631 DOI: 10.1186/s12870-015-0577-3
    The R2R3-MYB genes regulate pigmentation and morphogenesis of flowers, including flower and cell shape, and therefore have importance in the development of new varieties of orchids. However, new variety development is limited by the long breeding time required in orchids. In this study, we identified a cDNA, DhMYB1, that is expressed during flower development in a hybrid orchid, Dendrobium hybrida (Dendrobium bobby messina X Dendrobium chao phraya) then used the direct application of dsRNA to observe the effect of gene silencing on flower phenotype and floral epidermal cell shape.
    Matched MeSH terms: Plant Proteins/chemistry; Transcription Factors/chemistry
  8. Choudhary MI, Ismail M, Shaari K, Abbaskhan A, Sattar SA, Lajis NH, et al.
    J Nat Prod, 2010 Apr 23;73(4):541-7.
    PMID: 20356064 DOI: 10.1021/np900551u
    Phytochemical and cytotoxicity investigations on organic solvent extracts of the aerial parts of Tinospora crispa have led to the isolation of 15 cis-clerodane-type furanoditerpenoids. Of these, nine compounds (1-9) were found to be new. Spectroscopic assignments of a previously reported compound, borapetoside A (13), were revised on the basis of HMQC and HMBC correlations. No discernible activity was observed when compounds 10-13 were subjected to evaluation in cytotoxicity assays against human prostate cancer (PC-3) and the normal mouse fibroblast (3T3) cell lines.
    Matched MeSH terms: Plants, Medicinal/chemistry*; Tinospora/chemistry*; Diterpenes, Clerodane/chemistry
  9. Deepak P, Kumar P, Arya DK, Pandey P, Kumar S, Parida BP, et al.
    Int J Pharm, 2023 Jul 25;642:123160.
    PMID: 37379892 DOI: 10.1016/j.ijpharm.2023.123160
    Current anticancer drug research includes tumor-targeted administration as a critical component because it is the best strategy to boost efficacy and decrease toxicity. Low drug concentration in cancer cells, nonspecific distribution, rapid clearance, multiple drug resistance, severe side effects, and other factors contribute to the disappointing results of traditional chemotherapy. As an innovative technique of treatments for hepatocellular carcinoma (HCC) in recent years, nanocarrier-mediated targeted drug delivery systems can overcome the aforesaid limitations via enhanced permeability and retention effect (EPR) and active targeting. Epidermal growth factor receptor (EGFR) inhibitor Gefitinib (Gefi) has dramatic effects on hepatocellular carcinoma. Herein, we developed and assessed an αvβ3 integrin receptor targeted c(RGDfK) surface modified liposomes for better targeting selectivity and therapeutic efficacy of Gefi on HCC cells. The conventional and modified Gefi loaded liposomes, i.e., denoted as Gefi-L and Gefi-c(RGDfK)-L, respectively, were prepared through the ethanol injection method and optimized via Box Behnken design (BBD). The FTIR and 1H NMR spectroscopy verified that the c(RGDfK) pentapeptides had formed an amide bond with the liposome surface. In addition, the particle size, Polydispersity index, zeta potential, encapsulation efficiency, and in-vitro Gefi release of the Gefi-L and Gefi-c(RGDfK)-L were measured and analyzed. As indicated by the MTT assay on HepG2 cells, Gefi-c(RGDfK)-L displayed considerably higher cytotoxicity than Gefi-L or Gefi alone. Throughout the incubation period, HepG2 cells took up significantly more Gefi-c(RGDfK)-L than Gefi-L. According to the in vivo biodistribution analysis, Gefi-c(RGDfK)-L accumulated more strongly at the tumor site than Gefi-L and free Gefi. Furthermore, HCC-bearing rats treated with Gefi-c(RGDfK)-L showed a substantial drop in liver marker enzymes (alanine transaminase, alkaline phosphatase, aspartate transaminase, and total bilirubin levels) compared to the disease control group. Gefi-c(RGDfK)-L suppresses tumour growth more effectively than Gefi-L and free Gefi, according to an in vivo analysis of their anticancer activities. Thus, c(RGDfK)-surface modified liposomes, i.e., Gefi-c(RGDfK)-L may serve as an efficient carrier for the targeted delivery of anticancer drugs.
    Matched MeSH terms: Liposomes/chemistry
  10. Ali H, Houghton PJ, Soumyanath A
    J Ethnopharmacol, 2006 Oct 11;107(3):449-55.
    PMID: 16678367
    Extracts of six selected Malaysian plants with a reputation of usefulness in treating diabetes were examined for alpha-amylase inhibition using an in vitro model. Inhibitory activity studied by two different protocols (with and without pre-incubation) showed that Phyllanthus amarus hexane extract had alpha-amylase inhibitory properties. Hexane and dichloromethane extracts of Anacardium occidentale, Lagerstroemia speciosa, Averrhoa bilimbiPithecellobium jiringa and Parkia speciosa were not active when tested without pre-incubation. Extraction and fractionation of Phyllanthus amarus hexane extract led to the isolation of dotriacontanyl docosanoate, triacontanol and a mixture of oleanolic acid and ursolic acid. Dotriacontanyl docosanoate and the mixture of oleanolic acid and ursolic acid are reported from this plant species for the first time. All compounds were tested in the alpha-amylase inhibition assay and the results revealed that the oleanolic acid and ursolic acid (2:1) mixture was a potent alpha-amylase inhibitor with IC(50)=2.01 microg/ml (4.41 microM) and that it contributes significantly to the alpha-amylase inhibition activity of the extract. Three pure pentacyclic triterpenoids, oleanolic acid, ursolic acid and lupeol were shown to inhibit alpha-amylase.
    Matched MeSH terms: Drugs, Chinese Herbal/chemistry; Enzyme Inhibitors/chemistry; Hypoglycemic Agents/chemistry
  11. Chin LF, Kong SM, Seng HL, Tiong YL, Neo KE, Maah MJ, et al.
    J Biol Inorg Chem, 2012 Oct;17(7):1093-105.
    PMID: 22825726 DOI: 10.1007/s00775-012-0923-y
    Two ternary Zn(II) complexes, with 1,10-phenanthroline (phen) as the main ligand and a carboxylate-containing ligand [dipicolinate (dipico) or L-threoninate (L-Thr)] as the subsidiary ligand, were prepared and characterized by elemental analysis, Fourier transform IR, UV, and fluorescence spectroscopy, X-ray diffraction, molar conductivity, and electrospray ionization mass spectrometry. X-ray structure analysis shows that both [Zn(phen)(dipico)(H(2)O)]·H(2)O (1) and [Zn(phen)(L-Thr)(H(2)O)Cl]·2H(2)O (2) have octahedral geometry about the Zn(II) atom. Both complexes can inhibit topoisomerase I, and have better anticancer activity than cisplatin against nasopharyngeal cancer cell lines, HK1 and HONE-1, with concentrations causing 50 % inhibition of cell proliferation (IC(50)) in the low micromolar range. Complex 2 has the highest therapeutic index for HK1. Both Zn(II) complexes can induce cell death by apoptosis. Changing the subsidiary ligand in the Zn(II) complexes affects the UV-fluorescence spectral properties of the coordinated phen ligand, the binding affinity for some DNA sequences, nucleobase sequence-selective binding, the phase at which cell cycle progression was arrested for treated cancer cells, and their therapeutic index.
    Matched MeSH terms: Antineoplastic Agents/chemistry; Cisplatin/chemistry; Phenanthrolines/chemistry*; Pyridines/chemistry*; Threonine/chemistry*; Zinc/chemistry*; Coordination Complexes/chemistry; Topoisomerase Inhibitors/chemistry
  12. Wu YL, Wang XH, Li YY, Hong HS, Li HY, Yin MD
    Huan Jing Ke Xue, 2009 Sep 15;30(9):2512-9.
    PMID: 19927796
    Polycyclic aromatic hydrocarbons (PAHs) in a sediment core collected from Langkawi Island of the Andaman Sea, Malaysia were determined by GC/MS, the vertical variations of concentration and distributions of PAHs were investigated. In combining with 210Pb-dating, the PAHs sedimentary record in the last 100 years was reconstructed and their possible sources were also discussed. The sigmaPAH concentration ranged from 13.2-60.1 ng x g(-1) in the whole sedimentary section (0-56 cm) with the dominant compounds of phenanthrene, naphthalene and perylene. The sediments contaminated to a lesser extent comparing with the surrounding waters. Before the 1920s, the concentrations of PAHs were considered to be the background level, which was implied from the natural inputs. The historical records of PAHs in the core showed that two distinct peaks which represented the input time of 1960s and 1980s, respectively, inferred that there were some relatively dramatically land-based inputs, and human activities leaded a clear impact to these waters during these periods. Furthermore, PAHs diagnostic ratios indicated that PAHs in the core sediments were mainly of pyrolytic origin (combustion), accompanied with minor petroleum origin. These were related with agriculture, industry, ocean import and export, and shipping activities in the surrounding regions. Meanwhile as the vital communication line, the marine transportation of the Strait of Malacca had influenced the environmental quality of the Andaman Sea. Meanwhile, based on the sedimentary record, PAHs concentrations were found to correlate positively with humanism activities and socioeconomic development (Gross Domestic Production) in the surrounding regions.
    Matched MeSH terms: Geologic Sediments/chemistry*
  13. Habib U, Cecilia DW, Maizatul SS
    Se Pu, 2017 Jun 08;35(6):656-664.
    PMID: 29048794 DOI: 10.3724/SP.J.1123.2017.02002
    Ionic liquids (ILs) based ultrasonic-assisted extract has been applied for the extraction of essential oil from Persicaria minor leaves. The effects of temperature, sonication time, and particle size of the plant material on the yield of essential oil were investigated. Among the different ILs employed, 1-ethyl-3-methylimidazolium acetate was the most effective, providing a 9.55% yield of the essential oil under optimum conditions (70 ℃, 25 min, IL:hexane ratio of 7:10 (v/v), particle size 60-80 mesh). The performance of 1-ethyl-3-methylimidazolium acetate in the extraction was attributed to its low viscosity and ability to disintegrate the structural matrix of the plant material. The ability of 1-ethyl-3-methylimidazolium acetate was also confirmed using the conductor like-screening model for realistic solvents. This research proves that ILs can be used to extract essential oils from lignocellulosic biomass.
    Matched MeSH terms: Plant Extracts/chemistry*; Plant Leaves/chemistry; Tracheobionta/chemistry*
  14. Sorokin EV, Tsareva TR, Sominina AA, Pisareva MM, Komissarov AV, Kosheleva AA, et al.
    Vopr. Virusol., 2014;59(6):27-31.
    PMID: 25929033
    A panel of five monoclonal antibodies (MAbs) to the HA1 molecule of the influenza B virus of the Victorian lineage with high virus-neutralizing activity was developed. For identification of the virus neutralizing epitopes in HA1 escape mutants (EM) of the influenza BIShandong/07/97 and B/Malaysia/2506/04 virus were selected using virus- neutralizing antibodies (MAbs). Three EMs had single, two--double and one--triple amino acid substitutions (AAS) in HA1 (H122N, A202E, K203T, K2031, K203N or A317V). In addition, AAS N197S was detected in three EMs. A correlation of AAS identified with peculiarities of interaction of EMs with Mabs was discussed.
    Matched MeSH terms: Antigen-Antibody Complex/chemistry; Epitopes/chemistry*; Hemagglutinin Glycoproteins, Influenza Virus/chemistry*
  15. Takayama H, Aimi N, Sakai S
    Yakugaku Zasshi, 2000 Oct;120(10):959-67.
    PMID: 11082707
    The leaves of a tropical plant, Mitragyna speciosa Korth. (Rubiaceae), have been traditionally used as a substitute for opium. By phytochemical studies on the constituents of the plant growing in Thailand as well as in Malaysia, several 9-methoxy-Corynanthe-type monoterpenoid indole alkaloids including new natural products were isolated. The structures of these new compounds were elucidated by the modern spectroscopic methods and/or chiral-total syntheses. The chiral total synthesis of (-)-mitragynine, a major component of this plant, was achieved. Potent opioid agonistic properties of mitragynine, which acts on mu- and delta-opioid subtype receptors, and of mitragynine pseudoindoxyl, whose analgesic activity is more potent than that of morphine, were clarified in in vitro experiments. The essential structural features in mitragynine for revealing the analgesic activity were elucidated by pharmacological evaluation of the natural and synthetic mitragynine derivatives.
    Matched MeSH terms: Plants, Medicinal/chemistry*
  16. Baig MR, Rajan G, Yunus N
    Gerodontology, 2012 Jun;29(2):e1140-5.
    PMID: 21615782 DOI: 10.1111/j.1741-2358.2010.00433.x
    Dental rehabilitation of a completely edentulous geriatric patient has always been a challenge to the clinician, especially in treating those with higher expectations and demands. Treatment duration and the amount of residual alveolar bone available are often important considerations when planning for dental implant-based fixed treatment for these patients. With the introduction of zygomatic implants, a graftless alternative solution has emerged for deficient maxillary bone with provision for immediate loading. This article describes the treatment of a completely edentulous elderly patient using zygomatic implants in conjunction with conventional implants. The implants were immediately loaded using a definitive acrylic resin fixed denture reinforced with a cast metal framework, to provide function and aesthetics.
    Matched MeSH terms: Acrylic Resins/chemistry; Chromium Alloys/chemistry; Dental Materials/chemistry
  17. Arshad R, Sohail MF, Sarwar HS, Saeed H, Ali I, Akhtar S, et al.
    PLoS One, 2019;14(6):e0217079.
    PMID: 31170179 DOI: 10.1371/journal.pone.0217079
    Post-operative surgical site infections (SSI) present a serious threat and may lead to complications. Currently available dressings for SSI lack mucoadhesion, safety, efficacy and most importantly patient compliance. We aimed to address these concerns by developing a bioactive thiolated chitosan-alginate bandage embedded with zinc oxide nanoparticles (ZnO-NPs) for localized topical treatment of SSI. The FTIR, XRD, DSC and TGA of bandage confirmed the compatibility of ingredients and modifications made. The porosity, swelling index and lysozyme degradation showed good properties for wound healing and biodegradation. Moreover, in-vitro antibacterial activity showed higher bactericidal effect as compared to ZnO-NPs free bandage. In-vivo wound healing in murine model showed significant improved tissue generation and speedy wound healing as compared to positive and negative controls. Over all, thiolated bandage showed potential as an advanced therapeutic agent for treating surgical site infections, meeting the required features of an ideal surgical dressing.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry; Biocompatible Materials/chemistry*; Sulfhydryl Compounds/chemistry*; Zinc Oxide/chemistry*; Nanoparticles/chemistry*
  18. Selvaraj M, Assiri MA, Singh H, Appaturi JN, Subrahmanyam C, Ha CS
    Dalton Trans, 2021 Jan 21.
    PMID: 33475664 DOI: 10.1039/d0dt04158k
    The Prins cyclization of styrene (SE) with paraformaldehyde (PFCHO) was conducted with mesoporous ZnAlMCM-41 catalysts for the synthesis of 4-phenyl-1,3-dioxane (4-PDO) using a liquid phase heterogeneous catalytic method. For a comparison study, the Prins cyclization reaction was also conducted over different nanoporous catalysts, e.g. mesoporous solid acid catalysts, AlMCM-41(21) and ZnMCM-41(21), and microporous catalysts, USY, Hβ, HZSM-5, and H-mordenite. The recyclable mesoporous ZnAlMCM-41 catalysts were reused in this reaction to evaluate their catalytic stabilities. Since ZnAlMCM-41(75) has higher catalytic activity than other solid acid catalysts, washed ZnAlMCM-41(75)/W-ZnAlMCM-41(75) was prepared using an efficient chemical treatment method and used with various reaction parameters to find an optimal parameter for the highly selective synthesis of 4-PDO. W-ZnAlMCM-41(75) was also used in the Prins cyclization of olefins with PFCHO and formalin (FN, 37% aqueous solution of formaldehyde (FCHO)) under different reaction conditions to obtain 1,3-dioxanes, which are widely used as solvents or intermediates in organic synthesis. Based on the nature of catalysts used under different reaction conditions, a reasonable plausible reaction mechanism for the Prins cyclization of SE with PFCHO is proposed. Notably, it can be seen from the catalytic results of all catalysts that the W-ZnAlMCM-41(75) catalyst has higher 4-PDO selectivity with exceptional catalytic activity than other microporous and mesoporous catalysts.
    Matched MeSH terms: Chemistry Techniques, Synthetic
  19. Bera H, Abbasi YF, Yoke FF, Seng PM, Kakoti BB, Ahmmed SKM, et al.
    Int J Biol Macromol, 2019 May 15;129:552-563.
    PMID: 30707999 DOI: 10.1016/j.ijbiomac.2019.01.171
    Novel diethanolamine-grafted high-methoxyl pectin (DGP)-arabic gum (AG) modified montmorillonite (MMT) composites were developed for intragastric ziprasidone HCl (ZIP) delivery by combining floating and mucoadhesion mechanisms. The ZIP-loaded clay-biopolymer matrices were accomplished by ionotropic gelation protocol utilizing zinc acetate in the presence or absence of covalent crosslinker, glutaraldehyde (GA). Various formulations exhibited excellent drug entrapment efficiency (DEE, %) and sustained drug release profiles, which were influenced by the polymer-blend (DGP:AG) ratios, reinforcing filler (MMT) existence and crosslinking procedure. The optimal composites (F-3) demonstrated DEE of 61% and Q8h of 52% with outstanding buoyancy, mucin adsorption ability and biodegradability. The release profile of F-3 was best fitted in the Korsmeyer-Peppas model with Fickian diffusion driven mechanism. The mucin adsorption to composites F-3 followed Freundlich isotherms. The molar mass between crosslinks of composites (F-3) calculated employing Flory-Rehner equation was increased with temperature. Moreover, the thermal, X-ray and infrared analyses confirmed a compatible environment of drug in the composites, except certain extent of transformation of the crystalline drug to its amorphous form. The SEM studies revealed the spherical morphology of the composites. Thus, the newly developed DGP-AG-MMT composites are appropriate for gastroretentive ZIP delivery over an extended period of time.
    Matched MeSH terms: Bentonite/chemistry*; Drug Carriers/chemistry*; Gum Arabic/chemistry*; Pectins/chemistry*; Piperazines/chemistry*; Thiazoles/chemistry*
  20. Hamid A, Ibrahim FW, Ming TH, Nasrom MN, Eusoff N, Husain K, et al.
    BMC Complement Altern Med, 2018 Mar 20;18(1):101.
    PMID: 29558939 DOI: 10.1186/s12906-018-2161-5
    BACKGROUND: Zingiber zerumbet (L.) Smith belongs to the Zingiberaceae family that is widely distributed throughout the tropics, particularly in Southeast Asia. It is locally known as 'Lempoyang' and traditionally used to treat fever, constipation and to relieve pain. It is also known to possess antioxidant and anti-inflammatory activities. Based on these antioxidant and anti-inflammatory activities, this study was conducted to investigate the effects of ethyl-acetate extract of Z. zerumbet rhizomes against ethanol-induced brain damage in male Wistar rats.

    METHOD: Twenty-four male Wistar rats were divided into four groups which consist of normal, 1.8 g/kg ethanol (40% v/v), 200 mg/kg Z. zerumbet extract plus ethanol and 400 mg/kg Z. zerumbet plus ethanol. The extract of Z. zerumbet was given once daily by oral gavage, 30 min prior to ethanol exposure via intraperitoneal route for 14 consecutive days. The rats were then sacrificed. Blood and brain homogenate were subjected to biochemical tests and part of the brain tissue was sectioned for histological analysis.

    RESULT: Treatment with ethyl-acetate Z. zerumbet extract at 200 mg/kg and 400 mg/kg significantly reduced the level of malondialdehyde (MDA) and protein carbonyl (p 

    Matched MeSH terms: Antioxidants/chemistry; Plant Extracts/chemistry; Zingiberaceae/chemistry*
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