Development of stability-indicating assay method and liquid chromatography-quadrupole-time-of-flight mass spectrometry-based structural characterization of the forced degradation products of alpelisib.

The US Food and Drug Administration and the European Medicines Agency approved alpelisib in 2019 for the treatment of metastatic breast cancer. A thorough literature review revealed that a stability-indicating analytical method (SIAM) is not available for the quantification of alpelisib and its degradation products (DPs). In this study, per the comprehensive stress study recommended by the International Council for Harmonisation (ICH), alpelisib was exposed to hydrolysis, oxidation, photolysis, and thermal stress. Degradation of the drug was observed under hydrolysis, oxidative, and photolysis conditions, whereas the drug was stable under thermal stress condition. We developed a SIAM for the separation of alpelisib and its major DPs that were formed under different stress conditions. The validation of the developed method was performed per ICH Q2(R1) guidelines. Five DPs were identified and characterized. Structure elucidation of all DPs was performed with the modern characterization tool of liquid chromatography-quadrupole time-of-flight mass spectrometer (LC-Q-TOF-MS/MS). The degradation pathway of the drug and its mechanisms were outlined, and in silico toxicity prediction was performed using the ProTox-II tool.

Synthesis and characterization of a series of N,N'-substituted urea derivatives by using electrospray ionization tandem mass spectrometry: Differentiation of positional isomers.

RATIONALE: Characterization of N,N'-substituted ureas was found to be challenging by nuclear magnetic resonance (NMR) spectroscopy, particularly N-di- and tri-alkylated ureas because of the absence of adjacent protons. In the present study, electrospray ionization tandem mass spectrometry has been used to differentiate positional isomeric pairs and to characterize a series of N,N'-substituted ureas, as these compounds have significant importance for drug discovery. Additionally, urea is an essential functionality in several bioactive compounds as well as a variety of clinically approved therapies. METHODS: High-resolution electrospray ionization tandem mass spectrometry (ESI-HR-MS/MS) has been used to characterize a series of N,N'-substituted urea derivatives and differentiate two pairs of positional isomers. The data was acquired by Xcaliber application in positive ionization mode. RESULTS: ESI-HR-MS/MS spectra of [M + H]+ ions of the positional isomeric urea derivatives 8a and 8b show distinct fragmentation patterns. For example, the MS/MS spectrum of the [M + H]+ ion of isomer 8a displays the abundant fragment ion at m/z 285.1595, which was totally absent in isomer 8b. This would be plausibly formed by the cleavage of the C-N bond of the urea group with the elimination of the isocyanate moiety. In contrast, the MS/MS spectrum of the [M + H]+ ion of isomer 8b shows an intense ion at m/z 311.1389 which is completely absent in isomer 8a which would be formed by the cleavage of the C-N bond attached to the ring nitrogen. Similarly, another pair of positional isomers, 8c and 8d, have been clearly distinguished by their fragmentation behaviour. In addition, a series of N,N'-substituted urea derivatives were studied to investigate the impact of different substitution on the fragmentation behaviour. CONCLUSIONS: The present study demonstrates that ESI-HR-MS/MS can be used to differentiate pairs of N,N'-substituted urea positional isomers and characterize a series of derivatives. It was observed that a characteristic fragment ion was formed by the C-N bond cleavage with the elimination of an isocyanate moiety. The proposed mechanism of fragmentation was supported by the change in the fragmentation pathway upon alkylation of the NH. In order to generalize this fragmentation pattern, a series of N-alkylated ureas was synthesized and studied by MS/MS.

A Serum Small Molecule Biosignature of Radiation Exposure from Total Body Irradiated Patients.

The potential for radiological accidents and nuclear terrorism has increased the need for the development of new rapid biodosimetry methods. In addition, in a clinical setting the issue of an individual's radiosensitivity should be taken into consideration during radiotherapy. We utilized metabolomics and lipidomics to investigate changes of metabolites in serum samples following exposure to total body ionizing radiation in humans. Serum was collected prior to irradiation, at 3-8 h after a single dose of 1.25-2 Gy, and at 24 h with a total delivered dose of 2-3.75 Gy. Metabolomics revealed perturbations in glycerophosphocholine, phenylalanine, ubiquinone Q2, and oxalic acid. Alterations were observed in circulating levels of lipids from monoacylglycerol, triacylglycerol, phosphatidylcholine, and phosphatidylglycerol lipid classes. Polyunsaturated fatty acids were some of the most dysregulated lipids, with increased levels linked to proinflammatory processes. A targeted metabolomics approach for eicosanoids was also employed. The results showed a rapid response for proinflammatory eicosanoids, with a dampening of the signal at the later time point. Sex differences were observed in the markers from the untargeted approach but not the targeted method. The ability to identify and quantify small molecules in blood can therefore be utilized to monitor radiation exposure in human populations.

Use of Hybrid Capillary Tube Apparatus on 400 MHz NMR for Quantitation of Crucial Low-Quantity Metabolites Using aSICCO Signal.

Metabolites of new chemical entities can influence safety and efficacy of a molecule and often times need to be quantified in preclinical studies. However, synthetic standards of metabolites are very rarely available in early discovery. Alternate approaches such as biosynthesis need to be explored to generate these metabolites. Assessing the quantity and purity of these small amounts of metabolites with a nondestructive analytical procedure becomes crucial. Quantitative NMR becomes the method of choice for these samples. Recent advances in high-field NMR (>500 MHz) with the use of cryoprobe technology have helped to improve sensitivity for analysis of small microgram quantity of such samples. However, this type of NMR instrumentation is not routinely available in all laboratories. To analyze microgram quantities of metabolites on a routine basis with lower-resolution 400 MHz NMR instrument fitted with a broad band fluorine observe room temperature probe, a novel hybrid capillary tube setup was developed. To quantitate the metabolite in the sample, an artificial signal insertion for calculation of concentration observed (aSICCO) method that introduces an internally calibrated mathematical signal was used after acquiring the NMR spectrum. The linearity of aSICCO signal was established using ibuprofen as a model analyte. The limit of quantification of this procedure was 0.8 mM with 10 K scans that could be improved further with the increase in the number of scans. This procedure was used to quantify three metabolites-phenytoin from fosphenytoin, dextrophan from dextromethorphan, and 4-OH-diclofenac from diclofenac-and is suitable for minibiosynthesis of metabolites from in vitro systems.

Quantitative Metabolomic Analysis of Urinary Citrulline and Calcitroic Acid in Mice after Exposure to Various Types of Ionizing Radiation.

With the safety of existing nuclear power plants being brought into question after the Fukushima disaster and the increased level of concern over terrorism-sponsored use of improvised nuclear devices, it is more crucial to develop well-defined radiation injury markers in easily accessible biofluids to help emergency-responders with injury assessment during patient triage. Here, we focused on utilizing ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) to identify and quantitate the unique changes in the urinary excretion of two metabolite markers, calcitroic acid and citrulline, in mice induced by different forms of irradiation; external γ irradiation at a low dose rate (LDR) of 3.0 mGy/min and a high dose rate (HDR) of 1.1 Gy/min, and internal exposure to Cesium-137 ((137)Cs) and Strontium-90 ((90)Sr). The multiple reaction monitoring analysis showed that, while exposure to (137)Cs and (90)Sr induced a statistically significant and persistent decrease, similar doses of external γ beam at the HDR had the opposite effect, and the LDR had no effect on the urinary levels of these two metabolites. This suggests that the source of exposure and the dose rate strongly modulate the in vivo metabolomic injury responses, which may have utility in clinical biodosimetry assays for the assessment of exposure in an affected population. This study complements our previous investigations into the metabolomic profile of urine from mice internally exposed to (90)Sr and (137)Cs and to external γ beam radiation.

Pharmacoinformatics approach for type 2 diabetes mellitus therapeutics using phytocompounds from Costus genus: an in-silico investigation.

Type 2 Diabetes Mellitus (T2DM), as a significant health concern globally, particularly in India, underscoring the vital need for effective therapeutics. Current drug therapies for T2DM may have limitations, leading researchers to explore natural products as alternatives. In this study. We have investigated the anti-diabetic compounds from the Costus genus, known as the insulin plant, which is abundant in southern India. The bioinformatics tools and software used for in-silico analysis to identify potential therapeutic compounds and hub genes associated with T2DM in the Indian population that could cut short the in-vitro and in-vivo experimental approaches in near future. The systematic review and combinatorial in-silico analysis revealed IGF2BP2, INS and TCF as the key targets that are associated with T2DM. The compounds stigmasterol, cycloartenol, and diosgenone were explored to be potent among all the 38 phytocompounds from genus Costus with binding energies -8.48, -10.07, and -10.31 kcal/mol against IGF2BP2, INS and TCF. The molecular dynamics (MD) simulation studies of these complexes demonstrated stable and consistent dynamic behavior, particularly in the INS-cycloartenol, IGF2BP2-stigmasterol and TCF7L2-diosgenone complexes. The identified compounds and associated targets represent potential candidates for T2DM therapeutics in the Indian population. The pharmacoinformatics approach presented in the study could streamline the drug discovery process by prioritizing compounds for further experimental validation.Communicated by Ramaswamy H. Sarma.

Isolation and characterization of bioactive alkaloids and GC-MS based identification of volatile oil metabolites from fruits of Glycosmis pentaphylla and evaluation of their cytotoxic activity.

Glycosmis pentaphylla, a member of the Rutaceae family, has been extensively studied for its pharmacological activities, focusing mainly on the cytotoxic properties of its roots and stems. Conversely, limited researched has been done in terms of the phytochemical composition of the fruits. The objective of this study is to isolate and identify the bioactive compounds found in the fruits of G. pentaphylla and then evaluate their potential for anti-cancer activity in oral cancer CAL 27 cell lines. The extraction of bioactive compounds from fruits was done by maceration, and the isolation of alkaloids and volatile oil fractions (F1-F5) was performed by column chromatography. The alkaloids, such as 3-O-methoxyglycocitrine II, noracronycine, 1-hydroxy-3-methoxy-10-methyl-9-acridone and kokusaginine, were first isolated from the fruits of G. pentaphylla. Additionally, GC-MS analysis identified 78 metabolites. The isolated compounds and identified volatile oil fractions were explored for their anti-cancer activity by cell viability assay. Results demonstrated that isolated compounds were found inactive, while the volatile fraction F1 was found active in CAL 27 cell line. Fraction F1 impeded wound healing in CAL 27 cells by scratch assay, and significantly inhibited colony formation in colony formation assay. In cell cycle analysis, treatment with fraction F1 redistributed cells to the S and G2 phases of the cell cycle. α-elemol (2) is the major metabolite identified from the F1 fraction by GC-MS, which could be responsible for the anti-cancer activity. There is potential for future work to further isolate volatile oil metabolites and evaluate their anti-cancer activity through in-vivo techniques.

Isolation, Characterization of Undescribed Alkaloids, and Semisynthetic Modifications of Cytotoxic Pyranoacridone Alkaloids from Glycosmis pentaphylla.

Two undescribed alkaloids (10 and 11), along with nine known alkaloids (1-9), have been isolated from the stem and root bark of Glycosmis pentaphylla. Among them are carbocristine (11), a carbazole alkaloid first time isolated from a natural source, and acridocristine (10), a pyranoacridone alkaloid first time isolated from the genus "Glycosmis". In vitro cytotoxicity of isolated compounds has been analyzed on breast cancer (MCF-7), lung cancer (CALU-3), and squamous cell carcinoma cell lines (SCC-25). The results demonstrated that compounds are moderately active. In order to study the structural activity relationship of majorly isolated compounds, semisynthetic modifications have been done on majorly isolated compounds such as des-N-methylacronycine (4) and noracronycine (1) to synthesize 11 semisynthetic derivatives (12-22) on functionalizable -NH and -OH groups of the pyranoacridone scaffold at 12th and 6th positions. Semisynthetic derivatives are explored on the same cell lines as isolated compounds, and the results exhibit that semisynthetic compounds showed potent cytotoxic activity compared with naturally isolated compounds. In the case of CALU-3, the dimer at -OH position of noracronycine (1), i.e., compound 22, showed 24-fold better activity with an IC50 of 4.49 µM compared with noracronycine (1) with IC50 97.5 µM. In MCF-7, the dimer at -OH position of noracronycine (1), i.e., compound 22, showed 14-fold better activity with an IC50 of 13.2 µM compared with noracronycine (1) with IC50 187 µM.

Exploring the rare variants associated with Type 2 Diabetes Mellitus in Indian population and its disease-drug association studies: an in-silico approach.

The diversified eating habits and religious culture of Indian population may be one of the reasons they largely contribute to the global diabetes burden. In the present investigation, an in-silico approach was carried out to explore hub genes in the Indian population with Type 2 Diabetes Mellitus (T2DM) that are scantily reported in the GWAS catalogue and probable potential anti-diabetic drugs from plants. This computational approach unwrapped LEP (leptin) as the hub gene among 170 genes analyzed with 14 non-synonymous single nucleotide polymorphisms (nsSNPs) with MAF < 0.01. The mutation of the LEP gene leads to a decrease in leptin concentration, which increases the risk of obesity and T2DM. According to the DUET webserver, 11 of 14 mutations examined were found to destabilize the LEP protein. Among 14, four barely reported LEP variants rs781301976 (I45N), rs776443424 (S52F), rs200915360 (D76Y), and rs1191666811 (D162N) were unzipped to be associated with T2DM, which may be the probable potential drug targets. The virtual screening revealed Vescalagin as having the highest binding energy among 336 natural compounds. Molecular docking of Vescalagin depicted higher binding energy (-9.0 kcal/mol) against mutated LEP [rs200915360 (D76Y)] compared to wild (-8.9 kcal/mol) and LEP-Metformin complexes. The trajectory analysis of MD simulations revealed that Vescalagin was more effective than Metformin in stabilizing the system. The present study suggests that the associations of the investigated nsSNPs in LEP [rs200915360 (D76Y)] and others can be key factors in the predominant role of T2DM morbidity in the Indian population that can be used as potential markers and drug targets for T2DM therapeutics.Communicated by Ramaswamy H. Sarma.

A strategy for evaluation of isotopic enrichment and structural integrity of deuterium labelled compounds by using HR-MS and NMR.

Determining the purity of deuterium labelled compounds is important due to the increasing use of these compounds in mass spectrometry (MS) based quantitative analyses for targeting metabolic flux, reducing toxicity, confirming reaction mechanisms during synthesis, predicting enzyme mechanisms, and enhancing the efficacy of drugs, in quantitative proteomics, and also as internal standards. In the present study, a strategy using liquid chromatography electrospray ionization high resolution mass spectrometry (LC-ESI-HR-MS) and nuclear magnetic resonance (NMR) spectroscopy was proposed to determine the isotopic enrichment and structural integrity of deuterium labelled compounds. The proposed strategy involves recording full scan MS, extracting and integrating isotopic ions, and calculating the isotopic enrichment of the desired labelled compounds. NMR analysis confirms structural integrity or positions of labelled atoms and can provide insights into the relative percent isotopic purity. This strategy was used to evaluate the isotopic enrichment and structural integrity of in-house synthesized compounds as well as a series of commercially available deuterium labelled compounds. The % isotopic purity for labelled compounds of a benzofuranone derivative (BEN-d2), tamsulosin-d4 (TAM-d4), oxybutynin-d5 (OXY-d5), eplerenone-d3 (EPL-d3), and propafenone-d7 (PRO-d7) was calculated and found to be 94.7, 99.5, 98.8, 99.9, and 96.5, respectively. All the samples were run in triplicate and the results were observed to be reproducible.

One pot synthesis and anticancer activity of dimeric phloroglucinols.

A series of dimeric phloroglucinol compounds were synthesized in a single step using commercially available phloroglucinol and methanesulfonic acid. Based on the reported anticancer activity of plant derived dimeric phloroglucinols, these synthesized compounds were evaluated for their in vitro anti-proliferative activities against various cancer cell lines. Several compounds demonstrated in vitro cytotoxic effects across a wide array of tumor cell types. The compound 29 with pyridin-3-yl group on linker methylene and two diisovaleryl phloroglucinol moieties was found to be the most active in all the five cancer cell lines having a low IC(50) of 5.5 µM in colon cancer cell lines (HCT116).

Quantitative NMR: an applicable method for quantitative analysis of medicinal plant extracts and herbal products.

INTRODUCTION: Quantitative analysis and standardisation of plant extracts or herbal products is a tedious process requiring time-consuming sample preparation and analytical method development for the resolution of analyte peaks from the complex natural extract. Quantitative analysis by HPLC requires a pure authentic standard of the compound being quantified. We report here a quantitative NMR (qNMR) method for quantitative analysis of three medicinal plant extracts and their herbal products without the need of authentic standards. Quantitation can be done by using any commercially available pure sample as an internal reference standard. OBJECTIVE: To develop a reliable method for standardisation and quantitative analysis of extracts from medicinal plants Eugenia jambolana, Withania somnifera and Aegle marmelos and their herbal products using qNMR. METHODOLOGY: The (1) H-NMR spectra of known amounts of crude plant extracts with internal standards were recorded in deuterated solvents and quantitation was performed by calculating the relative ratio of the peak area of selected proton signals of the target compounds and the internal reference standard. Anthocyanins [delphinidin-3,5-diglucoside (1), petunidin-3,5-diglucoside (2) and malvidin-3,5-diglucoside (3)] for E. jambolana fruit extract and imperatorin (4) for A. marmelos fruit extract were selected as marker constituents for quantitation and 1,3,5-trimethoxybenzene (TMB) was used as an internal reference standard. Total withanolide content was determined for W. somnifera using 2,4-diformyl phloroglucinol as an internal reference standard. RESULTS: The (1) H-NMR gave a linear response for the marker constituents, anthocyanins, withaferin A and imperatorin. Using the described method, the amount of anthocyanins in Amberlite(R) XAD7HP and Sephadex enriched extracts of E. jambolana was 3.77% and 9.57% (delphinidin-3,5-diglucoside), 4.72% and 12.0% (petunidin-3,5-diglucoside), 6.55% and 15.70% (malvidin-3,5-diglucoside), respectively. The imperatorin content was 0.424% in A. marmelos fruit and 0.090 % and 0.114% in sharbat and candies. Total withanolides content was 0.191% in the chloroform extract and 0.234% in the capsule extract. These values are in accordance with HPLC results. CONCLUSION: This qNMR technique could be used for NMR fingerprinting and quantitation for the purpose of quality control and standardisation of many plant-based herbal products and medicines and has certain advantages over HPLC.

Herbal nanomedicines: Recent advancements, challenges, opportunities and regulatory overview.

BACKGROUND: Herbal Nano Medicines (HNMs) are nano-sized medicine containing herbal drugs as extracts, enriched fractions or biomarker constituents. HNMs have certain advantages because of their increased bioavailability and reduced toxicities. There are very few literature reports that address the common challenges of herbal nanoformulations, such as selecting the type/class of nanoformulation for an extract or a phytochemical, selection and optimisation of preparation method and physicochemical parameters. Although researchers have shown more interest in this field in the last decade, there is still an urgent need for systematic analysis of HNMs. PURPOSE: This review aims to provide the recent advancement in various herbal nanomedicines like polymeric herbal nanoparticles, solid lipid nanoparticles, phytosomes, nano-micelles, self-nano emulsifying drug delivery system, nanofibers, liposomes, dendrimers, ethosomes, nanoemulsion, nanosuspension, and carbon nanotube; their evaluation parameters, challenges, and opportunities. Additionally, regulatory aspects and future perspectives of herbal nanomedicines are also being covered to some extent. METHODS: The scientific data provided in this review article are retrieved by a thorough analysis of numerous research and review articles, textbooks, and patents searched using the electronic search tools like Sci-Finder, ScienceDirect, PubMed, Elsevier, Google Scholar, ACS, Medline Plus and Web of Science. RESULTS: In this review, the authors suggested the suitability of nanoformulation for a particular type of extracts or enriched fraction of phytoconstituents based on their solubility and permeability profile (similar to the BCS class of drugs). This review focuses on different strategies for optimising preparation methods for various HNMs to ensure reproducibility in context with all the physicochemical parameters like particle size, surface area, zeta potential, polydispersity index, entrapment efficiency, drug loading, and drug release, along with the consistent therapeutic index. CONCLUSION: A combination of herbal medicine with nanotechnology can be an essential tool for the advancement of herbal medicine research with enhanced bioavailability and fewer toxicities. Despite the challenges related to traditional medicine's safe and effective use, there is huge scope for nanotechnology-based herbal medicines. Overall, it is well stabilized that herbal nanomedicines are safer, have higher bioavailability, and have enhanced therapeutic value than conventional herbal and synthetic drugs.

RP-HPLC separation of interconvertible rotamers of a 5-tetrahydroisoquinolin-6-yl-pyridin-3-yl acetic acid derivative and confirmation by VT NMR and DFT study.

Due to emergence of drug resistance and drug tolerability, there is urgent need for discovery of new chemical entity for the treatment of HIV infection. As a part of in-house small molecule drug discovery program for HIV infection, sodium-2-(tert-butoxy)- 2-(5-(2-(2-chloro-6-methylbenzyl)- 1,2,3,4-tetrahydroisoquinolin-6-yl)- 4-(4,4-dimethylpiperidin-1-yl)- 2,6-dimethylpyridin-3-yl) acetate (SCMTDDA) was prepared as an intermediate for the synthesis of an API, designed as a HIV-1 integrase inhibitor. Initially, the final compound was isolated as a mixture of rotamers. In the current study, we have developed a simple and efficient achiral, reversed phase (RP) HPLC method to separate the interconvertible rotamers of SCMTDDA. The effect of several parameters, including stationary phase, buffer, modifiers and column temperature, were optimized for the chromatographic separation and it was observed that best separation was achieved on a SunFire C18 column using TFA/acetonitrile (ACN) - methanol (MeOH) (1:1 v/v) as the mobile phase at 10 0C. The chromatographic observations were complemented with variable-temperature NMR and energy barrier calculations using density functional theory (DFT).

Traditional uses, phytochemistry, pharmacology, toxicology and formulation aspects of Glycosmis species: A systematic review.

The present article is a systematic and constructive review of the traditional medicinal uses, chemistry, pharmacology, toxicology, and formulation aspects of Glycosmis species. The genus Glycosmis comprise 51 accepted species broadly distributed in Australia, China, India, and South-East Asia. Traditionally, Glycosmis species are used in folk medicines to treat cancer, anaemia, rheumatism, fever, cough, liver-related problems, skin ailments, intestinal worm infections, wounds, and facial inflammation. This review aims to provide readers with the latest information highlighting chemical constituents isolated from the Glycosmis species, plant parts utilized for their isolation and their pharmacological activities. So far, 307 chemical constituents have been isolated and characterized from different species of the genus Glycosmis; among these constituents, alkaloids, flavonoids, terpenoids, phenolics, and sulphur-containing amides are the major bioactive compounds. Modern pharmacological studies have shown that the crude extracts and compounds isolated from this genus exhibit a broad spectrum of biological activities like anticancer, antimicrobial, anti-inflammatory, antipyretic, antidiabetic, antioxidant, larvicidal, insecticidal, hepatoprotective, wound healing, antiviral, antidiarrheal, and anxiolytic. The carbazole and acridone alkaloids from this genus have shown potential anticancer activity in various in vitro and in vivo studies. Rare scaffolds like dimeric carbazoles, dimeric acridone alkaloids, flavanocoumarins and sulphur-containing amides from this genus need further exploration for their potential bioactivity. This article also briefs about the toxicological screening and discusses various polyherbal and nano formulation aspects of Glycosmis species. Most of the pharmacological studies reported from this genus were carried out in vitro. An in-depth in vivo and toxicology evaluation of the crude extracts and isolated specialized compounds is required to explore the full therapeutic potential of this genus.

TGFß Drives Metabolic Perturbations during Epithelial Mesenchymal Transition in Pancreatic Cancer: TGFß Induced EMT in PDAC.

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy wherein a majority of patients present metastatic disease at diagnosis. Although the role of epithelial to mesenchymal transition (EMT), mediated by transforming growth factor beta (TGFß), in imparting an aggressive phenotype to PDAC is well documented, the underlying biochemical pathway perturbations driving this behaviour have not been elucidated. We used high-resolution mass spectrometry (HRMS) based molecular phenotyping approach in order to delineate metabolic changes concomitant to TGFß-induced EMT in pancreatic cancer cells. Strikingly, we observed robust changes in amino acid and energy metabolism that may contribute to tumor invasion and metastasis. Somewhat unexpectedly, TGFß treatment resulted in an increase in intracellular levels of retinoic acid (RA) that in turn resulted in increased levels of extracellular matrix (ECM) proteins including fibronectin (FN) and collagen (COL1). These findings were further validated in plasma samples obtained from patients with resectable pancreatic cancer. Taken together, these observations provide novel insights into small molecule dysregulation that triggers a molecular cascade resulting in increased EMT-like changes in pancreatic cancer cells, a paradigm that can be potentially targeted for better clinical outcomes.

Biomimetic synthesis and anti-HIV activity of dimeric phloroglucinols.

Plants are an important source of a variety of bioactive compounds with different modes of action. Anti-HIV agents from plant sources can be useful in developing novel therapies for inhibiting HIV infection. Based on the reported anti-HIV activity of plant derived phloroglucinols, several new dimeric phloroglucinols were synthesized in the present study by varying substitution on aromatic ring and at methylene bridge. Some of the synthesized compounds have shown good HIV inhibitory activity in a human CD4+ T cell line (CEM-GFP) infected with HIV-1 NL(4.3) virus isolate. Structure-activity studies indicate that phenyl, 4-benzyloxy-1-phenyl and cyclohexyl substitution at methylene bridge gave compounds with better anti-HIV activity. Compounds 22 and 24 showed highest anti-HIV activity with an IC(50) of 0.28 microM and 2.71 microM, respectively, former was more active than the positive standard AZT in cell based assay.

Applications of 2, 2, 2 trifluoroethanol as a versatile co-solvent in supercritical fluid chromatography for purification of unstable boronate esters, enhancing throughput, reducing epimerization, and for additive free purifications.

Analysis and purification of boronic acid pinacol esters by RPLC is very challenging due to their degradation in aqueous and alcoholic solvents. These compounds are difficult to purify by SFC too as they are equally sensitive to traditional co-solvents like methanol, ethanol, and 2-propanol. 2,2,2 trifluoroethanol (TFE), which has been reported for the purification of a few alcohol sensitive compounds, was evaluated as a co-solvent in this study for the purification of chiral and achiral boronate esters by SFC. Examples of twelve compounds were presented in this paper where degradation of boronic acid pinacol esters was successfully controlled by replacing methanol with TFE as the co-solvent in SFC. A separate study showed that TFE can also control the epimerization of the enantiomers of 3 substituted 1,4 benzodiazepine analogues during the purification process. In addition to above benefits, 2,2,2trifloroethanol showed improved selectivity and resolution for most of the compounds. With its stronger solvent strength compared to other alcohols, TFE could also be used to reduce the co-solvent percentage needed for elution and to shorten retention time of highly polar samples which did not elute even in 50% of other co-solvents in SFC. A case study of compound B demonstrated that TFE provided a reduced co-solvent percentage and a shorter cycle time with much improved resolution as compared to methanol, thus resulting in higher loading and throughput with reduction of total solvent consumption.

Small molecule HIV entry inhibitors: Part I. Chemokine receptor antagonists: 2004 - 2010.

INTRODUCTION: HIV/AIDS is one of the most devastating diseases in the world affecting > 40 million people worldwide. Morbidity and mortality from AIDS are significantly reduced due to the advent of highly active antiretroviral therapy (HAART). Long-term toxicity, emergence of drug resistant HIV strains and drug-drug interactions limit the effectiveness of HAART therapy. Chemokine receptor antagonists can provide drugs with lesser side effects and enhanced anti-HIV activity. Maraviroc, a chemokine co-receptor 5 (CCR5) antagonist from Pfizer, is already in clinical use. AREAS COVERED: This review covers patents and patent applications for small molecule CCR5 and CXC chemokine receptor 4 (CXCR4) antagonists published between 2004 and 2010 and related literature with a focus on recent developments based on lead generation and lead modification. The reader will gain information about the development of small molecule CCR5 and CXCR4 antagonists from the major pharmaceutical and biopharmaceutical companies. EXPERT OPINION: Several small lead molecules (CCR5 and CXCR4 antagonists) have been modified over this period for enhanced therapeutic activity and to obtain drug-like properties. CCR5 antagonists such as TBK-652 and TBK-220 from Tobira Therapeutics, and vicriviroc from Schering Plough showed a lot of promise in the developmental stage.

Small molecule HIV entry inhibitors: Part II. Attachment and fusion inhibitors: 2004-2010.

INTRODUCTION: The first US FDA approved HIV entry inhibitor drug Enfuvirdine belongs to the fusion inhibitor category. Earlier efforts in this area were focused on peptides and monoclonal antibodies; recently, the focus has shifted towards the development of small molecule HIV attachment and fusion inhibitors. They can be used for prophylactic purposes and also hold potential for the development of HIV microbicides. AREAS COVERED: In a previous paper ('Small molecule HIV entry inhibitors: Part I'), we reviewed patents and patent applications for small molecule chemokine receptor antagonists from major pharmaceutical companies. In this paper, the development of small molecule HIV attachment and fusion inhibitors is discussed in detail. It covers patents and patent applications for small molecule HIV attachment and fusion inhibitors published between 2004 and 2010 and related literature with a focus on recent developments based on lead generation and lead modification. EXPERT OPINION: To augment the potency of currently available antiretroviral drug combinations and to fight drug-resistant virus variants, more effective drugs which target additional steps in the viral replication cycle are urgently needed. HIV attachment and fusion processes are such targets. Inhibitors of these targets will provide additional options for the treatment of HIV drug-resistant strains. Small molecule HIV attachment inhibitors such as BMS-378806 and analogs from Bristol Myers Squibb, N-aryl piperidine derivatives from Propharmacon, and NBD-556 and NBD-557 from New York Blood Center may have potential as vaginal microbicidal agents and can be an economical alternative to monoclonal antibodies.