4',9,9'-Trihydroxy-3'-methoxy-3,7'-epoxy-4,8'-oxyneolignan

Crystal structure of 2,2''-bis-(2,7-di-chloro-9-hy-droxy-9H-fluoren-9-yl)-1,1':4',1''-terphenyl tri-ethyl-amine trisolvate.[Pubmed:26870400]

Acta Crystallogr E Crystallogr Commun. 2015 Nov 4;71(Pt 12):1439-43.

In the title solvate, C44H26Cl4O2.3C6H15N, the asymmetric part of the unit cell comprises two halves of the diol mol-ecules, 2,2''-bis-(2,7-di-chloro-9-hy-droxy-9H-fluoren-9-yl)-1,1':4',1''-terphenyl, and three mol-ecules of tri-ethyl-amine, i. e. the diol mol-ecules are located on crystallographic symmetry centres. Two of the solvent mol-ecules are disordered over two positions [occupancy ratios of 0.567 (3):0.433 (3) and 0.503 (3):0.497 (3)]. In the diol mol-ecules, the outer rings of the 1,1':4',1''-terphenyl elements are twisted with reference to their central arene ring and the mean planes of the fluorenyl moieties are inclined with respect to the terphenyl ring to which they are connected, the latter making dihedral angles of 82.05 (8) and 82.28 (8) degrees . The presence of two 9-fluoren-9-ol units attached at positions 2 and 2'' of the terphenyl moiety induces a 'folded' geometry which is stabilized by intra-molecular C-Hcdots, three dots, centeredO hydrogen bonds and pi-pi stacking inter-actions, the latter formed between the fluorenyl units and the central ring of the terphenyl unit [centroid-centroid distances = 3.559 (1) and 3.562 (1) A]. The crystal is composed of 1:2 complex units, in which the solvent mol-ecules are associated with the diol mol-ecules via O-Hcdots, three dots, centeredN hydrogen bonds, while the remaining solvent mol-ecule is linked to the host by a C-Hcdots, three dots, centeredN hydrogen bond. The given pattern of inter-molecular inter-actions results in formation of chain structures extending along [010].

Twist, tilt, and orientational order at the nematic to twist-bend nematic phase transition of 1'',9''-bis(4-cyanobiphenyl-4'-yl) nonane: A dielectric, (2)H NMR, and calorimetric study.[Pubmed:26764709]

Phys Rev E Stat Nonlin Soft Matter Phys. 2015 Dec;92(6):062505.

The nature of the nematic-nematic phase transition in the liquid crystal dimer 1'',9''-bis(4-cyanobiphenyl-4'-yl) nonane (CB9CB) has been investigated using techniques of calorimetry, dynamic dielectric response measurements, and (2)H NMR spectroscopy. The experimental results for CB9CB show that, like the shorter homologue CB7CB, the studied material exhibits a normal nematic phase, which on cooling undergoes a transition to the twist-bend nematic phase (N(TB)), a uniaxial nematic phase, promoted by the average bent molecular shape, in which the director tilts and precesses describing a conical helix. Modulated differential scanning calorimetry has been used to analyze the nature of the N(TB)-N phase transition, which is found to be weakly first order, but close to tricritical. Additionally broadband dielectric spectroscopy and (2)H magnetic resonance studies have revealed information on the structural characteristics of the recently discovered twist-bend nematic phase. Analysis of the dynamic dielectric response in both nematic phases has provided an estimate of the conical angle of the heliconical structure for the N(TB) phase. Capacitance measurements of the electric-field realignment of the director in initially planar aligned cells have yielded values for the splay and bend elastic constants in the high temperature nematic phase. The bend elastic constant is small and decreases with decreasing temperature as the twist-bend phase is approached. This behavior is expected theoretically and has been observed in materials that form the twist-bend nematic phase. (2)H NMR measurements characterize the chiral helical twist identified in the twist-bend nematic phase and also allow the determination of the temperature dependence of the conical angle and the orientational order parameter with respect to the director.

Spectroscopic and electrochemical behavior of newly synthesized high fluorescent symmetric 4'-nitrophenyl-3,4,9,10-perylenebisdiimide-azo hybrid dyes.[Pubmed:26125985]

Spectrochim Acta A Mol Biomol Spectrosc. 2015 Dec 5;151:72-9.

The investigation has been made in the synthesis of azo hybrid rylene dyes. The hybridization of perylene bis-diimide with phenolic azo-dyes was carried out by the nucleophilic substitution (SNAr) reaction of tetrachloroperylene-3,4,9,10-bisdiimide 3 with phenolic azo-dyes 4a-g in basic medium. The hybrid dyes exhibited two absorption maxima lambdamax in the range 300-350, 426-438 nm in ethanol due to presence of azo linkage and highly conjugated framework of pi bonds. Fluorescence spectra of these dyes in water showed sharp emission peaks with small bandwidths in the range 490-495 nm, and fluorescence quantum yield was 0.71-0.83 in comparison with standard reference fluorescein. The structures of perylene-azo dyes were elucidated by FTIR and NMR spectroscopy. Luminescence was determined by LS-100 meter which was found to be excellent in limits 0.208-0.239 cd/m(2). Cyclic voltammetric studies were made by Electrochemical Analyzer CH1830C which showed the oxidation chemical potential of these hybrid dyes.

Diethyl-4,4'-dihydroxy-8,3'-neolign-7,7'-dien-9,9'-dionate exhibits antihypertensive activity in rats through increase in intracellular cGMP level and blockade of calcium channels.[Pubmed:28159537]

Eur J Pharmacol. 2017 Mar 15;799:84-93.

We report here the antihypertensive and vasorelaxant potential of some steroidal and non-steroidal compounds identified through a library of compounds. All the novel analogues showed vasorelaxant potential in isolated rat aorta. The most potent lead neolignan1 (Diethyl-4,4'-dihydroxy-8,3'-neolign-7,7'-dien-9,9'-dionate) produced concentration dependent relaxation with [pD2 5.16+/-0.05; n=16 and Emax 96.97%+/-1.12%; n=16]. The neolignan1 relaxation is independent of endothelium and is sensitive to ODQ (1H-[1, 2, 4] oxadiazolo [4, 3-a] quinoxalin-1-one; a blocker of soluble guanylyl cyclase (sGC) which synthesizes cGMP (cyclic guanosine monophosphate)). ELISA analysis of treated arterial tissues showed concentration-dependent increase in cGMP level in treated tissues compared to control (2.03 and 7.16 fold of control at 10 and 30microM of neolignan1, respectively) and a synergistic increase in cGMP level by 26.66 fold compared to control when used in combination with sildenafil (10microM; a known inducer of cGMP level by selectively blocking cGMP specific phosphodiesterase 5). Our present study reports for the first time that neolignans produce relaxation in isolated rat aorta through increase in intracellular cGMP level. The ODQ resistant relaxation of neolignan1 is mediated by blockade of voltage dependent L-type calcium channel (VDCC) as observed in the experiment with CaCl2. Neolignan1 upon intravenous administration via tail vein in Spontaneously Hypertensive Rats (SHR) produced significant decrease in systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial blood pressure (MAP). The present study concludes that neolignan1 exhibited antihypertensive potential in rats through rise in intracellular cGMP and blockade of VDCC.