Enhanced Enzymatic Transformation of 1-Naphthol in the Presence of Catechol by Peroxidase

Islam, A.K.M. Mydul,Lee, Sung-Eun,Kim, Jang-Eok The Korean Society for Applied Biological Chemistr 2014 Applied Biological Chemistry (Appl Biol Chem) Vol.57 No.2

Effect of catechol on 1-naphthol transformation by horse radish peroxidase (HRP) was examined. The impact of catechol to 1-naphthol ratio, enzyme activity, pH, and reaction time in solution were studied. The results obtained indicated that, in the presence of catechol, 1-naphthol transformation by peroxidase shows enhancement greater than that in an equivalent catechol free system. Only 27% of 1-naphthol (0.3 mM) was able to transform when catechol was absent in solution, but reached 79% in its presence (3.0 mM) in 0.1M sodium phosphate buffer (pH 7.0), and 0.3 mM $H_2O_2$ by peroxidase (0.5 unit/mL) after 3 h. The 1-naphthol transformation rate was accelerated by increase of pH or HRP concentration. High-performance liquid chromatography analysis was performed to characterize transformation products based on their relative polarities, and molecular weights of products were identified by mass spectrometry. The transformation products were found to be (hydroxy) naphthoquinones, 1-naphthol: hydroxy-naphthoquinone, and 1-naphthol oligomers (dimer, trimer, tetramer) with the molecular weights (m/z) ranging 100-600. Liquid chromatography-tandem mass spectrometry technique, to the best of our knowledge, was used for the first time to elucidate the product structure at m/z 191. The study shows that 1-naphthol is transformed rapidly by peroxidase when catechol is present, which could be useful information for improving the efficiencies of decontamination techniques.

Enhanced Enzymatic Transformation of 1-Naphthol in the Presence of Catechol by Peroxidase

A. K. M. Mydul Islam,이성은,김장억 한국응용생명화학회 2014 Applied Biological Chemistry (Appl Biol Chem) Vol.57 No.2

Effect of catechol on 1-naphthol transformation byhorse radish peroxidase (HRP) was examined. The impact ofcatechol to 1-naphthol ratio, enzyme activity, pH, and reactiontime in solution were studied. The results obtained indicated that,in the presence of catechol, 1-naphthol transformation byperoxidase shows enhancement greater than that in an equivalentcatechol free system. Only 27% of 1-naphthol (0.3 mM) was ableto transform when catechol was absent in solution, but reached79% in its presence (3.0 mM) in 0.1M sodium phosphate buffer(pH 7.0), and 0.3 mM H2O2 by peroxidase (0.5 unit/mL) after 3 h. The 1-naphthol transformation rate was accelerated by increase ofpH or HRP concentration. High-performance liquid chromatographyanalysis was performed to characterize transformation productsbased on their relative polarities, and molecular weights of productswere identified by mass spectrometry. The transformation productswere found to be (hydroxy) naphthoquinones, 1-naphthol:hydroxy-naphthoquinone, and 1-naphthol oligomers (dimer, trimer,tetramer) with the molecular weights (m/z) ranging 100–600. Liquid chromatography-tandem mass spectrometry technique, tothe best of our knowledge, was used for the first time to elucidatethe product structure at m/z 191. The study shows that 1-naphtholis transformed rapidly by peroxidase when catechol is present,which could be useful information for improving the efficienciesof decontamination techniques.

Iturin produced by Bacillus pumilus HY1 from Korean soybean sauce (kanjang) inhibits growth of aflatoxin producing fungi

Cho, K.M.,Math, R.K.,Hong, S.Y.,Asraful Islam, S.Md.,Mandanna, D.K.,Cho, J.J.,Yun, M.G.,Kim, J.M.,Yun, H.D. Butterworths ; Taylor Francis ; Elsevier Science 2009 FOOD CONTROL Vol.20 No.4

A new strain of Bacillus pumilus, designated HY1, was isolated from Korean soybean sauce (kanjang). This classification was based on morphological, physiological, and chemotaxonomic features of the organism that identified it as a Gram-positive bacillus, and confirmed by 16S rDNA based phylogenetic analysis. Strain HY1 showed strong antifungal activity against the aflatoxin-producing fungi Aspergillus flavus and Aspergillus parasiticus, two common contaminants of fermented soybean foods. MALDI-TOF mass analysis revealed that the antifungal compound was similar to the known lipopeptide iturin. Iturin purified from strain HY1 had three isoforms with protonated masses of m/z 1,043.4, 1,057.4, and 1,071.4, and different structures in combination with Na<SUP>+</SUP> ion using MALDI-TOF MS. Purified iturin from HY1 also exhibited antifungal activity against A. flavus and A. parasiticus.

Synthesis, Characterization, and Reactivity of Novel 6H-1,3,5-Oxathiazine S,S-Dioxides

Islam, M. R.,Takikawa, Y.,Lim, K. T. Wiley-Blackwell 2014 Journal of heterocyclic chemistry Vol.51 No.3

A series of novel 6H-1,3,5-oxathiazine S,S-dioxides were synthesized by the m-CPBA oxidation (2.2 equiv) of 6H-1,3,5-oxathizines. The synthetic utilities of the newly synthesized cyclic sulfones were investigated. In a thermal condition, compounds 6H-1,3,5-oxathiazine S,S-dioxides were found relatively stable, but Lewis acid-induced thermal reaction afforded the corresponding amides. The plausible pathway to amides from 6H-1,3,5-oxathiazine S,S-dioxides was also discussed in this account.

Endotoxins of Enteric Pathogens Are Chemotactic Factors for Human Neutrophils

Islam, Laila N.,Nabi, A.H.M. Nurun,Ahmed, K. Mokim,Sultana, Novera Korean Society for Biochemistry and Molecular Biol 2002 Journal of biochemistry and molecular biology Vol.35 No.5

Early activation of human peripheral blood polymorphonuclear neutrophils is characterized by their morphological changes from spherical to polarized shapes. The endotoxins from enteric pathogens (S. dysenteriae type 1, V. cholerae Inaba 569B, S. typhimurium, and K. pneumoniae) were assessed by their ability to induce morphological polarization of the neutrophils as measures of early activation. Phagocytic activity, adhesion, chemokinetic locomotion, and nitroblue tetrazolium (NBT) dye-reduction ability measured the later activation of the cells. Neutrophils showed distinct morphological polarization in suspension over a wide range of concentrations of these endotoxins when were compared with those that were induced by the standard chemotactic factor, N-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP). It was discovered that all of the endotoxins induced locomotor responses in neutrophils in suspension that were dose- and time-dependent. The optimum concentration for the endotoxins of S. dysenteriae, V. cholerae, and K. pneumoniae was 1 mg/ml in which 71, 69, and 66% of the neutrophils were polarized. However, the S. typhimurium dose was 2 mg/ml in which 50% of the cells responded. Neutrophils that were stimulated with endotoxins also showed increased random locomotion (p<0.005) through cellulose nitrate filters, but an enhanced adhesion of the cells to glass surfaces (p<0.03). These are important functions of these cells to reach and phagocytose damaged cells, as well as invading microorganisms. Interestingly, the endotoxins had a highly-significant inhibitory effect upon the proportions of neutrophils phagocytosing opsonized yeast (p<0.01) with a small number of yeast that were engulfed by the cells (p<0.02). Further, endotoxin-treated cells showed an enhanced ability to reduce NBT dye (p<0.03). Therefore, we concluded that endotoxins of enteric pathogens are neutrophil chemotactic factors.

Endotoxins of Enteric Pathogens Are Chemotactic Factors for Human Neutrophils

(Laila N. Islam),(A. H. M. Nurun Nabi),(K. Mokim Ahmed),(Novera Sultana) 생화학분자생물학회 2002 BMB Reports Vol.35 No.5

Early activation of human peripheral blood polymorphonudear neutrophils is characterized by their morphological changes from spherical to polarized shapes. The endotoxins from enteric pathogens (S. dysenteriae type 1, V cholerae Inaba 569B, S. typhimurium, and K. pneumoniae) were assessed by their ability to induce morphological polarization of the neutrophils as measures of early activation. Phagocytic activity, adhesion, chemokinetic locomotion, and nitroblue tetrazolium (NBT) dyereduction ability measured the later activation of the cells. Neutrophils showed distinct morphological polarization in suspension over a wide range of concentrations of these endotoxins when were compared with those that were induced by the standard chemotactic factor, N-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP). It was discovered that all of the endotoxins induced locomotor responses in neutrophils in suspension that were dose- and time-dependent. The optimum concentration for the endotoxins of S. dysenteriae, V. cholerae, and K pneumoniae was 1 mg/ml in which 71, 69, and 66% of the neutrophils were polarized. However, the S. typhimurium dose was 2 mg/ml in which 50% of the cells responded. Neutrophils that were stimulated with endotoxins also showed increased random locomotion (p<0.005) through cellulose nitrate filters, but an enhanced adhesion of the cells to glass surfaces (p<0.03). These are important functions of these cells to reach and phagocytose damaged cells, as well as invading microorganisms. Interestingly, the endotoxins had a highly-significant inhibitory effect upon the proportions of neutrophils phagocytosing opsonized yeast (p<0.01) with a small number of yeast that were engulfed by the cells (p<0.02). Further, endotoxin-treated cells showed an enhanced ability to reduce NBT dye (p<0.03). Therefore, we concluded that endotoxins of enteric pathogens are neutrophil chemotactic factors.

DEVELOPMENT OF STRAW BASED RATION FOR FEEDING RUMINANTS

Kibria, S.S.,Islam, M.R.,Saha, C.K. Asian Australasian Association of Animal Productio 1991 Animal Bioscience Vol.4 No.3

A CRD experiment with thirty growing cross bred calves were assigned at random to three treatments rations. 1) $T_0$, 0% Urea + 20% M. O. cake, 2) $T_1$, 1% Urea + 10% M. O. cake and 3) $T_2$, 2% Urea + 0% M. O. cake to develop a rice straw based ration for ruminants. Sweetish odour and yellowish colour were observed in good recovered silage. Organic matter varied from 87.45% to 89.63% whereas crude protein varied from 14.0% to 14.5% in each treatment. No significant differences were found among the nutrient composition of the ration. The dry matter in take (DMI) and dry matter digestibility was higher in $T_0$ (0% Urea) than those of ration containing 1% ($T_1$) and 2% Urea ($T_2$). The organic matter digestibility decreases with increasing doses of urea. The crude protein & nitrogen-free-extract digestibility were found higher in the ration $T_1$ containing 1% urea whereas crude fibre digestibility and available metabolizable energy (ME) were higher in $T_0$ containing no urea as compared to $T_1$ and $T_2$. Total digestible nutrient (TDN) decreases with the increase of urea level. The highest feed efficiency was found in $T_0$ having no urea and lowest was in $T_2$. The animals gained in weights from each ration. Highest gain in weight was found in $T_0$ ration, then followed $T_1$, and $T_2$. This is due to natural protein available in M. O. cake only. It is concluded that supplemetation of urea or M. O. cake with readily available energy source as molasses upto 20% of total dietary dry matter in a complete ration may increase the intake of low quality fibrous roughage only when nitrogen and mineral are not limiting factor.

The Impact of Shariah Supervisory Board and Shariah Audit Committee on Corporate Social Responsibility Adoption at Islamic Banks in Bangladesh

ISLAM, K.M. Anwarul,SADEKIN, Mohammad Shamsus,RAHMAN, Md. Tahidur,CHOWDHURY, Md. Ariful Haque Korea Distribution Science Association 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.3

Although corporate social responsibility (CSR) is an extensively studied topic, its determinants in the field of Islamic banking are scarce. In Bangladesh, CSR plays a vital role in gaining customer loyalty and confidence. Therefore, this research aims to identify and analyze the influence of the Shariah Supervisory Board (SSB) and the Shariah Audit Committee (SAC) on CSR adoption in Islamic banks in Bangladesh. The study population is managers and second managers of 160 Islamic bank branches of different commercial banks in Dhaka, Bangladesh. The sampling technique used is convenience sampling where the first available primary data source was used for the research without additional requirements. The study developed a survey questionnaire from examining previous related studies in Islamic banking and CSR context. The final sample size in this research was n = 309, indicating the survey response rate was about 97%. The study used SPSS 23.0 software to interpret the statistical findings, and the findings revealed that support from the SSB and the presence of a strong and effective SAC has a strong correlation with CSR adoption and significantly influence CSR adoption in Islamic banks in Bangladesh. Finally, the study proposes several significant and crucial policy guidelines for Islamic bank branches to adopt CSR activities.

Principal Milk Components in Buffalo, Holstein Cross, Indigenous Cattle and Red Chittagong Cattle from Bangladesh

Islam, M.A.,Alam, M.K.,Islam, M.N.,Khan, M.A.S.,Ekeberg, D.,Rukke, E.O.,Vegarud, G.E. Asian Australasian Association of Animal Productio 2014 Animal Bioscience Vol.27 No.6

The aim of the present study was to get a total physical and chemical characterization and comparison of the principal components in Bangladeshi buffalo (B), Holstein cross (HX), Indigenous cattle (IC) and Red Chittagong Cattle (RCC) milk. Protein and casein (CN) composition and type, casein micellar size (CMS), naturally occurring peptides, free amino acids, fat, milk fat globule size (MFGS), fatty acid composition, carbohydrates, total and individual minerals were analyzed. These components are related to technological and nutritional properties of milk. Consequently, they are important for the dairy industry and in the animal feeding and breeding strategies. Considerable variation in most of the principal components of milk were observed among the animals. The milk of RCC and IC contained higher protein, CN, ${\beta}$-CN, whey protein, lactose, total mineral and P. They were more or less similar in most of the all other components. The B milk was found higher in CN number, in the content of ${\alpha}_{s2}-$, ${\kappa}$-CN and ${\beta}$-lactalbumin, free amino acids, unsaturated fatty acids, Ca and Ca:P. The B milk was also lower in ${\beta}$-lactoglobulin content and had the largest CMS and MFGS. Proportion of CN to whey protein was lower in HX milk and this milk was found higher in ${\beta}$-lactoglobulin and naturally occuring peptides. Considering the results obtained including the ratio of ${\alpha}_{s1}-$, ${\alpha}_{s2}-$, ${\beta}$- and ${\kappa}$-CN, B and RCC milk showed best data both from nutritional and technological aspects.

A numerical study of the turbulent fluctuating flow around a square cylinder for different inlet shear

Islam, A.K.M. Sadrul,Hasan, R.G.M. Techno-Press 2002 Wind and Structures, An International Journal (WAS Vol.5 No.1

This paper reports the numerical calculations of uniform turbulent shear flow around a square cylinder. The predictions are obtained by solving the two-dimensional unsteady Navier-Stokes equations in a finite volume technique. The turbulent fluctuations are simulated by the standard $k-{\varepsilon}$ model and one of its variant which takes care of the realizability constraint in order to suppress the excessive generation of turbulence in a stagnation condition. It has been found that the Strouhal number and the mean drag coefficient are almost unaffected by the shear parameter but the mean lift coefficient is increased. The present predictions are compared with available experimental data.