Pharmacophore Modeling and Binding Affinity of Secondary Metabolites from Angelica keiskei to HMG Co-A Reductase.

Statins are cholesterol-lowering drugs with a mechanism of inhibiting 3-hydroxy-3-methylglutaryl-CoA reductase, but long-term use can cause side effects. An example of a plant capable of reducing cholesterol levels is Angelica keiskei (ashitaba). Therefore, this study aimed to obtain suitable compounds with inhibitory activity against the HMG-CoA reductase enzyme from ashitaba through in silico tests. The experiment began with screening and pharmacophore modeling, followed by molecular docking on ashitaba's compounds, statins groups, and the native ligand was (3R,5R)-7-[4-(benzyl carbamoyl)-2-(4-fluorophenyl)-5-(1-methylethyl)-1H-imidazole-1-yl]-3,5-dihydroxyheptanoic acid (4HI). Based on the results of the molecular docking simulations, 15 hit compounds had a small binding energy (ΔG). Pitavastatin, as the comparator drug (ΔG = -8.24 kcal/mol; Ki = 2.11 µM), had a lower ΔG and inhibition constant (Ki) than the native ligand 4HI (ΔG = -7.84 kcal/mol; Ki = 7.96µM). From ashitaba's compounds, it was found that 4'-O-geranylnaringenin, luteolin, isobavachalcone, dorsmannin A, and 3'-carboxymethyl-4,2'-dihydroxy-4'-methoxychalcone have low ΔG of below -6 kcal/mol. The lowest ΔG value was found in 3'-carboxymethyl-4,2'-dihydroxy-4'-methoxy chalcone with a ΔG of -6.67 kcal/mol and Ki value of 16.66 µM, which was lower than the ΔG value of the other comparator drugs, atorvastatin (ΔG = -5.49 kcal/mol; Ki = 1148.17 µM) and simvastatin (ΔG = -6.50 kcal/mol; Ki = 22.34 µM). This compound also binds to the important amino acid residues, including ASN755D, ASP690C, GLU559D, LYS735D, LYS691C, and SER684C, through hydrogen bonds. Based on the results, the compound effectively binds to six important amino acids with good binding affinity and only requires a small concentration to reduce half of the enzyme activity.

Validation of bioanalytical method for quantification of Vitamin K2 (MK-4) in human plasma by high-performance liquid chromatography-ultraviolet.

Vitamin K can reduce warfarin's anticoagulant action, causing a variance in response among individuals taking warfarin. Vitamin K comes in two forms, namely Vitamin K1 (phylloquinone) and K2 (menaquinones). Menaquinone-4 (MK-4) is a kind of Vitamin K2 found in meat and dairy products. Analysis of MK-4 levels in human plasma is very useful for patients who receive warfarin therapy. High-performance liquid chromatography (HPLC) can be used for warfarin's bioanalysis, and it must be validated. The purpose of this study was to validate the bioanalytical method for quantification of Vitamin K2 (MK-4) in human plasma according to the 2019 European Medicines Agency (EMA) guideline. Vitamin K2 (MK-4) was extracted using acetonitrile. HPLC with an ultraviolet detector at 245 nm, using a T3 column set at 30°C and an isocratic mobile phase containing methanol: phosphate buffer (95:5) at pH 3, a flow rate of 1 mL/min was used in this study. The warfarin concentration of 0.5-3 µg/mL was used. About 5.50%-17.42% and 6.18%-8.74%, respectively, were the average ranges of percentage coefficient of variation and percentage difference. There was no response at the analyte's retention time in the six blank plasmas and at the analyte's retention time in the blank after the injection of upper limit of quantification, indicates that the procedure was very selective and did not result in any carryover. This bioanalytical method fulfills the parameters of selectivity, accuracy, precision, and carryover based on the 2019 EMA guidelines.

A Polymer-Based Indicator for Detecting Dexamethasone in Herbal Medicine Using Polymethylmethacrylate (PMMA).

Dexamethasone is a chemical drug that is usually added to herbal medicine because of its effects on pain relief, arthritis, anti-inflammation, etc. Chemical drugs should not be used in herbal medicine because uncontrolled consumption causes some side effects. A polymer-based indicator was developed to detect dexamethasone in herbal medicine samples in a fast and simple way compared to instrumental analysis. The indicator strips were made by mixing polymethylmethacrylate (PMMA) polymer with sulfuric acid (H2SO4) as a reagent. When reacting with dexamethasone, H2SO4 can cause the color to change into a specific light pink-purple color. Indicator strips were prepared with a composition of 5% PMMA in ethyl acetate:H2SO4 (9:1) by using the reagent blending method. The indicator strips showed a pink-purple color when they were applied to a positive herb containing dexamethasone. The indicator strips could selectively detect dexamethasone rather than other active substances that are often found in herbal medicine. These indicator strips could also detect dexamethasone with the smallest detection limit of 13.13 ppm, and they had a stability of up to 36 days. Detection was carried out in real samples to show the performance of the indicator strips. The result showed that of nine samples, five were confirmed to contain dexamethasone. These results showed a good agreement with the results of thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). According to the result, these indicator strips provide a simple and applicable method for on-site analysis to detect dexamethasone in samples.

Isolation, Characterization, and Evaluation of Protease Activity of Crude Bromelain of Pineapple Peel, Core, and Crown from Subang District, Indonesia.

Context: Bromelain is distributed to all parts of pineapple (Ananas comusus (L.) Merr), including the peel, core, and crown, which are agricultural waste that has not been utilized properly. Aims: The purpose of this study was to determine the character and protease activity of crude bromelain from the Indonesian pineapple peel, core, and crown. The pineapple was collected from Subang district, West Java Province, Indonesia. Methods and Material: The three crude bromelains were obtained through the precipitation process with ethanol, then a protein qualitative and quantitative analysis was performed. Protease activity was determined by measuring the tyrosine produced from casein hydrolysis. The characters of crude bromelains were determined by evaluating the protease activity in various pH, temperature, and substrate concentration. Statistical Analysis Used: One-way analysis of variance was conducted to analyze the data statistically. Results: The three crude bromelains can be isolated from the peel, core, and crown of pineapple fruit with protease activity in the range of 38.32-46.78 units. Crude bromelains have an optimum temperature of 55°C for the peel and core and 35°C for the crown. All crude bromelains have an optimum pH of pH 7. The three crude bromelains have Vmax in the range of 140.85 to 285.71 units and KM in the range of 15298.59 to 18370.86 ppm. Conclusions: It concluded that the three crude bromelains have protease activity with the specific character and kinetic parameter.

A Review: Using Multiple Templates for Molecular Imprinted Polymer: Is It Good?

A multi-template molecularly imprinting polymer (MT-MIP) strategy has been proposed and is increasingly utilised to synthesise MIP with multiple recognition sites in a single polymer using multiple target species as templates. This approach can expand MIP applications for simultaneous recognition and extraction of more than one analyte. The advantages of MT-MIP are simultaneous analyte extraction in one process, lower solvent consumption, cost-effectiveness, and short analysis time. The use of multiple templates to prepare a MIP reduces the effort required to prepare different MIPs for different analytes separately. Although there are many studies about developing MT-MIP, there are no review articles that discuss the success rate of MT-MIP. Therefore, in this review, we summarise MT-MIP synthesis, including the polymerisation method being used, the important factors that affect the quality of MT-MIP, and MT-MIP applications. MT-MIP has great potential in chemical isolation and analysis. MT-MIP produces a product that has good sensitivity, selectivity, and reusability. Furthermore, many templates, functional monomers, and crosslinkers can be formulated as MT-MIP and have a high success rate. This is evidenced by the good values of the maximum absorption capacity (Qmax), imprinting factor (IF), and reusability. We expect that the evidence presented in this review can encourage additional research on the development and application of MT-MIP.

Nanoparticulate System for the Transdermal Delivery of Catechin as an Antihypercholesterol: In Vitro and In Vivo Evaluations.

Gambir (Uncaria gambir, Roxb.) contains catechins that is often empirically used to treat various diseases. Catechins can reduce cholesterol levels by inhibiting coenzyme HMG-CoA reductase that plays a role in cholesterol metabolism. Research has been carried out covering the optimization of transethosomal catechins, the formulation of Transethosomal Catechin Gel (TCG) and Non-Transethosomal Catechin Gel (NTCG), which were then tested for catechin permeation from these gel preparations in vitro using Franz's diffusion cell with PTFE membranes. The anti-hypercholesterol activity test was carried out with Simvastatin orally as a positive control using 25 male Wistar rats (Rattus norvegicus). The catechin transetosomes have a size of 176.1 ± 5.8 nm, Zeta potential -11.6 ± 5.28, and Entrapment Efficacy of 96.77% ± 0.05. The result of cumulative catechins that permeated from TCG and NTCG were and 172.454 ± 5.287 and 112.741 ± 2.241 µg respectively. Permeation test graphs showed similar permeation and flux profiles. TCG can reduce total cholesterol and LDL (Low Density Lipoprotein) values in rats by 39.77% and 51.52% respectively during 14 days of use.

Factors Affecting Preparation of Molecularly Imprinted Polymer and Methods on Finding Template-Monomer Interaction as the Key of Selective Properties of the Materials.

Molecular imprinting is a technique for creating artificial recognition sites on polymer matrices that complement the template in terms of size, shape, and spatial arrangement of functional groups. The main advantage of Molecularly Imprinted Polymers (MIP) as the polymer for use with a molecular imprinting technique is that they have high selectivity and affinity for the target molecules used in the molding process. The components of a Molecularly Imprinted Polymer are template, functional monomer, cross-linker, solvent, and initiator. Many things determine the success of a Molecularly Imprinted Polymer, but the Molecularly Imprinted Polymer component and the interaction between template-monomers are the most critical factors. This review will discuss how to find the interaction between template and monomer in Molecularly Imprinted Polymer before polymerization and after polymerization and choose the suitable component for MIP development. Computer simulation, UV-Vis spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Proton-Nuclear Magnetic Resonance (1H-NMR) are generally used to determine the type and strength of intermolecular interaction on pre-polymerization stage. In turn, Suspended State Saturation Transfer Difference High Resolution/Magic Angle Spinning (STD HR/MAS) NMR, Raman Spectroscopy, and Surface-Enhanced Raman Scattering (SERS) and Fluorescence Spectroscopy are used to detect chemical interaction after polymerization. Hydrogen bonding is the type of interaction that is becoming a focus to find on all methods as this interaction strongly contributes to the affinity of molecularly imprinted polymers (MIPs).

Effect of the Molecularly Imprinted Polymer Component Ratio on Analytical Performance.

Molecular imprinting technology is a new analytical method that is highly selective and specific for certain analytes in artificial receptor design. The renewal possibilities of this technology make it an ideal material for sundry application fields. Molecularly imprinted polymers (MIPs) are polymeric matrices that have molecules printed on their surfaces; these surfaces can chemically interact with molecules or follow the pattern of the available template cavities obtained using imprinting technology. A MIP is useful for separating and analysing complex samples, such as biological fluids and environmental samples, because it is a strong analytical recognition element that can mimick natural recognition entities like biological receptors and antibodies. The MIP components consist of the target template, functional monomer, crosslinker, polymerisation initiator, and porogen. The effectiveness and selectivity of a MIP are greatly influenced by variations in the components. This review will provide an overview of the effect of MIP component ratio on analytical performance to each target analyte; it will also provide a strategy to obtain the best MIP performance. For every MIP, each template : monomer : crosslinker ratio shows a distinct performance for a specific analyte. The effects of the template : monomer : crosslinker ratio on a MIP's analytical performances-measured by the imprinting factor, sorbent binding capacity, and sorbent selectivity-are briefly outlined.

Microsphere Polymers in Molecular Imprinting: Current and Future Perspectives.

Molecularly imprinted polymers (MIPs) are specific crosslinked polymers that exhibit binding sites for template molecules. MIPs have been developed in various application areas of biology and chemistry; however, MIPs have some problems, including an irregular material shape. In recent years, studies have been conducted to overcome this drawback, with the synthesis of uniform microsphere MIPs or molecularly imprinted microspheres (MIMs). The polymer microsphere is limited to a minimum size of 5 nm and a molecular weight of 10,000 Da. This review describes the methods used to produce MIMs, such as precipitation polymerisation, controlled/'Living' radical precipitation polymerisation (CRPP), Pickering emulsion polymerisation and suspension polymerisation. In addition, some green chemistry aspects and future perspectives will also be given.

Formulation of Antioxidant Gel from Black Mulberry Fruit Extract (Morus nigra L.).

BACKGROUND: Ultraviolet (UV) radiation from the sun that is composed of UVA and UVB can cause premature aging when exposed to the skin. Black mulberry fruit (Morus nigra L.) contains anthocyanins as antioxidants that can be protective against UV exposure. The aim of this research was to produce gel formulation from the extract of black mulberry as an antioxidant and sunscreen. MATERIALS AND METHODS: This research started with the maceration process using 96% ethanol solvent. Later, antioxidant activity of the extract was determined using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and compared with vitamin C. Furthermore, the extracts were formulated into gel with variations of hydroxypropyl methylcellulose, sodium carboxymethyl cellulose, Carbopol 934, and extract concentrations. The products were then physically evaluated, including organoleptic evaluation, homogeneity, pH, viscosity, and dispersion, as well as the hedonic test, irritation test, and antioxidant activity test. RESULTS: The results showed that black mulberry extract had antioxidant activity with the half maximal inhibitory concentration (IC50) value of 146.73ppm and its antioxidant strength was 39.6 times lower than that of vitamin C. The formulation with best physical evaluation results was given by formula 4 (Carbopol 934, 1.5%) with extract concentration 0.61%. This formula showed antioxidant activity with an IC50 value of 104.659ppm. Furthermore, on the basis of hedonic test and irritation test, this formula was the most popular and was categorized as a safe topical gel. CONCLUSION: The gel of black mulberry extract had antioxidant activity and was categorized as a safe topical gel.

Extraction of atenolol from spiked blood serum using a molecularly imprinted polymer sorbent obtained by precipitation polymerization.

Atenolol (ATE) is a cardio-selective ß-blocker that is used in the treatment of hypertension over extended periods. However, ATE, like propranolol, has major potential for misuse as a performance-enhancing drug in several sports. Therefore, an efficient and selective separation method is required to detect and monitor the level of ATE in the body. This paper presents a molecularly imprinted polymer with specific and selective binding to ATE using precipitation polymerization. We show that when employed in an optimized molecular imprinted solid phase extraction (MI-SPE) protocol, recoveries of 93.65 ± 1.29% from spiked blood serum with excellent discrimination from other ß-blocker drugs is possible. The methodology used in this study includes molecular modeling interaction between ATE and itaconic acid (ITA) as functional monomer, followed by determination of binding constants with spectrophotometry, synthesis of the polymer using precipitation polymerization and ending with characterization and application of polymers to extract ATE in serum. Docking analysis revealed a binding affinity between ATE and ITA of -2.0 kcal/mol with the formation of hydrogen bonding. The association constant between ATE and ITA was studied by UV titration in two different solvents, with evidence of an association constant 6.277 × 102 M-1 measured in acetonitrile: methanol (1:1). An optimized MI-SPE protocol was developed for the extraction of ATE from spiked blood serum, obtaining recoveries of 93.65% with excellent selectivity toward other ß-blocker drugs.

Antioxidant Activity of Crude Bromelain of Pineapple (Ananas comosus (L.) Merr) Crown from Subang District, Indonesia.

BACKGROUND: Antioxidants are chemical compounds that can donate one or more electrons to free radicals to prevent degenerative diseases. The crown of pineapple (Ananas comosus (L.) Merr.) contains bromelain, that is, a proteolytic enzyme, which can act as an antioxidant. AIMS AND OBJECTIVES: The aim of this study was to determine the antioxidant activity of crude bromelain from pineapple crowns that were collected from Subang district, West Java, Indonesia. MATERIALS AND METHODS: Antioxidant activity was determined by the method of 2,2-diphenyl-1-picrylhydrazyl (DPPH) with vitamin C as a standard and measured with visible spectrophotometer. RESULTS: The pineapple crown was produced 0.26% of dried crude bromelain with total protein content 44.10% and IC50 value 3624 µg/mL of crude bromelain, which was equivalent to 1590.18 µg/mL of total protein. CONCLUSION: Crude bromelain has medium antioxidant activity.