3-hydroxypropyl Groups Research Articles

1,2-Disubstituted ferrocenyl water-soluble selenoether and telluroether ligands and their palladium (II) complexes: CV and variable temperature NMR studies

The 1,2 disubstituted ferrocenylated unsymmetrical potentially tridentate selenoether and telluroether ligands, containing Oxygen and Nitrogen at the other donor sites and their respective palladium complexes were synthesized. The molecular structures of all the palladium complexes were determined by X-ray crystallography which confirms that these ligands coordinate in a bidentate fashion. The structures show intramolecular and intermolecular interactions type E···E, E···O, CH···Cl, and E···Cl interactions (E = Se or Te). Interestingly chalcogenoether ligands containing the 3-hydroxy propyl group and their palladium complexes are soluble in water and 1H NMR spectra of these ligands do not show OH proton signal at room temperature but at low temperature broad deshielded proton signal confirms the involvement of –OH group in secondary interactions with Se or Te atom as an intramolecular chalcogen bonding. The cyclic voltammograms of selenoether and their complexes present single reversible and quasi reversible waves while telluroether ligands present three quasi reversible processes and their complexes show three nonreversible redox processes.

Tetra- and dinuclear manganese complexes of xanthene-bridged O,N,O-Schiff bases with 3-hydroxypropyl or 2-hydroxybenzyl groups: ligand substitution at a triply bridging site

Complexation properties of U-shaped ligands, L1 and L2, which are Schiff bases of 5,5'-(9,9-dimethylxanthene-4,5-diyl)bis(salicylaldehyde) (H2xansal) with 3-amino-1-propanol or 2-hydroxybenzylamine, respectively, were investigated to construct polynuclear manganese complexes. In these ligands, two O,N,O-Schiff bases are bridged by a xanthene backbone. The reactions of H4L1 or H4L2 with manganese salts afforded tetra- and dinuclear manganese complexes, including the tetramanganese(ii,ii,iii,iii) complex [Mn4(L1)2(μ-OAc)2] with a Mn4O6 core exhibiting an incomplete double-cubane structure. In the Mn4O6 core, phenolate and alkoxide O atoms bridge the manganese ions. Deprotonated 3-hydroxypropyl groups were crucial to the assembly of four manganese ions because the phenolate-bridged dimanganese(iii,iii) complex [Mn2(H2L1)2]2+ was obtained in the absence of a base, and H4L2, which has 2-hydroxybenzyl groups instead of 3-hydroxypropyl groups in H4L1, afforded the cyclic dimanganese(iv,iv) complex [Mn2(L2)2]. We disclosed that [Mn4(L1)2(μ-OAc)2] was converted to the oxo-bridged tetramanganese(iii,iii,iii,iii) complex [Mn4(L1)(HL1)(μ3-O)(μ-OAc)2]+ by treating with NH4PF6 or NH4BF4: a triply bridging alkoxide was protonated and replaced by an oxide ligand. The cyclic voltammograms of [Mn4(L1)(HL1)(μ3-O)(μ-OAc)2]+ suggested that the reverse reaction forming [Mn4(L1)2(μ-OAc)2] occurred in the electrochemical processes and was assisted by protonation.

Polyurethane composites based on silsesquioxane derivatives of different structures

A series of siloxane–silsesquioxane resins with Q8 structures, as network nodes containing reactive Si–H groups in the siloxane backbone, connecting silsesquioxane moieties, were prepared in a hydrolytic condensation process and successfully functionalized by hydrosilylation of allyl alcohol. The proposed material being an alternative to the well-defined silsesquioxanes has been characterized and used for preparation of a series of polyurethane (PU)-based composites by simple reaction of 3-hydroxypropyl groups of siloxane–silsesquioxane resin with 1,6-diisocyanatohexane and subsequently with 1,6-hexanediol to get polyurethane composite. A series of composites based on PU and octakis(3-hydroxypropyldimethylsiloxy)octasilsesquioxane were prepared in the same manner to investigate the influence of the filler amount (1, 3 or 5%) and its structure on thermal properties of the obtained materials.

Antiviral and Cytotoxic Isocoumarin Derivatives from an Endophytic Fungus Aspergillus oryzae.

Oryzaeins A-D (1-4), four new isocoumarin derivatives, along with five known ones (5-9) were isolated from solid cultures of an endophytic fungus Aspergillus oryzae. Their structures were elucidated by detailed spectroscopic analysis and by comparison with reported data of related derivatives. Among them, compounds 1 and 2 represent the first examples of isocoumarins possessing an unusual 2-oxopropyl group and a rare 3-hydroxypropyl group. Compounds 1 and 2 displayed moderate anti-tobacco mosaic virus activities with inhibition rates of 28.4% and 30.6%, respectively, at the concentration of 20 µM. The new compounds showed moderate inhibitory activities against several human tumor cell lines with IC50 values in the range of 2.8-8.8 µM. Supporting information available online at http://www.thieme-connect.de/products.

Substitution at carbon 2 of 19-nor-1α,25-dihydroxyvitamin D 3 with 3-hydroxypropyl group generates an analogue with enhanced chemotherapeutic potency in PC-3 prostate cancer cells

The active form of vitamin D 3, 1α,25-dihydroxyvitamin D 3(1α,25(OH) 2D 3), has anti-proliferative and anti-invasive activities in prostate cancer cells. Because of 1α,25(OH) 2D 3 therapeutic potential in treating cancers, numerous analogues have been synthesized with an attempt to increase anti-proliferative and/or decrease calcemic properties. Among these analogues, 19-nor-1α,25(OH) 2D 2 while being less calcemic has equivalent potency as 1α,25(OH) 2D 3 in several in vitro and in vivo systems. We recently showed that 19-nor-2α-(3-hydroxypropyl)-1α,25(OH) 2D 3 (MART-10) was at least 500-fold and 10-fold more active than 1α,25(OH) 2D 3 in inhibiting the proliferation of an immortalized normal prostate PZ-HPV-7 cells and the invasion of androgen insensitive PC-3 prostate cancer cells, respectively. In this study, we further investigated the effects of MART-10 and 1α,25(OH) 2D 3 on the dose- and time-dependent induction of CYP24A1 gene expression in PC-3 prostate cancer cells. We found that MART-10 induced CYP24A1 gene expression at a lower concentration with a longer duration compared to 1α,25(OH) 2D 3, suggesting that MART-10 is less susceptible to CYP24A1 degradation. Molecular docking model of human CYP24A1 and MART-10 indicates that its side chain is far away from the heme ion and is less likely to be hydroxylated by the enzyme. Furthermore, MART-10 was a more potent inhibitor of PC-3 cell proliferation and invasion compared to 1α,25(OH) 2D 3. In addition, MART-10 down-regulated matrix metalloproteinase-9 (MMP-9) expression which could be one mechanism whereby MART-10 influences cancer cell invasion. Finally, we observed that subcutaneous administration of MART-10 up-regulated the CYP24A1 mRNA expression in rat kidneys without affecting their plasma calcium levels. Thus, our findings demonstrate that MART-10 is biologically active in vivo and may be an effective vitamin D analogue for clinical trials to treat prostate cancer.

Synthesis of quadruped-shaped polyfunctionalized o-carborane synthons

o-Carborane derivatives with precisely defined patterns of substitution have been prepared from 8,9,10,12-I(4)-1,2-closo-C(2)B(10)H(8) by replacing the iodine atoms, bonded to four adjacent boron vertices in the cluster, with allyl, and subsequently 3-hydroxypropyl groups. The resulting structures, comprising four pendant arms and two reactive vertices located on opposite sides of a central o-carborane core, can be envisaged as versatile precursors for dendritic growth.

Self-aggregation of synthetic zinc-chlorophylls possessing an interactive w-hydroxyalkyl group

Zinc-chlorins possessing 2-hydroxyethyl (Zn-EtOH-Chl) or 3-hydroxypropyl groups (Zn-PrOH-Chl) at the 3-position were synthesized as model compounds of self-aggregative chlorophylls in light-harvesting antenna complex (chlorosome) of green bacteria. Their self-aggregation behavior was examined in nonpolar solution and compared with that of zinc-chlorin possessing hydroxymethyl group (Zn-MeOH-Chl), which is a good model for chlorosomal chlorophylls. Effect of covalent linkage between the interactive hydroxy group and chlorin moiety on the self-assembly was investigated. In 1%THF-hexane, Zn-EtOH-Chl formed self-aggregates having Qy absorption maxima at 704 nm, of which red-shifted value from the corresponding monomeric band at 644 nm in THF was smaller than that of Zn-MeOH-Chl (644® 740 nm). The aggregated Zn-EtOH-Chl gave specific CD signals characteristic of self-aggregates, which were weaker than those of aggregated Zn-MeOH-Chl. These results indicate that Zn-EtOH-Chl excitonically coupled in the aggregates more weakly than Zn-MeOH-Chl did. IR spectra of the solid aggregates of Zn-EtOH-Chl showed that three interactive sites (32-OH, Zn, 13-C=O) formed intermolecular C=O···H?O···Zn bonding as Zn-MeOH-Chl did. Therefore, change of 3-CH2OH to 3-CH2CH2OH does not disturb C=O···H?O···Zn bonding but disturbs close p-p interaction between chlorin chromophores in their aggregation. On the contrary, Zn-PrOH-Chl possessing 3-CH2CH2CH2OH gave no red-shifted absorption and specific CD signals even in 1%THF-hexane. Moreover, IR spectra of the solid aggregates of Zn-PrOH-Chl showed lack of the C=O···H?O···Zn bonding. Therefore, insertion of a methylene group to the 3-31 bond of Zn-EtOH-Chl disturbs C=O···H?O···Zn bonding as well as tight p-p interaction.

ChemInform Abstract: Stereoselective Synthesis of α- and β-C-Glucosides via Radical Cyclization with an Allylsilyl Tether. Control of the Stereoselectivity by Changing the Conformation of the Pyranose Ring.

Abstract An efficient method for preparing both 1α- and 1β-C-glucosides having a 3-hydroxypropyl group at the anomeric position via a radical cyclization reaction with an allylsilyl tether was developed. The stereoselectivity of the radical cyclization can be controlled by the conformation of the pyranose ring, which is effectively manipulated by the hyroxyl protecting groups.

Stereoselective synthesis of α- and β- C-glucosides via radical cyclization with an allylsilyl tether. Control of the stereoselectivity by changing the conformation of the pyranose ring

An efficient method for preparing both 1α- and 1β- C-glucosides having a 3-hydroxypropyl group at the anomeric position via a radical cyclization reaction with an allylsilyl tether was developed. The stereoselectivity of the radical cyclization can be controlled by the conformation of the pyranose ring, which is effectively manipulated by the hyroxyl protecting groups.

Renin inhibitors. I. Synthesis and structure-activity relationships of transition-state inhibitors containing homostatine analogues at the scissile bond.

The synthesis and structure-activity relationships of transition-state renin inhibitors containing the homostatine analogues at the scissile bond are described. These inhibitors incorporate the amino acid side chains corresponding to positions 7-12 (P4-P2') of angiotensinogen. Ethyl, 2-hydroxyethyl and 3-hydroxypropyl groups at position 2 of the homostatine analogues (P1') are more effective for increasing potency than the isopropyl group. A combination of residues at P1, P3 and P4 is important for potency and this result suggests that S1, S3 and S4 form a huge hydrophobic core together in renin.

Synthese d'oligomeres de polydimethylsiloxane reticulables—partie I. introduction de groupements acryliques sur des polydimethylsiloxanes possedant des groupements 3-hydroxypropyle

We describe the synthesis of polydimethylsiloxane with 3-hydroxypropyl groups in the chain or at the ends by copolycondensation of 3-acetoxypropyl methyl dichlorosilane with various α, ω-disilanols. The length of the chain was controlled by addition of vinyl or 3-acetoxy propyl monochloro dimethyl silane. Methacryoyl chloride was then grafted to give a polyunsaturated product. These oligomers were crosslinked by u.v. with reactive diluents and photoinitiators to give products with very good “release properties” especially with the longer siloxane chains.

Conformational studies of copoly (N 5-ω-hydroxyalkyl-L-glutamine-L-glutamic acid)s

Copoly (α-amino acid)s consisting ofL-glutamic acid residue andN5-ω hydroxyalkyl-L-glutamine residue, i.e., 2-hydroxyethyl, 3-hydroxypropyl, and di-2-hydroxyethyl derivatives were prepared by the reactions of copoly (L-glutamic acid) containing succinimide ester with corresponding amino alcohols. The conformation of these copolymers was examined by the CD and infrared measurements. These three copolymers containing about 20–30% hydroxyalkyl groups undergo a methanol-induced and a pH-induced conformational transitions. The copolymer containing about 50% 3-hydroxypropyl group assumes the α-helical conformation in the pH region from 2.5 to 11.6, and in a methanol-water mixture (9∶1). On the other hand, the copolymer containing about 60% di-2-hydroxyethyl groups does not allow any helical conformation even at lower pH and also even in a trifluoroethanol-water mixture (9∶1), suggesting that the branched hydroxyalkyl group is unfavorable for the formation of α-helix. Furthermore, the poly(N5-di-2-hydroxyethyl-L-glutamine) is shown to have a rather disordered structure in the solid state.