Ultrasound-assisted aqueous two-phase extraction of total flavonoids from Tremella fuciformis and antioxidant activity of extracted flavonoids.

Here, the extraction of total flavonoids from Tremella fuciformis (TF) by aqueous two-phase extraction combined with ultrasound is presented. The extraction was optimized via a single-variable approach using the variables of mass fraction of ethanol and NaH2PO4, ultrasonication time, and TF sample amount. Response surface methodology (RSM) was then applied to determine the best conditions for extraction using the following three key parameters: ultrasonication time, ethanol mass fraction, and NaH2PO4 mass fraction. The optimum conditions were as follows: an aqueous two-phase system of ethanol/NaH2PO4, an ethanol mass fraction of 23%, a NaH2PO4 mass fraction of 27.18%, and an extraction time of 8.25 min. Under these conditions, the maximum extraction rate of total flavonoids was 0.158 mg/g. The scavenging rates for superoxide anion and hydroxyl radical, as well as the antioxidant activity of total flavonoids in TF, were studied. Total flavonoids from TF showed some scavenging ability, but the scavenging effects were lower than those of vitamin C (Vc) at the same concentrations. Nevertheless, ultrasound-assisted two-phase extraction was considered an efficient and rapid method that can be used to extract total flavonoids from TF.

Bioassay-guided isolation and characterisation of α-glucosidase inhibitors from Sanghuangporus baumii.

Bioassay-guided fractionation of the isopropanol extract of the medicinal mushroom Sanghuangporus baumii led to the isolation and characterisation of a new acorane-type sesquiterpenoid bauminene (1) and seven known compounds 2-8. The planar structure of 1 was elucidated on the basis of extensive spectroscopic analysis, including 1D, 2D NMR and HR-ESI-MS. The relative configuration of 1 was determined by a combination of ROESY experiment, density functional theory calculation of 13C NMR, and DP4+ probability analysis, while the absolute configuration of 1 was established by comparative electronic circular dichroism (ECD) spectra analysis. In the in vitro bioassay, compounds 1-8 exhibited potent to moderate α-glucosidase inhibitory activity with IC50 values ranging from 6.8 ± 0.68 to 221.4 ± 6.57 µM. The presences of these bioactive constituents in the sclerotia of S. baumii may be related to the use of the fungus as 'Sanghuang' for the adjuvant treatment of DM.

Secondary metabolites from Penicillium sp. HS-11, a fungal endophyte of Huperzia serrata.

Three new sorbicillinoids sorbicatechols E-G (1-3), along with seven known compounds 4-10, were obtained from the ethanol extract of Penicillium sp. HS-11, a fungal endophyte of the medicinal plant Huperzia serrata. The structures of 1-3 were established by detailed interpretation of the spectroscopic data and their absolute configurations were established by comparative analyses of the ECD spectra. Sorbicatechol G (3) represented the first hybrid sorbicillinoid bearing a tetralone skeleton. In the in-vitro bioassay, trichodimerol (5) exhibited moderate inhibitory activity against the Escherichia coli ß-glucuronidase (EcGUS) with an IC50 value of 92.0 ± 9.4 µM.

Diterpenoids and a diarylheptanoid from Hedychium coronarium with significant anti-angiogenic and cytotoxic activities.

Two new labdane diterpenoids, namely hedycoronals A and B (1 and 2, resp.), were isolated from the rhizomes of Hedychium coronarium, together with eight known diterpenoids, 4-11, and a known diarylheptanoid, 3. The structures of 1 and 2 were established by detailed interpretation of their 1D- and 2D-NMR spectra and HR-ESI-MS data. Inhibitory activities against human umbilical vein endothelial cells (HUMECs) proliferation and cytotoxic activities against four cancer cell lines were assessed for all the isolates. Most of these metabolites showed moderate or potent cytotoxic activities against four cancer cell lines. Moreover, compounds 3 and 8 exhibited promising inhibitory activities against HUMECs with the IC(50) values of 6.4 to 3.3 µM.

Effects of tetracycline on the secondary metabolites and nutritional value of oilseed rape (Brassica napus L.).

Secondary metabolism, which helps a plant cope with external stress, is sensitive to environmental changes and plays a prominent role in maintaining plant health. However, few studies of the effects of tetracycline on the relationships between secondary metabolism and plant stress responses have been performed. Here, secondary metabolism, nutritional value, and oxidative stress responses in oilseed rape (Brassica napus L.) exposed to tetracycline for 14 days were investigated. Tetracycline inhibited growth and biomass accumulation and decreased the chlorophyll content. The sinapine, phenol, and flavonoid contents were 118.46%, 99.67%, and 93.07% higher, respectively, but the carotenoid content was 76.47% lower in plants exposed to 8 mg/L tetracycline than the control plants. Tetracycline affected the nutritional value of oilseed rape. Tetracycline decreased the dietary fiber, soluble sugar contents, and microelement (Fe, Mn, and Zn) contents. The antioxidant system also responded strongly to tetracycline. The catalase and peroxidase activities were increased and the superoxide dismutase activity was decreased by tetracycline. Tetracycline caused oxidative damage and secondary metabolite disturbances and adversely affected oilseed rape growth and quality. The results provide a new perspective on the effects of tetracycline on plants in relation to secondary metabolites and improve our understanding involved in the toxicity of tetracycline.

Dibenzocyclooctadiene lignans from the stems of Schisandra sphaerandra.

Chemical investigation into the stems of the medicinal plant Schisandra sphaerandra led to the isolation and identification of a new dibenzocyclooctadiene lignan sphaerandrin A (1) and 11 known ones gomisin B (2), schirubrisin B (3), kadsuphilin B (4), schizandrin (5), benzoylgomisin Q (6), angeloylgomisin Q (7), gomisin G (8), schisanwilsonin O (9), isogomisin O (10), schisantherin D (11), and wuweizisu C (12). The structure of the new compound was elucidated by comprehensive spectroscopic methods including 1 D/2D NMR, HRESIMS, and CD spectrometry. To the best of our knowledge, compounds 2 - 11 were obtained from this species for the first time. All the compounds were evaluated for the cytotoxic activity against the triple-negative breast cancer cell lines MDA-MB-231 and HCC-1937.

α-Glucosidase and Bacterial ß-Glucuronidase Inhibitors from the Stems of Schisandra sphaerandra Staph.

α-Glucosidase (AGS) is a therapeutic target for Type 2 diabetes mellitus (T2DM) that tends to complicate with other diseases. Some medications for the treatment of T2DM complications have the risk of inducing severe adverse reactions such as diarrhea via the metabolism of intestinal bacterial ß-glucuronidase (BGUS). The development of new AGS and/or BGUS inhibitors may improve the therapeutic effects of T2DM and its complications. The present work focused on the isolation and characterization of AGS and/or BGUS inhibitors from the medicinal plant Schisandra sphaerandra. A total of eight compounds were isolated and identified. Sphaerandralide A (1) was obtained as a previously undescribed triterpenoid, which may have chemotaxonomy significance in the authentication of the genus Schisandra and Kadsura. 2'-acetyl-4',4-dimethoxybiphenyl-2-carbaldehyde (8) was obtained from a plant source for the first time, while compounds 2-7 were isolated from S. sphaerandra for the first time. In the in vitro assay, compounds 1-5 showed potent to moderate activity against AGS. Interestingly, compound 3 also exhibited significant BGUS inhibitory activity, demonstrating the potential of being developed as a bifunctional inhibitor that may find application in the therapy of T2DM and/or the diarrhea induced by medications for the treatment of T2DM complications.

Preparation, characterization, and antibacterial properties of biofilms comprising chitosan and ε-polylysine.

Of late, the demand for food-packaging materials, in particular, multifunction packaging materials that are biodegradable; antibacterial; have good mechanical and barrier properties; and are edible and transparent, has increased considerably. In this study, we prepared chitosan (CS)/ε-polylysine (PL) biofilms with different CS-to-PL ratios. We studied the preparation, mechanical properties, microstructures, thermal stability, transparency, water-vapor permeability, oil permeability, and antibacterial properties of the composite CS/PL biofilms. The results demonstrate that CS/PL biofilms are mechanically strong, have good thermal stability, high transparency, low water-vapor and oil permeability, and extensive antibacterial properties that act against Escherichia coli, Bacillus subtilis, and yeast. Therefore, we therefore conclude that CS/PL biofilms are promising food-packaging materials.

[Effects of single and co-exposure of Cu and chlorpyrifos on the toxicity of earthworm].

Combined pollution of heavy metal and pesticide had posed a serious threat to soil ecology and human living environment. As two common types of pollutants in soil environment, the environmental effects of combined pollution of Cu and chlorpyrifos are worth for attention. The acute lethal effects and avoiding behavior of single and co-exposure of Cu and chlorpyrifos on earthworms were analyzed by using the methods of standard OECD filter paper test and artificial soil test. Results showed that the LC(50,48 h) and LC(50,14 d) of the acute toxicity of Cu on earthworm in filter paper test and in artificial soil test were 2.23 microg x cm(-2) and 496.05 mg x kg(-1), respectively. The LC(50,48 h) and LC(50,14 d) of the acute toxicity of chlorpyrifos on earthworm in filter paper test and in artificial soil test were 5.94 microg x cm(-2) and 186.07 mg x kg(-1), respectively. In filter paper test and artificial soil test, the joint acute toxicity of Cu and chlorpyrifos showed an additive effect while the concentration was 1:1. The type of combined effects of co-exposure of Cu and chlorpyrifos was synergistic effect and antagonistic effect in filter paper test and artificial soil test, respectively, while the toxicity was 1:1. The results of avoidance behavior test showed that the joint effect of Cu and chlorpyrifos on the avoidance behavior of earthworms was antagonistic.

[Cellular response of freshwater green algae to the toxicity of tetracycline antibiotics].

Tetracycline antibiotics are a group of antibiotics which has been extensively used in most countries and are also the most widely used veterinary drugs and food additives in aquaculture and livestock industries of China. Because the substances are poorly adsorbed in the gut of animals and are only partially eliminated in sewage treatment plants, the antibiotics and their metabolites reach surface water where they may affect the aquatic organisms and human health. Herein, using green algae as test organisms, we studied the effects of tetracycline (TC), chlortetracycline (CTC) and deoxyteracycline (DC) on the cell permeability and growth inhibition of Chlorella pyrenoidosa and Scenedesmus obliquus. After 96 h of antibiotics exposure, the permeability of the cell membranes of both algae was decreased in the entire concentration range of doxycycline and was increased after exposure to a low concentration of tetracycline and chlortetracycline, then was decreased with the increase of the two antibiotics concentrations. The growth inhibiting effects of these three antibiotics on Chlorella pyrenoidosa and Scenedesmus obliquus were in an order of DC > TC > CTC. The ecotoxic response of Scenedesmus obliquus to tetracycline antibiotics was more sensitive than Chlorella pyrenoidosa.