Role of Natural Products in Developing Novel Anticancer Agents: A Perspective.

Cancer is a heterogeneous disease and is one of the significant health issues, especially in public health systems around the world. Natural products and their structural derivatives with outstanding chemical diversity have been investigated for potential anti-cancer agents. Many natural products revealing potential anti-cancer properties such as cytotoxicity, proliferation inhibition, induced apoptosis, retard metastasis, suppressing angiogenesis, and improved chemotherapy have been isolated from various plants and herbs. Several promising lead molecules have been identified recently; a few are in the clinical trial stage. This short communication summarises the role of natural products and their analogs in anti-cancer drug developments, especially plant, marine and microbial-based anti-cancer agents.

Recent Progress in the Multicomponent Synthesis of Pyran Derivatives by Sustainable Catalysts under Green Conditions.

Pyrans are one of the most significant skeletons of oxygen-containing heterocyclic molecules, which exhibit a broad spectrum of medicinal applications and are constituents of diverse natural product analogues. Various biological applications of these pyran analogues contributed to the growth advances in these oxygen-containing molecules. Green one-pot methodologies for synthesising these heterocyclic molecules have received significant attention. This review focuses on the recent developments in synthesising pyran ring derivatives using reusable catalysts and emphasises the multicomponent reaction strategies using green protocols. The advantages of the catalysts in terms of yields, reaction conditions, and recyclability are discussed.

Chemical and elemental analysis of the edible fruit of five Carpobrotus species from South Africa: assessment of nutritional value and potential metal toxicity.

Edible wild fruits of five Carpobrotus species (C. acinaciformis, C. deliciosus, C. dimidiatus, C. edulis subspecies edulis and C. mellei) were assessed for their nutritional value by determining the proximate chemical composition. Fruits were high in moisture (77.6% to 90.3%), carbohydrates (58.8% to 70.3%) and energy (1240 to 1370 kJ 100 g-1), with adequate amounts of protein (8.1% to 26.0%) and low in lipids (0.9% to 2.4%). Elemental concentrations were in decreasing order of Ca > Mg > Fe > Mn > Zn ~ Cu > Cr > Se ~ Ni ~ Co. Most fruits were rich in Cr (contributing between 30% and 143% towards its RDA) and C. delicious and C. mellei being rich in Mn, contributing 49 to 156% towards its RDA. Except for C. dimidiatus, toxicity studies revealed all species to contain low levels of toxic metals (As, Cd and Pb) making them suitable for human consumption.

Toxic metals (As and Pb) in Sargassum elegans Suhr (1840) and its bioactive compounds.

Sargassum elegans Suhr 1840 (Phaeophyta) is a brown marine macro alga, which is used both nutritionally and medicinally in the coastal areas of Southern Africa. Consequently, we conducted a phytochemical and analytical investigation on samples of this species collected from seven sites along the coast of KwaZulu-Natal, South Africa. Sargassum elegans was found to be rich in ß-sitosterol, fucosterol and phaeophytin a as confirmed by spectroscopic techniques. Concentrations of essential and toxic elements varied significantly with location and were in the order of Ca > Mg> Fe > As > Cu > Zn > Mn > Ni > Pb > Co > Se > Cr > Cd. The accumulation of As by S. elegans was also evident as concentrations ranged from 42 to 105 mg kg-1, of which, 21 to 53 mg kg-1 was in inorganic form; consumption of this species may therefore increase dietary exposure to inorganic arsenic. Abbreviation: CRM: Certified reference material; NMR: Nuclear magnetic resonance; ICP - OES: Inductively coupled plasma - optical emission spectroscopy; PCA: Principal component analysis.

Elemental distribution in the edible leaves of Celosia trigyna from the western and northern regions of Nigeria.

Celosia trigyna, which belongs to the plant family Amaranthaceae, is a plant used in traditional medicine to treat several conditions such as sores, chest pains, diarrhoea and menstrual cramps in many countries in Africa. It is also consumed by the local people in Nigeria as soups, sauces and stews. In this study, the distribution and bioaccumulation of the elements in C. trigyna species and growth soil from the western and northern regions of Nigeria was investigated to determine the effects of geographical location on the uptake of elements by the plant. Elemental concentrations in the leaves from the western region were found to be in decreasing order of Ca > Mg > Fe > Mn > Zn > Cu > Pb > As > Ni. Concentrations of elements in the leaves from the northern region were found to be in decreasing order of Ca > Mg > Fe > Mn > Zn > Cu > As > Pb > Ni > Co > Cd. Proximate analysis of leaves from both regions compared well with the recommended dietary allowance making the leaves safe for human consumption. Principal component analysis was used to group elements having the same sources irrespective of their geographical locations. Cd, Co and Cr were not detected in the leaves from the western region. Concentrations of As and Pb were above maximum permissible limits in both regions, while Ayegunle and Bida (in the northern region) had the highest concentrations of Cd. The high level of these toxic metals may be attributed to anthropogenic activities. It is therefore important that the Nigerian agricultural extension system emphasizes the dangers of heavy metal contamination in leafy vegetables to farmers. Activities of the manufacturing industries in the study area should be adequately monitored under standard environmental protection laws.

SECONDARY METABOLITES ISOLATED FROM TWO MEDICINAL PLANT SPECIES, BRIDELIA MICRANTHA AND SIDEROXYLON INERME AND THEIR ANTIOXIDANT ACTIVITIES.

The indigenous medicinal plant species, Bfidelia micrantha and Sideyoxylon ineime (both known as 'uMhlalamagwababa' in isiZulu), are used interchangeably by traditional healers in KwaZulu-Natal, South Africa, to treat a variety of ailments due to morphological similarities. In this study, a phytochemical investigation was done on B. inicrantha and S. inenne to determine if they have a chemotaxonomic link. Three penta- cyclic triterpenes, one carotenoid and one megastigmane were isolated from S. inerme. Two flavonoids and two triterpenes were isolated from B. micrantha. These compounds were not previously isolated from these plant species. The antioxidant capacity of the isolated flavonoids was comparable to that of the known antioxidant - ascorbic acid. Profiling of the fruit extracts from both plant species by gas chromatography-mass spectrometry showed different classes of compounds in the extracts. This study corroborates the use of S. inerme and B. mici-ntha by traditional healers but does not support their use interchangeably.

Dual active pyrimidine-based carbocyclic nucleoside derivatives: synthesis, and in silico and in vitro anti-diabetic and anti-microbial studies.

Diabetes mellitus (DM) is a chronic metabolic disorder marked by high blood glucose levels, impairing glucose production in the body. Its prevalence has steadily risen over the past decades, leading to compromised immunity and heightened susceptibility to microbial infections. Immune dysfunction associated with diabetes raises vulnerability, while neuropathy dulls sensation in the extremities, reducing injury awareness. Hence, the development of novel chemical compounds for anti-diabetic and anti-infective treatments is imperative to mitigate adverse effects. In this study, we designed and synthesized pyrimidine-based carbocyclic nucleoside derivatives with C-4 substitution to assess their potential in inhibiting α-glucosidase for managing diabetes mellitus (DM) and microbial infections. Compounds 8b and 10a displayed promising IC50 values against α-glucosidase (43.292 nmol and 48.638 nmol, respectively) and noteworthy docking energies (-9.4 kcal mol-1 and -10.3 kcal mol-1, respectively). Additionally, compounds 10a and 10b exhibited better antimicrobial activity against Bacillus cereus, with the zone of inhibition values of 2.2 ± 0.25 mm and 1.4 ± 0.1 mm at a 100 µl concentration, respectively. Compound 10a also exhibited a modest zone of inhibition of 1.2 ± 0.15 mm against Escherichia coli at 100 µl.

Synthesis and Trace-Level Quantification of Mutagenic and Cohort-of-Concern Ciprofloxacin Nitroso Drug Substance-Related Impurities (NDSRIs) and Other Nitroso Impurities Using UPLC-ESI-MS/MS-Method Optimization Using I-Optimal Mixture Design.

Globally, the pharmaceutical industry has been facing challenges from nitroso drug substance-related impurities (NDSRIs). In the current study, we synthesized and developed a rapid new UPLC-MS/MS method for the trace-level quantification of ciprofloxacin NDSRIs and a couple of N-nitroso impurities simultaneously. (Q)-SAR methodology was employed to assess and categorize the genotoxicity of all ciprofloxacin N-nitroso impurities. The projected results were positive, and the cohort of concern (CoC) for all three N-nitroso impurities indicates potential genotoxicity. AQbD-driven I-optimal mixture design was used to optimize the mixture of solvents in the method. The chromatographic resolution was accomplished using an Agilent Poroshell 120 Aq-C18 column (150 mm × 4.6 mm, 2.7 µm) in isocratic elution mode with 0.1% formic acid in a mixture of water, acetonitrile, and methanol in the ratio of 475:500:25 v/v/v at a flow rate of 0.5 mL/min. Quantification was carried out using triple quadrupole mass detection with electrospray ionization (ESI) in a multiple reaction monitoring technique. The finalized method was validated successfully, affording ICH guidelines. All N-nitroso impurities revealed excellent linearity over the concentration range of 0.00125-0.0250 ppm. The Pearson correlation coefficient of each N-nitroso impurity was >0.999. The method accuracy recoveries ranged from 93.98 to 108.08% for the aforementioned N-nitrosamine impurities. Furthermore, the method was effectively applied to quantify N-nitrosamine impurities simultaneously in commercially available formulated samples, with its efficiency recurring at trace levels. Thus, the current method is capable of determining the trace levels of three N-nitroso ciprofloxacin impurities simultaneously from the marketed tablet dosage forms for commercial release and stability testing.

Quality by Design Tool Assessed Ultraperformance Liquid Chromatography Method for the Analysis of Remogliflozin and Teneligliptin in Oral Dosage Form.

The UPLC methodology was used to establish a method for determining the qualitative and quantitative content of teneligliptin and remogliflozin tablets in oral solid dose form, as no simultaneous method was available. The developed liquid chromatography method consists of an X-Bridge C18 100 mm × 3.5 mm, 2.1 mm column with an economical 0.2 mL/min flow rate. A wavelength of 248 nm was used for detection, and the temperature of the column compartment was 30 °C. The method was evaluated using a static tool quality by design after it was validated as per the regulations. The data from validation result in linearity for both analytes with a correlation coefficient of more than 0.999. The accuracy data were found from a minimum of 98.1 to a maximum of 100.9. All of the validation results met the acceptance criteria. The stability of the analytical solutions proved for 24 h at bench and refrigerator temperatures. Studies of force degradation proved the stability indicating the nature of the method. A factorial design was used to evaluate the method performance.

New oxindole carboxamides as inhibitors of DENV NS5 RdRp: Design, synthesis, docking and Biochemical characterization.

Dengue is a mosquito-borne disease caused by the dengue virus belonging to family flaviviridae and has grown to be a major global public health issue. Despite decades of effort, the global comeback of dengue is evidence of the inadequacy of present management techniques. Due to the loss of healthy lives and the depletion of scarce medical resources, dengue has a significant negative economic impact in underdeveloped countries. In recent years, research for tackling the incidences of dengue infection has increased. The structure of the viral genome has been deciphered with the non-structural protein, known as NS5 serving as a potential target. NS5 consisting of an MTase domain involved in RNA capping and an RdRp domain involved in viral replication. In the presented work, a series of new Oxindoline Carboxamide derivatives were designed and synthesized for inhibiting the viral RNA dependent RNA-polymerase (RdRp) activity of DENV. The novel compounds were put through tests including molecular docking and surface plasmon resonance (SPR) binding analysis to evaluate their affinity for the viral protein and their potential as novel inhibitors of the virus. From a total of 12 derivative compounds, four compounds OCA-10c, OCA-10f, OCA-10j & OCA-10i, were found to exhibit high affinity for NS5 RdRp, the KD values being 1.376 µM, 1.63 µM, 7.08 µM & 9.32 µM respectively. Overall, we report novel inhibitors of DENV RdRp activity with potential to be utilized against DENV for treating humans after further optimization.

Convenient synthesis, characterization and biological evaluation of novel 1-phenylcyclopropane carboxamide derivatives.

Small, strained ring molecules of phenylcyclopropane carboxamide have rigid, defined conformations and unique electronic properties. For these reasons many groups, seek to use these subunits to form biologically active compounds. Herein we report a generally applicable approach for preparing a small cyclopropane ring containing 1-phenylcyclopropane carboxamide derivatives to a wide range of the different aromatic compounds by α-alkylation of 2-phenyl acetonitrile derivatives with 1, 2-dibromo ethane in good yields followed by the conversion of cyano group to acid group by the reaction with concentrated hydrochloric acid. This obtained acid derivative undergoes acid amine coupling with various Methyl 2-(aminophenoxy)acetate to form 1-Phenylcyclopropane Carboxamide. These compounds possess distinct effective inhibition on the proliferation of U937, pro-monocytic, human myeloid leukaemia cell line while these compounds did not show cytotoxic activity on these cells. The structure-activity relationships of these compounds are discussed.

Design, synthesis, anticancer evaluation and molecular docking studies of 1,2,3-triazole incorporated 1,3,4-oxadiazole-Triazine derivatives.

A new library of 1,2,3-triazole-incorporated 1,3,4-oxadiazole-triazine derivatives (9a-j) was designed, synthesized, and tested in vitro for anticancer activity against PC3 and DU-145 (prostate cancer), A549 (lung cancer), and MCF-7 (breast cancer) cancer cell lines using the MTT assay with etoposide as the control drug. The compounds exhibited remarkable anticancer activity, with IC50 values ranging from 0.16 ± 0.083 µM to 11.8 ± 7.46 µM, whereas the positive control ranged from 1.97 0.45 µM to 3.08 0.135 µM. Compound 9 d with a 4-pyridyl moiety shown exceptional anticancer activity against PC3, A549, MCF-7, and DU-145 cell lines, with IC50 values of 0.17 ± 0.063 µM, 0.19 ± 0.075 µM, 0.51 ± 0.083 µM, and 0.16 ± 0.083 µM, respectively.

Antiproliferative Activity of New Pyrazole-4-sulfonamide Derivatives: Synthesis and Biological Evaluation.

Pyrazole and sulfonamide constitute an important class of drugs, with several types of pharmacological agents. Facile synthesis of two new series of 3,5-dimethyl-1H-pyrazole-4-sulfonamide and 1,3,5-trimethyl-1H-pyrazole-4-sulfonamide derivatives was designed and synthesized. These pyrazole-4-sulfonamide derivatives are characterized by Fourier transform infrared (FT-IR), 1H NMR, 13C NMR, and elemental analysis, and their biological evolution data are presented. This paved way for the development of new pyrazole-4-sulfonamide derivatives. These compounds are tested for their in vitro antiproliferative activity against U937 cells by the CellTiter-Glo Luminescent cell viability assay using Mitomycin C. Cytotoxicity detection is based on the measurement of LDH activity, while these compounds did not exhibit cytotoxic activity on these cells. Half maximal inhibitory concentration (IC50) was calculated by Graph Pad Prism software for each dose. Their structure-activity relationships were obtained and discussed.

Identification, isolation, and structural characterization of novel forced degradation products of Ertugliflozin using advanced analytical techniques.

The research elucidates the stress degradation behavior of Ertugliflozin, which is used for the treatment of type-2 diabetics. The degradation was conducted as per ICH guidelines and Ertugliflozin is relatively stable in thermal, photolytic, neutral, and alkaline hydrolysis conditions; however, considerable degradation was detected in acid hydrolysis and oxidative hydrolysis. Degradation products were identified by ultra-high-performance liquid chromatography-mass spectrometry, isolated by semi-preparative high-performance liquid chromatography, and structural characterization using high-resolution mass spectrometry and nuclear magnetic resonance spectroscopy. Total four degradation products were identified and isolated in acid degradation, which are degradation products 1, 2, 3, and 4. Whereas in oxidative conditions, degradation product 5 was identified. All the five degradation products formed are novel, which was not reported earlier. This is the first time documented complete structural characterization of all five degradation products by using a hyphenated analytical technique. High-resolution mass, and nuclear magnetic resonance spectroscopy were used in the present study to get concrete confirmation of degradation products structures. The current method is also used to identify degradation products with shorter runtime in the future.

Regulatory Perspective Reverse Engineering Analysis of the Mast Cell Stabilizer and the Histamine Receptor Antagonist (Olopatadine HCl): Instrumental and Classical Methods for Multiple Formulations.

This study evaluates the unknown qualitative (Q1) and quantitative (Q2) formulas for nasal spray and ophthalmic solution formulations of olopatadine HCl by classical and instrumental techniques to match the generic formula with reference-listed drugs to avoid clinical study. Reverse engineering of olopatadine HCl nasal spray 0.6% and ophthalmic solution 0.1, 0.2% formulations was accurately quantified using a simple and sensitive reversed-phase high-performance liquid chromatography (HPLC) method. Both formulations possess similar components, namely ethylenediaminetetraacetic acid (EDTA), benzalkonium chloride (BKC), sodium chloride (NaCl), and dibasic sodium phosphate (DSP). These components were qualitatively and quantitatively determined using the HPLC, osmometry, and titration techniques. With derivatization techniques, EDTA, BKC, and DSP were determined by ion-interaction chromatography. NaCl in the formulation was quantified by measuring the osmolality and using the subtraction method. A titration method was also used. All the employed methods were linear, accurate, precise, and specific. The correlation coefficient was >0.999 for all components in all the methods. The recovery results ranged from 99.1 to 99.7% for EDTA, 99.1-99.4% for BKC, 99.8-100.8% for DSP, and 99.7-100.1% for NaCl. The obtained % relative standard deviation for precision was 0.9% for EDTA, 0.6% for BKC, 0.9% for DSP, and 1.34% for NaCl. The specificity of the methods in the presence of other components, diluent, and the mobile phase was confirmed, and the analytes were specific.

Green Chromatographic Method for Determination of Active Pharmaceutical Ingredient, Preservative, and Antioxidant in an Injectable Formulation: Robustness by Design Expert.

We report an efficient HPLC method for simultaneous qualitative and quantitative analysis of lincosamide antibiotic injectable formulations containing Clindamycin phosphate (CMN), benzyl alcohol (BA), and ethylenediaminetetraacetic acid (EDTA) as major ingredients. The three components were separated by Phenomenex prodigy C8 (250 mm × 4.6 mm, 5 µm) HPLC column, flow rate 1.1 mL/min, injection volume 30 µL, and column temperature 35 °C, using 0.05 M sodium acetate buffer (pH 4.5) with acetonitrile (ACN) in the ratio of 80:20 (v/v). The detection wavelength was set as 240 nm. The method was validated as per International Conference on Harmonization (ICH) guidelines and was confirmed to be specific, precise, accurate, and linear. Method robustness was executed by utilizing quality in the design of the experiment. Accuracy results were found to be 99.3-100.5% for CMN, 99.3-100.8% for BA, and 99.1-100.3% for EDTA. Precision results were obtained as % relative standard deviation (RSD): 0.6% for CMN, 0.4% for BA, and 0.4% for EDTA. Correlation coefficient (r 2) values were obtained as >0.999 for the three components. Analytical solutions are stable for 48 h at benchtop and refrigerator conditions. The greenness of the analytical method was evaluated by the Green Analytical Procedure Index (GAPI), National Environmental Method Index (NEMI), analytical eco-scale, and Analytical Greenness (AGREE) tools to confirm that the method is eco-friendly.

AQbD based green UPLC method to determine mycophenolate mofetil impurities and Identification of degradation products by QToF LCMS.

We report an ideal method for quantifying impurities in mycophenolate mofetil drug substances and their oral suspension preparations. We developed a systematic and eco-friendly analytical approach utilizing quality by design (QbD) and green chemistry principles. Initially, the critical method parameters (CMPs) were screened using a D-optimal design. The robust final method conditions were optimized using a systematic central composite design (CCD). Through graphical and numerical optimization, the protocol conditions were augmented. The pH of mobile phase buffer (25 mM KH2PO4) (MP-A), initial gradient composition (% MP-A), flow rate (mL min-1), and column oven temperatures (°C) are 4.05, 87, 0.4, and 30, respectively. The best possible separation between the critical pairs was achieved while using the Waters Acquity UPLC BEH C18 (100 × 2.1) mm, 1.7 µm analytical column. A mixture of water and acetonitrile in the ratio of 30:70 (v/v) was used as mobile phase-B for the gradient elution. The analytical method was validated in agreement with ICH and USP guidelines. The specificity results revealed that no peaks interfered with the impurities and MPM. The mean recovery of the impurities ranged between 96.2 and 102.7%, and the linearity results r > 0.999 across the range of LOQ - 150%. The precision results (%RSD) ranged between 0.8 and 4.5%. The degradation products formed during the base-induced degradation were identified as isomers of mycophenolic acid and sorbitol esters using Q-ToF LC-MS and their molecular and fragment ion peaks. The developed method eco-friendliness and greenness were assessed using analytical greenness (AGREE), green analytical procedure index (GAPI), and analytical eco score, and found it is green.

Unique Quality by Design Approach for Developing HPLC and LC-MS Method for Estimation of Process and Degradation Impurities in Pibrentasvir, Antiviral Agent for Hepatitis C.

Pibrentasvir (PIB) was approved for treating hepatitis C patients. A specific, accurate, linear, robust, and stability-indicating method was developed and validated for determining degradation impurities present in the PIB drug substance by studying the quality by design (QbD) principles. All identified degradation impurities were separated with the stationary phase HALO C18, 150 mm × 4.6 mm, 2.7 µm. Mobile phase A contains pH 2.5 phosphate buffer and acetonitrile in the ratio of (70:30, v/v), and mobile phase B contains water and acetonitrile in the ratio of (30:70, v/v), respectively. The chromatographic conditions were optimized, such as flow rate of 0.8 mL/min, UV detection at 252 nm, injection volume of 20 µL, and column temperature of 40 °C. The proposed method was validated per the current ICH Q2 (R1) guidelines. The recovery study and linearity ranges were established from limit of quantification (LOQ) to 300% optimal concentrations. The method validation results were between 98.6% and 106.2% for recovery, and linearity r 2 was more than 0.999 for all identified impurities. The method precision results achieved below 5% relative standard deviation (RSD). The forced degradation results demonstrated that the drug was sensitive to chemical stress conditions. During the stress study, degrading impurities were identified by the LC-MS technique and the mechanism pathway. A QbD-based experimental design (DoE) approach was used to establish the robustness of the method.

Nutritional value, antioxidant and antidiabetic properties of nettles (Laportea alatipes and Obetia tenax).

Nettles are commonly consumed in South Africa, Europe and Asia and are used in traditional medicine to treat a variety of ailments. In this study, the nutritional value of the leaves of nettles (Laportea alatipes and Obetia tenax) was evaluated and compared, when cooked and uncooked. The results showed a decrease in the concentrations of crude protein, vitamin A, vitamin E and metals after cooking of nettles. Although cooking reduced the concentrations of essential elements in nettles, their contribution to the diet remained adequate. L. alatipes presented with reduced levels of Cd (from 1.86 to 0.810 mg kg-1) and Pb (from 2.87 to 1.88 mg kg-1) after cooking. Similarly, Cd (from 2.97 to 0.780 mg kg-1) and Pb (from 2.21 to 0.795 mg kg-1) levels in O. tenax decreased after cooking, demonstrating the significance of cooking. The antioxidant activity of the nettles was determined using the 2,2-diphenyl-l-picrylhydrazyl (DPPH) free radical and ferric reducing antioxidant power (FRAP) assays. The methanol extract of Obetia tenax showed high ferric reducing power whilst the radical scavenging activity was due to the presence of the bioactive molecule, ß-carotene, in the plants which exhibited higher DPPH radical scavenging ability relative to test samples and standards. The in vitro antidiabetic activity of the extracts and compounds from the nettles was better than or comparable to that of the known standard, acarbose, which underscores the prospective antidiabetic properties of nettles. Overall, our study provides scientific validation for the ethno-medicinal use of nettles and supports their consumption, which highlights their potential as nutraceuticals.