Isoxazoles and isoxazolines are five-membered heterocyclic molecules containing nitrogen and oxygen. Isoxazole and isoxazoline are the most popular heterocyclic compounds for developing novel drug candidates. Over 80 molecules with a broad range of bioactivities, including antitumor, antibacterial, anti-inflammatory, antidiabetic, cardiovascular, and other activities, were reviewed. A review of recent studies on the use of isoxazoles and isoxazolines moiety derivative activities for natural products is presented here, focusing on the parameters that affect the bioactivity of these compounds.

In this study, the polysaccharides of Coreopsis tinctoria buds (CTBPs) were extracted by hot water, ultrasound, alkali solution, and acid solution, and the four kinds of extracted polysaccharides were denoted Hw, Ultra, Al, and Ac. Then, the Hw were degraded by ultrasound, an alkali solution, and an acid solution, and the three resultant kinds of polysaccharides were denoted Ultra-Post-proc, Al-Post-proc, and Ac-Post-proc. The study comprehensively compared and analyzed the physical and chemical characteristics, structural properties, and in vitro activities of each polysaccharide. The extraction and treatment methods significantly affected the chemical composition, molecular weight (Mw) and potential of the CTBPs. The contents of carbohydrates, total phenol, and protein in Al were the highest, at 78.79 ± 0.62%, 81.69 ± 0.70 mg GAE/g and 4.82 ± 0.10%, respectively. The different methods did not change the monosaccharide composition of CTBPs, but affected the monosaccharide proportion and reduced the Mw of CTBPs. The absolute zeta potential value of Al was the highest, indicating that the solution was the most stable. CTBPs had the characteristic structure of polysaccharides, and Al-Post-proc had a triple helix structure. Additionally, CTBPs also had good water and oil holding abilities, as well as bile acid binding ability. CTBPs displayed good activity in vitro, among which Al possessed the best α-glucosidase inhibitory activity and the strongest free radical scavenging ability, and also well inhibited the generation of glycosylation products and protein oxidation products in the bovine serum albumin (BSA)-fructose model. These findings provide support for a theoretical basis for the application of polysaccharide from Coreopsis tinctoria bud in pharmaceutical and functional foods.

Cucumber seeds are the seeds of Cucumber (Cucumis sativus L.), which include a large number of essential fatty acids, plant sterols, glycosides, volatile oils, as well as Ca, Mg, and other inorganic elements. Cucumber seed oil has good UV absorption effect because it is rich in an unsaturated functional group structure. Plant sterol in cucumber seed oil shows strong permeability toward the skin, which promotes skin metabolism and inhibits skin inflammation. β-sitosterol in plant sterols can also effectively protect the peroxide of low-density lipoprotein, so they have an antioxidant effect. In this study, cucumber seed oil was extracted by the Soxhlet extraction method as plant-based sunscreen, in which cucumber seed oil was used as the main component, and an appropriate amount of titanium dioxide was used as an antioxidant. Taking the settling solvent ratio as the index, the orthogonal experiment was designed to determine the prescription composition of the pure matrix. Then the single factor experiments of cucumber seed oil, titanium dioxide, and vitamin E were carried out. The effects of three components on UV absorption were investigated by orthogonal experiments, and the optimum formula with cucumber seed oil as the main component was finally determined and verified. In conclusion, our plant sunscreen was produced by cucumber seed oil as raw material instead of hormone. There was no harm to the skin. It has the potential to develop plant-based sunscreen with cucumber seed oil and provides a reference for the development of plant sunscreen and skin care products.

A novel dimeric flavonol glycoside, Cynanflavoside A (1), together with six analogues, kaempferol-3-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside (2), quercetin-3-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside (3), kaempferol-3-O-α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranoside (4), quercetin-3-O-α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranoside (5), kaempferol-3-O-β-D-glucopyranosyl-7-O-α-L-rhamnopyranoside (6), and quercetin-3-O-galactoside (7) were isolated from the n-butyl alcohol extract of Cynanchum acutum subsp. sibiricum. Their structures were determined spectroscopically and compared with previously reported spectral data. All compounds were evaluated for their anti-complementary activity in vitro, and only compound 5 exhibited anti-complement effects with CH₅₀ value of 0.33 mM.