Water-based efficient alkyne transformation towards α-acetoxy/imido-ketones via oxidative coupling reactions using an alkylamine catalyst.

A novel approach is unveiled for the expedited synthesis of valuable α-substituted ketones, utilising aliphatic amine catalysis to drive the oxidative C-O/C-N coupling reaction between alkynes and an appropriate nucleophile. This one-pot synthesis employs hypervalent iodine as both the oxidant and coupling agent. A fast, metal-free, and environmentally benign method is developed for synthesising α-acetoxyketones and α-imidoketones in an aqueous medium. To demonstrate the potential for larger-scale production, a gram-scale reaction is conducted. Moreover, the newly developed methodology has successfully enabled the direct synthesis of cathinone, a psychoactive drug. Overall, this work holds significant promise for the efficient and sustainable synthesis of α-substituted ketones and the potential development of novel biologically active compounds.

Cancer Biomarkers for Integrative Oncology.

PURPOSE OF REVIEW: There has been an increasing interest in using complementary and alternative medicine (CAM) approaches to treat cancer. It is therefore relevant and timely to determine if CAM biomarkers can be identified and developed to guide cancer diagnosis and treatment. Herein, we review the status of cancer biomarkers in CAM research and treatment to stimulate further research in this area. RECENT FINDINGS: Studies on promising anti-cancer natural products, such as PHY906, honokiol, bryostatin-1, and sulforaphane have demonstrated the existence of potential cancer biomarker(s). Additional studies are required to further develop and ultimately validate these biomarkers that can predict clinical activity of the anti-cancer natural products used alone or in combination with chemotherapeutic agents. A systematic approach is needed to identify and develop CAM treatment associated biomarkers and to define their role in facilitating clinical decision-making. The expectation is to use these biomarkers in determining potential options for CAM treatment, examining treatment effects and toxicity and/or clinical efficacy in patients with cancer.

Modulated photophysics of an anthracene-based fluorophore within bile-salt aggregates: the effect of the ionic strength of the medium on the aggregation behavior.

In this article, the binding interactions of a promising chloride channel blocker 9-methyl anthroate (9-MA) with a series of bile-salt aggregates of varying hydrophobicity have been thoroughly demonstrated. The altered photophysical properties of the fluorescent probe within the concerned microheterogeneous environments have been exploited spectroscopically to assess the communication between the aggregates and the guest. The contrived hydrophobic environment provided by the aggregates appreciably diminishes the water-assisted non-radiative decay channels and thus extends the fluorescence lifetime and the rotational relaxation time of the probe. NaDC aggregates, being more rigid and hydrophobic, provide a better protection to the bound guest from the external influence which is apparent from a much longer fluorescence lifetime and rotational correlation time for the encapsulated probe in NaDC aggregates compared to those in NaC and NaTC aggregates, as is further validated by fluorescence quenching experiments. Salt induced alterations of the binding behavior of the probe with the bile-salt aggregates have also been evaluated via fluorimetric studies, which conclude larger and tighter aggregate formation resulting in a superior degree of rigidity imposed on the aggregate-bound probe at high ionic strength of the medium.

Spectroscopic and viscometric elucidation of the interaction between a potential chloride channel blocker and calf-thymus DNA: the effect of medium ionic strength on the binding mode.

The present study demonstrates a detailed characterization of the binding interaction of a potential chloride channel blocker 9-methyl anthroate (9-MA) with calf-thymus DNA. The modulated photophysical properties of the emissive molecule within the microheterogeneous bio-assembly have been spectroscopically exploited to monitor the drug-DNA binding interaction. Experimental results based on fluorescence and absorption spectroscopy aided with DNA-melting, viscometric and circular dichroism studies unambiguously establish the binding mode between the drug and DNA to be principally intercalative. Concomitantly, a discernible dependence of the mode of binding between the concerned moieties on the ionic strength of the medium is noteworthy. A dip-and-rise characteristic of the rotational relaxation profile of the drug within the DNA environment has been argued to be originating from a substantial difference in the lifetime as well as amplitude of the free and DNA bound drug molecule. In view of the prospective biological applications of the drug, the issue of facile dissociation of the intercalated drug from the DNA helix via a simple detergent-sequestration technique has also been unveiled. The utility of the present work resides in exploring the potential applicability of the fluorescence properties of 9-MA for studying its interactions with other relevant biological or biomimicking targets.

Interaction of triblock co-polymer micelles with phospholipid-bilayer: a spectroscopic investigation using a potential chloride channel blocker.

Interaction of a potential chloride channel blocker, 9-methyl anthroate (9-MA), has been studied with zwitterionic l-α-phosphatidylcholine (egg-PC) lipid vesicles, which ascertains the utility of the drug as an efficient molecular reporter for probing the microheterogeneous environment of lipid-bilayers. The effect of a non-ionic triblock co-polymer P123 on the stability of these drug-bound lipid-bilayers has also been investigated by means of steady state and time-resolved spectroscopic techniques exploiting the fluorescence properties of the drug. Experimental results reveal that the addition of P123 to the drug-bound lipid results in a preferential complexation of the drug with the Pluronic leaving the lipid vesicles aside, which has been attributed to a substantially stronger binding interaction of the drug with P123 than that with egg-PC. The result is of potential interest from a medical perspective owing to the context of excess drug desorption from bio-membranes.

Interaction of a potential chloride channel blocker with a model transport protein: a spectroscopic and molecular docking investigation.

The present work demonstrates a detailed characterization of the interaction of a potential chloride channel blocker, 9-methyl anthroate (9-MA), with a model transport protein, Bovine Serum Albumin (BSA). The modulated photophysical properties of the emissive drug molecule within the microheterogeneous bio-environment of the protein have been exploited spectroscopically to monitor the probe-protein binding interaction. Apart from evaluating the binding constant, the probable location of the neutral molecule within the protein cavity (subdomain IB) is explored by an AutoDock-based blind docking simulation. The absence of the Red-Edge Effect has been corroborated by the enhanced lifetime of the probe, being substantially greater than the solvent reorientation time. A dip-and-rise characteristic of the rotational relaxation profile of the drug within the protein has been argued to originate from a significant difference in the lifetime as well as amplitude of the free and protein-bound drug molecule. Unfolding of the protein in the presence of the drug molecule has been probed by the decrease of the α-helical content, obtained via circular dichroism (CD) spectroscopy, which is also supported by the gradual loss of the esterase activity of the protein in the presence of the drug molecule.

Selective fluorescence sensing of Cu(II) and Zn(II) using a new Schiff base-derived model compound: naked eye detection and spectral deciphering of the mechanism of sensory action.

A new Schiff base compound 2-((benzylimino)-methyl)-naphthalen-1-ol (2BIMN1O) has been synthesized and characterized by (1)H NMR, (13)C NMR, DEPT, FT-IR and mass spectroscopic techniques. The significantly low fluorescence yield of the compound has been rationalized in connection with photo-induced electron transfer (PET) from the imine receptor moiety to the naphthalene fluorophore unit. Subsequently, an evaluation of the transition metal ion-induced modification of the fluorophore-receptor communication reveals a promising prospect for the title compound to function as a fluorosensor for Cu(2+) and Zn(2+) ions selectively, through remarkable fluorescence enhancement. While perturbation of the PET process in 2BIMN1O has been argued to be the responsible mechanism behind the fluorescence enhancement, the selectivity for these two metal ions has been interpreted on the grounds of an appreciably strong binding interaction. Particularly notable aspects regarding the chemosensory activity of the compound are its ability to detect the aforesaid transition metal ions down to the level of micromolar concentration (detection limit being 0.82 and 0.35 µM respectively), along with a simple and efficient synthetic procedure. Also the spectral modulation of 2BIMN1O in the presence of the transition metal ions paves the way for the construction of a calibration curve in the context of its fluorescence signaling potential.

Expulsion of a potent cancer-cell photosensitizer from its micelle-bound state using ß-cyclodextrin: A tenable model for efficient drug release.

The present study delves into the interaction of a potent cancer-cell photosensitizer Norharmane (NHM) with non-ionic triblock copolymer P123, followed by the assessment of the stability of the formed complex in the presence of ß-cyclodextrin (ß-CD). Spectroscopic results unveil the modulation of the prototropic equilibrium of NHM within the constrained microheterogeneous medium of the copolymer micelle to be favoured towards the neutral species of NHM over the cationic counterpart; which has been aptly rationalized invoking the key role of hydrophobic interaction in the association process and is further reinforced from steady-state and time-resolved spectroscopic measurements. The micropolarity of the probe-binding site has been evaluated by the archetypal ET(30) analysis revealing that the cationic probe remains in the corona region of the micelle instead of penetrating deeper into the micellar core. Moreover, the effect of ß-CD on the stability of the NHM-bound P123 aggregates has also been investigated, revealing that ß-CD can be used as a potential host for the release of the micelle-encapsulated drug through an inclusion complex formation with the P123 monomers. The result is expected to be of potential interest from medical perspective owing to the context of efficient drug release at their potential sites.

Extracellular RNAs as potential biomarkers for cancer.

The discovery that all cells secrete extracellular vesicles (EVs) to shuttle proteins and nucleic acids to recipient cells suggested they play an important role in intercellular communication. EVs are widely distributed in many body fluids, including blood, cerebrospinal fluid, urine and saliva. Exosomes are nano-sized EVs of endosomal origin that regulate many pathophysiological processes including immune responses, inflammation, tumour growth, and infection. Healthy individuals release exosomes with a cargo of different RNA, DNA, and protein contents into the circulation, which can be measured non-invasively as biomarkers of healthy and diseased states. Cancer-derived exosomes carry a unique set of DNA, RNA, protein and lipid reflecting the stage of tumour progression, and may serve as diagnostic and prognostic biomarkers for various cancers. However, many gaps in knowledge and technical challenges in EVs and extracellular RNA (exRNA) biology, such as mechanisms of EV biogenesis and uptake, exRNA cargo selection, and exRNA detection remain. The NIH Common Fund-supported exRNA Communication Consortium was launched in 2013 to address major scientific challenges in this field. This review focuses on scientific highlights in biomarker discovery of exosome-based exRNA in cancer and its possible clinical application as cancer biomarkers.

Inhibition of lipopolysaccharide activation of Kupffer cells by transition metals.

BACKGROUND: Bacterial endotoxins are the principal agents causing sepsis and septic shock. Cytokine cascades produced by cellular interactions to endotoxins can cause cardiovascular failure followed by multi-organ failure and death. Endotoxin intravenously administered to mice can have fatal consequences. Previous studies have shown that the transition metals Mn2+ and Cr3+ can be protective. METHODS: The effects of Mn2+, Cr3+, Zn2+, and Cu2+ on lipopolysaccharide (LPS) binding to rat Kupffer cell extracts were analyzed using dot-blots, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and Western transfer. Kupffer cells were isolated from rat livers by collagenase perfusion, differential centrifugation, and adhesion to plastic. RESULTS: Five millimolar of Mn2+, Zn2+, Cr3+, and Cu2+ completely inhibited LPS binding. Isolated Kupffer cells were also exposed to Mn2+ and to LPS and tumor necrosis factor-alpha release measured. The presence of Mn2+ significantly (P < 0.05) reduced tumor necrosis factor-alpha production by Kupffer cells in response to LPS. Experiments to determine if these effects were mediated by binding to LPS-binding proteins showed this was not the case. More likely a complex occurs between the metal and LPS. We also showed significantly enhanced uptake of LPS into Kupffer cells in the presence of Mn2+. CONCLUSIONS: The data are consistent with the metals binding to LPS via its two phosphate groups and neutralizing their charge. These data also support the hypothesis that there is enhanced cellular uptake by non-receptor-mediated methods such as absorptive pinocytocis. At the same time receptor binding and activation of the cells is inhibited. This can explain the effects of transition metals on LPS toxicity.

Interaction of a cationic amphiphile with monomeric and polymeric electrolytes: From morphological transition to associative phase separation.

The discrete effects of a series of structurally divergent monomeric viz. Sodium Chloride (NaCl), Tetra-butyl Ammonium Chloride (TBAC) and Sodium Benzoate (NaBz) and polymeric viz. Sodium Polystyrene Sulfonate (NaPSS) electrolytes towards the morphological and/or aggregation properties of Octadecyl-trimethyl Ammonium Bromide (OTAB) micelles have been quantified spectroscopically by means of the modulations of the absorption and emission spectral properties of an extrinsic anthracene-based probe 9-methyl anthroate (9-MA) within the concerned media. Further corroboration of the spectroscopic results was acquired from the non-invasive dynamic light scattering technique. The qualitatively similar mode of action of all the monomeric salts has been explained on the basis of the archetypal Israelachvili model whereas the corresponding extent of the morphological transition of the micelles, which is found to follow the order NaBz > NaCl > TBAC, has been explained invoking the co-sphere overlap model. Conversely, to explain the aggregation behaviour of the micelles in the presence of the polymeric electrolyte, a two-step model has been formulated. According to this model, at the low concentration regime, the polymeric salt is found to only neutralize the surface charge of the micelles inducing micellar growth; whereas further increment in the concentration of the polymer assists the hydrophobic association between the micelles leading to the formation of larger aggregates, eventually causing a phase separation.

A phenolic acid based colourimetric 'naked-eye' chemosensor for the rapid detection of Cu(II) ions.

The crucial role of chemosensor for the immediate recognition of environment pollutant motivates the researchers to develop variety of sensing protocols. Of various chemosensory protocols, the colour change observed by the naked eye is considered to be a conceivable and on-site way to indicate the presence of an analyte. We herein report a colourimetric and commercially available absorption probe, sinapic acid (SA) that is completely ready to use for "on-site" visual determination of copper ions. The molecule, SA is well-known phenolic acid, often utilized for its antibacterial activity. In this work, for the first time, we are exploring its ability to work as an efficient Cu2+ sensor. This sensor molecule selectively detected Cu2+ ions by changing its colour from colourless to pink within detection limit of 64.5nM, which is much lower than other reported sensor molecules and the suggested limit by World Health Organization (WHO) and U. S. Environmental Protection Agency (EPA) guidelines. The sensing mechanism was investigated through UV-vis and 1H NMR titration along with ESI-MS spectroscopy and further confirmed by DFT computational studies. Studies revealed the participation of hydroxyl group (OH) and methoxy group (OMe) of SA in complexation with Cu2+. The binding stoichiometry of SA to Cu2+ was found to be 1:2 through Job's plot and ESI-MS analysis. Importantly, paper strips of SA were prepared which could be used for a rapid "on-site" determination of Cu2+ containing samples.

Modulation of probe-genomic DNA interaction within the confined interior of a reverse micelle: Is the bulk-like properties of water truly achieved in large reverse micelles?

The prime motivation of the present study is to explore the effect of reverse micellar confinement on the binding interaction of an anthracene-based probe 9-methyl anthroate with herring-sperm DNA. The structural modification of the genomic DNA from its native B-form to the non-native C-form and subsequently to the condensed Ψ-form as a function of the level of hydration (W0, defined as [water] / [surfactant]) of the reverse micellar core is found to reveal a remarkable regulatory role on the stability of the stacking interaction (intercalation) of the probe within the DNA helix; the interaction being progressively stabilized at higher W0. Particularly, a close perusal of the dynamical aspects of the interaction is found to be counter-intuitive to the popular notion of the properties of the confined water within the reverse micelles typically approaching bulk-like properties at sufficiently high hydration levels (W0 > 10).

Binding mode dependent signaling for the detection of Cu2+: An experimental and theoretical approach with practical applications.

Two amido-schiff bases (3-Hydroxy-naphthalene-2-carboxylic acid pyren-1-ylmethylene-hydrazide and Naphthalene-2-carboxylic acid pyren-1-ylmethylene-hydrazide) have been synthesized having a common structural unit and only differs by a -OH group in the naphthalene ring. Both of them can detect Cu2+ ion selectively in semi-aqueous medium in distinctly different output modes (one detects Cu2+ by naked-eye color change where as the other detects Cu2+ by fluorescence enhancement). The difference in the binding of Cu 2+ with the compounds is the reason for this observation. The detection limit is found to be micromolar region for compound which contains -OH group whereas the compound without -OH group detects copper in nano-molar region. DFT calculations have been performed in order to demonstrate the structure of the compounds and their copper complexes. Practical utility has been explored by successful paper strip response of both the compounds. The biological applications have been evaluated in RAW 264.7.

India-United States Dialogue on Traditional Medicine: Toward Collaborative Research and Generation of an Evidence Base.

Therapies originating from traditional medical systems are widely used by patients in both India and the United States. The first India-US Workshop on Traditional Medicine was held in New Delhi, India, on March 3 and 4, 2016, as a collaboration between the Ministry of Ayurveda, Yoga and Naturopathy, Unani, Siddha, and Homoeopathy (AYUSH) of the Government of India, the US National Cancer Institute (NCI), National Institutes of Health, and the Office of Global Affairs, US Department of Health and Human Services. It was attended by Indian and US policymakers, scientists, academics, and medical practitioners from various disciplines. The workshop provided an opportunity to open a dialogue between AYUSH and NCI to identify promising research results and potential topics for Indo-US collaboration. Recommendations that emerged from the workshop underlined the importance of applying rational and scientific approaches for drug development; standardizing traditional medicine products and procedures to ensure reliability and reproducibility; promotion of collaboration between Indian traditional medicine practitioners and researchers and US researchers; greater integration of evidence-based traditional medicine practices with mainstream medical practices in India; and development of training programs between AYUSH and NCI to facilitate crosstraining. Several positive developments took place after the thought-provoking deliberations.

A selective chemosensor for fluoride ion and its interaction with Calf Thymus DNA.

The amido-Schiff base 1 (N1, N3-bis (2-nitrobenzylidene)benzene-1,3-dicabohydrazide) containing a CONH group and CHN linkage has been synthesized by the condensation between isophthalic acid dihydrazide and o-nitrobenzaldehyde. This molecule can act as a fluoride ion sensor with high selectivity and sensitivity. Presence of nitro group in the phenyl ring may be responsible for the detection of fluoride ion visually with a dramatic color change from colorless to deep red in aqueous dimethyl sulphoxide solution. This Schiff base can be used as test kit for sensing of fluoride ion in the solid state. Compound 1 can detect fluoride also in commercially available toothpaste. As the compound has adequate solubility in DMSO-water mixture (7:93, v/v) and having some hydrogen bond donor and acceptor centers, we have investigated its nature of binding with Calf Thymus-DNA (CT-DNA) using theoretical molecular modelling and other experimental methods like UV-vis spectroscopy, circular dichroic and thermal melting studies. Thermodynamic parameters have been obtained using the well known Van't Hoff's equation. From both theoretical and experimental findings it has been observed that it can interact effectively with CT-DNA with binding energy -7.55kcal/mol to -7.50kcal/mol.

Development and validation of a Luminex assay for detection of a predictive biomarker for PROSTVAC-VF therapy.

Cancer therapies can provide substantially improved survival in some patients while other seemingly similar patients receive little or no benefit. Strategies to identify patients likely to respond well to a given therapy could significantly improve health care outcomes by maximizing clinical benefits while reducing toxicities and adverse effects. Using a glycan microarray assay, we recently reported that pretreatment serum levels of IgM specific to blood group A trisaccharide (BG-Atri) correlate positively with overall survival of cancer patients on PROSTVAC-VF therapy. The results suggested anti-BG-Atri IgM measured prior to treatment could serve as a biomarker for identifying patients likely to benefit from PROSTVAC-VF. For continued development and clinical application of serum IgM specific to BG-Atri as a predictive biomarker, a clinical assay was needed. In this study, we developed and validated a Luminex-based clinical assay for measuring serum IgM specific to BG-Atri. IgM levels were measured with the Luminex assay and compared to levels measured using the microarray for 126 healthy individuals and 77 prostate cancer patients. This assay provided reproducible and consistent results with low %CVs, and tolerance ranges were established for the assay. IgM levels measured using the Luminex assay were found to be highly correlated to the microarray results with R values of 0.93-0.95. This assay is a Laboratory Developed Test (LDT) and is suitable for evaluating thousands of serum samples in CLIA certified laboratories that have validated the assay. In addition, the study demonstrates that discoveries made using neoglycoprotein-based microarrays can be readily migrated to a clinical assay.

Identification of two novel LPS-binding proteins in Kupffer cells: implications in TNF-alpha production.

Using a combination of gel-exclusion chromatography and ligand binding with [(125)I]-lipopolysaccharide (LPS), we discovered two novel endotoxin-binding proteins, p31(LPB) and p34(LPB), in Kupffer cells. Their molecular masses suggest that these are previously undescribed LPS-binding proteins (LBPs). Evidence from detergent-based cell extractions shows that these proteins are probably transmembrane or located on the inner leaflet of the lipid bilayer. We have partially purified the proteins from detergent extracts of Kupffer cells and proven that they bind diphosphoryl lipid A, an interaction associated with TNF-alpha production. The proteins do not bind monophosphoryl lipid A. Diphosphoryl lipid A binding occurs in the absence of serum, suggesting a mechanism of cytokine production distinct from that involving CD14 and lipopolysaccharide-binding protein (LPB). The two proteins were not detectable in resident peritoneal macrophages or in a number of other cell lines of the macrophage/monocyte lineage, suggesting specificity towards terminally differentiated macrophages such as Kupffer cells.

Inclusion of an Anthracene-based Fluorophore within Molecular Containers: A Comparative Study of the Cucurbituril and Cyclodextrin Host Families.

In this paper, the binding interaction of a promising chloride channel blocker, 9-methyl anthroate (9-MA), with two different classes of molecular containers, ß-cyclodextrins (ß-CD and methyl-ß-CD) and cucurbit[7]uril, having comparable cavity dimensions, has been thoroughly demonstrated via inspection of the modulation of the excited-state properties of the emissive molecule. Spectral data suggest that CB7 encapsulates the probe more efficiently in a 1:2 fashion, whereas the efficacies of ß-CDs are relatively less and the corresponding stoichiometry is 1:1. Interestingly, despite being thermodynamically much more favorable than the probe-ß-CD complexation equilibria, the fraction of probe-CB7 complex formed is appreciably smaller with respect to that of probe-ß-CD complexes. This apparent inconsistency has been addressed via the proposition that since the formation of a 1:2 complex is entropically disadvantageous, it is anticipated that the activation barrier of the corresponding reaction is reasonably high, and thus only a small fraction of the reactants are able to surpass the energy barrier to form the products. This proposition has been thoroughly corroborated by fluorescence lifetime measurements at different temperatures.

Effect of the binding interaction of an emissive niacin derivative on the conformation and activity of a model plasma protein: A spectroscopic and simulation-based approach.

The present work demonstrates a detailed photophysics of bio-active drug-like acid viz., 2-hydroxynicotinic acid (2-HNA) and its interaction with a model plasma protein Bovine Serum Albumin (BSA). The drug which is in essence a vitamin-B3 derivative, is capable of exhibiting ultrafast lactim-lactam cross-over response and thereby the modulation of the lactam emission within the bio-environment of the protein has been depicted spectroscopically to reveal the drug-protein interaction. Apart from evaluating the binding constant, the probable location of the neutral drug molecule within the protein cavity (hydrophobic subdomain IIIA) has been explored by AutoDock-based blind docking simulation technique. In this microheterogeneous medium, slow solvent reorientation time with respect to the emissive lifetime of the drug explicate the Red Edge Effect (REE). To complement the findings about the binding process, chaotrope-induced protein denaturation has also been inspected. The probe also illustrates a perceptible difference in rotational relaxation time in confined medium than in aqueous medium which strengthen our verdict. Unfolding of the protein in the presence of the drug molecule has been probed by the decrease of the α-helical content, obtained via circular dichroism (CD) spectroscopy, which is also supported by the gradual slaughter of the esterase activity of the protein in the presence of the drug molecule.