沙蜇(Stomolophus meleagris)刺丝囊毒素生物活性的初步分析

从沙蜇触手提取刺丝囊细胞毒素,并对该毒素进行溶血活性、致死活性、SOD活性和抗肿瘤活性的研究。结果显示,沙蜇毒素具有明显的溶血活性,其半溶血率(HU50)约为10.5μg/ml;该毒素还对草鱼显示出较强的致死活性,半致死量(LD50)为50μg毒素/g鱼;同时该毒素具有明显的SOD活性和抗肿瘤活性,当毒素浓度为18μg/ml时其总SOD活性为161 U/mg,而毒素浓度为1 mg/ml时,该毒素对肝癌细胞Bel-7402表现出显著的抑制效果,其抑制率达到54.9%。因此,有必要对沙蜇毒素内的生物活性组分进行深入研究,为沙蜇毒素的开发利用提供依据。     

Biological activities of two macroalgae from Adriatic coast of Montenegro

In the present investigation the acetone extracts of macroalgae Ulva lactuca and Enteromorpha intestinalis were tested for antioxidant, antimicrobial and cytotoxic potential. Antioxidant activity was evaluated by measuring the scavenging capacity of tested samples on DPPH and superoxide anion radicals, reducing the power of samples and determination of total phenolic and flavonoid compounds in extracts. As a result of the study, U. lactuca extract was found to have a better free radical scavenging activity (IC₅₀ = 623.58 μg/ml) than E. intestinalis extract (IC₅₀ = 732.12 μg/ml). Moreover, the tested extracts had effective ferric reducing power and superoxide anion radical scavenging. The total content of phenol in extracts of U. lactuca and E. intestinalis was 58.15 and 40.68 μg PE/mg, while concentrations of flavonoids were 39.58 and 21.74 μg RE/mg, respectively. Furthermore, among the tested species, extracts of U. lactuca showed a better antimicrobial activity with minimum inhibitory concentration values ranging from 0.156 to 5 mg/ml, but it was relatively weak in comparison with standard antibiotics. Bacillus mycoides and Bacillus subtilis were the most susceptible to the tested extracts. Contrary to this Aspergillus flavus, Aspergillus fumigatus and Penicillium purpurescens were the most resistant. Finally, cytotoxic activity of tested extracts was evaluated on four human cancer cell lines. Extract of E. intestinalis expressed the stronger cytotoxic activity towards all tested cell lines with IC₅₀ values ranging from 74.73 to 155.39 μg/ml.     

Analysis of anti-bacterial and anti oxidative activity of Azadirachta indica bark using various solvents extracts

Herbal medications have been used for relief of symptoms of disease. Regardless of the great advances observed in current medicine in recent decades, plants still make a significant contribution to health care. An alarming increase in bacterial strains resistant to a number of antimicrobial agents demands that a renewed effort be made to seek antibacterial agents effective against pathogenic bacteria resistant to or less sensitive to current antibiotics. Anti-bacterial activity of Azadirachta indica stem bark was tested against pathogenic Salmonella paratyphi and Salmonella typhi using various solvent extracts. The in vitro anti-bacterial activity was performed by agar well diffusion method and the results were expressed as the average diameter of zone of inhibition of bacterial growth around the well. The ethanol and methanol extracts showed better anti-bacterial activity with zone of inhibition (20–25 mm) when compared with other tested extracts and standard antibiotic Erythromycin (15 mcg) with zone of inhibition (13–14 mm). Using Fisher’s exact test of significance difference was found between two Salmonella strains sensitivity patterns against tested extracts (P ⩽ 0.035). Extracts of A. indica stem bark also exhibited significant antioxidant activity, thus establishing the extracts as an antioxidant. The results obtained in this study give some scientific support to the A. indica stem bark for further investigation of compounds and in future could be used as drug.     

Synthesis and evaluation of the antiplasmodial activity of novel indeno[2,1-c]quinoline derivatives

With the aim to explore the potentiality of new chemical scaffolds for the design of new antimalarials, a set of new indeno[2,1-c]quinolines bearing different basic heads has been synthesized and tested in vitro against chloroquine sensitive (CQ-S) and chloroquine resistant (CQ-R) strains of Plasmodium falciparum. Most of the synthesized compounds exhibited a moderate antiplasmodial activity, inhibiting the growth of both CQ-S and CQ-R strains of P. falciparum with IC₅₀ ranging from 0.24 to 6.9 μM and with a very low resistance index. The most potent compounds (1.2–1.3-fold the CQ on the W-2 strain) can be considered as promising ‘lead compounds’ to be further optimized to improve efficacy and selectivity against Plasmodia.     

Volatile Nitrogenous Compounds from Bacteria: Source of Novel Bioactive Compounds

Bacteria can produce nitrogenous compounds via both primary and secondary metabolic processes. Many bacterial volatile nitrogenous compounds produced during the secondary metabolism have been identified and reported for their antioxidant, antibacterial, antifungal, algicidal and antitumor activities. The production of these nitrogenous compounds depends on several factors, including the composition of culture media, growth conditions, and even the organic solvent used for their extraction, thus requiring their identification in specific conditions. In this review, we describe the volatile nitrogenous compounds produced by bacteria especially focusing on their antimicrobial activity. We concentrate on azo-compounds mainly pyrazines and pyrrolo-pyridines reported for their activity against several microorganisms. Whenever significant, extraction and identification methods of these compounds are also mentioned and discussed. To the best of our knowledge, this is first review describing volatile nitrogenous compounds from bacteria focusing on their biological activity.     

Sesquiterpenes from the aerial parts of Artemisia tournefortiana

Sixteen eudesmane-type sesquiterpenes, including six unknown ones (1−6), were isolated from the aerial part of A. tournefortiana. NMR, HERIS-MS, IR spectra and ECD calculation assigned their relative and absolute configurations. Six (6, 7, 9, 13, 15, and 16) were tested for cytotoxic and anti-inflammatory activities, and seven (6, 7, 8, 12, 13, 15, and 16) were tested for antimicrobial activity. Among them, compound 15 showed significant cytotoxicity with IC₅₀ values in the range of 1.49–5.30 μM and moderate antimicrobial activity.     

Comparative assessment of biological activities of different parts of halophytic plant Tamarix articulata (T. articulata) growing in Saudi Arabia

Owing to extremely high salinity and harsh environmental conditions, T. articulata is one of the most abundant wild plants growing in the deserts of Saudi Arabia. Such plants may contain novel compounds to display promising biological activities. Here, in this study, we evaluate the biological activities of methanolic extracts of fresh leaves, dry leaves, stem, and roots of T. articulata. The antioxidant activity was determined by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and total phenolic and flavonoid content were determined using standard colorimetric methods. Whereas antimicrobial and ant-proliferative activities were determined by standard well-diffusion and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) methods, respectively. Our results demonstrate that all methanolic extracts of T. articulata showed antioxidant activity, however, the methanolic extract of dry leaves exhibits promising antioxidant effect with IC₅₀ value 49.08 ± 1.98, which was strongly supported by total phenolic (409.92 ± 6.03 mg GAE/g DW) and flavonoid (177.71 mg QE/g DW) content. Although, antimicrobial activity was also exhibited by all the methanolic extracts, however, methanolic extract of dry leaves exhibits promising antimicrobial activity in Gram-positive bacteria Staphylococcus epidemidis. Furthermore, MTT assay revealed that all methanolic extracts exhibit antiproliferative activity in MCF-7 (breast cancer) and RKO (colorectal cancer) cells with IC₅₀ values ranges from 219 ± 5.112 µg/ml to 253 ± 5.231 µg/ml and 220 ± 4.330 µg/ml to 325 ± 6.213 µg/ml, respectively. However, the most promising antiproliferative effect was displayed by methanolic extract of dry leaves with IC₅₀ values 219 ± 5.112 µg/ml and 220 ± 4.330 µg/ml, respectively. In summary, these findings provide evidence that T. articulata has promising biological activities and can be used for many pharmaceutical activities in the future.     

Diversity of natural products of the genera Curvularia and Bipolaris

Covering from 1963 to 2017.This review provides a summary of some secondary metabolites isolated from the genera Curvularia and Bipolaris from 1963 to 2017. The study has a broad objective. First to afford an overview of the structural diversity of these genera, classifying them depending on their chemical classes, highlighting individual examples of chemical structures. Also some information regarding their biological activities are presented. Several of the compounds reported here were isolated exclusively from endophytic and pathogenic strains in culture, while few from other sources such as sea Anemone and fish. Some secondary metabolites of the genus Curvularia and Bipolaris revealed a fascinating biological activities included: anti-malarial, anti-biofouling, anti-larval, anti-inflammatory, anti-oxidant, anti-bacterial, anti-fungal, anti-cancer, leishmanicidal and phytotoxicity. Herein, we presented a bibliography of the researches accomplished on the natural products of Curvularia and Bipolaris, which could help in the future prospecting of novel or new analogues of active metabolites from these two genera.     

Bioactivity-based analysis and chemical characterization of hypoglycemic and antioxidant components from Artemisia argyi

Diabetes is one of the metabolic disorders in the world. It is the prime reason of mortality and morbidity owing to hyperglycemia which is link with numerus obstacles. Artemisia argyi is commonly used as an ingredient in healthy foods as well as an herbal medicine in Asian countries. The present research aims to evaluate the hypoglycemic effects of A. argyi and reveal its the potentially active constituents. The chemical composition was identified by HPLC-DAD-Q-TOF-MS, and fractionation was performed by extraction. The fractions were assessed by the blood glucose level, oral glucose tolerance and small intestinal α-glucosidase inhibitory tests, and an analysis of the total phenolic content (TPC), antioxidant and α-glucosidase inhibitory activities. In our efforts to characterize the compounds responsible for hypoglycemic effect, bioactivity-guided fraction of the MeOH extract and chemical investigation of its active EtOAc fraction led to the successful identification of caffeoylquinic acids, which were elucidated by molecular docking, using the crystal structure of S. cerevisiae isomaltase (PD code: 3AXI). In summary, this bio-guided search revealed that caffeoylquinic acids from A. argyi as potential active constituents displayed with hypoglycemic activity, which provided a basis for further study of pharmacological activity.     

In-vitro antioxidant,antimutagenic and cancer cell growth inhibition activities of Rhododendron arboreum leaves and flowers

In the current investigation, the active principles of the methanol extracts of Rhododendron arboreum leaves (MEL) and flowers (MEF) were investigated with the help of ultra-high performance liquid chromatography (UHPLC), amino acid analyzer and gas chromatography mass spectrometry (GC-MS). UHPLC revealed different polyphenols present in the extracts. GC-MS identified 20 phytochemicals in leaves and 17 in the flowers, whereas, amino acid analyzer confirmed 11 amino acids in leaves and 10 in the flowers. The extracts were subjected to the investigation of biological activity through analysis of antioxidant activity in different in vitro assays, antimutagenic activity in Ames assay and cancer cell growth inhibition activity by MTT (3-4,5 dimethylthiazol-2,5 diphenyltetrazolium bromide) assay. MEL showed higher antioxidant activity in lipid peroxidation inhibition assay (95.32 ± 0.37%) than MEF (77.09 ± 4.17%) with IC₅₀103.6 µg/ml for MEL and 271.17 µg/ml for MEF. In nitric oxide scavenging assay, an activity of 94.46 ± 0.32% (IC₅₀ 150.13) was observed in MEF followed by 83.71 ± 0.74% (IC₅₀ 179.52) in MEL. The antimutagenic activity of both the extracts was evaluated against sodium azide, 4-nitro-O-phenylenediamine and 2-aminofluorene mutagens in TA-98 and TA-100 strains of Salmonella typhimurium. The analysis was carried out using pre- and co-incubation modes. However, both extracts were observed to possess considerable antimutagenic activity against different known mutagens, flowers came out to be more effective than the leaves in terms of % inhibition. The extracts also exhibited significant cancer cell growth inhibition activity, when tested against 3 cancer cell lines namely, Human cervical cancer cell line (HeLa), Breast cancer cell line (MCF7) and Lung cancer cell line (A549). In case of HeLa and A549, MEL showed higher activity of 64.62 ± 2.65 and 75.08 ± 1.68% as compared to 53.11 ± 2.84 and 45.92 ± 2.43% in MEL, respectively. The EC₅₀ values for MEL in HeLa and A549 were noted to be 232.76 and 155.38 µg/ml, respectively, whereas, MEF had EC₅₀ of 395.50 µg/ml in HeLa and 660.26 µg/ml in A549. Further, MEF showed higher cytotoxicity in MCF7 cell line (84.93 ± 1.17%) followed by the MEL (73.57 ± 1.27%) with EC₅₀ value of 95.16 µg/ml for MEF followed by 172.19 µg/ml for MEL. The biological activities of the extracts can be attributed to the phyto-constituents identified by sophisticated instruments.The biological activities of the extracts can be attributed to the active principles identified by sophisticated instruments.     

Synthesis and bioactivities evaluation of l-pyroglutamic acid analogues from natural product lead

A series of l-pyroglutamic acid analogues from natural product lead were designed and synthesized, as well as their antifungal activities against Phytophthora infestans, neuritogenic activities, antibacterial activities and anti-inflammatory activities are described. The bioassays and SAR study showed that the majority of l-pyroglutamic acid esters have a significant antifungal activity against P. infestans, especially 2d and 2j demonstrated the best activities with EC₅₀ values of 1.44 and 1.21?μg?mL^?1, which were about seven times that of commercial azoxystrobin (7.85?μg?mL^?1). Moreover, compounds 2e, 2g and 4d displayed anti-inflammatory activity against LPS-induced NO production in BV-2 microglial cells; neuritogenic activity in NGF-induced PC-12 cells is the same activity. This study demonstrates that compounds 2d and 2j are potential drugs to control P. infestans.     

In vitro screening of pentamidine analogs against bacterial and fungal strains

A series of linear pentamidine analogs exhibiting low cytotoxicity, active against Pneumocystis carinii, were evaluated for in vitro activities against bacterial and fungal strains. The majority of the tested bis-amidines exhibited marked activities against Gram-positive strains. In view of the fact that the highest potency was found for 1,5-bis(4-amidinophenoxy)-3-thiapentane dihydrochloride 1j with the S atom in the middle of the aliphatic linker, four new pentamidines bearing S atoms were synthesized and also evaluated against MRSA strains. N,N′-Dialkylated pentamidines with S atoms in the linker are the promising lead structures for antimicrobials development.     

Glutathione S-transferase pi (GST-pi) inhibition and anti-inflammation activity of the ethyl acetate extract of Streptomyces sp. strain MJM 8637

To investigate the anti-cancer properties of soil-borne actinobacteria, MJM 8637, the glutathione S-transferase pi (GST-pi) assay, anti-tumor necrosis factor (TNF)-α assay, the level of antioxidant potential by DPPH radical scavenging activity, NO scavenging activity, and ABTS radical scavenging activity in ethyl acetate extract were determined. The 16S rDNA sequencing analysis revealed that Streptomyces sp. strain MJM 8637, which was isolated from Hambak Mountain, Korea, has 99.5% similarity to Streptomyces atratus strain NBRC 3897. The physiological and the morphological characteristics of the strain MJM 8637 were also identified. The ethyl acetate extract of MJM 8637 inhibited TNF-α production approximately 61.8% at concentration 100 μg/ml. The IC₅₀ value of the strain MJM 8637 extract on GST-pi was identified to be 120.2 ± 1.6 μg/ml. In DPPH, NO, and ABTS radical scavenging assays, the IC₅₀ values of the strain MJM 8637 extract were found to be 977.2 μg/ml, 1143.7 μg/ml, and 454.4 μg/ml, respectively. The ethyl acetate extract of the strain MJM 8637 showed 97.2 ± 1.3% of cell viability at 100 μg/ml in RAW 264.7 cell viability assay. The results obtained from this study suggest that the ethyl acetate extract of Streptomyces sp. strain MJM 8637 could be considered as a potential source of drug for the cancers that have multidrug resistance with its GST-pi inhibition and anti-inflammation activities, and low cytotoxicity.     

Phytochemical Diversity and Pharmacological Properties of Rhus coriaria

Rhus coriaria L. (Anacardiaceae), sumac, is a common condiment, appetizer and souring agent in the Mediterranean region that has a long history in traditional medicine. R. coriaria has been prescribed for the treatment of many ailments including diarrhea, ulcer, hemorrhoids, hemorrhage, wound healing, hematemesis, and eye ailments like ophthalmia and conjunctivitis. The plant is also used as diuresis, antimicrobial, abortifacient and as a stomach tonic. Sumac is known to be rich in different classes of phytochemicals including tannins, polyphenols, flavonoids, organic acids and essential oils and continues to be a hot topic for extensive research work designed for revealing its phytochemical constituents and evaluating its bioactive properties. This review summarizes the recent phytochemical and diverse bioactivity studies on R. coriaria, especially those concerned with antitumor, antioxidant, hypoglycemic, antimicrobial, and anti‐inflammatory studies.     

Weekend and weekday patterns of physical activity in overweight and normal-weight adolescent girls

Objective: To describe the patterns (specifically comparing weekdays and weekends classified by intensities) of physical activity (PA) measured by accelerometry in adolescent girls. Research Methods and Procedures: Healthy sixth grade girls (n = 1603), 11 to 12 years old, were randomly recruited from 36 schools participating in the Trial of Activity in Adolescent Girls. Age, ethnicity, socioeconomic status, weight, and height were taken. PA patterns were measured for 6 days using accelerometry. Results: Adolescent girls spend most of their time in sedentary (52% to 57% of the day) and light activity (40% to 45% of the day) on weekdays and weekends. In all girls, total PA comprised 44.5% of the day (41.7% light, 2.2% moderate, and 0.7% vigorous) with sedentary activity comprising 55.4%. Moderate‐to‐vigorous PA (MVPA) was higher (p < 0.001) on weekdays than weekends in all girls, but MVPA was lower in at‐risk of overweight + overweight girls (p < 0.001) on both weekdays and weekends compared with normal‐weight girls. Discussion: Adolescent girls are more active at moderate and vigorous intensities on weekdays than on weekends, and at‐risk of overweight and those overweight spend less time engaging in MVPA than normal‐weight girls.     

Production of leucinostatins and nematicidal activity of Australian isolates of Paecilomyces lilacinus (Thom) Samson

AIMS: To evaluate the relationship between leucinostatin production by Paecilomyces lilacinus isolates and their biological activities. METHODS AND RESULTS: The nematicidal, parasitic and enzymatic activity of Australian P. lilacinus isolates were investigated. Nematicidal activities of culture filtrates were measured by mortality and inhibition of reproduction of Caenorhabditis elegans, whereas egg-parasitic activity was measured by colonization on Meloidogyne javanica. Enzymatic activities (protease and chitinase) were assayed on solid media. The results suggest that leucinostatins in P. lilacinus are indicators of nematicidal activity, whereas chitinase activity might be related to parasitism. CONCLUSIONS: Nematicidal activity of culture filtrates of Paecilomyces lilacinus strains related to their ability to produce leucinostatins. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study describing the leucinostatins as nematicides.     

Kinetic properties of tetrameric glycogen phosphorylase b in solution and in the crystalline state.

R-state monoclinic P2(1) crystals of phosphorylase have been shown to be catalytically active in the presence of an oligosaccharide primer and glucose-1-phosphate in 0.9 M ammonium sulfate, 10 mM beta-glycerophosphate, 0.5 mM EDTA, and 1 mM dithiothreitol, the medium in which the crystals are grown or equilibrated for crystallographic studies (Barford, D. & Johnson, L.N., 1989, Nature 360, 609-616; Barford, D., Hu, S.-H., & Johnson, L.N., 1991, J. Mol. Biol. 218, 233-260). Kinetic data suggest that the activity of crystalline tetrameric phosphorylase is similar to that determined in solution for the enzyme tetramer. However, large differences were found in the maximal velocities for both oligosaccharide or glucose-1-phosphate substrates between the soluble dimeric and crystalline tetrameric enzyme.     

Antiproliferative and Proapoptotic Activities of a New Class of Pyrazole Derivatives in HL‐60 Cells

A series of N‐substituted pyrazole derivatives have been synthesized and tested for their anticancer effect on the HL‐60 leukaemia cell line. Four were active both in cell‐growth inhibition and in inducing apoptosis. The inhibition of cell growth mainly reflects a compound‐induced reduction in the number of cells in phases from S to M, whereas the induction of apoptosis involves inhibition of expression of Bcl‐2 and enhanced expression of Bax with consequent reduced activation of the proapoptotic caspase 3. Finally, preliminary experiments carried out with tumor cells from myelogenous leukaemic patients showed that the compounds 4c, 4l, 4m , and 4n are indeed capable of inducing apoptosis.