Guangying Chen

A new naphthoquinone and other antibacterial constituents from the roots of Xanthium sibiricum

Reinvestigating the chemical constituents of the roots of Xanthium sibiricum led to the isolation of a new naphthoquinone (1), together with 13 known compounds (2–14). Their structures were elucidated by using spectroscopic analyses, including HR-ESI-MS, 1D and 2D NMR, and by comparing their NMR data with those of related compounds. Compound 1 showed moderate antibacterial activity against Escherichia coli, Bacillus subtilis, Micrococcus tetragenus and Staphylococcus aureus, while 6 and 12 showed stronger antibacterial activity than the positive control ciprofloxacin against E. coli, with minimum inhibitory concentration values of 0.17 and 0.35 μg/mL, respectively.

Lactones from Ficus auriculata and their effects on the proliferation function of primary mouse osteoblasts in vitro

Bioassay-guided fractionation of the petroleum ether, chloroform and EtOAc extracts of the stems of Ficus auriculata led to the isolation of five new 12-membered lactones (3R,4R)-4-hydroxy-de-O-methyllasiodiplodin (1), 6-oxolasiodiplodin (2) and ficusines A-C (3-5), together with three known related analogues (6-8). The structures of the new compounds were elucidated by comprehensive spectroscopic data. The absolute configurations of 3 and 8 were established by single crystal X-ray diffraction analysis. Compounds 3-5 represent the first 12-membered lactones with a quinone ring unit. Compounds 6 and 7 exhibited significant proliferation function of primary osteoblasts (OBs) in vitro. Especially, the promotion rate of 6 reached 151.55±1.34% (P<0.001) at the concentration of 100 μM.

A new asymmetric diamide from the seed cake of Jatropha curcas L.

A new asymmetric diamide (E)-N-(3-acetamidopropyl)-cinnamamide named curcamide (1) has been isolated from the ethanol extract of the seed cake of Jatropha curcas L. along with 7 known compounds identified as isoamericanin (2), isoprincepin (3), caffeoylaldehyde (4), isoferulaldehyde (5), glycerol monooleate (6), syringaldehyde (7), and β-ethyl-d-glucopyranoside (8). The synthesis and antibacterial activity of the new compound have been also studied.

Five new degraded diterpenoids from Trigonostemon xyphophylloides.

Five new degraded diterpenoids trigoxyphins J-N (1-5), among them trigoxyphins K and L have a novel carbon skeleton, together with four known analogues (6-9) have been obtained from the ethanol extract of the twigs of Trigonostemon xyphophylloides. Compounds 1-5 were evaluated for their cytotoxic activity in vitro against three human tumor cell lines by MTT assay. The results exhibited that Trigoxyphin N (5) showed moderate cytotoxicities against SPC-A-1 and SGC-7901 cancer cell lines.

Purification, characterization and immunomodulatory activity of a novel polysaccharide from Grifola frondosa

A novel bioactive polysaccharide, GFP-22, was isolated from the fruit bodies of Grifola frondosa by anion-exchange and gel filtration chromatography. Structure of GFP-22 was investigated using gas chromatography-mass spectrometry (GC-MS), methylation, nuclear magnetic resonance (NMR), high-performance size exclusion chromatography-multi-angle laser light scattering-refractive index detector (HPSEC-MALLS-RI) and atomic force microscopy (AFM) analysis. The backbone of GFP-22 is composed of 1,4-β-d-Glcp, 1,3-β-d-Glcp, 1,6-α-d-Glcp, 1,6-α-d-Galp, 1,4,6-α-d-Manp and 1,3,6-α-d-Manp units. Molecular weight of GFP-22 is 2.72 × 104 Da. GFP-22 has a linear filamentous structure. The administration of GFP-22 could improve or reverse the CTX-induced immunosuppression, significantly enhance the spleen and thymus indices, spleen lymphocyte proliferation and cytokines production in splenocytes. These findings suggest that GFP-22 could be explored as a natural and potential immunomodulatory agent and as an alternative means of lessening chemotherapy-induced immunosuppression.

Green aqueous biphasic systems containing deep eutectic solvents and sodium salts for the extraction of protein

Deep eutectic solvents (DESs), a new type of green solvents, were applied for the extraction of proteins with aqueous biphasic systems (ABSs) in this study. The structures of the prepared DES were confirmed by FT-IR and 1H NMR. The DES–salt (NaH2PO4/Na2CO3/Na3C6H5O7)-based ABSs were established and applied to extract the bovine serum albumin and papain. DES–Na2CO3 ABS was selected as the suitable extraction system. Single-factor experiments were investigated to achieve complete extraction by properly tailoring the concentration of different compositions (e.g. proteins, Na2CO3, DES), the temperature and pH values. The experimental results indicated that the extraction efficiency could reach up to 95.16% for bovine serum albumin and 90.95% for papain under the optimum conditions. UV-vis spectra, fluorescence spectra and CD spectra were investigated to confirm that the conformation of bovine serum albumin did not change after extraction. The transmission electron microscopy (TEM) was used to explore the mechanism of the extraction. All of these results indicated that DES-based ABSs may provide a new possibility for the separation of proteins.

Se-enriched G. frondosa polysaccharide protects against immunosuppression in cyclophosphamide-induced mice via MAPKs signal transduction pathway

To assess the immunomodulatory and antioxidant activities of a Se-polysaccharide from Se-enriched G. frondosa (Se-GFP-22), immunosuppressed mice models were generated by cyclophosphamide (CTX) administration and then treated with Se-GFP-22. Results showed that Se-GFP-22 could increase thymus and spleen indices, phagocytic index, co-mitogenic (ConA- or LPS-stimulated) activities on splenocytes, DTH reaction, serum hemolysin formation and immunoglobulin (Ig G, Ig A and Ig M) levels in CTX-treated mice. Se-GFP-22 significantly enhanced the antioxidant activity in CTX-treated mice, as shown by the evaluation of GSH-Px, SOD and CAT activities, as well as MDA levels in serum, liver and kidney. Se-GFP-22 strongly stimulated inflammatory cytokines (IL-2 and IFN-γ) and NO productions by up-regulating mRNA expressions of IL-2, IFN-γ and iNOS. Se-GFP-22 possessed the immunomodulatory activity by up-regulating various transcription factors (JNK, ERK, and p38) in MAPKs signaling pathways. This study suggested that Se-GFP-22 may provide an alternative strategy in lessening chemotherapy-induced immunosuppression.

Fabrication of oxygen-defective tungsten oxide nanorods for deep oxidative desulfurization of fuel

Owing to the increasingly serious environmental issues caused by the sulfur burnt in fuel, desulfurization has become an important topic. In this work, an amphiphilic oxygen-defective tungsten oxide was synthesized by a colloidal chemistry method. The amphiphilic property and oxygen defects were well characterized, and the structure of the oxygen-defective tungsten oxide catalyst was investigated. In addition, the catalyst was employed in oxidative desulfurization system of fuel, and deep desulfurization was achieved. It was found that the very high oxidative desulfurization performance of oxygen-defective tungsten oxide catalyst resulted from both the amphiphilic property and oxygen defects. This work can provide a strategy for preparation of highly active metal oxide catalysts with oxygen defects in oxidative desulfurization reaction of fuel.

A novel Se-polysaccharide from Se-enriched G . frondosa protects against immunosuppression and low Se status in Se-deficient mice

In this study, a Se-deficient mice model was successfully developed by feeding a Se-deficient diet (0.02 mg Se/kg diet) for 4 weeks, and Se supplementation by Se-polysaccharides (Se-GFP-22) was lasted for 4 weeks. The immunomodulatory activity and Se supplementation of Se-GFP-22 from Se-enriched G. frondosa was investigated. Results showed that Se-GFP-22 remarkably enhanced glutathione peroxidase (GSH-Px) and thioredoxin reductase (TrxR) activities in liver, kidney and plasma, and serum, liver, spleen and kidney Se levels of Se-deficient mice. Se-GFP-22 increased the thymus and spleen indices, phagocytic index, co-mitogenic (ConA- or LPS-stimulated) activities on splenocytes and DTH reaction. Se-GFP-22 caused significant increments in cytokine (IL-1β, TNF-α and IFN-γ) levels and Ig G, Ig A, Ig M and Ig E levels. Se-GFP-22 exhibited superior immunomodulatory effects than GFP-22. These findings indicated that Se-GFP-22 promote the protective effects against Se deficiency-induced immunosuppression and could be a potential immunomodulatory agent and a dietary Se-supplement.