STEREO SELECTIVE SYNTHESIS OF NOVEL LIGNAN INTERMEDIATES AS ANTIMICROBIAL AGENTS

Objectives: The aim of the present study was to synthesize a series of new lignan intermediates as potential antimicrobial agents.Methods: Substituted benzene and aromatic acids or acid chlorides were converted to benzophenones 1(a-f). The benzophenones 1(a-f) on Stobbe condensation with and diethyl succinate in the presence of potassium t-butoxide yielded 4-(4-aryl)-4-(4-aryl)-3-ethoxycarbonyl-but-3-enoic acids (2a, 2f) and a mixture of E and Z-isomers of 4,4-diaryl-3-ethoxycarbonyl-but-3-enoic acids 2(b-e) and 3(b-e) in relatively good yields. The synthesized compounds were tested for their antimicrobial susceptibility against different fungi and bacteria species.Results: The Stobbe condensation of benzophenones 1(a-f) and diethyl succinate in the presence of potassium t-butoxide yielded 4-(4-aryl)-4-(4-aryl)-3-ethoxycarbonyl-but-3-enoic acids (2a, 2f) and a mixture of E and Z-isomers of 4,4-diaryl-3-ethoxycarbonyl-but-3-enoic acids 2(b-e) and 3(b-e) in good yields. The compounds 1a and 1f yielded only 2a and 2f but not 3a and 3f due to symmetrical substitution in the aromatic rings. The structures of the new lignan intermediates were confirmed by spectral studies and elemental analysis.Conclusions: Results of the antimicrobial activity reveal that some of the compounds particularly 2c, 2d, 3c and 3d act as potential antimicrobial agents different fungal and bacterial organisms.Â

Synthesis and antimicrobial activity of novel 1,3-oxazolidine nucleoside analogues

The synthesis of novel 1,3-oxazolidine pyrimidine nucleoside analogues are described. These analogues are all derived from the key stereochemically defined intermediate N-tert-butoxy-carbonyl-2-hydroxymethyl-1,3-oxazolidine-4-ol which was accessible in 57% yield. starting from L-serine methylester hydrochloride. The heterocyclic bases eg; uracil, thymine etc are efficiently introduced onto the 1,3-oxazolidine by the Vorbruggen procedures. The antimicrobial activity of novel 1,3-okazolidine nucleoside analogues are highlighted. The compounds 7d and 7e showed significant activity against bacteria and fungus

Synthesis in the field of podophyllotoxin and related analogues: Part X- Synthesis of indan analogue of tridemethoxy-β-apopicropodophyllin and ethyl-1-oxo-4-(3', 4', 5'-trimethoxyphenyl)-6, 7-trimethylene-1,2,3, 4-tetrahydro-3-naphthoate as an intermediate for indan analogue of β-apopicropodophyllin

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Synthesis and antimicrobial activity evaluation of poly ethylene imine (pei) dendrimer modified with 1,3,4 oxadiazole derivatives

Dendrimers have wide range of applications in industry, Pharmaceutical and medicine. Oxadiazole compounds also have many applications in Pharmaceutical and medicine. Modification of dendrimers which have many branches like NH2 functional groups with heterocyclic derivatives make them capable to show variety properties. In this article, PEI-dend-4N(Ts)(2-(methyl)-5-aryl-1,3,4 oxadiazole) ]] 8a-f have been synthesized from PEI (Poly ethylene imine) dendrimer which modified with 1,3,4 oxadiazole derivatives and investigated their antimicrobial activitie

The motion of the 2D hydrodynamic Chaplygin sleigh in the presence of circulation

We consider the motion of a planar rigid body in a potential flow with circulation and subject to a certain nonholonomic constraint. This model is related to the design of underwater vehicles. The equations of motion admit a reduction to a 2-dimensional nonlinear system, which is integrated explicitly. We show that the reduced system comprises both asymptotic and periodic dynamics separated by a critical value of the energy, and give a complete classification of types of the motion. Then we describe the whole variety of the trajectories of the body on the plane.Comment: 25 pages, 7 figures. This article uses some introductory material from arXiv:1109.321

Alternative Chelator for 89Zr Radiopharmaceuticals: Radiolabeling and Evaluation of 3,4,3-(LI-1,2-HOPO)

Zirconium-89 is an effective radionuclide for antibody-based positron emission tomography (PET) imaging because its physical half-life (78.41 h) matches the biological half-life of IgG antibodies. Desferrioxamine (DFO) is currently the preferred chelator for 89Zr4+; however, accumulation of 89Zr in the bones of mice suggests that 89Zr4+ is released from DFO in vivo. An improved chelator for 89Zr4+ could eliminate the release of osteophilic 89Zr4+ and lead to a safer PET tracer with reduced background radiation dose. Herein, we present an octadentate chelator 3,4,3-(LI-1,2-HOPO) (or HOPO) as a potentially superior alternative to DFO. The HOPO ligand formed a 1:1 Zr-HOPO complex that was evaluated experimentally and theoretically. The stability of 89Zr-HOPO matched or surpassed that of 89Zr-DFO in every experiment. In healthy mice, 89Zr-HOPO cleared the body rapidly with no signs of demetalation. Ultimately, HOPO has the potential to replace DFO as the chelator of choice for 89Zr-based PET imaging agents

The Dynamics of a Rigid Body in Potential Flow with Circulation

We consider the motion of a two-dimensional body of arbitrary shape in a planar irrotational, incompressible fluid with a given amount of circulation around the body. We derive the equations of motion for this system by performing symplectic reduction with respect to the group of volume-preserving diffeomorphisms and obtain the relevant Poisson structures after a further Poisson reduction with respect to the group of translations and rotations. In this way, we recover the equations of motion given for this system by Chaplygin and Lamb, and we give a geometric interpretation for the Kutta-Zhukowski force as a curvature-related effect. In addition, we show that the motion of a rigid body with circulation can be understood as a geodesic flow on a central extension of the special Euclidian group SE(2), and we relate the cocycle in the description of this central extension to a certain curvature tensor.Comment: 28 pages, 2 figures; v2: typos correcte

ZO-1 interactions with F-actin and occludin direct epithelial polarization and single lumen specification in 3D culture

Epithelia within tubular organs form and expand lumens. Failure of these processes can result in serious developmental anomalies. Although tight junction assembly is crucial to epithelial polarization, the contribution of specific tight junction proteins to lumenogenesis is undefined. Here, we show that ZO-1 (also known as TJP1) is necessary for the formation of single lumens. Epithelia lacking this tight junction scaffolding protein form cysts with multiple lumens and are defective in the earliest phases of polarization, both in two and three dimensions. Expression of ZO-1 domain-deletion mutants demonstrated that the actin-binding region and U5-GuK domain are crucial to single lumen development. For actin-binding region, but not U5-GuK domain, mutants, this could be overcome by strong polarization cues from the extracellular matrix. Analysis of the U5-GuK binding partners shroom2, α-catenin and occludin showed that only occludin deletion led to multi-lumen cysts. Like ZO-1-deficiency, occludin deletion led to mitotic spindle orientation defects. Single lumen formation required the occludin OCEL domain, which binds to ZO-1. We conclude that ZO-1–occludin interactions regulate multiple phases of epithelial polarization by providing cell-intrinsic signals that are required for single lumen formation

Identification of QTLs and candidate genes for high grain Fe and Zn concentration in sorghum [Sorghum bicolor (L.)Moench]

Sorghum is a major food crop in the semi-arid tropics of Africa and Asia. Enhancing the grain iron (Fe) and zinc (Zn) concentration in sorghum using genetic approaches would help alleviate micronutrient malnutrition in millions of poor people consuming sorghum as a staple food. To localize genomic regions associated with grain Fe and Zn, a sorghum F6 recombinant inbred line (RIL) population (342 lines derived from cross 296B PVK 801) was phenotyped in six environments, and genotyped with simple sequence repeat (SSR), DArT (Diversity Array Technology) and DArTSeq (Diversity Array Technology) markers. Highly significant genotype environment interactions were observed for both micronutrients. Grain Fe showed greater variation than Zn. A sorghum genetic map was constructed with 2088 markers (1148 DArTs, 927 DArTSeqs and 13 SSRs) covering 1355.52 cM with an average marker interval of 0.6 cM. Eleven QTLs (individual) and 3 QTLs (across) environments for Fe and Zn were identified. We identified putative candidate genes from the QTL interval of qfe7.1, qzn7.1, and qzn7.2 (across environments) located on SBI-07 involved in Fe and Zn metabolism. These were CYP71B34, and ZFP 8 (ZINC FINGER PROTEIN 8). After validation, the linked markers identified in this study can help in developing high grain Fe and Zn sorghum cultivars in sorghum improvement programs globally