33208-98-9Relevant articles and documents
A General Strategy to Enhance Donor-Acceptor Molecules Using Solvent-Excluding Substituents
Asbury, John B.,Hoelzel, Conner A.,Hu, Hang,Jung, Kwan Ho,Karim, Basel A.,Li, Xiaosong,Liu, Yu,Munson, Kyle T.,Wolstenholme, Charles H.,Yennawar, Hemant P.,Zhang, Han,Zhang, Xin
supporting information, p. 4785 - 4792 (2020/02/11)
While organic donor-acceptor (D-A) molecules are widely employed in multiple areas, the application of more D-A molecules could be limited because of an inherent polarity sensitivity that inhibits photochemical processes. Presented here is a facile chemical modification to attenuate solvent-dependent mechanisms of excited-state quenching through addition of a β-carbonyl-based polar substituent. The results reveal a mechanism wherein the β-carbonyl substituent creates a structural buffer between the donor and the surrounding solvent. Through computational and experimental analyses, it is demonstrated that the β-carbonyl simultaneously attenuates two distinct solvent-dependent quenching mechanisms. Using the β-carbonyl substituent, improvements in the photophysical properties of commonly used D-A fluorophores and their enhanced performance in biological imaging are shown.
Compounds binding to the S2-S3 pockets of thrombin
Nilsson, Mikael,H?m?l?inen, Markku,Ivarsson, Maria,Gottfries, Johan,Xue, Yafeng,Hansson, Sebastian,Isaksson, Roland,Fex, Tomas
experimental part, p. 2708 - 2715 (2010/01/16)
A set of compounds designed to bind to the S2-S3 pockets of thrombin was prepared. These compounds included examples with no interactions in the S1 pocket. Proline, a common P2 in many thrombin inhibitors, was combined with known P3 residues and P1 substituents of varying size and lipophilicity. Binding constants were determined using surface plasmon resonance (SPR) biosensor technology and were found to be in good agreement with results from an enzyme assay. A dramatic increase in affinity (100-1000 times) was seen for compounds incorporating an amino group capable of forming a hydrogen bond with gly216 in the protein backbone. The ligand efficiency was increased by including substituents that form stronger hydrophobic interactions with the P1 pocket. The binding mode was confirmed by X-ray analysis, which revealed the anticipated binding motif that included hydrogen bonds as well as a tightly bound water molecule. A QSAR model indicated that hydrogen bonding and lipophilicity were important for the prediction of binding constants. The results described here may have implications for how directed compound libraries for shallow protein pockets, like S2 and S3 in serine proteases, can be designed.
Highly efficient stereoconservative amidation and deamidation of α-amino acids
Shendage, Deepak M.,Froehlich, Roland,Haufe, Guenter
, p. 3675 - 3678 (2007/10/03)
(Chemical Equation Presented) An overall stereoconservative protection and deprotection method of amino and carboxyl groups is presented. N-Phthaloyl N-alkyl secondary amides of α-amino acids can be generated from corresponding N-phthaloyl amino acids by coupling reaction of N-alkylamines using mixed anhydride method. These secondary amides can be transformed by thermal rearrangement of intermediate nitrosoamides to O-alkyl esters with retention of configuration and excellent yields.
First successful synthesis of acryloyl-L-prolylamide derivatives
Yonezawa,Jingu,Katakai
, p. 1239 - 1246 (2007/10/02)
Acryloyl-L-prolylamide (1b) and its two simple derivatives, acryloyl-L- propyl-N',N'-dimethylamide (1a) and acryloyl-L-prolyl-N'-methylamide (1c), were synthesized for the first time.
