Scale Effect of a Fluorescent Waveguide in Organic Micromaterials: A Case Study Based on Coumarin Microfibers.

The classical method for evaluating the waveguide ability only focuses on the optical loss coefficient. However, for the micro- or submicroscale, an organic waveguide is demonstrated by the present study whose scale effect should not be neglected. We found that the optical loss coefficient increased remarkably when decreasing the sectional size of the microfibers. Furthermore, simulations based on Finite-Difference Time-Domain also demonstrated the size-dependent effect of the waveguide. Both the experimental and simulating results showed that the optical loss coefficient converges to a certain value, which means that the scale effect can be neglected as the sectional size is large enough. On the basis of the present study, we suggest that the scale-dependent effect on the sectional size of the waveguide should be investigated by evaluating the waveguide ability by the optical loss coefficient.

Evaluation and in vivo efficacy study of pyrano[3,2-c]quinoline analogues as TNF-α inhibitors.

A series of pyrano[3,2 c]quinoline was evaluated for its in vivo efficacy as TNF-α inhibitor using LPS, phosphodiesterase (PDE)-4, and CIA assays in different mice/rat models. The synthesis was performed using one-pot multicomponent condensation between 2,4-dihydroxy-1-methylquinoline, malononitrile, and diverse un(substituted) aromatic aldehydes. In vivo efficacy of the title compounds was evaluated using LPS assay in BALB/c mice, PDE4 inhibition in ketamine-xylazine-induced anesthetize SD rats, and CIA assay was performed in DBA/1J mice as per the standard literature protocols. The outcome of the study revealed that compound 4v was found to be most promising candidate of the series. It was efficacious with 48.8 ± 13.0% inhibition of TNF-α release at 100 mg/kg p.o., in the LPS assay in Balb/c mice model. It was effective in PDE4 assay in ketamine-xylazine-induced anesthetize SD rats with duration of 38.3 ± 4.5 min for reversal of anesthetic effect and also showed significant inhibition of PDE4 in salbutamol treated U937 cell assay. It was also abolished TNF-α induced phosphorylation and degradation of IκBα. Ultimately, its effect on CIA-related bone and cartilage damage was found statistically similar to Enbrel.

Evaluation of Pyrano[3,2 C] Quinoline Analogues as Anticancer Agents.

BACKGROUND: Quinoline analogues exhibited diversified biological activities depending on the structure type. A number of natural products with pyrano[3,2-c]quinolone structural motifs and patented chromenes were reported as promising cytotoxic agents. OBJECTIVE: The present study is aimed to evaluate a new series of pyrano[3,2-c]quinoline scaffolds derived from the fusion of bioactive quinolone pharmacophore with structurally diverse aryl substituted chromene for its cytotoxicity. METHODS: A library of pyrano[3,2-c]quinoline analogues was prepared from one-pot multi component synthesis using various aromatic aldehydes, malononitrile and 2,4-dihydroxy-1-methylquinoline. The new synthetics were primarily screened for its cytotoxicity (IC50) against different human cancer cell lines in vitro. The promising synthetics were further evaluated in vitro for their potency against different kinase activity. The promising compounds were finally tested for their in vivo efficacy in SCID type mice HCT-116 tumor model. RESULTS: The screening results revealed that compounds 4c, 4f, 4i and 4j showed promising activity in in vitro study. However, compound 4c was found to be the most potent candidate with 23% tumor growth inhibition in HCT-116 tumor mice model. CONCLUSION: The structure activity relationship suggested that 3-substitution on the aryl ring at C4 position of the pyrano[3,2 c]quinolone moiety seems to have an important position for cytotoxicity activity. However, 3- chloro substitution at C4 aryl ring showed a significant alteration of the bioactive conformer of the parent scaffold and outcome with compound 4c as the most potent candidate of the series.

Synthesis and Biological Screening of Pyrano[3,2-c]quinoline Analogues as Anti-inflammatory and Anticancer Agents.

A series of pyrano[3,2-c]quinoline based structural analogues was synthesized using one-pot multicomponent condensation between 2,4-dihydroxy-1-methylquinoline, malononitrile, and diverse un(substituted) aromatic aldehydes. The synthesized compounds were evaluated for their anti-inflammatory and cytotoxicity activity. Initially, all the compounds were evaluated for the percent inhibition of cytokine release, and cytotoxicity activity and 50% inhibitory concentrations (IC50) were also determined. Based on the primary results, it was further studied for their ability to inhibit TNF-α production in the human peripheral blood mononuclear cells (hPBMC) assay. The screening results revealed that compound 4c, 4f, 4i, and 4j were found most active candidates of the series against both anti-inflammatory and anticancer activity. The structure-activity relationship is discussed and suggested that 3-substitution on the aryl ring at C4 position of the pyrano[3,2-c]quinolone structural motif seems to be an important position for both TNF-α and IL-6 inhibition and anticancer activity as well. However, structural diversity with electron withdrawing, electron donating, sterically hindered, and heteroaryl substitution sincerely affected both the inflammation and anticancer activities.

Dihedral angle study in Hesperidin using NMR Spectroscopy.

Hesperidin is flavonoid molecule found in citrus fruits (Citrus reticulata), especially difficult to extract, classify and characterize. Present work is to study the unresolved relative configuration of Hesperidin through the dihedral angle, coupling constant and different NMR techniques. The Karplus equation and its modifications have been originated from the valence bond theory and associated with dihedral angle and coupling constant. The result data set of calculated dihedral angle can probe significant method to assign the virtual configuration of natural products and also resolved stereochemistry of Hesperidin at C-2 position in. Copyright © 2016 John Wiley & Sons, Ltd.

Domino Heck/borylation sequence towards indolinone-3-methyl boronic esters: trapping of the σ-alkylpalladium intermediate with boron.

Pd-catalyzed domino Heck/borylation of acrylamides with B2pin2 is reported to generate synthetically useful indolinone-3-methyl boronic esters, via capturing σ-alkyl palladium with boron. Further functionalization of the obtained boronic ester qualify it as a new starting point for the functionalization of specific C(sp(3))-H bond. Moreover, the application of an Ugi-adduct as starting material or B2nep2 as an alternative boron source works equally well, making this a broadly applicable and robust method for the formation of a C-C and C-B bond in a single operation.

Targeting dormant tuberculosis bacilli: results for molecules with a novel pyrimidone scaffold.

Our inability to completely control TB has been due in part to the presence of dormant mycobacteria. This also renders drug regimens ineffective and is the prime cause of the appearance of drug-resistant strains. In continuation of our efforts to develop novel antitubercular agents that especially target dormant mycobacteria, a set of 55 new compounds belonging to the pyrimidone class were designed on the basis of CoMFA and CoMSIA studies, and these were synthesized and subsequently tested against both the dormant and virulent BCG strain of M. tuberculosis. Some novel compounds have been identified which selectively inhibit the dormant tuberculosis bacilli with significantly low IC50 values. This study reports the second molecule after TMC-207, having the ability to inhibit tuberculosis bacilli exclusively in its dormant phase. The synthesis was accomplished by a modified multicomponent Biginelli reaction. A classification model was generated using the binary QSAR approach--recursive partitioning (RP) to identify structural characteristics related to the activity. Physicochemical, structural, topological, connectivity indices, and E-state key descriptors were used for generation of the decision tree. The decision tree could provide insights into structure-activity relationships that will guide the design of more potent inhibitors.

Solvent switchable cycloaddition: a (one-pot) metal-free approach towards N-substituted benzo[e]- or [f]isoindolones via C(sp(2))-H functionalization.

The tuning of selective ring closure is a nontrivial challenge in synthetic organic chemistry. Herein we report a solvent switchable metal-free [4 + 2] cycloaddition approach via Csp(2)-H functionalization. The protocol is highly atom economical with water being the only by-product, delivering N-substituted benzo[e]- or [f]isoindolones in high yields.

Development and validation of a reversed-phase ultra-performance liquid chromatographic method for the simultaneous determination of six drugs used for combined hypertension therapy.

A simple, rapid, and reliable ultra-performance LC assay method has been developed for the simultaneous estimation of orally administered hypertension drugs (atenolol, hydrochlorothiazide, amlodipine besylate, indapamide, nifedipine, and lercanidipine hydrochloride), any of which may be administered with atenolol in combined hypertension therapy. Chromatography was carried out at 25 degrees C on a 2.1 x 50 mm id, 1.7 microm particle size Acquity BEH C18 column with the isocratic mobile phase 0.01 M, 4.0 pH aqueous phosphate buffer-acetonitrile (50 + 50, v/v) at a flow rate of 0.35 mL/min. All drugs were separated in less than 4 min with good resolution and minimal tailing, without interference by excipients. The method was validated according to International Conference on Harmonization guidelines, and the acceptance criteria for accuracy, precision, linearity, specificity, and system suitability were met in all cases. The column effluent was monitored at 230 nm. The detector response was linear in the range of 1-20 microg/mL of these drugs. LOD obtained was 0.04 microg/mL for atenolol, 0.02 microg/mL for hydrochlorothiazide, 0.03 microg/mL for amlodipine besylate, 0.03 microg/mL for indapamide, 0.02 microg.mL for nifedipine, and 0.01 microg/mL for lercanidipine hydrochloride. The suggested method has the advantage that all the drugs can be quantified alone or in combination with atenolol using a single mobile phase.

Synthesis, in vitro antitubercular activity and 3D-QSAR study of 1,4-dihydropyridines.

In continuation of our research program on new antitubercular agents, this article is a report of the synthesis of 97 various symmetrical, unsymmetrical, and N-substituted 1,4-dihydropyridines. The synthesized molecules were tested for their activity against M. tuberculosis H (37)Rv strain with rifampin as the standard drug. The percentage inhibition was found in the range 3-93%. In an effort to understand the relationship between structure and activity, 3D-QSAR studies were also carried out on a subset that is representative of the molecules synthesized. For the generation of the QSAR models, a training set of 35 diverse molecules representing the synthesized molecules was utilized. The molecules were aligned using the atom-fit technique. The CoMFA and CoMSIA models generated on the molecules aligned by the atom-fit method show a correlation coefficient (r (2)) of 0.98 and 0.95 with cross-validated r (2)(q (2)) of 0.56 and 0.62, respectively. The 3D-QSAR models were externally validated against a test set of 19 molecules (aligned previously with the training set) for which the predictive r(2)(r(r)(pred)) is recorded as 0.74 and 0.69 for the CoMFA and CoMSIA models, respectively. The models were checked for chance correlation through y-scrambling. The QSAR models revealed the importance of the conformational flexibility of the substituents in antitubercular activity.

1,5-Benzothiazepine, a versatile pharmacophore: a review.

1,5-Benzothiazepine and 1,5-benzodiazipine are the two main seven-membered heterocyclic ring systems reported for their cardiac and psychotherapeutic activities. Successful introduction of diltiazem and clentiazem for angina pectoris, hypertension, arrhythmias and other related cardiac disorders proved potential of 1,5-benzothiazepine moiety. Subsequently 1,5-benzodiazepines were highlighted as important biologically active scaffolds. Also, discovery of thiazesim and quetiapine fumarate as psychotropic agents attracted much attention worldwide. The current review article focuses on pharmacological profile associated with 1,5-benzodiazepines. This article mainly covers structural modifications done for various targets along with the brief description of the targets.

Recent advances in selective alpha1-adrenoreceptor antagonists as antihypertensive agents.

Hypertension is one of the most serious health problems of the modern world with a continuous rise in the number of patients. Selective alpha(1)-adrenoreceptor antagonists though have many advantages and uses in the management of arterial hypertension, their lack of specificity at the level of alpha(1)-adr subtypes leads to multiple side effects. Existence of multiple alpha(1)-adr subtypes holds great promise for the discovery and development of more specific and selective drug molecules, targeting only one alpha(1)-adr subtype at a time and thus relative freedom from side effects. Herein, the research done on the discovery and evaluation of a variety of chemically diverse structures as selective antagonists of alpha(1)-adr and alpha(1)-adr subtypes in recent years has been reviewed.

Recent advances in proton pump inhibitors and management of acid-peptic disorders.

Acid-peptic ulcers and diseases have been increasingly on rise in today's era of globalization, which is characterized by hurry, worry, and curry. This review summarizes various disorders associated with increased gastric acid secretion and various therapeutic strategies to control them. The emphasis has been laid, in particular, on the role of proton pump inhibitors (PPIs) widely used nowadays for the treatment of gastric acid diseases. The medicinal chemistry aspects and mechanism of action of irreversible PPIs and APAs have been discussed at molecular levels. The ongoing research status in this field has also been covered. Further, biological evaluation methods that can be used for screening of PPIs are also discussed in short.