In Silico Docking Analysis of A-type Proanthocyanidins to α-Glucosidase Constructed by Correlation with in Vitro Bioassay
Sheau Ling Ho,
Yili Lin,
Shengfa Tsai,
Shoeisheng Lee
Issue:
Volume 5, Issue 4, December 2019
Pages:
47-60
Received:
21 November 2019
Accepted:
7 December 2019
Published:
23 December 2019
Abstract: The type A proanthocyanidins (2−8) with (2β→O→7, 4β→8) interflavane linkage, isolated from Machilus philippinensis, have been found to possess inhibitory activity against α-glucosidase (EC 3.2.1.20 from Bacillus stearothermophilus). To rationalize such activity, computer assisted docking of these compounds and the positive control, acarbose, on the conformation model of α-glucosidase (AG), built by using human intestinal maltase glucoamylase as a template, was undertaken in this study. The result showed good correlation between IC50 values and docking scores, expressed as binding energy (ΔG), obtained from London (trimatch)-refinement (forcefield AffinityΔG) mode. Among these isolates, the most potent aesculitannin B (2) (IC50 3.5μM) showed the best docking score (ΔG -21.48 kcal/mol). Being interested in clarification of structure and activity relationship, virtual screening on the related compounds, including the de-unit III homologs of 2−8 (i.e., nor- series) and additional 13 stereoisomers of the trimeric 2 at the C-2 and C-3 positions of units II and III, was further carried out. This docking study indicated the de-unit III homologs of 2−8 did not have better binding energies than 2. As for the trimers, 3-entC, 3C-entE, 3ent-C, 3C, and 3ent, showed comparable docking score to 2. The verification of this virtual screening was partially done by evaluating the inhibitory activity of the dimeric 2-nor-ent, 3-nor, 3-nor-ent, and iso-2-nor-ent, isolated from peanut skins, against α-glucosidase. Of these, iso-2-nor-ent, the only proanthocyanidin with (2β→O→7, 4β→6) interflavane linkage, showed the best activity (IC50 9.72 μM). Their simulation profiles of docking score also displayed a reasonable qualitative consistency with the overall trend of the bioassay results. This study demonstrates that virtual screening using this built model to search α-glucosidase inhibitors is facile and feasible and peanut skin might be used as a hypoglycemic food.
Abstract: The type A proanthocyanidins (2−8) with (2β→O→7, 4β→8) interflavane linkage, isolated from Machilus philippinensis, have been found to possess inhibitory activity against α-glucosidase (EC 3.2.1.20 from Bacillus stearothermophilus). To rationalize such activity, computer assisted docking of these compounds and the positive control, acarbose, on the...
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Source Tracking and Carcinogenic Risk of Polycyclic Aromatic Hydrocarbons in Contaminated Farmlands of Egi, Niger Delta, Nigeria
Elechi Owhoeke,
Michael Horsfall Jnr,
Charles Ikenna Osu
Issue:
Volume 5, Issue 4, December 2019
Pages:
61-66
Received:
20 October 2019
Accepted:
4 November 2019
Published:
6 January 2020
Abstract: The levels of Polycyclic Aromatic Hydrocarbons (PAHs) in contaminated farmland soil from three oil-producing communities (Oboburu, Obagi, and Ogbogu) in Egi, Niger Delta were assessed for variability, origin and health risks. The result showed that tPAHs of Oboburu were 1344±1685 mg/kg for carcinogenic while BaP (257.3±270.5 mg/kg) had the greatest value. Obagi had 4154±3461 mg/kg for cPAHs with BkF (861.5±543.7 mg/kg) having the greatest amount. Ogbogu was 354.7±360.7 mg/kg for total cPAHs while BgP (104.1±141.8 mg/kg) had highest amount. The dominant PAHs were BbF, BkF, DbA, BaP, IdP and BgP. The principal component analysis (PCA) indicated that the PAHs were majorly of pyrogenic and petrogenic origin. The predicted risk due to PAHs in soil for children showed tPAHs was 1.68E-2, with high risk for BaP (9.05E-3), IdP (5.05E-3), BbF (1.63E-3) and BkF (1.04E-3), while the adults estimation showed tPAHs was 1.13E-2 and high risk were for BaP (2.30E-3), IdP (1.08E-3) and BkF (2.57E-4). These values are more than the limit of the US EPA risk management criterion (10-6 to 10-4) where management decisions should be considered. The trend indicated that their presence in the environment makes it unsafe for the dwellers.
Abstract: The levels of Polycyclic Aromatic Hydrocarbons (PAHs) in contaminated farmland soil from three oil-producing communities (Oboburu, Obagi, and Ogbogu) in Egi, Niger Delta were assessed for variability, origin and health risks. The result showed that tPAHs of Oboburu were 1344±1685 mg/kg for carcinogenic while BaP (257.3±270.5 mg/kg) had the greatest...
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