nonpolar organic
Recently Published Documents


TOTAL DOCUMENTS

194
(FIVE YEARS 10)

H-INDEX

35
(FIVE YEARS 0)

2021 ◽  
pp. 118501
Author(s):  
Xinling Li ◽  
Jialiang Feng ◽  
Yingjie Li ◽  
Pengcheng Zhao ◽  
Xiaoxuan Pan ◽  
...  

Author(s):  
Fadhilah Alduraiei ◽  
Priyanka Manchanda ◽  
Bruno Pulido ◽  
Gyorgy Szekely ◽  
Suzana P. Nunes

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3690
Author(s):  
Shuyue He ◽  
Xiaoyan Cui ◽  
Afsar Khan ◽  
Yaping Liu ◽  
Yudan Wang ◽  
...  

Anneslea fragrans Wall., commonly known as “Pangpo Tea”, is traditionally used as a folk medicine and healthy tea for the treatment of liver and intestine diseases. The aim of this study was to purify the antioxidative and cytoprotective polyphenols from A. fragrans leaves. After fractionation with polar and nonpolar organic solvents, the fractions of aqueous ethanol extract were evaluated for their total phenolic (TPC) and flavonoid contents (TFC) and antioxidant activities (DPPH, ABTS, and FRAP assays). The n-butanol fraction (BF) showed the highest TPC and TFC with the strongest antioxidant activity. The bio-guided chromatography of BF led to the purification of six flavonoids (1–6) and one benzoquinolethanoid (7). The structures of these compounds were determined by NMR and MS techniques. Compound 6 had the strongest antioxidant capacity, which was followed by 5 and 2. The protective effect of the isolated compounds on hydrogen peroxide (H2O2)-induced oxidative stress in HepG2 cells revealed that the compounds 5 and 6 exhibited better protective effects by inhibiting ROS productions, having no significant difference with vitamin C (p > 0.05), whereas 6 showed the best anti-apoptosis activity. The results suggest that A. fragrans could serve as a valuable antioxidant phytochemical source for developing functional food and health nutraceutical products.


PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0245677
Author(s):  
Tianxiang Zhang ◽  
Weijiang Jin ◽  
Shuang Yang ◽  
Yimeng Li ◽  
Meishan Zhang ◽  
...  

Musk is a secretion of the forest musk deer (Moschus berezovskii). Normal musk is a brown solid secretion with a light fragrance. In this study, abnormal types of musk, namely, white and black musks, were discovered during the musk collection process. Researchers have long been concerned with the components of musk. Herein, GC-MS, headspace solid-phase microextraction (HS-SPME), and nonmetric multidimensional scaling (NMDS) were used to analyze the nonpolar organic components, volatile organic components, and sample similarities among different musks, respectively. Abundant steroid hormones and proteins were also found in the musk. The steroid hormone concentrations were detected using a radioimmunoassay (RIA). Proteins in the samples were hydrolyzed and the amino acids concentrations were detected. The steroid hormone and amino acid concentrations in white musk were significantly lower than in normal and black musks (p<0.05). The components were subjected to NMDS analysis to understand the differences in components among different types of musk, with the results suggesting that white musk was different from normal and black musks.


Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1560
Author(s):  
Pradip K. Bhowmik ◽  
Tae S. Jo ◽  
Jung J. Koh ◽  
Jongwon Park ◽  
Bidyut Biswas ◽  
...  

A series of poly(pyridinium salt)s-fluorene main-chain ionic polymers with various organic counterions were synthesized by using ring-transmutation polymerization and metathesis reactions. Their chemical structures were characterized by Fourier Transform Infrared (FTIR), proton (1H), and fluorine 19 (19F) nuclear magnetic resonance (NMR) spectrometers. These polymers showed a number-average molecular weight (Mns) between 96.5 and 107.8 kg/mol and polydispersity index (PDI) in the range of 1.12–1.88. They exhibited fully-grown lyotropic phases in polar protic and aprotic solvents at different critical concentrations. Small-angle X-ray scattering for one polymer example indicates lyotropic structure formation for 60–80% solvent fraction. A lyotropic smectic phase contains 10 nm polymer platelets connected by tie molecules. The structure also incorporates a square packing motif within platelets. Thermal properties of polymers were affected by the size of counterions as determined by differential scanning calorimetry and thermogravimetric analysis measurements. Their ultraviolet-visible (UV-Vis) absorption spectra in different organic solvents were essentially identical, indicating that the closely spaced π-π* transitions occurred in their conjugated polymer structures. In contrast, the emission spectra of polymers exhibited a positive solvatochromism on changing the polarity of solvents. They emitted green lights in both polar and nonpolar organic solvents and showed blue light in the film-states, but their λem peaks were dependent on the size of the counterions. They formed aggregates in polar aprotic and protic solvents with the addition of water (v/v, 0%–90%), and their λem peaks were blue shifted.


Soft Matter ◽  
2021 ◽  
Author(s):  
Huijiao Cao ◽  
Wenlin Xu ◽  
Xia Guo

Wormlike micelles (or reverse wormlike micelles) are flexible cylindrical chains that are normally formed in water (or a nonpolar organic solvent) at 25.0 °C or above; the formation of wormlike micelles at lower temperatures is rare.


2021 ◽  
Author(s):  
Jonathan T Stoffel ◽  
Kimberly Riordan ◽  
Emily Y Tsui

Nucleophilic 1,2-aminothiol compounds readily reduce typically-insoluble elemental sulfur to polysulfides in both water and nonpolar organic solvents. The resulting anionic polysulfide species are stabilized through hydrogen-bonding interactions with the proximal...


Sign in / Sign up

Export Citation Format

Share Document