Isolation, purification, and biological activities of polysaccharides from <i>Amorpha fruticosa</i> flowers

The extraction, isolation, structural characterisation and biological activities of polysaccharides from Amorpha fruticosa flowers were investigated. First, the crude polysaccharide AFP was extracted, and two major purified polysaccharide fractions AFP-2 and AFP-3 were isolated. The molecular weight and monosaccharide compositions of AFP-2 and AFP-3 were determined. Then the antioxidant activities of AFP, AFP-2 and AFP-3 were assessed by DPPH radical, β-Carotene bleaching and hydroxyl radical assays. All three tested polysaccharides showed good antioxidant activity while AFP was the strongest one. The study also showed that AFP, AFP-2 and AFP-3 have good tyrosinase inhibition, moisture absorption and retention activities. The results will provide a helpful reference for the application of polysaccharide from Amorpha fruticosa flowers as a natural cosmetic ingredient.</p

Oxygen Vacancy Engineering of Fe-Doped NiMoO₄ for Electrocatalytic N₂ Fixation to NH₃

Electrochemical nitrogen reduction reaction (NRR) is a promising method for ammonia synthesis under ambient conditions. However, the NRR performance is limited to an extremely strong NN bond in N2 and the competing hydrogen evolution reaction. Introducing oxygen vacancies (OVs) has been considered as a forceful means to accelerate the sluggish NRR reaction kinetics. Herein, we reported the design of Fe-doped NiMoO4 catalysts for NRR. Fe doping can increase the amount of OVs in the catalyst and contribute to lattice strain enhancement, thereby leading to the improvement of the electron transport rate and catalytic active for NRR. In 0.1 M Na2SO4 solution, the 5% Fe-NiMoO4 catalyst achieves a NH3 yield rate of 15.36 μg h–1 mgcat.–1 and a Faradaic efficiency of 26.85% under −0.5 V versus RHE. Furthermore, the 5% Fe-NiMoO4 catalyst exhibits excellent stability (up to 13 h) during the reaction