catena-Poly[[tri-phenyl-tin(IV)]-µ-N-(4-acetyl-phen-yl)maleamato].

The crystal structure of the polymeric title compound, [Sn(C6H5)3(C12H10NO4)] n , comprises polymeric chains whereby adjacent Sn atoms are bridged by carboxyl-ate and amide carbonyl O atoms [Sn-O = 2.115 (15) and 2.653 (1) Å, respectively]. The Sn(IV) atom is five-coordinated showing a distorted trigonal-bipyramid geometry, with the three phenyl ipso-C atoms defining the trigonal plane and the axial positions occupied by O atoms [O-Sn-O = 171.91 (5)°]. Intra-molecular N-H⋯O hydrogen bonding leads to a seven-membered loop. There is an intra-molecular C-H⋯O inter-action within the polymeric chain. An inter-molecular C-H⋯O inter-action along c links the polymeric chains into sheets which are linked into a three-dimensional network via C-H⋯π inter-actions.

The development of chiral metal-organic frameworks for enantioseparation of racemates.

MIL-101(Cr), an achiral metal-organic framework, made up of a terephthalic acid ligand and a metal chromium ion was selected as a template. Its structural features are unsaturated Lewis acid sites that can be easily activated and it has an extremely high specific surface area, big pore size, and good thermal/chemical/water stability. This achiral framework was modified to introduce chirality within the structure to develop chiral metal-organic frameworks (CMOFs). Here, natural chiral ligands, amino acids (l-proline, l-thioproline and l-tyrosine), were selected for post synthetic modification (PSM) of MIL-101(Cr). This is a very simple, clean and facile methodology with respect to the reactants and reaction conditions. CMOFs 1-3 abbreviated as MIL-101-l-proline (CMOF-1), MIL-101-l-thioproline (CMOF-2) and MIL-101-l-tyrosine (CMOF-3) were prepared by introducing l-proline, l-thioproline and l-tyrosine as chiral moieties within the framework of (Cr). These CMOFs were characterized by FTIR, PXRD, SEM, and thermo gravimetric analysis. Chirality within these CMOFs 1-3 was established by circular dichroism (CD) and polarimetric methods. These three CMOFs 1-3 showed enantioselectivity towards RS-ibuprofen, RS-mandelic acid and RS-1-phenylethanol to varying extents. Their enantioselectivity towards racemates was studied by chiral HPLC and polarimetry.

Synthesis and Antioxidant Studies of 2,4-Dioxothiazolidine-5-acetic Acid Based Organic Salts: SC-XRD and DFT Approach.

In the current study, two organic salts (1 and 2) are synthesized, and then crystalline structures are characterized by FTIR, UV spectroscopy, and X-ray crystallographic studies. The organic salts 1 and 2 are optimized at the M06/6-311G(d,p)level of theory and further utilized for analysis of natural bond orbitals (NBOs), natural population, frontier molecular orbitals (FMOs), and global reactivity parameters, which confirmed the stability of the studied compounds and charge transfer phenomenon in the studied compounds. The studies further revealed that 1 and 2 are more stable than 3. The lowest energy merged monomer-coformer conformations were docked as flexible ligands with rigid fungal proteins and DNA receptors. The stagnant binding of the monomer through two H bonds with protein was observed for ligands 1 and 3 while different pattern was found with 2. The coformers formed a single H bond with the active site in 2 and 3 and a single pi-arene H interaction in 1. The two-point ligand-receptor interactions hooked the monomer between DNA base pairs for partial intercalation; pi stacking with additive hydrogen bonding with the base pair led to a strong benzimidazole interaction in 1 and 2, whereas ethylene diamine formed weak H bonding. Thus, the molecular docking predicted that the coformer exhibited DNA intercalation reinforced by its salt formation with benzimidazole 1 and methyl benzimidazole 2. Antioxidant studies depicted that 3 has a higher IC50 value than that of 2,4-D and also the largest value among the studied compounds, whereas 2 showed the lowest value among the studied compounds.

Caffeine-N-phthaloyl-ß-alanine (1/1).

The title co-crystal [systematic name: 3-(1,3-dioxoisoindolin-2-yl)propanoic acid-1,3,7-trimethyl-1H-purine-2,6(3H,7H)-dione (1/1)], C(8)H(10)N(4)O(2)·C(11)H(9)NO(4), is the combination of 1:1 adduct of N-phthaloyl-ß-alanine with caffeine. The phthalimide and purine rings in the N-phthaloyl-ß-alanine and caffeine mol-ecules are essentially planar, with r.m.s. deviations of the fitted atoms of 0.0078 and 0.0118 Å, respectively. In the crystal, the two mol-ecules are linked via an O-H⋯N hydrogen bond involving the intact carb-oxy-lic acid (COOH) group. The crystal structure is consolidated by C-H⋯O inter-actions. The H atoms of a methyl group of the caffeine mol-ecule are disordered over two sets of sites of equal occupancy.

The 1:1 adduct of caffeine and 2-(1,3-dioxoisoindolin-2-yl)acetic acid.

IN THE CRYSTAL STRUCTURE OF THE TITLE ADDUCT [SYSTEMATIC NAME: 2-(1,3-dioxoisoindolin-2-yl)acetic acid-1,3,7-trimethyl-1,2,3,6-tetra-hydro-7H-purine-2,6-dione (1/1)], C(8)H(10)N(4)O(2)·C(10)H(7)NO(4), the components are linked by an O-H⋯N hydrogen-bond and no proton transfer occurs.

catena-Poly[[diaqua-calcium]bis-[µ-2-(1,3-dioxoisoindolin-2-yl)acetato]-κO,O':O;κO:O,O'].

In the title complex, [Ca(C(10)H(6)NO(4))(2)(H(2)O)(2)](n), the Ca(II) atom lies on a twofold rotation axis and adopts a dodeca-hedral geometry. The Ca(II) atom is octa-coordinated by two O atoms from two water mol-ecules and six O atoms from four acetate ligands. Each acetate acts as a tridentate ligand bridging two Ca(II) atoms, resulting in a chain running along the c axis. O-H⋯O and C-H⋯O hydrogen bonds connect the chains into a two-dimensional network parallel to [011]. π-π inter-actions between adjacent isoindoline-1,3-dione rings [centroid-centroid distance = 3.4096 (11) Å] further consolidate the structure. One of the carboxylate O atoms is disordered over two sites in a 0.879 (12):0.121 (12) ratio.

Development of biodegradable thin films for efficient, specific and controlled delivery of capecitabine.

Cancer is the leading cause of death worldwide. Capecitabine (CP) shows severe side effects because of early metabolism in stomach that affects the normal cells and organs, particularly liver and stomach. In this scope, we report the biocompatible, nontoxic polymeric thin films loaded with anti-cancer drug, CP for target specific, sublingual delivery of CP. Chitosan (CS) and polyvinyl alcohol (PVA) were used as biodegradable polymers alongwith glutaraldehyde (GLA) cross linker. CP-loaded thin films (TFCP1-TFCP5) were fabricated by solvent casting method. The results of Fourier transform infrared spectroscopy confirmed the presence of CP and polymers (CS and PVA) with GLA which binds through hydrogen bonding, and compatibility of drug with different excipients. Thermogravemetric analysis showed that the thin films are highly stable while differential scanning calorimeter thermograms confirmed the complete miscibility/entrapment of CP within PVA/CS thin film matrix. X-ray diffraction patterns revealed the molecular ineractions between CP and polymer matrix. High degree of swelling index of thin films at pH 7.4 was observed in comparison to pH 5.5. CP release studies in acetate (pH 5.5) and phosphate buffer (pH 7.4) showed that the thin films swell and result in drug diffusion faster in phosphate buffer through diffusion governed by Higuchi's model. Cytotoxicity results displayed that CPTFs killed MCF-7 and T47D (human breast adenocarcinoma) cells more effectively as compared to CP alone. The results of adhesion assay also showed that the PVA and CS both are safe and biocompatible. TFCP1 and TFCP3 thin films efficiently induced the apoptosis as compared to CP alone. The improved ability of TFCP1 and TFCP3 to induce cytotoxicity in MCF-7 cells reflects the potential of these thin films for targeted drug delivery. The CPTFs were stable for 4 months at 4 °C/60% ± 2%RH and 25 °C/70% ± 2%RH. In conclusion, the thin film formulations showed target specific controlled and burst release properties and thus could prove to be effective for human breast cancer treatment.

2-[2-(1,3-Dioxoisoindolin-2-yl)acetamido]-acetic acid.

The title mol-ecule, C(12)H(10)N(2)O(5), is non-planar with dihedral angles of 89.08 (7) and 83.21 (7)° between the phthalimide and acetamide mean planes, and the acetamide and acetic acid mean planes, respectively. In the crystal, symmetry-related mol-ecules are linked via N-H⋯O and O-H⋯O hydrogen bonds, forming an undulating two-dimensional network. There are also a number of weak C-H⋯O inter-actions, leading to the formation of a three-dimensional arrangement.

Pt-Ni@PC900 Hybrid Derived from Layered-Structure Cd-MOF for Fuel Cell ORR Activity.

Fuel cell technology is the supreme alternate option for the replacement of fossil fuel in the current era. Pt alloys can perform well as fuel cell electrodes for being used as catalytic materials to perform the very notorious oxygen reduction reaction. In this regard, first, a layered metal-organic framework with empirical formula [C8H10CdO7] n ·4H2O is synthesized and characterized using various experimental and theoretical techniques. Then, a nanostructured porous carbon material with a sheet morphology (PC900) having a high BET surface area of 877 m2 g-1 is fabricated by an inert-atmosphere thermal treatment of the framework upon heating up to 900 °C. Pt and Ni nanoparticles are embedded into PC900 to prepare a homogenized hybrid functional material, i.e., Pt-Ni@PC900. The Pt-Ni@PC900 hybrid is proved to be an excellent ORR catalyst in terms of half-wave potential and limiting current density with 7% Pt loading compared with the commercially available 20% Pt/C catalyst. Pt-Ni@PC900 also shows stability of current up to 12 h with only a very small variation in current. This work highlights the importance of Pt alloys in future large-scale commercial applications of fuel cells.

Targeted drug delivery systems: synthesis and in vitro bioactivity and apoptosis studies of gemcitabine-carbon dot conjugates.

Gemcitabine (GEM) is used to treat various cancers such as breast, pancreatic, non-small lung, ovarian, bladder, and cervical cancers. GEM, however, has the problem of non-selectivity. Water-soluble, fluorescent, and mono-dispersed carbon dots (CDs) were fabricated by ultrasonication of sucrose. The CDs were further conjugated with GEM through amide linkage. The physical and morphological properties of these carbon dot-gemcitabine (CD-GEM) conjugates were determined using different analytical techniques. In vitro cytotoxicity and apoptosis studies of CD-GEM conjugates were evaluated by various bioactivity assays on human cell lines, MCF-7 (human breast adenocarcinoma), and HeLa (cervical cancer) cell lines. The results of kinetic studies have shown a maximum drug loading efficacy of 17.0 mg of GEM per 50.0 mg of CDs. The CDs were found biocompatible, and the CD-GEM conjugates exhibited excellent bioactivity and exerted potent cytotoxicity against tumor cells with an IC50 value of 19.50 µg ml-1 in HeLa cells, which is lower than the IC50 value of pure GEM (∼20.10 µg ml-1). In vitro studies on CD-GEM conjugates demonstrated the potential to replace the conventional administration of GEM. CD-GEM conjugates are more stable, have a higher aqueous solubility, and are more cytotoxic as compared to GEM alone. The CD-GEM conjugates show reduced side effects in the normal cells along with excellent cellular uptake. Hence, CD-GEM conjugates are more selective toward cancerous cell lines as compared to non-cancerous cells. Also, the CD-GEM conjugates successfully induced early and late apoptosis in cancer cell lines and might be effective and safe to use for in vivo applications.

Design, Synthesis, and Targeted Delivery of Fluorescent 1,2,4-Triazole-Peptide Conjugates to Pediatric Brain Tumor Cells.

Most of the chemotherapeutics and drug-delivery models pose serious health problems and several undesirable side effects due to nonspecificity, lack of proper targeting system, and their large sizes. The rational design and synthesis of target-specific chemotherapeutics are highly important. This research work is focused on the rational design, synthesis, and anticancer studies of fluorescent 1,2,4-triazole-peptide conjugates for the development of target-specific anticancer drugs. Three novel 1,2,4-triazole derivatives: 4-(4-fluorobenzylidenamino)-3-hydrazino-5-mercapto-1,2,4-triazole (4FBAHMT, 2a), 4-(3,4,5-trimethoxybenzylidenamino)-3-hydrazino-5-mercapto-1,2,4-triazole (TMOBAHMT, 2b), and 4-(4-benzyloxy-2-methyloxbenzylidenamino)-3-hydrazino-5-mercapto-1,2,4-triazole (4BO2MOBAHMT, 2c) were synthesized after screening through molecular docking procedures. The docking studies were performed between ligand molecules and αvß6 integrin protein. Fluorescent carbon nanoparticles (CNPs, 3) were conjugated with 1,2,4-triazole derivatives (2a-c) and l-carnosine (LC) dipeptide to get their corresponding conjugates (4a-c). The title double conjugates were characterized by spectroscopic (UV/vis spectroscopy, fluorescence spectroscopy, and FTIR spectroscopy) and microscopic (scanning electron microscopy, transmission electron microscopy, and atomic force microscopy) techniques. In vitro efficacy of fluorescent 1,2,4-triazole-peptide conjugates was investigated against two pediatric brain tumor cell lines (CHLA-200 & SJGBM2) and human embryonic kidney cell line (HEK293 as a control) by employing cell proliferation assay/MTS assay and fluorescence microscopy. 1,2,4-Triazole derivatives and their conjugates showed potent and selective anticancer activity against CHLA-200 and SJGBM2 cell lines. Cell proliferation assay and fluorescence microscopy results revealed that conjugates were more highly selective and cytotoxic than control drug temozolomide (TM) against both cell lines. CNPs are highly biocompatible and the quantum-sized conjugates were nontoxic for normal embryonic kidney cell line (HEK 293). The experimental results of MTS bioactivity assay and fluorescence microscopy were in close agreement with the theoretical results of molecular docking studies.

2-(4-Amino-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-3-ylmeth-yl)isoindoline-1,3-dione.

The title compound, C(11)H(9)N(5)O(2)S, was synthesized from N-phthaloylglycine and thio-carbohydrazide by the fusion method. This is the first report of a triazole derivative of N-phthaloylglycine. The title compound exists in the thione form. The mol-ecule is non-planar, with a dihedral angle between the isoindoline ring system and the triazole ring system of 82.24 (5)°. The crystal structure is stabilized by inter-molecular hydrogen bonding linking the mol-ecules into a three-dimensional network.

2-Propyl-4H-thia-zolo[3,2-a][1,3,5]triazine-4-thione.

In the title compound, C(8)H(9)N(3)S(2), the n-propyl chain is disordered over two orientations (site-occupancy ratio = 0.522:0.478) and is roughly perpendicular to the fused thia-zolotriazine system. The angle between the fused ring and the propyl chain is 83.6 (1)° [ 82.2 (1)° for the disordered chain]. The structure is stabilized by C-H⋯N hydrogen bonds.

Ethyl 4-(3-benzoyl-thio-ureido)benzoate.

The title compound, C(17)H(16)N(2)O(3)S, crystallizes in the thio-amide form with an intra-molecular N-H⋯O hydrogen bond across the thio-urea system. Mol-ecules are connected in chains parallel to [10] by hydrogen bonds from the second thio-urea N-H group to the benzoate C=O function.

N-(Thia-zol-2-yl)acetamide.

The title compound, C(5)H(6)N(2)OS, was synthesized from acetyl chloride and 2-amino-thia-zole in dry acetone. The asymmetric unit contains two mol-ecules. The crystal structure is stabilized by N-H⋯N and C-H⋯O hydrogen bonds.

1-(4-Acetyl-phen-yl)-3-butyrylthio-urea.

The title compound, C(13)H(16)N(2)O(2)S, crystallizes in the thio-amide form with an intra-molecular hydrogen bond of type N-H⋯O(butyr-yl). Mol-ecules are linked into chains parallel to [10] by a further hydrogen bond of type N-H⋯O(acet-yl). C-H⋯O and C-H⋯S hydrogen bonds are also present.

1-(1,3-Benzothia-zol-2-yl)-3-benzoyl-thio-urea.

The title compound, C(15)H(11)N(3)OS(2), was synthesized from benzoyl thio-cyanate and 2-amino-benzothia-zole in dry acetone. The thio-urea group is in the thio-amide form. The mol-ecules are stabilized by two inter-molecular C-H⋯S and C-H⋯O hydrogen bonds. Intra-molecular N-H⋯O hydrogen bonding results in a pseudo-S(6) planar ring with dihedral angles of 11.23 and 11.91° with the benzothiazole ring system and the phenyl ring, respectively.

Synthesis, characterization and in vitro evaluation of methotrexate conjugated fluorescent carbon nanoparticles as drug delivery system for human lung cancer targeting.

Nanotechnology based cancer therapeutics have rapidly advanced towards the solution of many limitations associated with other drug delivery agents such as nonspecific distribution within the body, low water solubility and non-biocompatibility. Carbon nanoparticles have demonstrated unique properties that are useful to combat with these issues, including their properties dependent on size, high stability in different solvents, compatible size for drug delivery and ease of surface modifications. Fluorescent carbon nanoparticles with good water solubility were obtained from a carbohydrate source by acid assisted ultrasonic treatment at 35kHz for 4h. This simple and economical method can be used for large scale production. Electron microscopic, spectroscopic and thermo gravimetric analysis techniques were used to characterize these carbon nanoparticles. Functionalized CNPs were further conjugated with anticancer drug-methotrexate and used as fluorescent nano-carriers. In this research work, we determined the in vitro bioactivity of CNPs-methotrexate conjugates by lactate dehydrogenase assay, cell adhesion assay and sulforhodamine B assay in human lung carcinoma cell line (H157). The CNPs showed promising biocompatibility and CNPs-MTX conjugates demonstrated potent cytotoxic effects and high anticancer activities in human lung cancer cell line.