Author: Hans-peter Deigner

0000000001308603

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Hans-peter Deigner

Complement C6 deficiency protects against diet-induced atherosclerosis in rabbits.

Abstract —Low-density lipoprotein (LDL) can be transformed to an atherogenic moiety by nonoxidative, enzymatic degradation. Enzymatically degraded LDL induces macrophage foam cell formation, provokes release of cytokines, and also activates complement. To determine whether complement activation may contribute to atherogenesis, 6 pairs of homozygous C6-deficient rabbits and their non–C6-deficient heterozygous siblings were fed a cholesterol-rich diet for 14 weeks. Cholesterol levels and plasma lipoprotein profiles of the animals in the C6-competent and C6-deficient groups did not significantly differ, and the high density lipoprotein and LDL cholesterol ratios at the end of the experiment w…

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1-(Pyridin-4-yl)-3-(2,4,6-trichlorophenyl)benz[4,5]imidazo[1,2-d][1,2,4]triazin-4(3H)-one

In the title compound, C20H10Cl3N5O, the 13-membered ring system makes dihedral angles of 78.64 (9)° with the trichlorophenyl ring and 62.60 (10)° with the pyridine ring. The crystal packing is dominated by π–π interactions between the 13-membered ring systems [centroid–centroid distance = 3.6655 (11)°].

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Crystal structures of pure 3-(4-bromo-2-chlorophenyl)-1-(pyridin-4-yl)benzo[4,5]imidazo[1,2-d][1,2,4]triazin-4(3H)-one and contaminated with 3-(4-bromophenyl)-1-(pyridin-4-yl)benzo[4,5]imidazo[1,2-d][1,2,4]triazin-4(3H)-one

The side product of the cyclocondensation reaction between ethyl benzimidazole-2-carboxylate and the nitrile imine of the corresponding hydrazonyl chloride, C20H11BrClN5O, crystallized in two crystal forms. Form (1) is a co-crystal of the target compound (without any chlorine substituent) and a side product containing a Cl atom in position 2 of the bromophenyl group, C20H12BrN5O·0.143C20H11BrClN5O. (2) contains the pure side product. The slightly different conformation of the ring systems leads to a different packing of (1) and (2), but both crystal structures are dominated by p-p interactions.

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Efficient Synthesis and X-ray Structure of [1,2,4]Triazolo[4,3-a]pyridines via Oxidative Cyclization Using N-Chlorosuccinimide (NCS)

Triazolopyridines are a family of compounds that, owing to their biological activity, have many pharmaceutical applications. In this study, 3-(pyridine-4-yl)-[1,2,4]triazolo[4,3-a]pyridine and 6-bromo-3-(pyridine-4-yl)-[1,2,4]triazolo[4,3-a]pyridine were synthesized by using the chlorinated agent NCS for hydrazones under very mild conditions. The characterization of these compounds was achieved by 1H NMR, 13C NMR, FTIR, MS and X-ray diffraction. The compound 3-(pyridine-4-yl)-[1,2,4]triazolo[4,3-a]pyridine was crystallized in the monoclinic space group P 21/c with a = 15.1413(12), b = 6.9179(4), c = 13.0938(8) Å, β = 105.102(6)°, V = 1324.16(16)Å3, Z = 4, and R = 0.0337. Also compound 6-bro…

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3-(2,4-Difluorophenyl)-1-(pyridin-4-yl)benzo[4,5]imidazo[1,2-d][1,2,4]triazin-4(3H)-one

In the title compound, C20H11F2N5O, the central 13-membered ring system (r.m.s. deviation = 0.028 Å) makes a dihedral angle of 53.13 (7)° with the difluorophenyl ring and 79.98 (7)° with the pyridine ring. The crystal packing features aromatic π–π interactions between the 13-membered rings [shortest distance between ring centroids = 3.5682 (8) Å].

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Design, Synthesis and Biological Evaluation of Novel Pyrazolo[1,2,4]triazolopyrimidine Derivatives as Potential Anticancer Agents

Three novel pyrazolo-[4,3-e][1,2,4]triazolopyrimidine derivatives (1, 2, and 3) were designed, synthesized, and evaluated for their in vitro biological activity. All three compounds exhibited different levels of cytotoxicity against cervical and breast cancer cell lines. However, compound 1 showed the best antiproliferative activity against all tested tumor cell lines, including HCC1937 and HeLa cells, which express high levels of wild-type epidermal growth factor receptor (EGFR). Western blot analyses demonstrated that compound 1 inhibited the activation of EGFR, protein kinase B (Akt), and extracellular signal-regulated kinase (Erk)1/2 in breast and cervical cancer cells at concentrations…

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