Bioactive Extracts: Strategies to generate Diversified Natural Product Like Libraries

Natural products have stimulated chemists owing to their abundant structural diversity and complexity. Indeed, natural products have performed an essential role, particularly in the cure of cancerous and infectious diseases, thereby posing medicinal researchers with a scope of unexplored chemotypes for the innovation of new drugs. Fusion of chemical derivatization and combinatorial synthesis forms the basis of the concept of chemo diversification of plants. Diverse libraries of natural product analogs are constructed through existing biological and chemical approaches using unique schemes to expand natural product frameworks. This review aims to present several approaches employed to offer innovative opportunities to synthesize NP-inspired compound libraries. Reactive molecular fragments present in most natural products are chemically converted to chemically engineered extracts (CEEs) or semisynthetic compounds constituting distinct libraries. Bio-guided isolation for natural products required vital tools like reverse phase chromatography and bioautographic assays. Different established strategies from DTS, BIOS, CtD, FOS, FBDD to Late-stage diversification facilitate the expansion of molecules with physicochemical properties. In particular, fragment-like natural products with novel skeletons may be used as preliminary points for chemical biology and medicinal chemistry programs with great capacity. In this review, we sum up how NPs have proven fruitful for the novel methodologies responsible for the diversification of complex natural products; thereby, it is worthy of going over the upcoming integration of natural products with combinatorial chemistry.

Structural and Functional Characterization of Four Novel Fibrinogen Mutations in FGB Causing Congenital Fibrinogen Disorder

Congenital fibrinogen disorders are caused by mutations in genes coding for fibrinogen and may lead to various clinical phenotypes. Here, we present a functional and structural analysis of 4 novel variants located in the FGB gene coding for fibrinogen Bβ chain-heterozygous missense BβY416C and BβA68S, homozygous nonsense BβY345*, and heterozygous nonsense BβW403* mutations. The cases were identified by coagulation screening tests and further investigated by various methods. Fibrin polymerization had abnormal development with decreased maximal absorbance in all patients. Plasmin-induced fibrin degradation revealed different lytic phases of BβY416C and BβW403* than those of the control. Fibrinopeptide cleavage measured by reverse phase high pressure liquid chromatography of BβA68S showed impaired release of fibrinopeptide B. Morphological properties, studied through scanning electron microscopy, differed significantly in the fiber thickness of BβY416C, BβA68S, and BβW403*, and in the fiber density of BβY416C and BβW403*. Finally, homology modeling of BβA68S showed that mutation caused negligible alternations in the protein structure. In conclusion, all mutations altered the correct fibrinogen function or structure that led to congenital fibrinogen disorders.

SIMPLE QUANTIFIED AND VALIDATED STABILITY INDICATING STRESS DEGRADATION STUDIES OF ORAL ANTI-DIABETIC AGENT DAPAGLIFLOZIN BY RP-HPLC METHOD

Objective: This method is focused on developing a precisely simplified and more accurate Reverse Phase–High Pressure Liquid Chromatography (RP-HPLC) method for the determination of Dapagliflozin in bulk and pharmaceutical dosage form as per guidelines of International Council for Harmonization (ICH). Methods: Evaluation and validation carried out using the RP-HPLC ZORBAX (C18) column (250 x 4.6 mm, 5 μm particle size) with a mobile phase consisting of Phosphate Buffer: Acetonitrile: Methanol in a ratio of 55:40:05 (v/v/v) at a flow rate of 1 ml/min with an injection volume of 10 μl. Results: Dapagliflozin was eluted at 2.12±0.05 min and detected at 225 nm. The regression equation y = 55762 x-29679 found to be linear with correlation coefficient r2 value of 0.9997. The developed RP-HPLC method was conveniently validated as per the ICH guidelines and found method was robust, sensitive, accurate, selective, specific, precise and linear. Conclusion: The proposed method was found to be accurate, precise, and robust for API and pharmaceutical dosage form as per experimentation analysis. The above developed method was found to be satisfied for Active Pharmaceutical Ingredient (API) and pharmaceutical formulation of Dapagliflozin to study its degradation products.

Isolation and Structural Elucidation of Impurity in Sulfonamide Intermediate of Glyburide

A reproducible isolation method by Reverse Phase (RP) preparative HPLC technique for the isolation of one crucial impurity at 1.65 RRT (Relative Retention Time) in sulfonamide stage of Glyburide API (Active Pharmaceuticals Ingredient) was developed. Preparative chromatography was done on Luna C8, 10µm (250 mm x 21.2mm) preparative HPLC column with acetonitrile: water in 70:30 % v/v proportion as a mobile phase and 8 ml/min as a flow rate. This impurity was detected at 300 nm UV-wavelength maximum. This impurity was isolated from synthesized crude impurity of sulfonamide stage of Glyburide substance by preparative HPLC by injecting 50 mg/ml concentration over 5 ml fixed loop. Isolated impurity was elucidated as N-methyl impurity of sulfonamide intermediate of Glyburide API by means of chromatographic and spectral data. Structural elucidation carried out by spectral data was reviewed. This impurity was analyzed by reverse phase HPLC for purity analysis. A Inertsil C8 (250 x 4.6) mm, 5µ particle size was employed for separation. The mobile phase consisted of Water: Acetonitrile: Methanol in the ratio of 60:15:25 % v/v. The flow rate was set at 1 ml/min. Detection was carried out at 300 nm. 10µL of 2 mg/ml concentration of sample in methanol was injected. The column oven temperature was at 25°C.

Analytical Method Development and Validation for Estimation of Mifepristone in Pure and Pharmaceutical Dosage Form

Mifepristone structurally belongs to the class of anti-progesterone steroids, which are used as an oral contraceptive. The reverse phase HPLC method was designed in a simplified and rapid way for the estimation of Mifepristone in bulk as well as tablets. The method was established using a Kromasil C18 column of dimensions of 250mm×4.6mm and a particle size of 5m.The used mobile phase was Acetonitrile: Water (70:30, v/v). The pump was pumped at 1 ml/min at a temperature of about 30 ± 2 °C and the eluted analyte was identified at 305 nm. Mifepristone eluted with a mean retention time of 6.27 minutes. The intended method was validated as per ICH (International Council for Harmonisation) guidelines, indicating a high degree of specificity, system suitability, accuracy, precision, and robustness. The LOD (Limit of detection) was found to be 0.7238 ppm and the limit of measurement was 0.9562 ppm. The method linearity was found to be between 1-6µg/ml, with an R2 of 0.9923. In accuracy studies, the percent recovery was found to be between 99.39% - 100.50%. The method was discovered to be precise as the values of the percent RSD were found to be less than 2.0% for both intraday and interday. The method was discovered to be reliable and robust. Mifepristone in marketed pharmaceutical tablet dosage form was effectively quantified using the established Reverse Phase HPLC method.

Simultaneous Determination of Four Marker Compounds in Lobelia chinensis Lour. Extract by HPLC-PDA

Lobelia chinensis Lour. (L. chinensis) has traditionally been used as a treatment for snake bites, high fever, jaundice, edema, and diarrhea, and modern studies have reported its anti-inflammatory, antioxidant, and antiviral activities. L. chinensis contains various compounds, such as flavonoids and coumarins, and its flavonoid components have been identified in many studies. In this study, a high-performance liquid chromatograph equipped with a photodiode array (PDA) detector and an Aegispak C18-L reverse-phase column (4.6 mm × 250 mm i.d., 5 μm) was used to simultaneously analyze four marker components in L. chinensis for standardization purposes. HPLC-PDA (detection at 340 nm), performed using a 0.1% formic acid-water/0.1% formic acid-acetonitrile gradient, separated the four marker compounds: luteolin-7-O-β-d-glucuronopyranosyl (1→2)-O-β-d-glucuronopyranoside, clerodendrin, chrysoeriol-7-O-diglucuronide, and diosmin. The developed analytical method showed excellent linearity values (r2 > 0.9991), limits of detection (LODs: 0.376–2.152 μg/mL), limits of quantification (LOQs: 1.147–6.521 μg/mL), intra- and inter-day precisions (RSD < 1.96%), and analyte recoveries (96.83–127.07%; RSD < 1.73%); thus, it was found to be suitable for the simultaneous analysis of these four marker compounds in L. chinensis.

Selective SGLT2 Inhibitor’s Estimation and Validation from Galenical Form by RP-HPLC Method

Aim: The recent analysis is required to do novel and simple, sensitive, precise, efficient, instant and reproducible reverse phase high performance liquid chromatography (RP-HPLC) method for estimation of antidiabetic drug in the unit dosage form. Validation of this method is also planned to make it suitable for the actual use. Study Design: Department of Pharmaceutical Chemistry, Datta Meghe Institute of Medical Sciences deemed to be university, Wardha in collaboration with Balkh university, Mazar-e-sharif, Afghanistan between August 2021 and December 2021. Methodology: In that article develop the method and validate it by estimation of antidiabetic drugs in solid dosage form by RP-HPLC, by using System suitability test, Repeatability, Precision studies (Intra-day and Interday/Intermediate), Linearity/Calibration studies, Robustness, Force degradation, Specificity, Drug recovery/accuracy studies. Results: as per ICH guidelines, the performance if system suitability in remogliflozin were achieved all guidelines; in that, tailing factor (T),separation factors(α),theoretical plates(N),capacity factor (k’), resolution (R) and RSD (%). The validated stress degradation studies under thermal, oxidative, alkali and acid, in few degradation products for remogliflozin (REM). Conclusion: From the results we conclude that, this novel technique which validated for exploration by reverse phase high performance liquid chromatography (RP-HPLC) should be used for routine quality control of remogliflozin (REM) prediction from developed formulation.