Displaying publications 1 - 20 of 65 in total

  1. Zhu J, Zhang B, Tan C, Huang Q
    Food Funct, 2019 Sep 13.
    PMID: 31517355 DOI: 10.1039/c9fo01333d
    The present study aims to investigate the relationship between in silico experimental data and in vitro inhibitory data of polyphenols against α-glucosidase. The CDOCKER protocol in Discovery Studio was used to dock various polyphenols to the Saccharomyces cerevisiae α-glucosidase crystal structure. -CDOCKER energy values and the energy gap between the highest occupied molecular orbital energy and the lowest unoccupied molecular orbital energy were used to study its consistency with in vitro inhibitory data. The results showed that the correlation trend was trustworthy regardless of the data deviation and low correlation coefficient. Despite slight disagreements with some specific polyphenols, the docking data generally explained the effect of the groups (-OH, glycosyl, galloyl, and caffeoyl). The docking results showed that compound 7, a quercetin derivative, can be recommended as a lead antidiabetic compound, with additional anti-obesity effects. Galloyl and caffeoyl moieties are favorable to develop novel αG inhibitors.
    Matched MeSH terms: alpha-Glucosidases
  2. Anouar el H, Zakaria NS, Alsalme A, Shah SA
    Mini Rev Med Chem, 2015;15(14):1148-58.
    PMID: 26205959
    A natural pentacyclic triterpenoid oleanolic acid 1 and its biotransformed metabolites 2-3 are potential α-glucosidase inhibitors. To elucidate the inhibitory mechanism of compounds 1, 2 and 3 against α-glucosidase, we calculated (i) their electronic and optical properties using DFT and TD-DFT at the B3LYP/6-31G(d) level in gas and IEF-PCM solvent; and (ii) their binding energies to α-glucosidase via docking study. DFT results showed that the α-glucosidase inhibtion is mainly depend on the polarity parameters of the studied compounds. Docking results revealed that the activity increased with binding energies (i.e. the stability of ligand-receptor complex). The specroscopic data of oleanolic acid 1 and its metabolites 2 and 3 are well predicetd for 13C NMR chemical shifts (R2=99%) and 1H NMR chemical shifts (R2=90%); and for (ii) UV/vis spectra. The assignments and interpretation of NMR chemical shifts and bathochromic shift of λMAX absorption bands are discussed.
    Matched MeSH terms: alpha-Glucosidases/metabolism*; alpha-Glucosidases/chemistry
  3. Rahim F, Ullah H, Javid MT, Wadood A, Taha M, Ashraf M, et al.
    Bioorg. Chem., 2015 Oct;62:15-21.
    PMID: 26162519 DOI: 10.1016/j.bioorg.2015.06.006
    A series of thiazole derivatives 1-21 were prepared, characterized by EI-MS and (1)H NMR and evaluated for α-glucosidase inhibitory potential. All twenty one derivatives showed good α-glucosidase inhibitory activity with IC50 value ranging between 18.23±0.03 and 424.41±0.94μM when compared with the standard acarbose (IC50, 38.25±0.12μM). Compound (8) (IC50, 18.23±0.03μM) and compound (7) (IC50=36.75±0.05μM) exhibited outstanding inhibitory potential much better than the standard acarbose (IC50, 38.25±0.12μM). All other analogs also showed good to moderate enzyme inhibition. Molecular docking studies were carried out in order to find the binding affinity of thiazole derivatives with enzyme. Studies showed these thiazole analogs as a new class of α-glucosidase inhibitors.
    Matched MeSH terms: alpha-Glucosidases/drug effects*; alpha-Glucosidases/chemistry
  4. Salar U, Taha M, Khan KM, Ismail NH, Imran S, Perveen S, et al.
    Eur J Med Chem, 2016 Oct 21;122:196-204.
    PMID: 27371923 DOI: 10.1016/j.ejmech.2016.06.037
    3-Thiazolylcoumarin derivatives 1-14 were synthesized via one-pot two step reactions, and screened for in vitro α-glucosidase inhibitory activity. All compounds showed inhibitory activity in the range of IC50 = 0.12 ± 0.01-16.20 ± 0.23 μM as compared to standard acarbose (IC50 = 38.25 ± 0.12 μM), and also found to be nontoxic. Molecular docking study was carried out in order to establish the structure-activity relationship (SAR) which demonstrated that electron rich centers at one and electron withdrawing centers at the other end of the molecules showed strong inhibitory activity. All the synthesized compounds were characterized by spectroscopic techniques such as EI-MS, HREI-MS, (1)H NMR and (13)C NMR. CHN analysis was also performed.
    Matched MeSH terms: alpha-Glucosidases/metabolism*; alpha-Glucosidases/chemistry
  5. Alam MA, Zaidul IS, Ghafoor K, Sahena F, Hakim MA, Rafii MY, et al.
    BMC Complement Altern Med, 2017 Mar 31;17(1):181.
    PMID: 28359331 DOI: 10.1186/s12906-017-1684-5
    BACKGROUND: This study was aimed to evaluate antioxidant and α-glucosidase inhibitory activity, with a subsequent analysis of total phenolic and total flavonoid content of methanol extract and its derived fractions from Clinacanthus nutans accompanied by comprehensive phytochemical profiling.

    METHODS: Liquid-liquid partition chromatography was used to separate methanolic extract to get hexane, ethyl acetate, butanol and residual aqueous fractions. The total antioxidant activity was determined by 2,2-diphenyl-1-picrylhydrazy (DPPH) radical scavenging and ferric reducing antioxidant power assay (FRAP). The antidiabetic activity of methanol extract and its consequent fractions were examined by α-glucosidase inhibitory bioassay. The chemical profiling was carried out by gas chromatography coupled with quadrupole time-of-flight mass spectrometry (GC Q-TOF MS).

    RESULTS: The total yield for methanol extraction was (12.63 ± 0.98) % (w/w) and highest fractionated value found for residual aqueous (52.25 ± 1.01) % (w/w) as compared to the other fractions. Significant DPPH free radical scavenging activity was found for methanolic extract (63.07 ± 0.11) % and (79.98 ± 0.31) % for ethyl acetate fraction among all the fractions evaluated. Methanol extract was the most prominent in case of FRAP (141.89 ± 0.87 μg AAE/g) whereas most effective reducing power observed in ethyl acetate fraction (133.6 ± 0.2987 μg AAE/g). The results also indicated a substantial α-glucosidase inhibitory activity for butanol fraction (72.16 ± 1.0) % and ethyl acetate fraction (70.76 ± 0.49) %. The statistical analysis revealed that total phenolic and total flavonoid content of the samples had the significant (p 

    Matched MeSH terms: alpha-Glucosidases/metabolism; alpha-Glucosidases/chemistry
  6. Taha M, Imran S, Rahim F, Wadood A, Khan KM
    Bioorg. Chem., 2018 02;76:273-280.
    PMID: 29223804 DOI: 10.1016/j.bioorg.2017.12.001
    Inhibition of α-glucosidase is an effective strategy for controlling post-prandial hyperglycemia in diabetic patients. Beside these α-glucosidase inhibitors has been also used as anti-obesity and anti-viral drugs. Keeping in view the greater importance of α-glucosidase inhibitors here in this study we are presenting oxindole based oxadiazoles hybrid analogs (1-20) synthesis, characterized by different spectroscopic techniques including 1H NMR and EI-MS and their α-glucosidase inhibitory activity. All compounds were found potent inhibitors for the enzyme with IC50 values ranging between 1.25 ± 0.05 and 268.36 ± 4.22 µM when compared with the standard drug acarbose having IC50 value 895.09 ± 2.04 µM. Our study identifies novel series of potent α-glucosidase inhibitors and further investigation on this may led to the lead compounds. A structure activity relationship has been established for all compounds. The interactions of the active compounds and enzyme active site were established with the help of molecular docking studies.
    Matched MeSH terms: alpha-Glucosidases/metabolism; alpha-Glucosidases/chemistry
  7. Loo KY, Leong KH, Sivasothy Y, Ibrahim H, Awang K
    Chem. Biodivers., 2019 Jun;16(6):e1900032.
    PMID: 30957403 DOI: 10.1002/cbdv.201900032
    The inhibition of carbohydrate-hydrolyzing enzymes in human digestive organs is crucial in controlling blood sugar levels, which is important in treating type 2 diabetes. In the current study, pahangensin A (1), a bis-labdanic diterpene characterized previously in the rhizomes of Alpinia pahangensis Ridl., was identified as an active dual inhibitor for α-amylase (IC50 =114.80 μm) and α-glucosidase (IC50 =153.87 μm). This is the first report on the dual α-amylase and α-glucosidase inhibitory activities of a bis-labdanic diterpene. The Lineweaver-Burk plots of compound 1 indicate that it is a mixed-type inhibitor with regard to both enzymes. Based on molecular docking studies, compound 1 docked in a non-active site of both enzymes. The dual inhibitory activity of compound 1 makes it a suitable natural alternative in the treatment of type 2 diabetes.
    Matched MeSH terms: alpha-Glucosidases/metabolism*; alpha-Glucosidases/chemistry
  8. Lee, S.Y., Mediani, A., Nur Ashikin, A.H., Abas, F., Azliana, A.B.S.
    The study was aimed to determine the antioxidant and α-glucosidase inhibition activities of
    the stem and leaf of five different traditional medicinal plants. The studied plants exhibited
    varied antioxidant and α-glucosidase inhibition activities. The antioxidant activities of the
    plants were determined through their free radical scavenging capabilities using DPPH assay.
    The most potent antioxidant activity was demonstrated by Neptunia oleracea with an IC50 of
    35.45 and 29.72 μg/mL for leaf and stem, respectively. For α-glucosidase inhibition activity,
    Neptunia oleracea exhibited potential α-glucosidase inhibition activity with IC50 value of
    19.09 and 19.74 μg/mL for leaf and stem, respectively. The highest total phenolic content
    (TPC) was also marked in Neptunia oleracea leaf and stem with value of 40.88 and 21.21 mg
    GAE/g dry weight, respectively. The results also showed that Strobilanthes crispus collected
    from two different locations possessed different levels of phenolic content, antioxidant and
    α-glucosidase inhibition activities. The study revealed that phenolic compounds could be the
    main contributors to the antioxidant and α-glucosidase inhibition activities with R values of 78.9
    and 67.4%, respectively. In addition, antioxidant and α-glucosidase were positively correlated
    (R = 81.9%). Neptunia oleracea could be suggested as a potential natural source of antioxidant
    and antidiabetic compounds that can be used for the prevention or treatment of diabetes.
    Matched MeSH terms: alpha-Glucosidases
  9. Easmin S, Sarker MZI, Ghafoor K, Ferdosh S, Jaffri J, Ali ME, et al.
    J Food Drug Anal, 2017 Apr;25(2):306-315.
    PMID: 28911672 DOI: 10.1016/j.jfda.2016.09.007
    Phaleria macrocarpa, known as "Mahkota Dewa", is a widely used medicinal plant in Malaysia. This study focused on the characterization of α-glucosidase inhibitory activity of P. macrocarpa extracts using Fourier transform infrared spectroscopy (FTIR)-based metabolomics. P. macrocarpa and its extracts contain thousands of compounds having synergistic effect. Generally, their variability exists, and there are many active components in meager amounts. Thus, the conventional measurement methods of a single component for the quality control are time consuming, laborious, expensive, and unreliable. It is of great interest to develop a rapid prediction method for herbal quality control to investigate the α-glucosidase inhibitory activity of P. macrocarpa by multicomponent analyses. In this study, a rapid and simple analytical method was developed using FTIR spectroscopy-based fingerprinting. A total of 36 extracts of different ethanol concentrations were prepared and tested on inhibitory potential and fingerprinted using FTIR spectroscopy, coupled with chemometrics of orthogonal partial least square (OPLS) at the 4000-400 cm-1 frequency region and resolution of 4 cm-1. The OPLS model generated the highest regression coefficient with R2Y = 0.98 and Q2Y = 0.70, lowest root mean square error estimation = 17.17, and root mean square error of cross validation = 57.29. A five-component (1+4+0) predictive model was build up to correlate FTIR spectra with activity, and the responsible functional groups, such as -CH, -NH, -COOH, and -OH, were identified for the bioactivity. A successful multivariate model was constructed using FTIR-attenuated total reflection as a simple and rapid technique to predict the inhibitory activity.
    Matched MeSH terms: alpha-Glucosidases
  10. Manaharan T, Palanisamy UD, Ming CH
    Molecules, 2012;17(5):5915-23.
    PMID: 22609782 DOI: 10.3390/molecules17055915
    Preliminary investigations on 14 plant extracts (obtained by ethanolic and aqueous extraction) identified those having high antioxidant and a significant total phenolic content. Antihyperglycemic, α-amylase and α-glucosidase inhibition activities were also observed. A correlation between the antihyperglycemic activity, total phenolic content and antioxidant (DPPH scavenging) activity was established. To further substantiate these findings, the possibility of tannins binding non-specifically to enzymes and thus contributing to the antihyperglycemic activity was also investigated. Our study clearly indicated that the antihyperglycemic activity observed in the plant extracts was indeed not due to non-specific tannin absorption.
    Matched MeSH terms: alpha-Glucosidases/metabolism
  11. Teng YS, Tan SG
    Hum. Hered., 1979;29(1):2-4.
    PMID: 367946
    Acid alpha-glucosidase from the placenta was electrophoretically surveyed in a total of 633 Malaysians, 236 of Malay, 261 of Chinese and 136 of Indian ancestries. A new variant, alpha-glucosidase 3-1 was observed in 1 Malay and 3 Indians. A polymorphism for this enzyme was observed among Indians, but in Chinese and Malays variants are rare. Phenotype 2-1 was observed once in a Chinese and once in a Malay.
    Matched MeSH terms: alpha-Glucosidases/genetics*
  12. Taha M, Ismail NH, Lalani S, Fatmi MQ, Atia-Tul-Wahab, Siddiqui S, et al.
    Eur J Med Chem, 2015 Mar 6;92:387-400.
    PMID: 25585009 DOI: 10.1016/j.ejmech.2015.01.009
    In an effort to design and synthesize a new class of α-glucosidase inhibitor, we synthesized benzothiazole hybrid having benzohydrazide moiety (5). Compound 5 was reacted with various substituted aryl aldehyde to generate a small library of compounds 6-35. Synthesis of compounds was confirmed by the spectral information. These compounds were screened for their α-glucosidase activity. They showed a varying degree of α-glucosidase inhibition with IC50 values ranging between 5.31 and 53.34 μM. Compounds 6, 7, 9-16, 19, 21-30, 32-35 showed superior activity as compared to standard acarbose (IC50 = 906 ± 6.3 μM). This has identified a new class of α-glucosidase inhibitors. The predicted physico-chemical properties indicated the drug appropriateness for most of these compounds, as they obey Lipinski's rule of five (RO5). A hybrid B3LYP density functional theory (DFT) was employed for energy, minimization of 3D structures for all synthetic compounds using 6-311 + G(d,p) basis sets followed by molecular docking to explore their interactions with human intestinal C- and N-terminal domains of α-glucosidase. All compounds bind to the prospective allosteric site of the C- terminal domain, and consequently, may be considered as mixed inhibitors. It was hypothesized that both the dipole moment and H-bond interactions govern the biological activation of these compounds.
    Matched MeSH terms: alpha-Glucosidases/metabolism*
  13. Sulaiman SF, Ooi KL
    J. Agric. Food Chem., 2014 Oct 1;62(39):9576-85.
    PMID: 25198055 DOI: 10.1021/jf502912t
    The present study compared pH, total soluble solids, vitamin C, and total phenolic contents, antioxidant activities, and α-glucosidase inhibitory activities of 40 fresh juices. The juice of Baccaurea polyneura showed the highest yield (74.17 ± 1.44%) and total soluble solids (32.83 ± 0.27 °Brix). The highest and lowest pH values were respectively measured from the juices of Dimocarpus longan (6.87 ± 0.01) and Averrhoa bilimbi (1.67 ± 0.67). The juice of Psidium guajava gave the highest total phenolic (857.24 ± 12.65 μg GAE/g sample) and vitamin C contents (590.31 ± 7.44 μg AAE/g sample). The juice of Phyllanthus acidus with moderate contents of total phenolics and vitamin C was found to exhibit the greatest scavenging (613.71 ± 2.59 μg VCEAC/g sample), reducing (2784.89 ± 3.93 μg TEAC/g sample), and α-glucosidase inhibitory activities (95.37 ± 0.15%). The juice of Barringtonia racemosa was ranked second in the activities and total phenolic content. Gallic and ellagic acids, which were quantified as the major phenolics of the respective juices, are suggested to be the main contributors to the antioxidant activities. The α-glucosidase inhibitory activity of the juices could be derived from myricetin and quercetin (that were previously reported as potent α-glucosidase inhibitors) in the hydrolyzed juice extracts. The juice of Syzygium samarangense, which was found to be highest in metal chelating activity (82.28 ± 0.10%), also was found to have these phenolics.
    Matched MeSH terms: alpha-Glucosidases/chemistry
  14. Zawawi NK, Taha M, Ahmat N, Wadood A, Ismail NH, Rahim F, et al.
    Bioorg. Chem., 2016 Feb;64:29-36.
    PMID: 26637946 DOI: 10.1016/j.bioorg.2015.11.006
    Newly synthesized benzimidazole hydrazone derivatives 1-26 were evaluated for their α-glucosidase inhibitory activity. Compounds 1-26 exhibited varying degrees of yeast α-glucosidase inhibitory activity with IC50 values between 8.40 ± 0.76 and 179.71 ± 1.11 μM when compared with standard acarbose. In this assay, seven compounds that showed highest inhibitory effects than the rest of benzimidazole series were identified. All the synthesized compounds were characterized by different spectroscopic methods adequately. We further evaluated the interaction of the active compounds with enzyme with the help of docking studies.
    Matched MeSH terms: alpha-Glucosidases/chemistry*
  15. Sivasothy Y, Loo KY, Leong KH, Litaudon M, Awang K
    Phytochemistry, 2016 Feb;122:265-269.
    PMID: 26712615 DOI: 10.1016/j.phytochem.2015.12.007
    A dimeric acylphenol and a potent α-glucosidase inhibitor, giganteone D (IC50 5.05μM), was isolated and characterized from the bark of Myristica cinnamomea King. The bark also yielded an acylphenol with an unprecedented skeleton for which the name cinnamomeone A (IC50 358.80μM) was proposed. Their structures were established by means of NMR and MS spectrometric analyses. The Lineweaver-Burk plot of giganteone D indicated that it was a mixed-type inhibitor. This is the first report on the α-glucosidase inhibiting potential of acylphenols.
    Matched MeSH terms: alpha-Glucosidases/drug effects*
  16. Hashim SE, Sirat HM, Yen KH, Ismail IS, Matsuki SN
    Nat Prod Commun, 2015 Sep;10(9):1561-3.
    PMID: 26594759
    Seven compounds were isolated from the n-hexane and chloroform extracts of the flowers and leaves of four Hornstedtia species and their structures were identified using spectroscopic techniques as 3,7,4'-trimethylkaempferol (1), 3,7-dimethylkaempferol (2), 7,4'-dimethylkaempferol (3), 3,5-dimethylkaempferol (4), 3-methylkaempferol (5), stigmast-4-en-3-one (6), and 6-hydroxy-stigmast-4-en-3-one (7). Compounds 1 to 7 were isolated from these species for the first time. They were assayed for free radical scavenging and α-glucosidase inhibition activities. The DPPH assay showed that 3-methylkaempferol (5) was the most potent antioxidant agent with an IC50 value 78.6 µM, followed by 7,4'-dimethylkaempferol (3) (IC50 = 86.1 µM). For α-glucosidase inhibition activity, 3-methylkaempferol (5) exhibited significant inhibitory activity with an IC50 value 21.0 µM. The present study revealed that Hornstedtia species have potential activities as antioxidant and α-glucosidase inhibitors.
    Matched MeSH terms: alpha-Glucosidases/metabolism*
  17. Taha M, Ismail NH, Imran S, Rokei MQB, Saad SM, Khan KM
    Bioorg. Med. Chem., 2015 Aug 01;23(15):4155-4162.
    PMID: 26183542 DOI: 10.1016/j.bmc.2015.06.060
    Oxadiazole derivatives (6-28) having hydrazone linkage, were synthesized through condensation reaction between benzohydrazide 5 with various benzaldehydes. The oxadiazoles derivatives (6-28) were evaluated for their α-glucosidase inhibitory activity. The IC50 values for inhibition activity vary in the range between 2.64 ± 0.05 and 460.14 ± 3.25 μM. The IC50 values were being compared to the standard acarbose (IC50=856.45 ± 5.60 μM) and it was found that compounds 6-9, 12, 13, 16, 18, 20, 22-28 were found to be more active than acarbose, while other compounds showed no activity. Structure-activity relationship (SAR) studies suggest that oxadiazole benzohydrazones (6-28) inhibitory potential is dependent on substitution of the N-benzylidene part. Compound 18 (IC50=2.64 ± 0.05 μM), which has trihydroxy substitution at C-2', C-4', and C-5' on N-benzylidene moiety, recorded the highest inhibition activity that is three-hundred times more active than the standard drug, acarbose (IC50=856.45 ± 5.60 μM). Compound 23 (IC50=34.64 ± 0.35 μM) was found to be the most active among compounds having single hydroxyl substitution. Shifting hydroxyl from C-2' to C-4' (6) and C-3' (7) reduces inhibitory activity significantly. Compounds with chlorine substituent (compounds 16, 28, and 27) showed potent activities but lower as compared to hydroxyl analogs. Substituent like nitro or methyl groups at any position suppresses enzyme inhibition activity. This reveals the important presence of hydroxyl and halo groups to have enzyme inhibitory potential.
    Matched MeSH terms: alpha-Glucosidases/metabolism
  18. Khan KM, Rahim F, Wadood A, Kosar N, Taha M, Lalani S, et al.
    Eur J Med Chem, 2014 Jun 23;81:245-52.
    PMID: 24844449 DOI: 10.1016/j.ejmech.2014.05.010
    In our effort directed toward the discovery of new anti-diabetic agent for the treatment of diabetes, a library of biscoumarin derivative 1-18 was synthesized and evaluated for α-glucosidase inhibitory potential. All eighteen (18) compounds displayed assorted α-glucosidase activity with IC50 values 16.5-385.9 μM, if compared with the standard acarbose (IC50 = 906 ± 6.387 μM). In addition, molecular docking studies were carried out to explore the binding interactions of biscoumarin derivatives with the enzyme. This study has identified a new class of potent α-glucosidase inhibitors.
    Matched MeSH terms: alpha-Glucosidases/metabolism*
  19. Rahim F, Malik F, Ullah H, Wadood A, Khan F, Javid MT, et al.
    Bioorg. Chem., 2015 Jun;60:42-8.
    PMID: 25955493 DOI: 10.1016/j.bioorg.2015.03.005
    Isatin base Schiff bases (1-20) were synthesized, characterized by (1)H NMR and EI/MS and evaluated for α-glucosidase inhibitory potential. Out of these twenty (20) compounds only six analogs showed potent α-glucosidase inhibitory potential with IC50 value ranging in between 2.2±0.25 and 83.5±1.0μM when compared with the standard acarbose (IC50=840±1.73μM). Among the series compound 2 having IC50 value (18.3±0.56μM), 9 (83.5±1.0μM), 11 (3.3±0.25μM), 12 (2.2±0.25μM), 14 (11.8±0.15μM), and 20 (3.0±0.15μM) showed excellent inhibitory potential many fold better than the standard acarbose. The binding interactions of these active analogs were confirmed through molecular docking.
    Matched MeSH terms: alpha-Glucosidases/metabolism*
  20. Al-Salahi R, Ahmad R, Anouar E, Iwana Nor Azman NI, Marzouk M, Abuelizz HA
    Future Med Chem, 2018 08 01;10(16):1889-1905.
    PMID: 29882426 DOI: 10.4155/fmc-2018-0141
    AIM: Using a simple modification on a previously reported synthetic route, 3-benzyl(phenethyl)-2-thioxobenzo[g]quinazolin-4(3H)-ones (1 and 2) were synthesized with high yields. Further transformation of 1 and 2 produced derivatives 3-26, which were structurally characterized based on NMR and MS data, and their in vitro α-glucosidase inhibitory activity was evaluated using Baker's yeast α-glucosidase enzyme.

    RESULTS: Compounds 2, 4, 8, 12 and 20 exhibited the highest activity (IC50 = 69.20, 59.60, 49.40, 50.20 and 83.20 μM, respectively) compared with the standard acarbose (IC50 = 143.54 μM).

    CONCLUSION: A new class of potent α-glucosidase inhibitors was identified, and the molecular docking predicted plausible binding interaction of the targets in the binding pocket of α-glucosidase and rationalized the structure-activity relationship (SARs) of the target compounds.

    Matched MeSH terms: alpha-Glucosidases/metabolism*
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