69113-98-0Relevant articles and documents
First total syntheses of two natural glycosides
Dong, Hongbo,Du, Weihong,Yao, Zhongquan,Wu, Min,Luo, Hongbing,He, Yujiao,Cao, Shenghua
, (2020/12/02)
Isosyringinoside (1) and 3-(O-β-D-glucopyranosyl)-α-(O-β-D-glucopyranosyl)-4-hydroxy phenylethanol (2), the natural bioactive compounds contained unique structures, were first totally synthesized using easily available materials in short convenient routes with overall yields of 20.2% and 27.0%, respectively. An efficient total synthesis of 1 was developed in six steps, which contained two key steps of highly regioselective glycosylation without any selective protection steps. The seven-step synthesis of 2 involved two steps of regioselective glycosylations using BF3–O(C2H5)2 and TMSOTf as catalysts, respectively.
Grafting Nature-Inspired and Bio-Based Phenolic Esters onto Cellulose Nanocrystals Gives Biomaterials with Photostable Anti-UV Properties
Allais, Florent,Browne, Christine,Garnier, Gil,Joram Mendoza, David,Mouterde, Louis M. M.,Simon, George P.,Singh Raghuwanshi, Vikram
, (2020/10/12)
New nature-inspired and plant-derived p-hydroxycinnamate esters and p-hydroxycinnamate diesters provide excellent protection against UV radiation when incorporated into a matrix. Herein, an efficient and sustainable pathway is reported to graft these phenolic compounds onto cellulose nanocrystals (CNCs) via click-type copper-catalyzed azide/alkyne cycloaddition (CuAAC) reaction. The successful grafting of the phenolic esters on CNC surface was evidenced by a range of chemical analyses, and the degrees of substitution (DS) of the CNC were found to depend on the structure of the phenolic ester grafted. Moreover, aqueous suspensions of the phenolic ester-grafted CNCs not only strongly absorb in both the UVA and UVB regions, but they also exhibit average to very high photostability. Their wide spectrum UV-absorbing properties and their stability upon exposure to UV are highly influenced by the structure of the phenolic ester, particularly by the extra ester group in p-hydroxycinnamate diesters. These findings demonstrate that cellulose nanocrystals decorated with such plant-derived and nature-inspired phenolic esters are promising sustainable nanomaterials for anti-UV applications.
A kinetic approach in the evaluation of radical-scavenging efficiency of sinapic acid and its derivatives
Niciforovi?, Neda,Polak, Toma?,Makuc, Damjan,Ulrih, Nata?a Poklar,Abramovic, Helena,McPhee, Derek J.
, (2017/03/15)
A kinetic approach was used to determine the radical scavenging activities of sinapic acid and its derivatives: sinapine, 4-vinylsyringol, syringic acid, syringaldehyde, and ethyl, propyl and butyl sinapate. The responses were expressed as rates of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) scavenging (RS), superoxide radical (O2-) scavenging (RFF), and β-carotene bleaching in the emulsion system (RB). For RS and RB, the esters of sinapic acid showed the highest responses while, for RFF, this was seen for syringic acid. The effectiveness of the selected compounds for scavenging these free radicals was also determined at a fixed endpoint. The early response parameters were demonstrated to be good discriminators in assessing differences for antioxidants with comparable fixed endpoint activity. The primary feature that ranks the kinetic data and the endpoint determinations is interpreted in terms of the mechanisms of the reactions involved in each of the assays conducted.
