Muhammad Mansha

Sonochemical assisted hydrothermal synthesis of pseudo-flower shaped Bismuth vanadate (BiVO4) and their solar-driven water splitting application

Bismuth vanadate (BiVO4) is a well-known photocatalyst due to its lower bandgap (Eg) and visible electromagnetic light absorption capacity. Herein, we reported the pulse ultra-sonochemical assisted hydrothermal approach to synthesize S-BiVO4. For the comparison purpose, H-BiVO4 is also synthesized via conventional hydrothermal approach. The surface morphology of S-BiVO4 through scanning electron microscope (SEM) indicates condensed microarrays (MAs) having pseudo-flower shapes. The energy dispersive X-rays (EDX) spectrum also confirmed the elemental percent composition of Bi, V and O in BiVO4. X-rays diffraction (XRD) pattern further confirmed the monoclinic scheelite phase of S-BiVO4. Fourier transformed infrared (FTIR) spectrum showed Bi-O and Bi-V-O vibrational bands at 1382 and 1630cm-1, respectively. The diffuse reflectance spectroscopy (DRS) indicated absorption edge at ∼515nm, corresponds to bandgap value (Eg) of 2.41eV, which is suitable range for water splitting applications. The photocurrent density from water splitting under artificial 1 SUN visible light source found at 60 and 50μA/cm2 for S-BiVO4 and H-BiVO4, respectively. The stability test through chronoamperometry showed that S-BiVO4 was more stable than H-BiVO4. It can be depicted from the growth mechanism that ultrasonication played a definite role in the overall synthesis of pseudo-flower shaped S-BiVO4 MAs.

Membrane protected micro-solid-phase extraction of organochlorine pesticides in milk samples using zinc oxide incorporated carbon foam as sorbent

In this work, zinc oxide nanoparticles incorporated carbon foam was utilized as sorbent for extraction and preconcentration of fifteen organochlorine pesticides in milk samples. The sorbent was prepared by a fast and single step reaction between the sucrose and zinc nitrate that was accomplished by heating the mixture for 10min. The resulting sorbent was characterized by scanning electron microscopy and X-ray diffraction. The sorbent was then employed in membrane protected micro-solid-phase extraction (μ-SPE) of OCPs in milk samples. This extraction technique is suitable for complex matrices such as milk because it provides effective protection of the sorbent inside the polypropylene membrane. The extracted samples were analyzed by gas chromatography mass spectrometry. The factors that affect the performance of μ-SPE were optimized. This method provided good linear range for all target compounds with coefficient of determinations up to 0.9998. Limits of detection ranged from 0.19 to 1.64ngmL-1. This method also provided satisfactory values for intra and inter-day precision with RSDs ranging between 2.3 to 10.2%.

Protein Geranylgeranyltransferase Type 1 as a Target in Cancer

The process of protein prenylation involves the covalent linkage of either farnesyl (15-carbon) or geranylgeranyl (20-carbon) isoprenoid lipds to conserved cysteine residues in the carboxyl-terminus of proteins. Protein geranylgeranyltransferase I (GGTase-I) is the enzyme that catalyzes the addition of the geranylgeranyl moiety from geranylgeranyl pyrophosphate to the target protein, which contains a Cterminal consensus sequence termed a CaaX motif. Geranylgeranylation is important to the function of a number of proteins, including the majority of Rho GTPases, G protein gamma subunits, and several other regulatory proteins. Studies over the past two decades have revealed that many of these proteins contribute to tumor development and metastasis. Blocking Rho GTPase activity through inhibition of GGTase-I in particular has been advanced as a potential strategy for disease therapy. This review will provide an overview of the CaaX prenyltransferases, the rationale for targeting GGTase-I in cancer in particular, and the current status of GGTase-I inhibitor (GGTI) development.

Synthesis, structures and photoluminescence properties of mixed ligand divalent metal–organic frameworks

Three new metal–organic frameworks [Co2(bmip)(bdc)2]·2DMF (1), [Cu(bmip)(bdc)]·6H2O (2) and [Zn2(bmip)(bdc)2(H2O)2] (3) have been prepared using a solvothermal process, derived from a flexible N,N′-donor spacer 1,3-bis(2-methylimidazolyl)propane (bmip) and 1,4-benzenedicarboxylic acid (H2bdc) ligands. Whereas compound 1 shows a three-dimensional (3D) framework, exhibiting a pcuα-Po network topology, compound 2 displays a two-dimensional (2D) network structure lying parallel to the plane (1 1 −1) and shows a dia topology. The 2D layers in 2 are further linked by hydrogen bonding that involves water solvate molecules, which in turn results in an infinite 3D hydrogen bonded framework. Compound 3 on the other hand shows a three-dimensional (3D) complicated framework with zigzag chains having a ThSi2 topology. The structural features of 1–3 display diverse variations from 3D, 2D and 3D frameworks, respectively, that are entirely different for each transition metal [Co(II), Cu(II), and Zn(II)] with the same combination of mixed ligands under similar reaction conditions. The physical and chemical properties of 1–3 were investigated by single crystal X-ray diffraction, elemental analysis, FTIR spectroscopy (FTIR), thermogravimetric analysis (TGA) and photoluminescence properties.

Microwave-Assisted Claisen Rearrangement: Synthesis of Naturally Occurring TRAIL-Resistance-Overcoming Tyrosine Derivative

Abstract Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a tumor necrosis factor (TNF) family ligand that binds on the death receptors, DR4 and DR5, activating apoptotic pathways selectively in cancer cells and thus has become a promising cancer therapeutic agent. Compound 1, isolated from Streptomyces sp. IFM 10937, has shown activity in overcoming TRAIL resistance in AGS cells. Synthesis of 1 has been accomplished from L-tyrosine in an overall high-yielding reaction sequence. GRAPHICAL ABSTRACT

The first total synthesis of potent antitumoral (±)-mafaicheenamine A, unnatural 6-fluoromafaicheenamine A and expedient synthesis of clausine E

The first total synthesis of potent antitumoral mafaicheenamine A (1) and its unnatural analogue, 6-fluoromafaicheenamine A (2) have been accomplished. An expedient synthesis of clausine E, a key intermediate in the course of synthesis of 1 and 2, was achieved in three steps from commercially available methyl 4-amino-3-(benzyloxy)benzoate (10) by copper-catalyzed N-arylation with aryllead triacetate, followed by cyclodehydrogenation of the resultant diarylamine under palladium(II) acetate catalysis. Moreover, palladium-catalyzed O-prenylation of clausine E and subsequent o-Claisen rearrangement under microwave irradiation rendered the advanced intermediate, C-prenylated phenol, which was eventually subjected to oxidative cyclization to construct the dihydroisocoumarin unit, leading to the synthesis of 1 and 2 in 12% and 15% overall yield, respectively, from 10.

Crystal structures of 1-aryl-4-(biarylmethylene)piperazine and piperidine, structurally related to adoprazine

Abstract8-(1-([1,1′-Biphenyl]-4-ylmethyl)piperidin-4-yl)-3,4-dihydroquinolin-2(1H)-one (1) and 8-(4-([1,1′- biphenyl]-4-ylmethyl)piperazin-1-yl)quinolin-2(1H)-one (2) are prepared in the crystalline state and studied by X-ray diffraction. The crystal packing drawing of compound (1) indicates that individual molecules are linked by pairs of N–H∙∙∙O hydrogen bonds forming A–A and B–B inversion dimers, with R22 (8) ring motifs. These dimers are stabilized by N–H∙∙∙O hydrogen bonds and linked via C–H∙∙∙O short contact interactions forming a two-dimensional network. In the case of compound (2), there are two independent molecules A and B linked by pairs of N–H∙∙∙O hydrogen bonds forming A–A and B–B inversion dimers, with R22 (8) ring motifs. These dimers are stabilized by N–H∙∙∙O hydrogen bonds and linked via C–H∙∙∙O short contact interactions forming a two-dimensional network.

Synthesis of structural analogues of GGT1-DU40, a potent GGTase-1 inhibitor

Abstract A series of new substituted pyrazoles 2–12 have been synthesized. The synthesized compounds are structural analogues of GGT1-DU40 1, a highly potent and selective inhibitor of protein geranylgeranyltransferase I (GGTase-I) both in vitro and in vivo. The implications of GGTase-I in oncogenesis have highlighted its potential as a cancer therapeutic target. Accordingly, the development of GGTase-I inhibitors has been a subject of much interest. The synthesis of 2–12 stemmed from the acetylation or acylation of N-function of amino acids to produce suitably modified amino acids. Meanwhile, the substituted pyrazole subunit originated from the reaction of ethyl nicotinate with γ-butyrolactone followed by condensation of the resultant β-keto lactone with (3,4-dichlorophenyl)hydrazine. The operations of O-alkylation and thioetherification on the resultant intermediate eventually produced the substituted pyrazole fragment. The amidation of the latter with amino acid derivatives finally rendered 2–12 in good to excellent yields.

Crystal structures of dual dopamine D2 and serotonin 5-HT1A active arylpiperidinyl-2(1H)-3,4-dihydroquinolinones

Abstract8-(1-((5-Cyclopentenylpyridin-3-yl)methyl)piperidin-4-yl)-3,4-dihydroquinolin-2(1H)-one (1) and 8-(1-(3- cyclopentenylbenzyl)piperidin-4-yl)-3,4-dihydroquinolin-2(1H)-one (2) are synthesized and obtained in the crystalline state for X-ray diffraction studies. In the asymmetric unit of compound 1, there are two independent molecules (A and B) having similar conformations. In the crystals of compounds 1 and 2, individual molecules are linked by pairs of N–H•••O hydrogen bonds forming A–A and B–B inversion dimers with R22 (8) ring motifs. The dimers are stabilized by N–H•••O hydrogen bonds and are linked via C–H•••O short contact interactions, forming a three-dimensional and two-dimensional networks in 1 and 2 respectively. The network in 2 is further stabilized by a number of C–H•••π interactions. Compounds 1 and 2 have a dual dopamine D2 and serotonin 5-HT1A receptor profile.