Top PDF Synthetic and structural studies of permethylscandocene and permethyltantalocene derivatives

Synthetic and structural studies of permethylscandocene and permethyltantalocene derivatives

Synthetic and structural studies of permethylscandocene and permethyltantalocene derivatives

Perhaps the best known is insertion of CO into the metal carbon bond, with coordination of 0 to the metal center to give an 112 acyl complex.s This coordination mode activates the CO tow[r]

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Synthetic studies on R207910, aza-Diospongin A and hydroxylamine derivatives

Synthetic studies on R207910, aza-Diospongin A and hydroxylamine derivatives

Nature has been the rich source of bioactive natural products and has laid basis for drug leads and new medicines since pre-historical era. Nearly half of the currently used drugs are of natural product origin derived either directly or designed based on pharmacophore. However the structural complexity, paucity, side effects of, these pharmacologically active natural compounds has set limitations to use them as drug candidates. Thus modification of bioactive natural products to structurally similar synthetic analogues with minimum molecular complexity while retaining pharmacological activity and reduced side effects has gained importance over time. In this context we chose to prepare aza-analogue of diospongin-A (1a).
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Synthetic, structural, and spectroscopic studies of sterically crowded tin chalcogen acenaphthenes

Synthetic, structural, and spectroscopic studies of sterically crowded tin chalcogen acenaphthenes

In the series of triphenyltin derivatives 1-4, the bulk of the ar- omatic rings coupled with the presence of the additional intramo- lecular Sn···E interaction forces the central tin atom to adopt a distorted tetrahedral geometry. C–Sn–C angles lie in the range 99.64(14)°-120.86(15)° and for each tin centre the three pseudo- equatorial C-Sn-C bond angles sum to 341-346° (Table 5), inter- mediate between an ideal tetrahedron (328.5°) and a perfect trigo- nal bipyramid (360°). The increased strength of the Sn-E interac- tion in 5-9 causes even greater distortion to the naturally tetrahe- dral tin environment, with the sum of the pseudo-equatorial C-Sn- C angles increasing to between 353-357°, more in line with a trigonal bipyramidal geometry (Table 5). This is supported by looking at the geometrical goodness [∆∑(θ) = ∆∑(θ eq ) - ∆∑(θ ax );
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Therapeutic journey of synthetic betacarboline derivatives:  A short review

Therapeutic journey of synthetic betacarboline derivatives: A short review

Quantitative structure–activity relationship (QSAR) studies have been performed on β- carboline derivatives to explore the structural necessities for antitumor activity. 3D QSAR studies were done using V-Life Sciences MDS 3.0 drug designing module to explain the structural requirements for the anti-tumor activity. The 3D- QSAR was performed using the Step Wise K Nearest Neighbour Molecular Field Analysis [(SW) kNN MFA] technique with the partial least-square (PLS) method on a database. Obtained best 3D- QSAR model having high predictive ability with q 2 = 0.743, r 2 = 0.721, pred_r 2 = 0.708 and standard error = 0.346, explaining the majority of the variance in the data with partial least square (PLS) components. The results of the present study may be useful on the designing of more potent compounds as antitumor drugs.
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A NEW HETEROMETALLIC [ALIII-BU2SNIV-BIII ]-Μ-OXOISOPROPOXIDE AND ITS DERIVATIVES WITH Β-DIKETONES: SYNTHETIC, SPECTRAL AND ELEMENTAL STUDIES

A NEW HETEROMETALLIC [ALIII-BU2SNIV-BIII ]-Μ-OXOISOPROPOXIDE AND ITS DERIVATIVES WITH Β-DIKETONES: SYNTHETIC, SPECTRAL AND ELEMENTAL STUDIES

The elucidation of structural features and reactivity patterns of polymetallic alkoxides has aroused deep scientific interest, because the complexes have been used as precursors for super or semi- conducting, ferroelectric, dielectric and even biocompatible oxide materials [1,2] . Further, the mixed metal oxides prepared from heterometallic-μ-oxoalkoxides [3-6] have been used for absorbing harmful chemicals [7] and gases such as SO 2, CCl 4 , and decontaminating chemical warfare agents [8] . Recently,

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Synthetic Resveratrol Derivatives and Their Biological Activities: A Review

Synthetic Resveratrol Derivatives and Their Biological Activities: A Review

Some reports had found that resveratrol could interfere in the nuclear factor (NF)- κ B signaling pathway, which regulates the expression of various genes involved in cancer and inflammation [7] [25] [26]. Some studies also indicated that the anticancer effect of resveratrol was mediated by inhibiting key proteins in signal transduction pathways such as mitogen-activated protein kinases, activator protein-1 (AP-1), and NF- κ B [3]. Resveratrol could also affect cell-cycle regulation and apoptosis [27]. The mentioned results suggested that resveratrol could be developed to be an effective cancer chemoprevention and therapeutics agent. Owing to resveratrol’s ex- tremely poor bioavailability, many scientists have applied themselves to searching for novel resveratrol deriva- tives with high efficiency, low toxicity, and minimum side effects. Herein, some studies of the structural mod- ifications were given to help understand the structure-activity relationships (SAR) of its anticancer activity better.
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STRUCTURAL STUDIES ON LAMELLARIN ALKALOIDS, TOTAL SYNTHESIS OF PURPURAMINE-K AND DEVELOPMENT OF NOVEL SYNTHETIC METHODOLOGIES.

STRUCTURAL STUDIES ON LAMELLARIN ALKALOIDS, TOTAL SYNTHESIS OF PURPURAMINE-K AND DEVELOPMENT OF NOVEL SYNTHETIC METHODOLOGIES.

The aza Diels-Alder reactions are becoming a mainstray for the synthesis of heterocycles and natural products, as they provide a rapid means of construction of functionalized heterocyclic rings with control of regio-, diasterio-, and enantio selectivity. Pyrano quinoline derivatives have been found to possess a wide spectrum of biological actions such as psychotropic, anti-allergic, anti-inflammatory and estrogenic activities. Tetrahydro quinoline ring systems are widely distributed in nature, and are an important class of compounds in the field of pharmaceuticals.
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STRUCTURAL DOCKING STUDIES AND BIOLOGICAL EVALUATION OF SOME NEWLY SYNTHESIZED SCHIFF BASE DERIVED QUINAZOLINONE DERIVATIVES

STRUCTURAL DOCKING STUDIES AND BIOLOGICAL EVALUATION OF SOME NEWLY SYNTHESIZED SCHIFF BASE DERIVED QUINAZOLINONE DERIVATIVES

Chemistry: Present work described the synthesis of nine analogous of 2,3-diaryl-3H-quinazolin-4- ones (6-14) and the synthetic strategy adopted for the synthesis of target compounds is outlined in Scheme 1. Benzoxazinones (4a-4c) were prepared from commercially available anthranilic acid and its treatment with differently substituted benzoyl chloride (3a, 3b, 3c). 3-Amino-2-phenyl- quinazolinones (5a-5c) were synthesized from various benzoxazinones by treatment with hydrazine hydrate in anhydrous pyridine. Final target compounds (6-14) were prepared from 3- amino-2-phenylquinazolinones (5a-5c), by adding different substituted acetophenones in acidic medium. Progress of the reaction was monitored by TLC using chloroform: methanol (9:1) as mobile phase. The structures of the newly synthesized compounds were confirmed by IR, NMR and mass spectral analysis followed by their physicochemical properties determination.
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Synthetic and structural studies of 1 halo 8 (alkylchalcogeno)naphthalene derivatives

Synthetic and structural studies of 1 halo 8 (alkylchalcogeno)naphthalene derivatives

intramolecular I···S(phenyl) peri-distance [4 3.338(11) Å] is noticeably longer than for the S(ethyl) derivative [2 3.2436(17) Å], but still shorter than the sum of van der Waals radii by 0.44 Å. [24] The peri-atoms essentially lie on the naphthyl plane in 4, with only a minor displacement observed [-0.07 Å & 0.05 Å]. Naphthalene skeletons for the two derivatives show similar deviations from planarity with central naphthalene ring torsion angles ca. 2-3º. I-C [2.12 Å] and S-C [1.77 Å] bond lengths in 4 are within the usual ranges [2.10, 1.77 ± 0.05 Å]. [28] Although intermolecular short contacts exist, there is no significant overlap of phenyl or naphthalene rings and no π-stacking in the molecular structure of 4.
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3-D structural interactions and quantitative structural toxicity studies of tyrosine derivatives intended for safe potent inflammation treatment

3-D structural interactions and quantitative structural toxicity studies of tyrosine derivatives intended for safe potent inflammation treatment

The hERG is the most critical channel involved in drug induced Torsade de Pointes (TdP) arrhythmias. Extra cellular application of celecoxib causes rapid suppres- sion of hERG channels which induces the cardiac dis- turbances [19]. Evaluation of spatial orientation of the designed molecule interactions with the hERG protein recognizes the cardiotoxicity level of molecules [20]. The results of docking studies indicated that among the 55 designed molecules, 52 molecules possessed more inter- action energy against the standard (Table 5). It revealed that these molecules are having less binding affinity to the active site residues of the hERG protein. In standard celecoxib, the benzyl ring creates π-π interaction with the Tyr 652 (Fig.  9). This enables the celecoxib to fit well
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Studies of synthetic chalcone derivatives as potential inhibitors of secretory phospholipase A2, cyclooxygenases, lipoxygenase and pro-inflammatory cytokines

Studies of synthetic chalcone derivatives as potential inhibitors of secretory phospholipase A2, cyclooxygenases, lipoxygenase and pro-inflammatory cytokines

Abstract: Arachidonic acid metabolism leads to the generation of key lipid mediators which play a fundamental role during inflammation. The inhibition of enzymes involved in arachidonic acid metabolism has been considered as a synergistic anti-inflammatory effect with enhanced spectrum of activity. A series of 1,3-diphenyl-2-propen-1-one derivatives were investigated for anti-inflammatory related activities involving inhibition of secretory phospholipase A 2 , cyclooxy- genases, soybean lipoxygenase, and lipopolysaccharides-induced secretion of interleukin-6 and tumor necrosis factor-alpha in mouse RAW264.7 macrophages. The results from the above mentioned assays exhibited that the synthesized compounds were effective inhibitors of pro- inflammatory enzymes and cytokines. The results also revealed that the chalcone derivatives with 4-methlyamino ethanol substitution seem to be significant for inhibition of enzymes and cytokines. Molecular docking experiments were carried out to elucidate the molecular aspects of the observed inhibitory activities of the investigated compounds. Present findings increase the possibility that these chalcone derivatives might serve as a beneficial starting point for the design and development of improved anti-inflammatory agents.
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Reactions of Oxygen Containing Ligands in the Coordination Sphere of Permethylhafnocene and Permethyltantalocene

Reactions of Oxygen Containing Ligands in the Coordination Sphere of Permethylhafnocene and Permethyltantalocene

Examples of organometallic species containing both oxo and alkyl ligands on the metal are more prevalent than species with olefin and oxo ligands.29 However, none of the examples yet rep[r]

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Synthetic and Structural Studies of Some Bivalent Transition Metal Complexes with Oxygen and Nitrogen Containing Schiff Base

Synthetic and Structural Studies of Some Bivalent Transition Metal Complexes with Oxygen and Nitrogen Containing Schiff Base

The present studies show that the ligand AEQS behaves as neutral tridentate chelating ligand and coordination proposes through amine nitrogen, imine nitrogen and Carbonyl oxygen atom of semicarbozone moiety. Thus on the basis of above mentioned studies it is proposed that the complexes of Co(II) and Ni(II) have octahedral geometry where as distorted octahedral geometry is recorded for Cu(II) complexes [Fig-1].

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Synthetic studies towards virantmycin

Synthetic studies towards virantmycin

One of the established methods for the conversion of aromatic aldehydes into the corresponding arylacetic acids is by acid treatment of the derived ketene dithioacetal 5-oxide ( l) .1 In the course of a synthetic study we needed to carry out such a transformation on the aldehyde (2). Reaction between (2) and MeSCHiSOMe, catalysed by Triton B .1 gave (3) as desired (58%, m.p. 160— 162 °C) but treatment of (3) with aqueous acid under a range of conditions failed to yield the desired acid (4). However, when (3) was stirred in dichloromethane containing 10 m HCl, two major products were isolated, to
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Synthetic studies of Microcolin B

Synthetic studies of Microcolin B

Both compounds contain the pyrrolin-2-one unit which makes them biologically active in nature. We report herein the synthesis of the octanoyl derivatice (11) of the acylated microcolin B. The most challenging steps of the synthesis are the addition of and mem protected cyclic acid compound with pyrrolinone moiety followed by removal of mem by Ticl4, and acetylation of this moiety, because of low yields.Three of the stereo centres of microcolins are still to be determined. The stereo center at the C-5 in the pyrrolidinone group and stereochemistry in the 2,4- dimethyl octanoic acid were not assigned in the synthesis work. In the majusculamides pyrrolinone moiety was declared as “S” configuration based on the degradation studies.
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In the credit derivatives arena, synthetic funding structures

In the credit derivatives arena, synthetic funding structures

The rapid expansion of the credit derivatives market has occurred during a period that has seen market corrections, large-scale market defaults and subsequent improving cred- it fundamentals. As more and more reference names, struc- tured finance and high-yield instruments are traded syn- thetically, we can expect to see more frequent application of these products by banks and other financial institutions for balance sheet management purposes. ■

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Synthetic, spectroscopic and structural studies of chalcogen peri substituted heterocycles : a solid state NMR perspective

Synthetic, spectroscopic and structural studies of chalcogen peri substituted heterocycles : a solid state NMR perspective

1.4 The use of J coupling to study weak interactions X-ray diffraction is usually used in peri-substituted systems to determine the presence or otherwise of weak interactions between the peri-atoms, by measuring the peri-distance. Although bond lengths, molecular conformations and interatomic distances offer some information on weak interactions, these indirect structural parameters are not very sensitive probes of electronic interactions. In contrast, NMR spectroscopy offers an extremely sensitive probe of the local, atomic-scale environment, through both the chemical shift and the indirect J coupling between two spins. The magnitude of the J coupling typically decreases as the number of bonds that connect two atoms increases, and coupling through more than four bonds is often too small to be observed. 16 However, significant J couplings
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Antioxidant activities of two novel synthetic methylbenzenediol derivatives 

Antioxidant activities of two novel synthetic methylbenzenediol derivatives 

Khairullina V.R., Kirlan S.A., Gerchikov A.Y., Tyurina L.A., Garifullina G.G., Monakov Y.B., Kirlan A.V. (2006). Computer-assisted prediction of antioxidant activi- ties and toxicities of ionol, 5-hydroxy-6-methyluracil, and their derivatives. Russian Chemical Bulletin, 55: 1322–1327. Li J.Y., Wang T., Wu H., Ho C.T., Weng X.C. (2006a): 1,1-Di- (2’,5’-dihydroxy-4’-tert-butylphenyl)ethane:anovel antioxi- dant. Journal of Food Lipids, 13: 331–340.

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Synthetic Studies and Antibacterial Activity of Nucleobases and their N- and S-Glucosidesfrom 2-Amino Benzoic Acid and its Benzamido Derivatives

Synthetic Studies and Antibacterial Activity of Nucleobases and their N- and S-Glucosidesfrom 2-Amino Benzoic Acid and its Benzamido Derivatives

From Table 1, it is shown that almost all synthetic nucleobases 7(a,b)-10(a,b) and glycoside 12a exhibited various effect on the representative bacteria. It seemed that it is difficult to generalize whether there are differences in activity between the aminophenylene nucleobases 7a-10a and their benzamido derivatives 7b-10b. There are only some cases where the effect exceeded the positive reference amykacine as in oxadiazole 7a on G(-) E.coli , activity of thiadiazole 8a upon G(+) B. cereus and activity of all tested nucleobases 7(a,b)-10(a,b) on G(-)P. aeraginosa. 5-(2’-Aminophenylene)-1,3,4- thiadiazole-2-S-glucoside (12a) exhibited a moderate effect upon G(+) S. aureus and G(-) E. coli ,while its
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Studies on the structural characteristics of various complexes formed with amino acid derivatives and the cu (ii)   ninhydrin reagent

Studies on the structural characteristics of various complexes formed with amino acid derivatives and the cu (ii) ninhydrin reagent

Ninhydrin was acquired from Pierce (Rockford, IL, USA). Cupric nitrate was of BDH, Analytical grade (Mumbai, India). Organic solvents and acids used were of highest purity available. Aluminium foil coated readymade TLC sheets were obtained from Anchrom, Mumbai. Whatman no.1 filter paper discs were obtained from Whatman International Limited, Maidstone, England. Spectral studies were carried out at the Central research laboratory of PSG Colle

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