Publications by authors named "Narsimha Reddy Penthala"

Chronic, low-grade inflammation has been implicated in aging and age-dependent conditions, including Alzheimer's disease, cardiomyopathy, and cancer. One of the age-associated processes underlying chronic inflammation is protein aggregation, which is implicated in neuroinflammation and a broad spectrum of neurodegenerative diseases such as Alzheimer's, Huntington's, and Parkinson's diseases. We screened a panel of bioactive thiadiazolidinones (TDZDs) from our in-house library for rescue of protein aggregation in human-cell and models of neurodegeneration.

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Glycogen synthase kinase-3β (GSK3β) controls many physiological pathways, and is implicated in many diseases including Alzheimer's and several cancers. GSK3β-mediated phosphorylation of target residues in microtubule-associated protein tau (MAPTAU) contributes to MAPTAU hyperphosphorylation and subsequent formation of neurofibrillary tangles. Inhibitors of GSK3β protect against Alzheimer's disease and are therapeutic for several cancers.

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A series of N-benzyl-7-azaindolequinuclidinone (7-AIQD) analogs have been synthesized and evaluated for affinity toward CB1 and CB2 cannabinoid receptors and identified as a novel class of cannabinoid receptor ligands. Structure-activity relationship (SAR) studies indicate that 7-AIQD analogs are dual CB1/CB2 receptor ligands exhibiting high potency with somewhat greater selectivity towards CB2 receptors compared to the previously reported indolequinuclidinone (IQD) analogs. Initial binding assays showed that 7-AIQD analogs 8b, 8d, 8f, 8g and 9b (1 μM) produced more that 50% displacement of the CB1/CB2 non-selective agonist CP-55,940 (0.

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The 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) oxidation of cellulose, when mediated with Oxone (KHSO), can be performed simply and under mild conditions. Furthermore, the products of the reaction can be isolated into two major components: Oxone-mediated TEMPO-oxidized cellulose nanomaterials Form I and Form II (OTO-CNM Form I and Form II). This study focuses on the characterization of the properties of OTO-CNMs.

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Age-progressive neurodegenerative pathologies, including Alzheimer's disease (AD), are distinguished and diagnosed by disease-specific components of intra- or extra-cellular aggregates. Increasing evidence suggests that neuroinflammation promotes protein aggregation, and is involved in the etiology of neurological diseases. We synthesized and tested analogs of the naturally occurring tubulin-binding compound, combretastatin A-4.

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Diagnosis of neurodegenerative diseases hinges on "seed" proteins detected in disease-specific aggregates. These inclusions contain diverse constituents, adhering through aberrant interactions that our prior data indicate are nonrandom. To define preferential protein-protein contacts mediating aggregate coalescence, we created click-chemistry reagents that cross-link neighboring proteins within human, APP-driven, neuroblastoma-cell aggregates.

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A series of novel tetrazole analogues of resveratrol were synthesized and evaluated for their anti-leukemic activity against an extensive panel of human cancer cell lines and against the MV4-11 AML cell line. These molecules were designed as drug-like derivatives of the resveratrol analogue DMU-212 and its cyano derivatives. Four compounds 8g, 8h, 10a and 10b exhibited LD values of 4.

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The aim of this study was to determine the uptake of intravenously administered N-[CH]-dimethylaminoparthenolide (DMAPT) into orthotopic 9LSF glioblastoma brain tumors in Fisher 344 rats from positron emission tomography (PET) imaging studies. [C]methyl iodide (CHI) was utilized as a [C]-labeling reagent to label the precursor methylaminoparthenolide (MAPT) intermediate. From PET imaging studies it was found that brain uptake of N-[CH]DMAPT into brain tumor tissue was rapid (30min), and considerably higher than that in the normal brain tissue.

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Dengue virus (DENV) causes a variety of difficult-to-treat diseases that threaten almost half of the world's population. Currently, no effective vaccine or antiviral therapy is available. We have examined a series of synthetic resveratrol analogs to identify potential anti-DENV agents.

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(Z)-5-[2-(Benzo[b]thio-phen-2-yl)-1-(3,5-di-meth-oxy-phen-yl)ethen-yl]-1H-tetrazole methanol monosolvate, C19H16N4O2S·CH3OH, (I), was prepared by the reaction of (Z)-3-(benzo[b]thio-phen-2-yl)-2-(3,5-di-meth-oxy-phen-yl)acrylo-nitrile with tri-butyl-tin azide via a [3 + 2]cyclo-addition azide condensation reaction. The structurally related compound (Z)-5-[2-(benzo[b]thio-phen-3-yl)-1-(3,4,5-tri-meth-oxy-phen-yl)ethen-yl]-1H-tetra-zole, C20H18N4O3S, (II), was prepared by the reaction of (Z)-3-(benzo[b]thio-phen-3-yl)-2-(3,4,5-tri-meth-oxy-phen-yl)acrylo-nitrile with tri-butyl-tin azide. Crystals of (I) have two mol-ecules in the asymmetric unit (Z' = 2), whereas crystals of (II) have Z' = 1.

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-Cyanocombretastatin A-4 (-CA-4) analogues have been structurally modified to afford their more stable CA-4-(2)-1,2,3-triazole analogues. Fifteen novel, stable 4-heteroaryl-5-aryl-(2)-1,2,3-triazole CA-4 analogues (, and ) were evaluated for anti-cancer activity against a panel of 60 human cancer cell lines. These analogues displayed potent cytotoxic activity against both hematological and solid tumor cell lines with GI values in the low nanomolar range.

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In the present study, we have designed and synthesized a series of 1-benzyl-2-methyl-3-indolylmethylene barbituric acid analogs (7a-7h) and 1-benzyl-2-methyl-3-indolylmethylene thiobarbituric acid analogs (7 i-7 l) as nucleophosmin 1 (NPM1) inhibitors and have evaluated them for their anti-cancer activity against a panel of 60 different human cancer cell lines. Among these analogs 7 i, 7 j, and 7 k demonstrated potent growth inhibitory effects in various cancer cell types with GI50 values <2 μM. Compound 7 k exhibited growth inhibitory effects on a sub-panel of six leukemia cell lines with GI50 values in the range 0.

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The title compounds, C26H28N2, (I), and C28H32N2, (II), were designed based on the structure of the potent α9α10 nicotinic acetyl-choline receptor antagonist ZZ161C {1,1'-[[1,1'-biphen-yl]-4,4'-diylbis(prop-2-yne-3,1-di-yl)]bis-(3,4-di-methyl-pyridin-1-ium) bromide}. In order to improve the druglikeness properties of ZZ161C for potential oral administration, the title compounds (I) and (II) were prepared by coupling 4,4'-bis-(3-bromo-prop-1-yn-1-yl)-1,1'-biphenyl with pyrrol-idine, (I), and (S)-2-methyl-pyrrolidine, (II), respectively, in aceto-nitrile at room temperature. The asymmetric unit of (I) contains two half mol-ecules that each sit on sites of crystallographic inversion.

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As part of a comprehensive program to discover α9α10 nicotinic acetyl-choline receptor antagonists, the title compounds C30H36N2, (I), and C36H48N2, (II), were synthesized by coupling 4,4'-bis-(3-bromo-prop-1-yn-1-yl)-1,1'-biphenyl with 4-methyl-piperidine and 2,2,6,6-tetra-methyl-piperidine, respectively, in aceto-nitrile at room temperature. In compound (I), the biphenyl system has a twisted conformation with a dihedral angle of 26.57 (6)° between the two phenyl rings of the biphenyl moiety, while in compound (II), the biphenyl moiety sits on a crystallographic inversion centre so the two phenyl rings are exactly coplanar.

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Novel carbamate (7a-7h) and carbonate (7i, 7j, and 8) dimers of melampomagnolide B have been synthesized by reaction of the melampomagnolide-B-triazole carbamate synthon 6 with various terminal diamino- and dihydroxyalkanes. Dimeric carbamate products 7b, 7c, and 7f exhibited potent growth inhibition (GI50 = 0.16-0.

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Heteroaromatic analogs of DMU-212 (8-15) have been synthesized and evaluated for their anti-cancer activity against a panel of 60 human cancer cell lines. These novel analogs contain a trans-3,4,5-trimethoxystyryl moiety attached to the C2 position of indole, benzofuran, benzothiazole or benzothiophene ring (8, 11, 13 and 14, respectively) and showed potent growth inhibition in 85% of the cancer cell lines examined, with GI50 values <1 μM. Interestingly, trans-3,4- and trans-3,5-dimethoxystyryl DMU-212 analogs 9, 10, 12 and 15 exhibited significantly less growth inhibition than their 3,4,5-trimethoxystyryl counterparts, suggesting that the trans-3,4,5-trimethoxystyryl moiety is an essential structural element for the potent anti-cancer activity of these heterocyclic DMU-212 analogs.

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A series of heterocyclic combretastatin analogues have been synthesized and evaluated for their anticancer activity against a panel of 60 human cancer cell lines. The most potent compounds were two 3,4,5-trimethoxy phenyl analogues containing either an (Z)-indol-2-yl (8) or (Z)-benzo[b]furan-2-yl (12) moiety; these compounds exhibited GI50 values of <10 nM against 74% and 70%, respectively, of the human cancer cell lines in the 60-cell panel. Compounds 8, and 12 and two previously reported compounds in the same structural class, i.

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The title compound, C19H17N3O3S (I), was prepared by a [3 + 2]cyclo-addition azide condensation reaction using sodium azide and l-proline as a Lewis base catalyst. N-Methyl-ation of compound (I) using CH3I gave compound (II), C20H19N3O3S. The benzo-thio-phene ring systems in (I) and (II) are almost planar, with r.

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The title compound, C20H23N3O6·CH3OH, was synthesized by [3 + 2] cyclo-addition of (Z)-2,3-bis-(3,4,5-tri-meth-oxy-phen-yl)acrylo-nitrile with sodium azide and ammonium chloride in DMF/water. The central nitro-gen of the triazole ring is protonated. The dihedral angles between the triazole ring and the 3,4,5-tri-meth-oxy-phenyl ring planes are 34.

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The title compound, C33H35NO6 [systematic name: (Z)-3-(4-{(E)-[(E)-1a,5-dimethyl-9-oxo-2,3,7,7a-tetra-hydro-oxireno[2',3':9,10]cyclo-deca-[1,2-b]furan-8(1aH,6H,9H,10aH,10bH)-yl-idene]meth-yl}phen-yl)-2-(3,4,5-tri-meth-oxy-phen-yl)acrylo-ni-trile methanol hemisolvate], C33H35NO6·0.5CH3OH, was prepared by the reaction of (Z)-3-(4-iodo-phen-yl)-2-(3,4,5-tri-meth-oxy-phen-yl)acrylo-nitrile with parthenolide [systematic name: (E)-1a,5-dimethyl-8-methyl-ene-2,3,6,7,7a,8,10a,10b-octa-hy-dro-oxireno[2',3':9,10]cyclo-deca-[1,2-b]furan-9(1aH)-one] under Heck reaction conditions. The mol-ecule is built up from fused ten-, five- (lactone) and three-membered (epoxide) rings with a {4-[(Z)-2-cyano-2-(3,4,5-tri-meth-oxy-phen-yl)ethen-yl]phen-yl}methyl-idene group as a substituent.

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Use of a novel reagent has been established for the synthesis of a series of 4,5-diaryl-2-1,2,3-triazoles ( and ) from cyanostilbene analogs of benzo[]thiophene, benzo[]furan and indole, catalyzed by L-proline via Lewis base-catalyzed one-step [3+2]cycloaddition of azide. This method provides an efficient, simple and environmentally benign procedure that affords good yields and relatively short reaction times.

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Melampomagnolide B (MMB) is a natural sesquiterpene structurally related to parthenolide (PTL). We have shown that MMB exhibits anti-leukemic properties similar to PTL. Unlike PTL, the presence of a primary hydroxyl group in the MMB molecule allows the opportunity for examining the biological activity of a variety of conjugated analogs of MMB.

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THE TITLE MONOSUCCINATE DERIVATIVE OF MELAMPOMAGNOLIDE B [SYSTEMATIC NAME: 4-(((1aR,7aS,10aS,10bS,E)-1a-methyl-8-meth-yl-ene-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-deca-hydro-oxireno[2',3':9,10]cyclo-deca-[1,2-b]furan-5-yl)meth-oxy)-4-oxo-butan-oic acid], C19H24O7, was obtained from the reaction of melampomagnolide B with succinic anhydride under nucleophilic addition reaction conditions. The mol-ecule is built up from fused ten-, five- (lactone) and three-membered (epoxide) rings. The inter-nal double bond in the ten-membered ring has the cis geometry (i.

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The title compound, C21H23BrO3 [systematic name: (3E,3aS,6Z,9R,9aS,9bS)-3-(2-bromo-benzyl-idene)-9-hy-droxy-6,9-dimethyl-3,3a,4,5,7,8,9,9a-octa-hydro-azuleno[4,5-b]furan-2(9bH)-one] was prepared by the reaction of 1-bromo-2-iodo-benzene with micheliolide [systematic name: (3aS,R,9aS,9bS,Z)-9-hy-droxy-6,9-dimethyl-3-methyl-ene-3,3a,4,5,7,8,9,9a-octa-hydro-azuleno[4,5-b]furan-2(9bH)-one] under Heck reaction conditions. The title compound exhibits intra-molecular O-H⋯O hydrogen bonding between the hy-droxy group and the lactone ring O atom, forming a ring of graph-set motif S(6). The 2-bromo-phenyl group is trans to the lactone ring, indicating that this is the E isomer (geometry of the exocyclic C=C bond).

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Aminoparthenolide derivatives have been prepared by reaction of parthenolide with various heterocyclic amines to afford corresponding Michael addition products. These novel compounds were evaluated for their modulatory effects on Xenopus oocyte maturation. Two compounds, 6e and 6f, were identified that promote G2-M cell cycle progression.

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