The functionalization of microcrystalline cellulose (MCC) is an important strategy for broadening its application fields. In the present work, MCC was functionalized by phosphorylation reaction with ...phytic acid (PA) for enhanced flame retardancy. The conditions of phosphorylation reaction including PA concentration, MCC/PA weight ratio and temperature were discussed, and the thermal degradation, heat release and char-forming properties of the resulting PA modified MCC were studied by thermogravimetric analysis and pyrolysis combustion flow calorimetry. The PA modified MCC, which was prepared at 90 °C, 50%PA and 1:3 weight ratio of MCC to PA, exhibited early thermal dehydration with rapid char formation as well as low heat release capability. This work suggests a novel strategy for the phosphorylation of cellulose using PA and reveals that the PA phosphorylated MCC can act as a promising flame retardant material.
Aspergillus niger metabolites exhibited a wide range of biological properties including antioxidant and neuro-protective effects and some physical properties as green synthesis of silver ...nanoparticles AgNP. The present study presents a novel evidence for the various biological activities of green synthesized AgNPs. For the first time, some isolated naphtho-gamma-pyrones from marine-derived Aspergillus niger, flavasperone (1), rubrofusarin B (2), aurasperone A (3), fonsecinone A (4) in addition to one alkaloid aspernigrin A (7) were invistigated for their inhibitory activity of acetylcholine esterase AChE, a hallmark of Alzheimer's disease (AD). The ability to synthesize AgNPs by compounds 3, 4 and 7 has been also tested for the first time. Green synthesized AgNPs were well-dispersed, and their size was ranging from 8-30 nm in diameter, their morphology was obviously spherical capped with the organic compounds. Further biological evaluation of their AChE inhibitory activity was compared to the parent compounds. AgNps dramatically increased the inhibitory activity of Compounds 4, 3 and 7 by 84, 16 and 13 fold, respectively to be more potent than galanthamine as a positive control with IC.sub.50 value of 1.43 compared to 0.089, 0.311 and 1.53 of AgNPs of Compounds 4, 3 and 7, respectively. Also compound 2 showed moderate inhibitory activity. This is could be probably explained by closer fitting to the active sites or the synergistic effect of the stabilized AgNPs by the organic compouds. These results, in addition to other intrinsic chemical and biological properties of naphtho-gamma-pyrones, suggest that the latter could be further explored with a view towards other neuroprotective studies for alleviating AD.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The anti-diabetic activity of ginger powder (
) has been recently promoted, with the recommendation to be included as one of the dietary supplements for diabetic patients. However, previous studies ...presented different results, which may be caused by degradation and metabolic changes of ginger components, gingerols, shogaols and paradols. Therefore, we prepared 10 ginger active components, namely 6-, 8-, 10-paradols, 6-, 8-, 10-shogaols, 6-, 8-, 10-gingerols and zingerone, and evaluated their anti-hyperglycemic activity. Among the tested compounds, 6-paradol and 6-shogaol showed potent activity in stimulating glucose utilization by 3T3-L1 adipocytes and C2C12 myotubes. The effects were attributed to the increase in 5' adenosine monophosphate-activated protein kinase (AMPK) phosphorylation in 3T3-L1 adipocytes. 6-Paradol, the major metabolite of 6-shogaol, was utilized in an in vivo assay and significantly reduced blood glucose, cholesterol and body weight in high-fat diet-fed mice.
Five new eudensamane-type sesquiterpene lactones, clasamanes A–E (1–5), three new dolabellane-type diterpenes, clabellanes A–C (6–8), and fifteen known compounds (9–23) were isolated from the ...ethanolic extract of Taiwanese soft coral Clavularia spp. The structures of all undescribed components (1–8) were determined by analysis of IR, mass, NMR, and UV spectroscopic data. The absolute configuration of new compounds was determined by using circular dichroism and DP4+ calculations. The cytotoxic activities of all isolated marine natural products were evaluated. Compound 7 showed a significant cytotoxic effect against oral cancer cell line (Ca9-22) with an IC50 value of 7.26 ± 0.17 μg/mL.
The role of antiviral prophylaxis in preventing hepatitis B virus (HBV) reactivation before rituximab-based chemotherapy in patients with lymphoma and resolved hepatitis B is unclear.
Eighty patients ...with CD20(+) lymphoma and resolved hepatitis B were randomly assigned to receive either prophylactic entecavir (ETV) before chemotherapy to 3 months after completing chemotherapy (ETV prophylactic group, n = 41) or to receive therapeutic ETV at the time of HBV reactivation and hepatitis B surface antigen (HBsAg) reverse seroconversion since chemotherapy (control group, n = 39).
Fifty-eight patients (72.5%) were positive for hepatitis B surface antibody, and HBV DNA was undetectable in 50 patients (62.5%). During a mean 18-month follow-up period, one patient (2.4%) in the ETV prophylactic group and seven patients (17.9%) in the control group developed HBV reactivation (P = .027). The cumulative HBV reactivation rates at months 6, 12, and 18 after chemotherapy were 8%, 11.2%, and 25.9%, respectively, in the control group, and 0%, 0%, and 4.3% in the ETV prophylactic group (P = .019). Four patients (50%) in the control group had HBsAg reverse seroconversion after HBV reactivation. The cumulative HBsAg reverse seroconversion rates at months 6, 12, and 18 since chemotherapy were 0%, 6.4%, and 16.3% in the control group, respectively, which were significantly higher than those in the ETV prophylactic group (P = .032). Patients with detectable or undetectable viral load could develop HBV reactivation and HBsAg reverse seroconversion.
Undetectable HBV viral load before chemotherapy did not confer reactivation-free status. Antiviral prophylaxis can potentially prevent rituximab-associated HBV reactivation in patients with lymphoma and resolved hepatitis B.
Root colonization by endophytic fungus Piriformospora indica facilitating growth/development and stress tolerance has been demonstrated in various host plants. However, global metabolomic studies are ...rare. By using high-throughput gas-chromatography-based mass spectrometry, 549 metabolites of 1,126 total compounds observed were identified in colonized and uncolonized Chinese cabbage roots, and hyphae of P. indica. The analyses demonstrate that the host metabolomic compounds and metabolite pathways are globally reprogrammed after symbiosis with P. indica. Especially, γ-amino butyrate (GABA), oxylipin-family compounds, poly-saturated fatty acids, and auxin and its intermediates were highly induced and de novo synthesized in colonized roots. Conversely, nicotinic acid (niacin) and dimethylallylpyrophosphate were strongly decreased. In vivo assays with exogenously applied compounds confirmed that GABA primes plant immunity toward pathogen attack and enhances high salinity and temperature tolerance. Moreover, generation of reactive oxygen/nitrogen species stimulated by nicotinic acid is repressed by P. indica, and causes the feasibility of symbiotic interaction. This global metabolomic analysis and the identification of symbiosis-specific metabolites may help to understand how P. indica confers benefits to the host plant.
Octocoral of the genus
is a kind of marine invertebrate possessing abundant cytotoxic secondary metabolites, such as prostanoids and dolabellanes. In our continuous natural product study of
spp., two ...previously undescribed prostanoids clavulone I-15-one (
) and 12-
-deacetylclavulone I (
) and eleven known analogs (
-
) were identified. The structures of these new compounds were elucidated based on analysis of their 1D and 2D NMR, HRESIMS, and IR data. Additionally, all tested prostanoids (
and
-
) showed potent cytotoxic activities against the human oral cancer cell line (Ca9-22). The major compound
showed cytotoxic activity against the Ca9-22 cells with the IC
value of 2.11 ± 0.03 μg/mL, which echoes the cytotoxic effect of the coral extract. In addition, in silico tools were used to predict the possible effects of isolated compounds on human tumor cell lines and nitric oxide production, as well as the pharmacological potentials.
The cancer‐cell‐cytotoxicity‐guided fractionation of the acetone extracts of two cultured marine‐derived Streptomyces strains belonging to the MAR4 group yielded six new napyradiomycins, compounds ...A–F (1–6), together with three known compounds, napyradiomycins B2–B4 (7–9). Napyradiomycins 1–4 are new members of the napyradiomycin “C‐type” meroterpenoids, which possess a linear monoterpene bridge between C‐7 and C‐10a. Compound 4 has an additional tetrahydropyran ring fused to the phenol moiety. Compounds 5–9 are related to the napyradiomycin “B‐type” meroterpenoids. The structures of all new compounds were assigned by interpretation of 1D and 2D NMR, MS, and other spectroscopic data. The relative configurations were assigned based upon interpretation of ROESY 2D NMR experiments. The cytotoxicity of 1–9 against the human colon carcinoma cell line HCT‐116 and their antibacterial activities against methicillin‐resistant Staphylococcus aureus (MRSA) are presented.
The cancer‐cell‐cytotoxicity‐guided fractionation of the acetone extracts of two cultured marine‐derived Streptomyces strains yields six new napyradiomycins (1–6). Napyradiomycins 1–4 are new members of the napyradiomycin “C‐type” meroterpenoids, which possess a linear monoterpene bridge between C‐7 and C‐10a. The cytotoxicity and antibacterial activities of 1–6 are presented.
The selective antiproliferation to oral cancer cells of Physalis peruviana-derived physapruin A (PHA) is rarely reported. Either drug-induced apoptosis and DNA damage or DNA repair suppression may ...effectively inhibit cancer cell proliferation. This study examined the selective antiproliferation ability of PHA and explored detailed mechanisms of apoptosis, DNA damage, and repair. During an ATP assay, PHA provided high cytotoxicity to two oral cancer cell lines (CAL 27 and Ca9-22) but no cytotoxicity to two non-malignant oral cells (HGF-1 and SG). This selective antiproliferation of PHA was associated with the selective generation of reactive oxygen species (ROS) in oral cancer cells rather than in non-malignant oral cells, as detected by flow cytometry. Moreover, PHA induced other oxidative stresses in oral cancer cells, such as mitochondrial superoxide generation and mitochondrial membrane potential depletion. PHA also demonstrated selective apoptosis in oral cancer cells rather than non-malignant cells in annexin V/7-aminoactinmycin D and caspase 3/7 activity assays. In flow cytometry and immunofluorescence assays, PHA induced γH2AX expressions and increased the γH2AX foci number of DNA damages in oral cancer cells. In contrast, the mRNA expressions for DNA repair signaling, including homologous recombination (HR) and non-homologous end joining (NHEJ)-associated genes, were inhibited by PHA in oral cancer cells. Moreover, the PHA-induced changes were alleviated by the oxidative stress inhibitor N-acetylcysteine. Therefore, PHA generates selective antiproliferation, oxidative stress, and apoptosis associated with DNA damage induction and DNA repair suppression in oral cancer cells.
Atopic dermatitis (AD, eczema) is a condition that causes dry, itchy, and inflamed skin and occurs most frequently in children but also affects adults. However, common clinical treatments provide ...limited relief and have some side effects. Therefore, there is a need to develop new effective therapies to treat AD. Epi-oxyzoanthamine is a small molecule alkaloid isolated from Formosan zoanthid. Relevant studies have shown that zoanthamine alkaloids have many pharmacological and biological activities, including anti-lymphangiogenic functions. However, there are no studies on the use of epi-oxyzoanthamine on the skin. In this paper, epi-oxyzoanthamine has been shown to have potential in the treatment of atopic dermatitis. Through in vitro studies, it was found that epi-oxyzoanthamine inhibited the expression of cytokines in TNF-α/IFN-γ-stimulated human keratinocyte (HaCaT) cells, and it reduced the phosphorylation of MAPK and the NF-κB signaling pathway. Atopic dermatitis-like skin inflammation was induced in a mouse model using 2,4-dinitrochlorobenzene (DNCB) in vivo. The results showed that epi-oxyzoanthamine significantly decreased skin barrier damage, scratching responses, and epidermal hyperplasia induced by DNCB. It significantly reduced transepidermal water loss (TEWL), erythema, ear thickness, and spleen weight, while also increasing surface skin hydration. These results indicate that epi-oxyzoanthamine from zoanthid has good potential as an alternative medicine for treating atopic dermatitis or other skin-related inflammatory diseases.
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