Kiramat Shah

Novel fluorene-based supramolecular sensor for selective detection of amoxicillin in water and blood

Synthesis, characterization and molecular recognition properties of fluorene based supramolecular cleft 1 is reported. The cleft molecule 1 was prepared in a single-step with good yield (85% yield), by linking Fluorene with 1-ethyl piperazine. The cleft molecule 1 was carefully characterized using various spectroscopic techniques such as NMR and mass spectrometry. The supramolecular interaction of cleft 1 with amoxicillin, 6APA, aspirin, captopril, cefotaxime, ceftriaxone, cefuroxime, diclofenac, penicillin, and cephradine was evaluated by fluorescent spectroscopy. The molecular recognition studies showed that amoxicillin selectively binds with cleft 1 in the presence of other drugs. The analytical method developed for the supramolecular interaction of molecular cleft 1 and amoxicillin was validated at varying pH, concentration and temperature during recognition process. Jobs plots indicated that the stochiometry of the interactions between the cleft 1 and the amoxicillin was 1:1.

Triazole-based highly selective supramolecular sensor for the detection of diclofenac in real samples.

A triazole-based supramolecular chemosensor 6 for the selective spectrophotometric detection of diclofenac in human plasma and tap water was developed. The 6 was synthesized through click approach and characterized via UV-vis spectroscopy, FT-IR, Mass and NMR spectroscopy. The supramolecular interaction of compound 6 with commonly used drugs has been investigated with the help of UV-vis spectral titrations, FT-IR and (1)H, (13)C NMR spectroscopy. The UV-visible spectral changes upon addition of various commonly used drugs showed that compound 6 is highly selective for diclofenac over other drugs. The supramolecule 6 exhibited a selective enhancement in the absorbance intensity after mixing with diclofenac in human plasma and water samples in the presence of other drugs at pH 6-7, with a linear range of 0.938 (R(2)=0.938) and a limit of detection 10µM. The relative standard deviation (RSD) for 100µM diclofenac was found to be 0.462. The Jobs plot analysis revealed that diclofenac bind to compound 6 in 1:1 stoichiometry.

Sterically stabilized fluorescent silver nanoconjugates for optical discrimination of Cu(II) in real samples and in vitro bioimaging of the Cu(II) scavenging process in human lymphocytes by atomic force microscopy

Highly fluorescent sterically stabilized silver nanoparticles (Cf-AgNPs) have been prepared by a facile thermochemical method in a single step and with excellent long-term stability. The method involves reduction of silver nitrate to Ag via carbonyl groups of the β-lactam ring and the amide of cefaclor. The materials have been characterized by fluorescence and absorption spectroscopy, atomic force microscopy, FT-IR spectroscopy, 1H NMR and MALDI-TOF-MS. The luminescence arises from small metal clusters (i.e., Ag2, Ag3 and Ag4), which is efficiently quenched by the paramagnetic quencher Cu(II). The Cf-AgNPs allowed us to detect Cu(II) in the range of 0.8 to 3.3 µM with a detection limit of 0.282 µM. Moreover, Cu(II) was selectively recognized in human blood plasma by Cf-AgNPs. We have also evaluated the cytotoxicity of Cf-AgNPs and explored their scavenging potential against Cu(II) in B and T lymphocytes with the help of AFM.

Di-tert-butyl 2,2'-[9H-fluorene-9,9-diylbis(p-phenyl-ene-oxy)]diacetate.

In the title molecule, C37H38O6, the non-fused C atom belonging to the five-membered ring of the fluorene system is connected to two p-phenylene rings, the rings opening up the Caryl–C—Caryl angle to 113.1 (1)°. The four-atom –O–CH2–C(=O)–O– chain between the p-phenylene ring and the tert-butyl group assumes a more regular W-shaped conformation for one substituent [O—C—C—C torsion angle = 171.9 (2)°] but a less regular W-shaped conformation for the other [torsion angle = 147.4 (2)°].

9,9-Bis[4-(prop-2-yn-yloxy)phen-yl]-9H-fluorene.

In the title compound, C31H22O2, the bond angle at the C atom belonging to the five-membered ring of the fluorene system is opened to 112.64 (12)°. The two benzene rings are twisted with respect to the fluorene ring system at dihedral angles of 72.81 (6) and 81.83 (6)°. One Caryl—O—C—C fragment is extended, with a C—O—C—C torsion angle of −178.77 (13)°, but the other Caryl—O—C—C fragment is bent, with a C—O—C—C torsion angle of 64.78 (19)°. Intermolecular weak C—H⋯O hydrogen bonding is present in the crystal structure.

Unprecedented chemosensing behavior of novel tetra-substituted benzimidazole zinc(II) phthalocynine for selective detection of Bi 3 + ion: Synthesis, characterization and ROS generation

In this work, synthesis of novel symmetrical 4-(2-bromo-4-(5-bromo-1H-benzo[d] imidazol-2-yl) phenoxy) tetra substituted zinc phthalocyanine has been reported. The novel benzimidazole zinc phthlocynine compound (3) has been characterized by MALDI-TOF MS, FT-IR, UV-vis, and 1H NMR spectroscopy. This new compound 3 displayed excellent selectivity towards Bi3+ ion in the presence of other competitive ions including Ca2+, Cd2+, Co2+ Cu2+, Fe3+, Hg2+, Sn2+, Mg2+, Na+, Ni2+ and Pb2+ respectively. Upon addition of Bi3+ into the solution of compound 3 in DMSO, dramatic change was observed in the Q- and the B-bands in UV-visible spectra as a result of donor acceptor interactions. Reactive oxygen species (ROS) were also studied using 2,7-dichlorofluorescin diacetate (DCFH-DA) a fluorescent probe which is converted to highly fluorescent dichlorofluorescein (DCF) in the presence of ROS. This property of non-aggregating zinc phthalocyanine is promising as a photosensitizer in photodynamic therapy of cancer.

4,4'-Bis[(E)-(2,3-diiodo-prop-2-en-1-yl)-oxy]biphen-yl.

Iodine adds across both triple bonds of 4,4′-bis(prop-2-ynyloxy)biphenyl, yielding the 4,4′-bis(2,3-diiodoallyloxy)biphenyl title compound, C18H14I4O2; the 2,3-diiodoallyoxy substituents have the I atoms in an E configuration. In the biphenyl portion of the molecule, the aromatic rings are inclined by 37.8 (2)°.

Synthesis and characterization of triazole based supramolecule for interaction with cefuroxime in tap water and blood plasma

In this study a new calix[4]arene triazole 5 was successfully synthesized using click reaction and characterized through UV-visible, FT-IR, 1H NMR spectroscopes and Mass Spectrometry. The supramolecular interaction of compound 5 towards commonly used drugs has been carried out using UV-Visible spectroscopy. The supramolecule 5 showed characteristic enhancement in the absorbance intensity after mixing with Cefuroxime at pH (2-12). Compound 5 displayed considerably good interactions with cefuroxime in the presence of other drugs. Compound 5 exhibits linear relationship with cefuroxime concentration in the range of (10-80µM) with regression value of 0.9954. The standard deviation for 50µM Cefuroxime was found to be 0.01 and the limit of detection for cefuroxime was calculated to be 2µM. Jobs plot experiments showed 1:1 (5: cefuroxime) binding stoichiometry between compound 5 and cefuroxime. Supramolecule 5 displayed fairly good spectrophotometric recognition of Cefuroxime in human blood plasma and tap water thus showing that the ingredients of tap water and plasma sample was inert in the recognition of cefuroxime.

Synthesis of Diamides and Diimines Derived from 4,4′-(1,3-Phenylenebis(oxy))dianiline, Units for Symmetrical Macrocycles

4,4′-(1,3-Phenylenebis(oxy))dianiline 1 is an aromatic diamine compound and has been very less utilized in the organic synthesis. Different diimines and diamides were synthesized by reacting compound 1 with aromatic and heterocyclic compounds having different functionalities. These longer electron rich spacer molecules were synthesized to utilize them in the near future in making macrocycles of different sizes and functionalities. A hydrazide was also prepared from a diamide spacer molecule containing ester group. A diamide prepared containing nibrobenzene moiety was further reduced to amine to obtain longer spacer diamine molecule than the starting molecule 1.

1,4-Bis{4-[bis-(prop-2-yn-1-yl)amino]-phen-oxy}benzene.

The asymmetric unit of the title compound, C30H24N2O2, contains two independent molecules, which both lie on centers of inversion. The central phenylene ring is inclined at 61.4 (2)° with respect to the flanking aromatic ring [dihedral angle = 70.7 (3)° in the second molecule].