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Fruits of Syzygium jambos (L.) are recognized as a "food", exhibiting significant antidiabetic activities. However, the α-glucosidase inhibition of the components from Syzygium jambos (L.) have not yet been investigated. In this study, a total of 14 compounds were isolated from Syzygium jambos (L.) Alston, eight of which showed significant inhibitory effects on α-glucosidase, with IC50 values in the range of 0.011–0.665 mM. Notably, compounds 1–3 (IC50: 0.013, 0.011 and 0.030 mM, respectively) exhibited much stronger activity than acarbose (IC50: 2.329 ± 0.109 mM). The enzyme kinetics study indicated that compound 1 was an uncompetitive inhibitor, and compounds 2–8 were mixed-type inhibitors. Moreover, the interactions between compounds and α-glucosidase were investigated by molecular docking, which further revealed that the number of olefin double bonds and 2-COOH of heptadeca-phenols had a notable effect on the α-glucosidase inhibitory activity. This study demonstrated that Syzygium jambos (L.) fruit might serve as a functional food for the prevention of diabetes mellitus. [ABSTRACT FROM AUTHOR]

Dendrobium nobile Lindl (DNL) is one of the main sources of traditional Chinese medicine, Shihu (Dendrobii caulis). In recent years, the strong antitumor activity of the extract from DNL makes it a hot research object. This paper systematically summarizes the researches of DNL from 1935 to 2022, including the botanical characteristics, herbal textual research, chemical composition, pharmacological activity and toxicology of DNL, in order to provide inspiration for the later research, further development, as well as reasonable application of DNL. The stems of DNL contains alkaloids, polysaccharides, sesquiterpenes, Phenanthrenes, benzenes and other chemical components. Among them, alkaloids and polysaccharides have been regarded as the main active constitutents, with dendrobine (1) the characteristic components. So far, as many as 213 compounds have been isolated from DNL, and 101 compounds have been identified from the flowers of DNL via gas chromatography-mass spectrometry (GC–MS). It has been found that the extract of DNL exhibit various pharmacological activities, such as anti-tumor, blood sugar reduction, nerve protection, immuneenhancement, anti-inflammation, and anti-aging. Most of the pharmacological researches are on the total polysaccharides and total alkaloids of DNL. Besides being used as a medicinal material, DNL also often appears in daily diet and health care. However, the toxicity of DNL was reported in some literatures. Therefore, more in-depth toxicological research is needed to ensure the safety of DNL in medicine and food consumption. [ABSTRACT FROM AUTHOR]

Strains of the fungal genus Pestalotiopsis are reported as large promising sources of structurally varied biologically active metabolites. Many bioactive secondary metabolites with diverse structural features have been derived from Pestalotiopsis. Moreover, some of these compounds can potentially be developed into lead compounds. Herein, we have systematically reviewed the chemical constituents and bioactivities of the fungal genus Pestalotiopsis, covering a period ranging from January 2016 to December 2022. As many as 307 compounds, including terpenoids, coumarins, lactones, polyketides, and alkaloids, were isolated during this period. Furthermore, for the benefit of readers, the biosynthesis and potential medicinal value of these new compounds are also discussed in this review. Finally, the perspectives and directions for future research and the potential applications of the new compounds are summarized in various tables. [ABSTRACT FROM AUTHOR]

The remarkable nonlinearity between the viscosity and temperature significantly reduces the extrusion formability of Nylon-66. The conventional extrusion methods, which obtain extrusion profiles with high precision through first extrusion and then sizing in calibrator, are unable to realize the extrusion of Nylon-66, especially for GF/Nylon-66 composite. In this paper, a one-step extrusion method, which realizes the fast sizing of extruded parts by taking advantages of the crystallization of GF/Nylon-66 melt, was proposed based on the viscosity change features and crystallization behavior of GF/Nylon-66 around its melting temperature ( T ). Thus, the sizing and cooling processes using standardized dies in conventional extrusion methods can be eliminated. In this study, the one-step extrusion process of GF/Nylon-66 was investigated from three aspects including the extrusion rheological performance, the equilibrium property of extrusion flow and crystallization sizing behavior, based on finite element simulations and experiments. The results revealed that the melt flow property can be improved by increasing temperature and shear rate. The rheological constitutive equation can precisely describe the rheological performance of materials under different temperatures and shear rates. Increasing melt temperature and screw speed will reduce the melt flow equilibrium. With the melt temperature at neck ring mold being the peak crystallizing temperature and screw speed being appropriate, an optimized dynamic balance among the melt flow property, the flow equilibrium performance and the crystallization sizing capability can be achieved. Thus, the extrusion molding of GF/Nylon-66 can be implemented via one-step extrusion. The method proposed can realize the extrusion molding of GF/Nylon-66 with improved efficiency and reduced cost. [ABSTRACT FROM AUTHOR]