- Straight, bendable and bent organic crystals
-
trans-4-Phenylazobenzoic acid (pab) crystallized in three different morphologies: long rod-like crystals, bendable long thin crystals, and bent crystals. Of them, the bent crystals were obtained by recrystallizing after subjecting pab to UV-irradiation in solution. A small amount of cis-form in the bent crystals is responsible for the bent nature, while the elastic bending of thin platy crystals can be understood from the crystal packing.
- Yadava, Khushboo,Qin, Xian,Liu, Xiaogang,Vittal, Jagadese J.
-
-
Read Online
- Light-controlled out-of-equilibrium assembly of cyclodextrins in an enzyme-mediated dynamic system
-
We show that the selective enzymatic synthesis of specific cyclodextrins can be modulated using light. We use enzyme-mediated dynamic combinatorial chemistry to generate a mixture of interconverting linear and cyclic α-1,4-glucans, and employ an azobenzene photoswitch as a template. Using UV or blue light to switch between photostationary states with different azobenzene cis/trans isomeric ratios, we can promote the out-of-equilibrium assembly of either α-cyclodextrin or β-cyclodextrin.
- Larsen, Dennis,Bjerre, Philip M.,Beeren, Sophie R.
-
-
Read Online
- Light-Switchable Antagonists for the Histamine H1 Receptor at the Isolated Guinea Pig Ileum
-
The histamine H1 G protein-coupled receptor (GPCR) plays an important role in allergy and inflammation. Existing drugs that address the H1 receptor differ in their chemical structure, pharmacology, and side effects. Light-controllable spatial and temporal activity regulation of photochromic H1 ligands may contribute to a better mechanistic understanding and the development of improved correlations between ligand structure and pharmacologic effects. We report photochromic H1 receptor ligands, which were investigated in an organ-pharmacological assay. Initially, five photochromic azobenzene derivatives of reported dual H1–H4 receptor antagonists were designed, synthesized, photochemically characterized, and organ-pharmacologically tested on the isolated guinea pig ileum. Among them, one compound [trans-19: (Z)-1-(4-chlorophenyl)-1-(4-methylpiperazin-1-yl)-N-(4-((E)-phenyldiazenyl)phenyl)methanimine] retained the antagonistic activity of its non-photochromic lead, and trans–cis isomerization by irradiation induced a fourfold difference in the pharmacological response. Further structural optimization resulted in two bathochromically shifted derivatives of 19 [NO2-substituted 35 {(Z)-1-(4-chlorophenyl)-1-(4-methylpiperazin-1-yl)-N-(4-((E)-(4-nitrophenyl)diazenyl)phenyl)methanimine} and SO3?-substituted 41 {4-((E)-(4-(((Z)-(4-chlorophenyl)(4-methylpiperazin-1-yl)methylene)amino)phenyl)diazenyl)benzenesulfonate}], which do not require the use of UV light for photoisomerization and which also have improved solubility and show reduced tissue impairment. The trans isomers of both compounds showed a remarkable increase in antagonistic activity relative to their lead trans-19; furthermore, a 46-fold difference in activity on the isolated guinea pig ileum was observed between trans- and cis-35.
- Rustler, Karin,Pockes, Steffen,K?nig, Burkhard
-
p. 636 - 644
(2019/02/14)
-
- Photoinduced viscosity control of lecithin-based reverse wormlike micellar systems using azobenzene derivatives
-
This report describes the controlled viscosity changes of photoresponsive reverse wormlike micellar systems formed by soybean lecithin (SoyPC), d-ribose, and azobenzene derivatives in decane. UV light irradiation produces a significant (150-fold) decrease in solution viscosity by triggering a structural transformation of the wormlike micelles. Subsequent visible light irradiation leads to recovery of the initial micellar structure and elevated solution viscoelasticity. This dramatic, reversible variation in solution viscosity by light irradiation can be applied to cosmetics, personal care products, and device components.
- Akamatsu, Masaaki,Shiina, Mayu,Shrestha, Rekha Goswami,Sakai, Kenichi,Abe, Masahiko,Sakai, Hideki
-
p. 23742 - 23747
(2018/07/13)
-
- Photoswitchable catalysis by a nanozyme mediated by a lightsensitive cofactor
-
The activity of a gold nanoparticle-based catalyst can be reversibly up-and down-regulated by light. Light is used to switch a small molecule between cis-and trans-isomers, which inhibits the catalytic activity of the nanoparticles to different extent. Th
- Neri, Simona,Martin, Sergio Garcia,Pezzato, Cristian,Prins, Leonard J.
-
supporting information
p. 1794 - 1997
(2017/02/15)
-
- Phenylcarboxyl-decorated tetraphenylethene with diverse molecular RIM-induced emission from host-guest inclusion and aggregation formation
-
A novel synthesized 4-carboxylphenoxy-decorated tetraphenylethene and α-cyclodextrin could form a host-guest inclusion complex with molecular RIM-induced Emission. On the basis of this, the TPE-COOH?α-CD inclusion complex exhibits a reversible fluorescence intensity change response to the photo-isomerization of 4-(phenylazo)benzoic acid (PBA) under alternate UV- and visible-light irradiation.
- Gao, Yan,Han, Bin,Chen, Yuting,Wang, Xi,Bai, Ming
-
p. 16581 - 16585
(2016/02/20)
-
- Chemoselective deprotonative lithiation of azobenzenes: Reactions and mechanisms
-
Whereas standard strong bases (n-BuLi, s-BuLi/TMEDA, n-BuLi/t-BuOK, TMPMgCl·LiCl, and LDA) reduce the N=N bond of the parent azobenzene (Y = H), aromatic H→Li permutation occurs with LTMP when a suitable director of lithiation (Y = OMe, CONEt2, F) is present in the benzene residue of the azo compound. The method allows direct access to new substituted azobenzenes.
- Nguyen, Thi Thanh Thuy,Boussonniere, Anne,Banaszak, Estelle,Castanet, Anne-Sophie,Nguyen, Kim Phi Phung,Mortier, Jacques
-
p. 2775 - 2780
(2014/04/17)
-
- Retinobenzoic acids. 3. Structure-activity relationships of retinoidal azobenzene-4-carboxylic acids and stilbene-4-carboxylic acids
-
Alkyl-substituted azobenzene-4-carboxylic acids are potent differentiation inducers of human promyelocytic leukemia cell line HL-60 to mature granulocytes. Their structure-activity relationships are very similar to those of other retinoidal benzoic acids which are generally represented by 4 and named retinobenzoic acids. The structure-activity relationships of azobenzenecarboxylic acids can also be applied to the known retinoid TTNPB (3). Thus, (E)-4-[2-(3,4-diisopropylphenyl)-1-propenyl]benzoic acid (St30 (28)), and (E)-4-[2-(3-tert-butylphenyl)ethenyl]benzoic acid (St40) (29)), the acyclic alkyl analogues of TTNPB, are nearly as active as retinoic acid. Among the oxidatively derived compounds (Az90, Ep series and Ox series) of azobenzene- or stilbenecarboxylic acids, Az90 (71) and Ep80 (61) have strong activities. However, all the bishydroxylated derivatives of TTNPB are inactive, while a diketo analogue Ox580 (69) has only weak potency. The activities of conformationally restricted compounds of TTNPB offer some information on the stereochemistry of the active form of these retinoidal compounds.
- Kagechika,Himi,Namikawa,Kawachi,Hashimoto,Shudo
-
p. 1098 - 1108
(2007/10/02)
-