Simultaneous Determination of Adulterants in Dietary Food Supplements Using Multivariate Data Analysis after Preconcentration with Novel Nanosorbents and Chromatographic Measurement.

BACKGROUND: The increasing popularity of dietary supplements and, consequently, related adulteration emphasizes the rising need to examine the association of food supplements with fraud. Intentional or unintentional fraud in food supplements by hazardous chemicals compounds is a problem that many countries are struggling with. Much effort have been made to effectively and reliably control the quality of food supplements. OBJECTIVE: Due to the importance of the subject, an analytical method for the simultaneous and reliable detection and quantitative determination of three key adulterants in dietary food supplements was developed. The proposed method benefits from analytical methods and multivariate calibration methods to progress the determination of adulterants in a complex matrix. METHODS: HPLC assisted by multivariate curve resolution-alternating least square (MCR-ALS) analysis was used to detect adulterants in real samples after separation and preconcentration using novel mesoporous carbon nanoparticles. Solid-phase extraction (SPE) optimization was accomplished by central composite design (CCD). In order to obtain the best results, the MCR-ALS model was compared with the parallel factor analysis 2 (PARAFAC2) model and validated by estimation of linearity, detection limits, and recovery. RESULTS: The detection limits and linear dynamics were calculated as 1.5, 4.27, and 4.77 µg/mL, and 1-50, 5-20, and 5-20 µg/mL for caffeine, ephedrine, and fluoxetine, respectively. Mean recovery for determination of caffeine, ephedrine, and fluoxetine using the developed method was reported as 101.75, 91.7, and 92.36, respectively. CONCLUSION: The results showed that to avoid negative health outcomes associated with the excessive consumption of adulterated food supplements releasing such products should be carefully regulated. The developed method was validated using statistical factors and showed acceptable and reliable results. HIGHLIGHTS: (1) The application of MCR-ALS coupled with HPLC-Diode-Array Detection data sets allowed the simultaneous identification and quantification of three key adulterants (caffeine, ephedrine, and fluoxetine) in dietary food supplements. (2) A small amount of the novel adsorbent was successfully used to preconcentrate the trace amounts of adulterants in samples. (3) This method benefits from the chemometrics tools and experimental design to significantly reduce the use of toxic solvents and complicated instruments to propose a less time-consuming method for quantification of multicomponents in the presence of uncalibrated interferents.

Pomegranate Punica granatum peel waste as a naked-eye natural colorimetric sensor for the detection and determination of Fe+3 and I- ions in water.

The utilization of renewable and abundant agricultural waste such as Pomegranate (Punica granatum L.) peel extract has been developed wherein a simple extraction of dried peel in water offered a natural sensor; ensuing yellowish solution comprising phenolic compounds reacted explicitly to detect Fe+3 and I- solutions by naked-eye. The UV-Vis absorption spectrum of the resulting extracted mixture was drastically changed toward the longer wavelengths only after the addition of the Fe3+ and I- while there was no discernible spectral change due to the addition of a broad range of other common cations and anions. In the case of Fe3+ and I-, the transformation can be followed by the naked eye in the concentration range of 5 × 10-4 M and 1 × 10-2 M, respectively. An acceptable and reasonable detection with 47.05426 µM efficiency was attained in comparison to other Fe3+ indicators such as ferroin.

In vitro and in silico pharmaceutical activities of the methylated cyclic pentapeptide, persipeptides.

AIMS: The persipeptides were recognized as a promising source of multiple pharmaceutical activities which were revealed following structure-activity prediction and examination in experimental analysis. METHODS AND RESULTS: The profile of toxicity, antioxidant, anti-inflammatory, anti-diabetic and anti-ageing activity of persipeptides and the crude extract were evaluated experimentally. The pure Persipeptide A and B revealed a moderate xanthine oxidase inhibition activity at the concentration of 10 µg/ml. Persipeptide exhibited α-glucosidase inhibition activity (~10% inhibition) and less than 2% tyrosinase inhibition activity at the concentration of 10 µg/ml. The extract exhibited the inhibition of less than 2% acetylcholine esterase inhibition activity, but the pure persipeptide showed 6%-14% inhibition activity at the concentration of 10 µg/ml. The molecular docking analysis revealed that the activities of Persipeptide A and B are due to interaction with xanthin oxidase, α-amylase, α-glucosidase, tyrosinase and acetylcholine esterase enzymes. CONCLUSIONS: The persipeptides showed a similar inhibition rate with positive control that might imply its potential as an anti-diabetic and anti-gout compound among. Only acetylcholine esterase inhibition of persipeptide was higher than the extract. The interacting amino acids of the molecules with different targets show that persipeptides might have antioxidant, anti-inflammatory, anti-diabetic, anti-ageing activity and even other potential pharmaceutical activities that were not investigated in this study. SIGNIFICANCE AND IMPACT OF THE STUDY: This report was presented to find some new pharmaceutical activities of Persipeptide A and B including the α-glucosidase inhibition activity as a molecular target of diabetes mellitus. Persipeptides also exhibited an effective inhibition of xanthine oxidase (XO) which can be a drug-like candidate in the treatment of diseases associated with XO like gout. The binding values indicated the interaction of persipeptides with these enzymes.

Identification of Essential 2D and 3D Chemical Features for Discovery of the Novel Tubulin Polymerization Inhibitors.

BACKGROUND: Tubulin polymerization inhibitors interfere with microtubule assembly and their functions lead to mitotic arrest, therefore they are attractive target for design and development of novel anticancer compounds. OBJECTIVE: The proposed novel and effective structures following the use of three-dimensionalquantitative structure activity relationship (3D-QSAR) pharmacophore based virtual screening clearly demonstrate the high efficiency of this method in modern drug discovery. METHODS: Combined computational approach was applied to extract the essential 2D and 3D features requirements for higher activity as well as identify new anti-tubulin agents. RESULTS: The best quantitative pharmacophore model, Hypo1, exhibited good correlation of 0.943 (RMSD=1.019) and excellent predictive power in the training set compounds. Generated model AHHHR, was well mapped to colchicine site and three-dimensional spatial arrangement of their features were in good agreement with the vital interactions in the active site. Total prediction accuracy (0.92 for training set and 0.86 for test set), enrichment factor (4.2 for training set and 4.5 for test set) and the area under the ROC curve (0.86 for training set and 0.94 for the test set), the developed model using Extended Class FingerPrints of maximum diameter 4 (ECFP_4) was chosen as the best model. CONCLUSION: Developed computational platform provided a better understanding of requirement features for colchicine site inhibitors and we believe the results of this study might be useful for the rational design and optimization of new inhibitors.

Docking of Natural Products against Neurodegenerative Diseases: General Concepts.

BACKGROUND: Since antiquity, humanity has used medicinal plant preparations to cure its ills, and, as research has progressed, new technologies have enabled more investigations on natural compounds which originate from plants, fungi, and marine species. The health benefits that these natural products provide have become a motive for treatment studies of various diseases. OBJECTIVE: Among them, the neurodegenerative diseases like Alzheimer's and Parkinson's, a major age-related neurodegenerative disorder. Studies with natural products for neurodegenerative diseases (particularly through molecular docking) search for, and then focus on those ligands which offer effective inhibition of the enzymes monoamine oxidase and acetylcholinesterase. METHOD: This review introduces the main concepts involved in docking studies with natural products: and also in our group, which has conducted a docking study of natural products isolated from Tetrapterys mucronata for inhibition of acetylcholinesterase. RESULTS: We observed that compounds 4 and 5 formed more interactions than the theoretical ligand, but that ligands with greater activity also interacted with residues HIS 381 and GLN 527. CONCLUSION: We have reported on our docking study performed with AChE and alkaloids isolated from the plant Tetrapterys mucronata. Our docking results corroborate the experiments conducted, and emphasize the positive contribution that these theoretical studies involving natural products bring to the fight against neurodegenerative diseases.

3D QSAR studies, pharmacophore modeling, and virtual screening of diarylpyrazole-benzenesulfonamide derivatives as a template to obtain new inhibitors, using human carbonic anhydrase II as a model protein.

A 3D-QSAR modeling was performed on a series of diarylpyrazole-benzenesulfonamide derivatives acting as inhibitors of the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1). The compounds were collected from two datasets with the same scaffold, and utilized as a template for a new pharmacophore model to screen the ZINC database of commercially available derivatives. The datasets were divided into training, test, and validation sets. As the first step, comparative molecular field analysis (CoMFA), CoMFA region focusing and comparative molecular similarity indices analysis (CoMSIA) in parallel with docking studies were applied to a set of 41 human (h) CA II inhibitors. The validity and the prediction capacity of the resulting models were evaluated by leave-one-out (LOO) cross-validation approach. The reliability of the model for the prediction of possibly new CA inhibitors was also tested.

Extraction optimization of pepsin-soluble collagen from eggshell membrane by response surface methodology (RSM).

Response surface methodology (RSM) was used to investigate the effect of extraction-process variables on pepsin-soluble collagen (PSC) from eggshell membrane. A central composite design (CCD) was employed for experimental design and analysis of the results to obtain the best possible combination of NaOH concentration (X1: 0.4-1.2 mol/l), alkali treatment time (X2: 6-30 h), enzyme concentration (X3: 15-75 U/mg) and hydrolysis time (X4: 12-60 h) for maximum PSC extraction. The experimental data obtained were fitted to a second-order polynomial equation using multiple regression analysis and analyzed by appropriate statistical methods. According to the results, optimum extraction conditions were as follows: NaOH concentration of 0.76 mol/l, alkali treatment time of 18 h, enzyme concentration of 50 U/mg and hydrolysis time of 43.42 h. The experimental extraction yield under optimal conditions was found to be 30.049%, which is in good agreement with the predicted value of 30.054%.

Simultaneous spectrophotometric determination of trace amounts of uranium, thorium, and zirconium using the partial least squares method after their preconcentration by alpha-benzoin oxime modified Amberlite XAD-2000 resin.

A new solid phase extraction method for separation and preconcentration of trace amounts of uranium, thorium, and zirconium in water samples is proposed. The procedure is based on the adsorption of U(VI), Th(IV) and Zr(IV) ions on a column of Amberlite XAD-2000 resin loaded with alpha-benzoin oxime prior to their simultaneous spectrophotometric determination with Arsenazo III using orthogonal signal correction partial least squares method. The enrichment factor for preconcentration of uranium, thorium, and zirconium was found to be 100. The detection limits for U(VI), Th(IV) and Zr(IV) were 0.50, 0.54, and 0.48microgL(-1), respectively. The precision of the method, evaluated as the relative standard deviation obtained by analyzing a series of 10 replicates, was below 4% for all elements. The practical applicability of the developed sorbent was examined using synthetic seawater, natural waters and ceramic samples.