Displaying publications 61 - 80 of 121 in total

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  1. High-performance thin-layer chromatographic methods in the evaluation of the antioxidant and anti-hyperglycemic activity of Myrmecodia platytyrea as a promising opportunity in diabetes treatment
    Agatonovic-Kustrin S, Morton DW, Adam A, Mizaton HH, Zakaria H
    J Chromatogr A, 2017 Dec 29;1530:192-196.
    PMID: 29132827 DOI: 10.1016/j.chroma.2017.11.012
    The steady increase of diabetes is becoming a major burden on health care systems. As diabetic complications arise from oxidative stress, an antioxidant therapy along with anti-diabetic drugs is recommended. Myrmecodia or ant plant is highly valued as a traditional medicine in West Papua. It is used as an alternative treatment for diabetes, as the substances produced by ants can reduce blood sugar levels. The aim of this study was to develop and establish high-performance thin-layer chromatographic (HPTLC)-bioautographic methods to measure the antioxidant and hypoglycemic effects in different extracts from Myrmecodia platytyrea and to compare them with sterol content. Antioxidant activity in methanol, ethanol, dichloromethane (DCM) and ethyl acetate (EA) extracts were measured with a direct HPTLC-2,2-diphenyl-1-picrylhydrazyl free radical (DPPH) assay, while hypoglycemic effects were assessed using a newly developed α-amylase inhibitory activity assay. Stigmasterol is observed, after derivatization with anisaldehyde, as purple colored zones under visible light at hRF values of 0.66. The highest antioxidant activity was observed in the ethanol extract which is rich in polyphenols and flavonoids, while the DCM extract did not show antioxidant activity, but had significant α-amylase inhibitory activity. The highest α-amylase inhibitory activity was observed in the EA and DCM extracts and was related to their stigmasterol content.
    Matched MeSH terms: alpha-Amylases/antagonists & inhibitors; alpha-Amylases/metabolism
  2. Malaysian brown seaweeds Sargassum siliquosum and Sargassum polycystum: Low density lipoprotein (LDL) oxidation, angiotensin converting enzyme (ACE), α-amylase, and α-glucosidase inhibition activities
    Nagappan H, Pee PP, Kee SHY, Ow JT, Yan SW, Chew LY, et al.
    Food Res Int, 2017 Sep;99(Pt 2):950-958.
    PMID: 28847432 DOI: 10.1016/j.foodres.2017.01.023
    Two Malaysian brown seaweeds, Sargassum siliquosum and Sargassum polycystum were first extracted using methanol to get the crude extract (CE) and further fractionated to obtain fucoxanthin-rich fraction (FRF). Samples were evaluated for their phenolic, flavonoid, and fucoxanthin contents, as well as their inhibitory activities towards low density lipoprotein (LDL) oxidation, angiotensin converting enzyme (ACE), α-amylase, and α-glucosidase. In LDL oxidation assay, an increasing trend in antioxidant activity was observed as the concentration of FRF (0.04-0.2mg/mL) and CE (0.2-1.0mg/mL) increased, though not statistically significant. As for serum oxidation assay, significant decrease in antioxidant activity was observed as concentration of FRF increased, while CE showed no significant difference in inhibitory activity across the concentrations used. The IC50 values for ACE inhibitory activity of CE (0.03-0.42mg/mL) were lower than that of FRF (0.94-1.53mg/mL). When compared to reference drug Voglibose (IC50 value of 0.61mg/mL) in the effectiveness in inhibiting α-amylase, CE (0.58mg/mL) gave significantly lower IC50 values while FRF (0.68-0.71mg/mL) had significantly higher IC50 values. The α-glucosidase inhibitory activity of CE (IC50 value of 0.57-0.69mg/mL) and FRF (IC50 value of 0.50-0.53mg/mL) were comparable to that of reference drug (IC50 value of 0.54mg/mL). Results had shown the potential of S. siliquosum and S. polycystum in reducing cardiovascular diseases related risk factors following their inhibitory activities on ACE, α-amylase and α-glucosidase. In addition, it is likelihood that FRF possessed antioxidant activity at low concentration level.
    Matched MeSH terms: alpha-Amylases/antagonists & inhibitors*; alpha-Amylases/metabolism
  3. Fulltext α-Amylase and dipeptidyl peptidase-4 (DPP-4) inhibitory effects of Melicope latifolia bark extracts and identification of bioactive constituents using in vitro and in silico approaches
    Quek A, Kassim NK, Lim PC, Tan DC, Mohammad Latif MA, Ismail A, et al.
    Pharm Biol, 2021 Dec;59(1):964-973.
    PMID: 34347568 DOI: 10.1080/13880209.2021.1948065
    CONTEXT: Melicope latifolia (DC.) T. G. Hartley (Rutaceae) was reported to contain various phytochemicals including coumarins, flavonoids, and acetophenones.

    OBJECTIVE: This study investigates the antidiabetic and antioxidant effects of M. latifolia bark extracts, fractions, and isolated constituents.

    MATERIALS AND METHODS: Melicope latifolia extracts (hexane, chloroform, and methanol), fractions, and isolated constituents with varying concentrations (0.078-10 mg/mL) were subjected to in vitro α-amylase and dipeptidyl peptidase-4 (DPP-4) inhibitory assay. Molecular docking was performed to study the binding mechanism of active compounds towards α-amylase and DPP-4 enzymes. The antioxidant activity of M. latifolia fractions and compounds were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and β-carotene bleaching assays.

    RESULTS: Melicope latifolia chloroform extract showed the highest antidiabetic activity (α-amylase IC50: 1464.32 μg/mL; DPP-4 IC50: 221.58 μg/mL). Fractionation of chloroform extract yielded four major fractions (CF1-CF4) whereby CF3 showed the highest antidiabetic activity (α-amylase IC50: 397.68 μg/mL; DPP-4 IC50: 37.16 μg/mL) and resulted in β-sitosterol (1), halfordin (2), methyl p-coumarate (3), and protocatechuic acid (4). Isolation of compounds 2-4 from the species and their DPP-4 inhibitory were reported for the first time. Compound 2 showed the highest α-amylase (IC50: 197.53 μM) and β-carotene (88.48%) inhibition, and formed the highest number of molecular interactions with critical amino acid residues of α-amylase. The highest DPP-4 inhibition was exhibited by compound 3 (IC50: 911.44 μM).

    DISCUSSION AND CONCLUSIONS: The in vitro and in silico analyses indicated the potential of M. latifolia as an alternative source of α-amylase and DPP-4 inhibitors. Further pharmacological studies on the compounds are recommended.

    Matched MeSH terms: alpha-Amylases/antagonists & inhibitors*; alpha-Amylases/chemistry
  4. Fulltext Protein engineering of selected residues from conserved sequence regions of a novel Anoxybacillus α-amylase
    Ranjani V, Janeček S, Chai KP, Shahir S, Abdul Rahman RN, Chan KG, et al.
    Sci Rep, 2014 Jul 28;4:5850.
    PMID: 25069018 DOI: 10.1038/srep05850
    The α-amylases from Anoxybacillus species (ASKA and ADTA), Bacillus aquimaris (BaqA) and Geobacillus thermoleovorans (GTA, Pizzo and GtamyII) were proposed as a novel group of the α-amylase family GH13. An ASKA yielding a high percentage of maltose upon its reaction on starch was chosen as a model to study the residues responsible for the biochemical properties. Four residues from conserved sequence regions (CSRs) were thus selected, and the mutants F113V (CSR-I), Y187F and L189I (CSR-II) and A161D (CSR-V) were characterised. Few changes in the optimum reaction temperature and pH were observed for all mutants. Whereas the Y187F (t1/2 43 h) and L189I (t1/2 36 h) mutants had a lower thermostability at 65°C than the native ASKA (t1/2 48 h), the mutants F113V and A161D exhibited an improved t1/2 of 51 h and 53 h, respectively. Among the mutants, only the A161D had a specific activity, k(cat) and k(cat)/K(m) higher (1.23-, 1.17- and 2.88-times, respectively) than the values determined for the ASKA. The replacement of the Ala-161 in the CSR-V with an aspartic acid also caused a significant reduction in the ratio of maltose formed. This finding suggests the Ala-161 may contribute to the high maltose production of the ASKA.
    Matched MeSH terms: alpha-Amylases/genetics; alpha-Amylases/metabolism; alpha-Amylases/chemistry*
  5. Sequence and structural investigation of a novel psychrophilic α-amylase from Glaciozyma antarctica PI12 for cold-adaptation analysis
    Ramli AN, Azhar MA, Shamsir MS, Rabu A, Murad AM, Mahadi NM, et al.
    J Mol Model, 2013 Aug;19(8):3369-83.
    PMID: 23686283 DOI: 10.1007/s00894-013-1861-5
    A novel α-amylase was isolated successfully from Glaciozyma antarctica PI12 using DNA walking and reverse transcription-polymerase chain reaction (RT-PCR) methods. The structure of this psychrophilic α-amylase (AmyPI12) from G. antarctica PI12 has yet to be studied in detail. A 3D model of AmyPI12 was built using a homology modelling approach to search for a suitable template and to generate an optimum target-template alignment, followed by model building using MODELLER9.9. Analysis of the AmyPI12 model revealed the presence of binding sites for a conserved calcium ion (CaI), non-conserved calcium ions (CaII and CaIII) and a sodium ion (Na). Compared with its template-the thermostable α-amylase from Bacillus stearothermophilus (BSTA)-the binding of CaII, CaIII and Na ions in AmyPI12 was observed to be looser, which suggests that the low stability of AmyPI12 allows the protein to work at different temperature scales. The AmyPI12 amino acid sequence and model were compared with thermophilic α-amylases from Bacillus species that provided the highest structural similarities with AmyPI12. These comparative studies will enable identification of possible determinants of cold adaptation.
    Matched MeSH terms: alpha-Amylases/classification; alpha-Amylases/genetics; alpha-Amylases/chemistry*
  6. Sago starch and its utilisation
    Abd-Aziz S
    J Biosci Bioeng, 2002;94(6):526-9.
    PMID: 16233345
    The importance and development of industrial biotechnology processing has led to the utilisation of microbial enzymes in various applications. One of the important enzymes is amylase, which hydrolyses starch to glucose. In Malaysia, the use of sago starch has been increasing, and it is presently being used for the production of glucose. Sago starch represents an alternative cheap carbon source for fermentation processes that is attractive out of both economic and geographical considerations. Production of fermentable sugars from the hydrolysis of starches is normally carried out by an enzymatic processes that involves two reaction steps, liquefaction and saccharification, each of which has different temperature and pH optima with respect to the maximum reaction rate. This method of starch hydrolysis requires the use of an expensive temperature control system and a complex mixing device. Our laboratory has investigated the possibility of using amylolytic enzyme-producing microorganisms in the continuous single-step biological hydrolysis of sago flour for the production of a generic fermentation medium. The ability of a novel DNA-recombinated yeast, Saccharomyces cerevisiae strain YKU 107 (expressing alpha-amylase production) to hydrolyse gelatinised sago starch production has been studied with the aim of further utilizing sago starch to obtain value-added products.
    Matched MeSH terms: alpha-Amylases
  7. Fulltext Potential inhibitors of α -glucosidase and α -amylase enzymes from locally available fruit wastes by solid state fermentation
    Barkat, Anumsima Ahmad, Jamal, Parveen, Azlin Suhaida Azmi, Noorbacha, Ibrahim Ali, Zulkarnain Mohamed Idris, Arbain, Dachyar
    Biological and Natural Resources Engineering Journal, 2019;2(1):56-63.
    MyJurnal
    A therapeutic approach for treating diabetes is to decrease thepost-prandial hyperglycaemia. This is done by retarding the absorption of glucose through the inhibition of carbohydrate hydrolyzing enzymes, α-amylaseand α-glucosidase, in the digestive tract. Inhibition of both enzymes helpsto reduce the glucose level in the blood of a diabetic patient. This study was aimed to investigate the production of α-glucosidase and α-amylase inhibitors from local fruit wastes (honeydew skin, banana peel, and pineapple skin) using solid state fermentation. Each of the fruit wastes was fermented with three different types of white rot fungus Phenarochaete chrysosporium(PC), Panus tigrinusM609RQY(M6) andRO209RQY(RO2)for 7 days. Sampling was carried out starting from day 4 to day 7 to determine the enzyme inhibition activity. The samples were extracted using water prior to enzyme analysis. Most of the fruit samples showed varying degree of percentage inhibition activity depending on the sampling time. Extract of fermented banana peels with RO2 on day 4 showed the higherα-glucosidase inhibition (56.57±0.32%), followed byhoneydew extract fermented with the same fungus on the same day (39.68±0.05%). Extracts of each fruit wastesample fermented with PCshowed the least α-glucosidase inhibition (below 15%). Meanwhile for α-amylase inhibition activity, the extract from fermented honeydew skins with PCon day7 showed the highest inhibition activity i.e.98.29±0.63%. The least inhibition activity (43.37±0.54%) was observed in the extract from honeydew skins fermented withM6 on day 5. All positive resultsshowed that fruit wastes could be the alternative sourcesfor antidiabetic agent especially for α-amylase and α-glucosidase inhibitors.
    Matched MeSH terms: alpha-Amylases
  8. High-performance thin layer chromatography-based phytochemical and bioactivity characterisation of anticancer endophytic fungal extracts derived from marine plants
    Lim SM, Agatonovic-Kustrin S, Lim FT, Ramasamy K
    J Pharm Biomed Anal, 2021 Jan 30;193:113702.
    PMID: 33160220 DOI: 10.1016/j.jpba.2020.113702
    Bioactive compounds from endophytic fungi exhibit diverse biological activities which include anticancer effect. Capitalising on the abundance of unexplored endophytes that reside within marine plants, this study assessed the anticancer potential of ethyl acetate endophytic fungal extracts (i.e. MBFT Tip 2.1, MBL 1.2, MBS 3.2, MKS 3 and MKS 3.1) derived from leaves, stem and fruits of marine plants that grow along Morib Beach, Malaysia. For identification of endophytic fungi, EF 4/ EF 3 and ITS 1/ ITS 4 PCR primer pairs were used to amplify the fungal 18S rDNA sequence and ITS region sequence, respectively. The resultant sequences were subjected to similarity search via the NCBI GenBank database. High-performance thin layer chromatography (HPTLC) hyphenated with bioassays was used to characterise the extracts in terms of their phytochemical profiles and bioactivity. Microchemical derivatisation was used to assess polyphenolic and phytosterol/ terpenoid content whereas biochemical derivatisation was used to establish antioxidant activities and α-amylase enzyme inhibition. The sulforhodamine B (SRB) assay was used to assess the anticancer effect of the extracts against HCT116 (a human colorectal cancer cell line). The present results indicated MBS 3.2 (Penicillium decumbens) as the most potent extract against HCT116 (IC50 = 0.16 μg/mL), approximately 3-times more potent than 5-flurouracil (IC50 = 0.46 μg/mL). Stepwise multiple regression method suggests that the anticancer effect of MBS 3.2 could be associated with high polyphenolic content and antioxidant potential. Nonlinear regression analysis confirmed that low to moderate α-amylase inhibition exhibits maximum anticancer activity. Current findings warrant further in-depth mechanistic studies.
    Matched MeSH terms: alpha-Amylases
  9. Fulltext The impact of four processing methods on trypsin-, chymotrypsin- and alpha-amylase inhibitors present in underutilised legumes
    Choi WC, Parr T, Lim YS
    J Food Sci Technol, 2019 Jan;56(1):281-289.
    PMID: 30728570 DOI: 10.1007/s13197-018-3488-0
    The global trend in increasing plant-based protein diets due to health and ideological reasons, has created an increased demand for food legumes that exceeds current production. To meet this demand, it is timely to reduce relying solely on soybean, and explore the potential of the underutilised legumes that are cultivated regionally. Underutilised legumes are rich in protein, carbohydrates and other nutrients that are essential for consumer. However, relatively little is known about their anti-nutritional properties and processing methods. Anti-nutritional factors (ANFs) such as enzyme inhibitors are prevalent in legumes and may interfere with digestibility and nutrient absorption. Nevertheless, an optimised food processing method will overcome this challenge and warrant a safe inclusion of legume in plant-based protein diets. Hence current study aimed to optimise the food processing methods (soaking, wet heating, autoclaving and freezing) and evaluate their efficiency in eliminating the enzyme inhibitors [trypsin, chymotrypsin (CIA) and α-amylase (AIA) inhibitors] present in seven underutilised legumes. Current study showed that autoclaving at 121 °C for 15 min reduced the AIA in all underutilised legumes tested. The AIA and CIA of bambara groundnut were successfully inactivated by wet heating at 50 °C for 60 min, and by autoclaving at 121 °C for 15 min. While the CIA of chickpea was successfully inactivated by freezing at - 80 °C for 24 h.
    Matched MeSH terms: alpha-Amylases
  10. Fulltext Kinetic modelling of ethanol fermentation process using cassava (Manihot esculenta) starch as carbon source
    Low, C.Y., Hii, S.L., Leong, L.K., Yim, Y.Y., Tan, H.W.
    ASM Science Journal, 2012;6(1):61-66.
    MyJurnal
    Cassava starch was used as feedstock for production of bioethanol by Saccharomyces cerevisiae. The cassava starch was hydrolyzed using commercial α-amylase and glucoamylase enzymes followed by a batch ethanol fermentation process using saccharified starch slurry. By using 110 g/L of reducing sugar from saccharified starch slurry, the ethanol yield was promising with maximum ethanol concentration of 20.6 g/L recorded after 55 hours of cultivation process. Three different models - the Logistic model, Luedeking-Piret-like equation and Gompertz equation - were used to characterize and explain the cell growth, reducing sugar consumption and production formation, respectively. The kinetic parameters were estimated by fitting the experimental data to the proposed models using non-linear regression analysis. The correlation coefficient r2 values for the Logistic model, Luedeking-Piret-like equation and the Gompertz equation were 0.994, 0.996 and 0.990, respectively. The high correlation coefficient values indicate that the proposed models were able to describe the ethanol fermentation process.
    Matched MeSH terms: alpha-Amylases
  11. Fulltext Physico-chemical, malting and biochemical properties of some improved Nigerian barley cultivars and their malts
    Makeri, M.U., Nkama, I., Badau, M.H.
    International Food Research Journal, 2013;20(4):1563-1568.
    MyJurnal
    Five improved Nigerian barley cultivars (ESCOBA, ASE – 2, ALOE, GOB – 2, SUMBARD) were obtained from Lake Chad Research Institute Maiduguri, Nigeria, and their physicochemical, malting and biochemical properties investigated employing standard procedures. Data were analyzed by means of ANOVA [at 95% significant level] and correlations using SPSS 14 software. Results showed GOB-2 grain and malt recording the highest kernel weight (47.50 g) and kernel volume (41.21 ml); whereas ALOE grain had the longest kernel length (13.40 mm) and GOB-2 the shortest (9.40 mm). GOB-2 had the largest major diameter (3.39 mm) and SUMBARD had the least (2.86 mm). ESCOBA, SUMBARD and ASE-2 cultivars had the highest protein values (as %N) of 14.90%, 13.90% and 13.69% respectively, while ALOE, ASE-2 and GOB-2 had the highest total carbohydrates of 69.97, 69.39 and 68.90% respectively. All the cultivars had good germinative capacities (> 90%), with GOB-2 and ASE-2 having the highest germinative energy values of 96.65% and 95.00%. No significant (p > 0.05) changes
    in the dimension of the kernels after malting. SUMBARD recorded the highest malt yields (88.55%) followed by ASE-2 (83.45%) and ALOE (82.00%). The highest α-amylase activities of 105.34 and 96.23 unit/mg protein/min were recorded by ASE-2 and ALOE, respectively, with corresponding diastatic powers of 81.92 and 76.23oL. Thousand kernel weight correlated positively with protein (r = 0.500, P < 0.05) and with total soluble solids (r = 0.435, p < 0.05) but negatively with α-amylase (r = -0.869, p < 0.05) and with diastatic power (r = -0.838, p < 0.05). This study showed that the cultivars have good potentials for use as malting materials in beverage making.
    Matched MeSH terms: alpha-Amylases
  12. Fulltext In vitro antioxidant capacities and antidiabetic properties of phenolic extracts from selected citrus peels
    Lim, S.M., Loh, S.P.
    International Food Research Journal, 2016;23(1):211-219.
    MyJurnal
    This study aims to determine the antioxidant capacities (AC) and antidiabetic properties of
    phenolic extracts (free and bound) from white Tambun pomelo peels, kaffir lime peels, lime
    peels and calamansi peels. AC, total phenolic content (TPC) and antidiabetic properties of
    selected citrus peels extracts were determined spectrophotometrically using 2,2-Diphenyl-1-
    picrylhydrazyl free radical (DPPH) scavenging, ferric-reducing antioxidant power (FRAP),
    Folin-Ciocalteu (FC) and α-amylase and α-glucosidase inhibition assay, respectively. This
    study found that the methanolic extract of kaffir lime showed the best AC with the lowest
    IC50 value of DPPH radical (7.51 ± 0.50 mg/ml) and highest FRAP value [369.48 ± 20.15
    mM Fe (II) E/g DW]. TPC of free phenolic extracts of all citrus peels were significantly (p<
    0.05) higher compared to the bound phenolic extracts with extract of calamansi showed the
    highest TPC. Free- and bound phenolic extract of calamansi also had the highest α-amylase
    inhibition activity (61.79 ± 4.13%; 45.30 ± 5.35%) respectively. The highest inhibitory effect in
    α-glucosidase inhibition assay of free- and bound phenolic extracts were white Tambun pomelo
    (41.06 ± 10.94%) and calamansi (43.99 ± 22.03%) respectively. Hence, the citrus peels could
    be furthered study for their potential in management and/or prevention of diabetes.
    Matched MeSH terms: alpha-Amylases
  13. Fulltext Valorizing guava (Psidium guajava L.) seeds through germination-induced carbohydrate changes
    Ling CX, Chang YP
    J Food Sci Technol, 2017 Jun;54(7):2041-2049.
    PMID: 28720961 DOI: 10.1007/s13197-017-2641-5
    Guava seeds are produced as a waste product by the guava processing industry. Their high carbohydrate contents may suit the carbohydrate needs of the feed sector but their high dietary fiber content limits their feed value. The feed values of fruit seeds can be improved through germination, which involves the mobilization of nutrients through seed enzymes and alters the seed carbohydrate composition. The changes of selected carbohydrates in guava (Psidium guajava L.) seeds brought by germination to those in red bean (Vigna angularis) and winter wheat (Triticum aestivum L.) were compared. The contents of soluble carbohydrates, digestible starch, resistant starch and cellulose in the seeds were determined. The radial diffusion method was used to detect carbohydrate-degrading enzymes in the seed extracts. Guava seeds were rich in cellulose (402.2 mg/g), which decreased progressively during germination, probably through the action of cellulase. Winter wheat contained the highest starch content (412.2 mg/g) and also distinct quantities of α-amylase and cellulase. The starch contents of all the seeds decreased, but the soluble carbohydrate contents in red beans and guava seeds increased significantly by the end of germination, suggesting the transient oversupply of reserve metabolites. The content of hydrolyzed polysaccharides increased in the germinated seeds with detectable amounts of cellulose-degrading enzymes present, indicating improved value as feed. Further research is warranted to explore the potential of guava seeds as a source of low-cost animal feed supplements.
    Matched MeSH terms: alpha-Amylases
  14. Fulltext Growth, substrate consumption, and product formation kinetics of Phanerochaete chrysosporium and Schizophyllum commune mixed culture under solid-state fermentation of fruit peels
    Olorunnisola KS, Jamal P, Alam MZ
    3 Biotech, 2018 Oct;8(10):429.
    PMID: 30305998 DOI: 10.1007/s13205-018-1452-3
    Kinetic analysis of solid-state fermentation (SSF) of fruit peels with Phanerochaete chrysosporium and Schizophyllum commune mixed culture was studied in flask and 7 kg capacity reactor. Modified Monod kinetic model suggested by Haldane sufficiently described microbial growth with co-efficient of determination (R2) reaching 0.908 at increased substrate concentration than the classical Monod model (R2 = 0.932). Leudeking-Piret model adequately described product synthesis in non-growth-dependent manner (R2 = 0.989), while substrate consumption by P. chrysosporium and S. commune fungal mixed culture was growth-dependent (R2 = 0.938). Hanes-Woolf model sufficiently represented α-amylase and cellulase enzymes synthesis (R2 = 0.911 and 0.988); α-amylase had enzyme maximum velocity (Vmax) of 25.19 IU/gds/day and rate constant (Km) of 11.55 IU/gds/day, while cellulase enzyme had Vmax of 3.05 IU/gds/day and Km of 57.47 IU/gds/day. Product yield in the reactor increased to 32.65 mg/g/day compared with 28.15 mg/g/day in shake flask. 2.5 cm media thickness was adequate for product formation within a 6 day SSF in the tray reactor.
    Matched MeSH terms: alpha-Amylases
  15. Flurbiprofen derivatives as novel α-amylase inhibitors: Biology-oriented drug synthesis (BIODS), in vitro, and in silico evaluation
    Khan M, Alam A, Khan KM, Salar U, Chigurupati S, Wadood A, et al.
    Bioorg Chem, 2018 12;81:157-167.
    PMID: 30125730 DOI: 10.1016/j.bioorg.2018.07.038
    Novel derivatives of flurbiprofen 1-18 including flurbiprofen hydrazide 1, substituted aroyl hydrazides 2-9, 2-mercapto oxadiazole derivative 10, phenacyl substituted 2-mercapto oxadiazole derivatives 11-15, and benzyl substituted 2-mercapto oxadiazole derivatives 16-18 were synthesized and characterized by EI-MS, 1H and 13C NMR spectroscopic techniques. All derivatives 1-18 were screened for α-amylase inhibitory activity and demonstrated a varying degree of potential ranging from IC50 = 1.04 ± 0.3 to 2.41 ± 0.09 µM as compared to the standard acarbose (IC50 = 0.9 ± 0.04 µM). Out of eighteen compounds, derivatives 2 (IC50 = 1.69 ± 0.1 µM), 3 (IC50 = 1.04 ± 0.3 µM), 9 (IC50 = 1.25 ± 1.05 µM), and 13 (IC50 = 1.6 ± 0.18 µM) found to be excellent inhibitors while rest of the compounds demonstrated comparable inhibition potential. A limited structure-activity relationship (SAR) was established by looking at the varying structural features of the library. In addition to that, in silico study was conducted to understand the binding interactions of the compounds (ligands) with the active site of α-amylase enzyme.
    Matched MeSH terms: alpha-Amylases
  16. Fulltext Valorizing cabbage (Brassica oleracea L. var. capitata) and capsicum (Capsicum annuum L.) wastes: in vitro health-promoting activities
    Liang JL, Yeow CC, Teo KC, Gnanaraj C, Chang YP
    J Food Sci Technol, 2019 Oct;56(10):4696-4704.
    PMID: 31686701 DOI: 10.1007/s13197-019-03912-5
    The capsicum seed core and cabbage outer leaves are common wastes generated in the vegetable processing industry. We explored the in vitro health-promoting activity of these waste products for valorization. Freeze-dried and pulverized cabbage wastes had a high bile acid binding capacity and the capsicum wastes inhibited glucose dialysis more effectively. Methanolic extracts prepared with conventional solvent extraction and ultrasound-assisted extraction were analyzed to determine their 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, in vitro α-amylase inhibitory, in vitro lipase inhibitory, and prebiotic activity. Crude extracts of cabbage and capsicum wastes were screened using GC-MS analysis. The cabbage waste extracts showed high antioxidant activities but did not inhibit α-amylase. The capsicum waste extracts inhibited both lipase and α-amylase activities and supported the growth of the probiotic bacterium, Lactobacilli brevis. Volatile compounds of the vegetables consisted mainly of phenols and fatty acid esters. In all assays except the α-amylase inhibition assay, the extracts prepared with ultrasound-assisted solvent extraction showed higher activity than those prepared using the conventional method. The capsicum seed core and cabbage outer leaves are potential sources of phytochemicals and antioxidant fibers. Capsicum waste extract supported probiotic bacterial growth without a lag phase. These waste products may be processed into high-value functional ingredients.
    Matched MeSH terms: alpha-Amylases
  17. Exploring efficacy of indole-based dual inhibitors for α-glucosidase and α-amylase enzymes: In silico, biochemical and kinetic studies
    Kawde AN, Taha M, Alansari RS, Almandil NB, Anouar EH, Uddin N, et al.
    Int J Biol Macromol, 2020 Jul 01;154:217-232.
    PMID: 32173438 DOI: 10.1016/j.ijbiomac.2020.03.090
    α-Glucosidase and α-amylase are enzymes which are associated with diabetic II. These enzymes break macromolecules of sugar into monosugar molecules which is soluble in body, hence increase the sugar level in blood. There is need to develop economical and save inhibitors to prevent them from breaking sugar macromolecules to soluble molecules which will control the level of sugar in blood. Therefore, we synthesized indole-based derivatives (1-18) and evaluated as dual inhibitor for α-glucosidase and α-amylase. These chemical scaffolds were built with variation in aryl ring which were found active with good to moderate activity for α-glucosidase having IC50 value ranging from 13.99 ± 0.10 to 59.09 ± 0.30 μM when compared with standard acarbose with IC50 of 11.29 ± 0.10 μM; for α-amylase IC50 value ranging from 13.14 ± 0.10 to 58.99 ± 0.30 μM when compared with the standard acarbose with IC50 of 11.12 ± 0.10 μM. Structure activity relationship (SAR) has been established for all compounds. Enzymatic kinetic study and molecular docking study have been carried out to investigate the binding interactions α-glucosidase and α-amylase enzyme.
    Matched MeSH terms: alpha-Amylases
  18. Fulltext HPLC-PDA Polyphenolic Quantification, UHPLC-MS Secondary Metabolite Composition, and In Vitro Enzyme Inhibition Potential of Bougainvillea glabra
    Saleem H, Htar TT, Naidu R, Anwar S, Zengin G, Locatelli M, et al.
    Plants (Basel), 2020 Mar 20;9(3).
    PMID: 32245104 DOI: 10.3390/plants9030388
    The plants of the Bougainvillea genus are widely explored regarding nutritive and medicinal purposes. In this study, dichloromethane (DCM) and methanol (MeOH) extracts of Bougainvillea glabra (Choisy.) aerial and flower parts were analyzed for high-performance liquid chromatography with photodiode array detection (HPLC-PDA), ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS) phytochemical composition, and enzyme inhibition potential against key enzymes involved in diabetes (α-amylase), skin problems (tyrosinase), and inflammatory disorders (lipoxygenase (LOX)). HPLC-PDA quantification revealed the identification of nine different polyphenolics, amongst which both flower extracts were richest. The flower MeOH extract contained the highest amount of catechin (6.31 μg/g), gallic acid (2.39 μg/g), and rutin (1.26 μg/g). However, none of the quantified compounds were detected in the aerial DCM extract. UHPLC-MS analysis of DCM extracts revealed the tentative identification of 27 secondary metabolites, where the most common belonged to terpenoid, alkaloid, and phenolic derivatives. Similarly, for enzyme inhibition, all the extracts presented moderate activity against tyrosinase and α-amylases, whereas, for LOX, both methanolic extracts showed higher percentage inhibition compared with DCM extracts. Based on our findings, B. glabra could be regarded as a perspective starting material for designing novel pharmaceuticals.
    Matched MeSH terms: alpha-Amylases
  19. Fulltext Optimisation and production of alpha amylase from thermophilic Bacillus spp. and its application in food waste biodegradation
    Msarah MJ, Ibrahim I, Hamid AA, Aqma WS
    Heliyon, 2020 Jun;6(6):e04183.
    PMID: 32566789 DOI: 10.1016/j.heliyon.2020.e04183
    This study employed Bacillus spp. with α-amylase production isolated from Malaysian hot spring for domestic kitchen food waste treatment contained grains, vegetables, chicken and tuna that mimic the food waste discharge from domestic kitchens in Malaysian household. Results showed that Bacillus licheniformis HULUB1 and Bacillus subtilis SUNGB2 possess excellent amylolytic properties. Highest α-amylase activity was obtained when both isolates were cultivated at pH 6.0 and 65 °C with concentrations of 18.15 U/mL for HULUB1 and 22.14 U/mL for SUNGB2. Stability of α-amylase with significant levels of enzyme activity were recorded at 55-85 °C and pH 5.0-9.0. The extracted mixed α-amylase of HULUB1 and SUNGB2 showed greatest reduction were achieved at day 12 with 45% ± 0.03 solid content at 65 °C. While the mixed culture of HULUB1 and SUNGB2 displayed an enhanced effect on the food waste contents reduction with 43% ± 0.02 solid content at 45 °C after day 12. The findings showed that the combination of the two Bacillus spp. isolates possessed degradation of food wastes at faster rate than α-amylase. It was also pointed out that the standard food waste (SFW) and the treatment process assimilated for this study was suitable for the growth of Bacillus spp.
    Matched MeSH terms: alpha-Amylases
  20. Fulltext Hydrolysis of native and annealed tapioca and sweet potato starches at subgelatinization temperature using a mixture of amylolytic enzymes
    Shariffa, Y.N., Uthumporn, U., Karim, A.A., Zaibunnisa, A.H
    International Food Research Journal, 2017;24(5):1925-1933.
    MyJurnal
    This study investigated the effect of annealing treatment (at 50°C for 72 h) on hydrolysis of tapioca and sweet potato starches using a raw starch hydrolyzing enzyme namely STARGEN 001 (a blend from fungal α-amylase and glucoamylase) at sub-gelatinization temperature (35°C) for 24 h. The degree of hydrolysis of the starches was evaluated based on the dextrose equivalent (DE) value. The hydrolyzed starches were then characterized in terms of its morphology, swelling power and solubility, gelatinization and pasting properties, amylose content and x-ray diffraction pattern. After 24 h of hydrolysis, annealed starches were hydrolyzed to a greater degree with higher DE value compared to native starches (40% vs 33% for tapioca; and 29% vs 24% for sweet potato starch). Scanning electron microscopy (SEM) micrographs revealed a more porous granules and rougher surface in annealed starches than their native counterparts. The swelling power and solubility of annealed starches decreased significantly. Annealing was found to affect the pasting properties of the starches appreciably and increase the starch gelatinization temperature. The amylose content in hydrolyzed annealed tapioca and sweet potato starches increased while no significant changes observed in the X-ray diffraction of those starches. This study shows that the annealing treatment can be used as a way to increase the degree of hydrolysis of tapioca and sweet potato starches at sub-gelatinization temperature using a raw starch hydrolyzing enzyme.
    Matched MeSH terms: alpha-Amylases
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