Angiotensin-converting enzyme inhibitory activity of polyphenolic compounds from Peperomia pellucida (L) Kunth: An in silico molecular docking study

This study aimed to predict the potential activity and interaction conformation of polyphenolic compounds fromPeperomia pellucida (L) Kunth (nine compounds) with angiotensin-converting enzyme (ACE) macromolecule by insilico molecular docking study. The crystal structure of ACE as a molecular target was obtained from the PDB database(PDB ID: 1UZF) with captopril as a native ligand. Molecular docking analysis was performed using AutoDockZn (100docking runs) based on the active site of Zn2+, the central grid was placed on Zn2+ with a box size of 40Á × 40Á ×40Á and a center of 40.835Á × 34.382Á × 44.607Á for selective inhibitors (MCO702) with a spacing of 0.375Á.Based on the docking results demonstrated that the prediction of each polyphenol compounds from P. pellucida hasthe potential of active as ACE inhibitors, it was indicated that docking results of each compound has lower affinitycompared to captopril (with binding affinity of −6.36 kcal/mol and the inhibition constant 21.81 μM), where themost moderate binding affinity (the most potential) was tetrahydrofuran lignin ((1R,2S,3S,5R)-3,5-bis(4-hydroxy3,5-dimethoxyphenyl)cyclopentane-1,2-diyl)bis-(methylene) diacetate) of −8.66 kcal/mol and the highest bindingaffinity (the less potential) was dillapiole (6-allyl-4,5-dimethoxybenzo[d][1,3]dioxole) of −4.99 kcal/mol, althoughwith different forms of interaction, bond, and constant inhibition. Based on the interaction of ACE binding site,5,6,7-trimethoxy-4-(2,4,5-trimethoxyphenyl)-3,4-dihydronaphthalen-1(2H)-one showed the most similar interactionwith the captopril ligand. These results are preliminary data for further research with predictions of target compoundbiological activity and interaction quickly, accurately, and inexpensively

A new angiotensin-converting enzyme inhibitor from Peperomia pellucida (L.) Kunth

Objective: To isolate, identify, and evaluate a new angiotensin-converting enzyme inhibitor from Peperomia pellucida (L.) Kunth herbs. Methods: A dried sample of Peperomia pellucida herb was successively macerated with n-hexane and ethyl acetate. The ethyl acetate extract solution was evaporated to obtain the crude extract. Vacuum liquid column chromatography and thin layer chromatography were performed to obtain two pure compounds. Then, both compounds were elucidated and identified using the spectroscopic method. Angiotensin-converting enzyme inhibitory activity studies of both compounds were determined using angiotensin-converting enzyme kit WST-1 with spectrophotometer microplate reader 96-well at 450 nm wavelength. Results: Two bioactive compounds were successfully isolated from Peperomia pellucida herb, including a new compound of 2,3,5-trimethoxy-9-(12,14,15-trimethoxybenzyl)-1H-indene and pellucidin A. Both compounds demonstrated angiotensin-converting enzyme inhibitory activity, with IC50 values of 72 μM (27.95 μg/mL) and 11 μM (4.4 μg/mL), respectively. Conclusions: In the present study, two active angiotensin-converting enzyme inhibitors were successfully isolated and purified from Peperomia pellucida which is used as an antihypertensive in traditional medicine, and support its use as an angiotensin-converting enzyme-inhibiting drug.

Optimization of ionic liquid-based microwave-assisted extraction of polyphenolic content from Peperomia pellucida (L) kunth using response surface methodology

Objective: To optimize the ionic liquid based microwave-assisted extraction (IL-MAE) of polyphenolic content from Peperomia pellucida (L) Kunth. Methods: The IL-MAE factors as experimental design parameters, including microwave power, extraction time, ionic liquid concentration, and liquid–solid ratio had been involved. Response surface methodology and Box–Behnken design were used to obtain predictive model (multivariate quadratic regression equation) and optimization of the extraction process. The response surface was analyzed by using the yields of total polyphenolic content as response value. Results: Based on the obtained results the optimum extraction condition, including microwave power of 30% Watts, extraction time of 18.5 min, the ionic liquid concen-tration of 0.79 mol/L, and the liquid–solid ratio of 10.72 mL/g 1-Buthyl-3-methylimidazolium tetrafluoroborate ([bmim]BF4) as a solvent was selected. The regression model was obtained to predicts the yields from Peperomia pellucida:Y = 30.250 – 1.356X1 + 2.655X2 + 2.252X3 – 0.565X4 + 0.990 X1X3 – 8.172 X1X4 – 3.439 X3X4 – 4.178 X12 – 3.210 X32 – 6.786 X42 – 7.290 X12X3 + 5.575 X1X32 – 4.843 X32X4 with R2 = 0.82519. Scale-up confirmation test was obtained the maximum yields of total polyphenolics content with the amount of 31.1725μg GAE/g. Conclusions: The IL-MAE method produced a higher extraction polyphenolic and performed rapidly, easily and efficiently.