Two New Triterpenes from Neonauclea sessilifolia

Two new triterpenoids, 3 β, 15α, 21 β, 23-tetrahydroxy-12-oleanen-28-oic acid (1), 3β , 6 α , 21β, 23-tetrahydroxy-12-oleanen-28-oic acid (2), together with seven known compounds, viz., paeonol (3), 3, 4-dihydroxybenzoic acid (4), scosoletin (5), anthraquinones chrysophanol (6), 4H-1-benzopyran-4-one, 5, 7-dihydroxy-2-methyl (7),β-sitosterol (8) and stigmasterol glucoside (9) were isolated by the chromatography of the silica gel, RP-18 and Sephadex-LH 20 from the EtOAc extract of Neonauclea sessilifolia (Roxb.) Merr. ( Rubiaceae ). Their structures were elucidated based on spectral analysis including 1D-, 2D-NMR (HMQC, HMBC), IR and EIMS. Among them, compound 6 was shown to possess inhibitory activity on the growth of Mycobacterium tuberculosis (Zopf) Lehmann et Neumann with a minimum inhibitory amount of 25μg, compounds 2 and 4 also showed weak inhibitory activities on the growteof M. tuberculosis.

Study on Anti-oxidation and Inhibitory Effect on Nonenzymatic Glycation Reaction of Fermentation Extract from Biotransformation of Ginkgo biloba L. (EGB) by Hericium erinaceus

[ Objective] In order to study the anti-oxidation and inhibitory effect on nonenzymatic glycation reaction of EGB fermentation extraction biotransformed by Hericium erinaceus. [ Method ] The free radical scavenging ability and reducing capacity of DPPH as well as inhibitory rate of nonenzymatic glycation reaction were measured targets for comparing changes of anti-oxidation and inhibitory effect on nonenzymatic glycation reaction of fermentation lyophilizer and fermentation extraction before and after EGB fermention adsorbed by AB-8 macroporous resin. The EGB fermention was biotransformed by Hericium erinaceus. [ Result ] After adsorbed by AB-8 macroporous resin, the bioactive matters were concentrated and separated. The free radical scavenging rate, reducing capacity and inhibitory rate of nonenzymatic glycation reaction were increased significantly after adsorbed by AB-8 macroporous resin. [ Conclusion] AB-8 macroporous resin could be used for preliminary concentration of EGB fermentation which was biotransformed by Hericium erinaceus.

Antibiotic Activity of Seven Fungicides against Alternaria panax Whetz

[Objective] This study was conducted to screen suitable fungicides to con-trol ginseng leaf blight caused by Alternaria panax_Whetz. [Method] The antifungal activity of seven fungicides against A. panax_ was determined based on mycelial growth rate in vitro. [Result] The results of in vitro antibiotic activity assay showed that there were significant differences in inhibition rate among different concentration treatments of each of the seven fungicides. Toxicity test results showed that among the seven fungicides, difenoconazole had the smal est EC50 （0.61 mg/L）, fol owed by streptomycin and captan, with EC50 value lower than 100 mg/L. [Conclusion] A fungicide which had strong antifungal activity on A. panax was screened out, and the results wil provide a theoretical basis for further field trial.

Research Advances in the Inhibition of Long Chain Fatty Acid to Methanogenic Activity in Anaeroic Digestion System

This article reviewed the inhibition mechanism of long chain fatty acid on the formation of anaerobic system, then thoroughly analyzed the inhibition factors of long chain fatty acid, and summarized the remission method to its inhibition, finally proposed some suggestions to further study on the influence of long chain fatty acid on anaerobic digestion system.

Effect of Inhibitor K-23 on O_2-evolution and Hill Activity of PSⅡ Membrane Fragments of Spinacia oleracea

研究了新的抑制剂K_2 3对波菜 (SpinaciaoleraceaMill.)PSⅡ放氧活性和 2 ,6_dichlorophenolindophenol (DCIP)光还原活性的影响。研究发现 :抑制剂K_2 3在低浓度时对PSⅡ放氧活性有明显促进作用 ,而对DCIP光还原活性的促进作用不太明显。在高浓度时抑制PSⅡ放氧活性和DCIP光还原。对K_2 3的抑制部位进行了初步探讨。

Cantharidin and Its Analogues:Anticancer and Ser/Thr Protein Phosphatase Inhibitory Activities

This paper mainly describes the anticancer activities and Ser/Thr protein phosphatase inhibitory activities of cantharidin and its analogues.

Suppressing progress of pancreatitis through selective inhibition of NF-κB activation by using NAC

Objective: To explore the characteristics of NF-闎 activation in the progress of pancreatitis, the relationship with expression of TNF- in the inflammatory reaction, and prevent the exacerbation of pancreatitis by using NAC. Method: Forty-eight rats were divided into three groups: therapy (group C), pancreatitis (group B) and control (group A). NAC served as the inhibitor of NF-闎 activation. In the time intervals of 1.5, 3.0, 6.0, 12.0 hour, NF-闎 activation was detected with flow cytometry (FCM) and the expression of TNF- mRNA and protein with in situ hybridization (ISH) and enzyme-linked immuno-sorbent assay (ELISA) respectively. Meanwhile, the level of lipase and amylase in the serum was assayed and the pathological change was evaluated. Result: NF-闎 activation in the pancreatitis group was higher than that in the control group (P<0.01), peaked at 3 hours, and was depressed by the inhibitor of NF-闎, NAC. The expression of TNF- as well as the level of lipase and amylase in the serum also rose synchronously with activation of NF-闎. In contrast to group A, it was significantly different (P<0.01) in group B. After using NAC in group C, all of these values were decreased and the in-flammatory reaction in the pancreas abated evidently. The pathology changes of the pancreas were shown to be alleviated in group C. Conclusion: First, NF-闎 activity is intensively initiated in the course of pancreatitis and shown to have closely relationship with the release of cytokines. Second, use of NAC markedly depressed NF-闎 activation. TNF- expression is down regulated by cytokines. It is suggested that NAC probably acts as a useful agent for treatment of pancreatitis by indirectly inhibiting activation of NF-闎.

Activator protein-1 involved in growth inhibition by RASSF1A gene in the human gastric carcinoma cell line SGC7901

AIM:To investigate the role of Ras association domain family protein 1 isoform A (RASSF1A) in gastric tumorigenesis. METHODS:Through over-expression of RASSF1A gene in the SGC7901 cell line which was induced by a lipofectamine-mediated gene transfer approach. Activator protein-1 (AP-1) DNA binding activity was measured by electrophoretic mobility shift assay (EMSA). RESULTS:Compared with the control clones, cells over- expressing RASSF1A exhibited significant inhibition of cell growth with G1 cell cycle arrest in vitro and in vivo. The over-expression of RASSF1A significantly inhibited AP-1 activity in SGC7901 cells (0.981±0.011 vs 0.354±0.053, P<0.001). In addition, both Western blot analysis and immunocytochemistry demonstrated that RASSF1A down-regulated the expression of c-Fos (0.975± 0.02 vs 0.095±0.024, P<0.001) but not c-Jun. CONCLUSION: Over-expression of RASSF1A inhibits the growth of SGC7901 cells by negatively regulating the AP-1 activity, the latter in turn negatively signals cell proliferation.

Reactive oxygen species: A double-edged sword in oncogenesis

Reactive oxygen species (ROS) are molecules or ions formed by the incomplete one-electron reduction of oxygen. Ofinterest, it seems that ROS manifest dual roles, cancer promoting or cancer suppressing, in tumorigenesis. ROS participate simultaneously in two signaling pathways that have inverse functions in tumorigenesis, Ras-Raf-MEK1/2-ERK1/2 signaling and the p38 mitogen-activated protein kinases (MAPK) pathway. It is well known that Ras-Raf-MEK1/2-ERK1/2 signaling is related to oncogenesis, while the p38 MAPK pathway contributes to cancer suppression, which involves oncogene-induced senescence, inflammationinduced cellular senescence, replicative senescence, contact inhibition and DNA-damage responses. Thus, ROS may not be an absolute carcinogenic factor or cancer suppressor. The purpose of the present review is to discuss the dual roles of ROS in the pathogenesis of cancer, and the signaling pathway mediating their role in tumorigenesis.

Chemical constituents of marine mangrove-derived endophytic fungus Alternaria tenuissima EN-192

A chemical investigation of the ethyl acetate extract of the fermentation broth of Alternaria tenuissima EN- 192, an endophytic fungus obtained from the stems of the marine mangrove plant Rhizophora stylosa, resulted in the isolation of nine known secondary metabolites, including four indole-diterpenoids： penijanthine A （1）, paspaline （2）, paspalinine （3）, and penitrem A （4）; three tricycloalternarene derivatives： tricycloalternarene 3a （5）, tricycloalternarene lb （6）, and tricycloalternarene 2b （7）; and two alternariol congeners： djalonensone （8） and alternariol （9）. The chemical structures of these metabolites were characterized through a combination of detailed spectroscopic analyses and their comparison with reports from the literature. The inhibitory activities of each isolated compound against four bacteria were evaluated and compounds 5 and 8 displayed moderate activity against the aquaculture pathogenic bacterium Vibrio anguillarum, with inhibition zone diameters of 8 and 9 mm, respectively, at 100 gg/disk. To the best of our knowledge, this is the first report on the secondary metabolites of mangrove-derived Alternaria tenuissima and also the first report of the isolation ofindole-diterpenoids from fungal genus Alternaria.

Selenium Distribution Pattern, Antineoplastic and Immunostimulatory Activities of a Novel Organoselenium Compound Eb

Aim To study the distribution pattern, antineoplastic activity and immunocompetence of a novel organoselenium compound Eb and investigate its in vivo antineoplastic potential. Methods Eb was administered to Kunming mice (dosage, 0.1 g·kg^(-1)·d^(-1)) intragastrically for 7 successive days. The contents of selenium in heart, liver, spleen, kidneys, lungs, stomach, brain, muscle, and bone were determined by fluorometric method on the eighth day. MTT assay was used to study tumor growth inhibition of Eb in vitro, and lymphocyte transformation, hemolysin formation and phagocytosis assay were used to study its immunocompetence. Results After 7 days′ administration of Eb, the tissue contents of sele-(nium) in liver, spleen, lungs, kidneys, and bone of mice increased, especially those in liver and spleen increased significan-tly, compared with controls; but no significant changes of such contents were found in muscle, heart, brain, and stomach. Eb demonstrated inhibitory effects on human Bel-7402, BGC-823, and Calu-3 cancer cell lines in vitro. Eb also showed ability to enhance lymphocyte transformation and serum hemolysin formation in vitro and increase the phagocytosis of macrophages. Conclusion The validated antitumor and immunostimulatory activities of Eb suggest a hypothesis that Eb may behave as a biological response modifier when used as an antitumor agent. Eb is worthy of further study in developing a new antineoplastic and immunity enhancing agent in the light of its antitumor activity, immunocompetence and specific distribution in liver, lungs, kidneys, bone, and spleen.

Ultrasonic Extraction of Polysaccharides from Laminaria japonica and Their Antioxidative and Glycosidase Inhibitory Activities

In the present study, ultrasonic extraction technique （UET） is used to improve the yield of polysaccharides from Lami- naria japonica （LJPs）. And their antioxidative as well as glycosidase inhibitory activities are investigated. Box-Behnken design （BBD） combined with response surface methodology （RSM） is applied to optimize ultrasonic extraction for polysaccharides. The optimized conditions are obtained as extraction time at 54 min, ultrasonic power at 1050 W, extraction temperature at 80℃ and ratio of material to solvent at 1：50 （g mL-1）. Under these optimal ultrasonic extraction conditions, an actual experimental yield （5.75% ＋ 0.3%） is close to the predicted result （5.67%） with no significant difference （P〉0.05）. Vitro antioxidative and glycosidase inhibitory activities tests indicate that the crude polysaccharides （LJP） and two major ethanol precipitated fractions （LJP1 and LJP2） are in a concentration-dependent manner. LJP2 （30%-60% ethanol precipitated polysaccharides） possesses the strongest α-glucosidase in- hibitory activity and moderate scavenging activity against hydroxyl radicals （66.09% ±2.19%, 3.0 mg mL-l）. Also, the inhibitory activity against a-glucosidase （59.08% ± 3.79%, 5.0 mg mL-1） is close to that of acarbose （63.99% ± 3.27%, 5.0 mg mL-l）. LJP 1 （30% ethanol precipitated polysaccharides） exhibits the strongest scavenging activity against hydroxyl radicals （99.80%q-0.00%, 3.0mg mL-1） and moderate a-glucosidase inhibitory activity （47.76%± 1.92%, 5.0 mgmL-1）. LJP shows the most remarkable DPPH scav- enging activity （66.20%±0.11%, 5.0mgmL-1） but weakest a-glucosidase inhibitory activity （37.77%±1.30%, 5.0mgmL-1）. How- ever, all these LJPs exert weak inhibitory effects against a-amylase. These results show that UET is an effective method for extract- ing bioactive polysaccharides from seaweed materials. LJP 1 and LJP2 can be developed as a potential ingredient in hypoglycemic agents or functional food for the management of diabetes. This study provides scientific evidence and advances in the preparation technology and a hypoglycemic activities evaluation method for seaweed polysaccharides, especially glycosidase inhibition in com- bination with an antioxidative activity evaluation method.

Inhibition of norsolorinic acid accumulation to Aspergillus parasiticus by marine actinomycetes

Thirty-six strains of marine actinomycetes were isolated from a sample of marine sediment collected from the Yellow Sea and evaluated in terms of their inhibitory activity on the growth of Aspergillus parasiticus and the production of norsolorinic acid using dual culture plate assay and agar diffusion methods.Among them,three strains showed strong antifungal activity and were subsequently identified as Streptomyces sp.by 16 S rRNA gene sequencing analysis.The supernatant from the fermentation of the MA01 strain was extracted sequentially with chloroform and ethyl acetate,and the activities of the extracts were determined by tip culture assay.The assay results show that both extracts inhibited mycelium growth and toxin production,and the inhibitory activities of the extracts increased as their concentrations increased.The results of this study suggest that marine actinomycetes are biologically important for the control of mycotoxins,and that these bacteria could be used as novel biopesticides against mycotoxins.

Purification and Characterization of Angiotensin I Converting Enzyme Inhibition Peptides from Sandworm Sipunculus nudus

Three angiotensin I converting enzyme(ACE) inhibition peptides were isolated from sandworm Sipunculus nudus protein hydrolysate prepared using protamex. Consecutive purification methods, including size exclusion chromatography and reverse-phase high performance liquid chromatography(RP-HPLC), were used to isolate the ACE inhibition peptides. The amino acid sequences of the peptides were identified as Ile-Asn-Asp, Val-Glu-Pro-Gly and Leu-Ala-Asp-Glu-Phe. The IC_(50) values of the purified peptides for ACE inhibition activity were 34.72 μmol L^(-1), 20.55 μmol L^(-1) and 22.77 μmol L^(-1), respectively. These results suggested that S. nudus proteins contain specific peptides that can be released by enzymatic hydrolysis. This study may provide an experimental basis for further systematic research, rational development and clinical utilization of sandworm resources.

Binding activity of H-Ras is necessary for in vivo inhibition of ASK1 activity

H-Ras is well known as one of the essential components of Ras/Raf/MEK/ERK cascade, which is a critical prosurvival signaling mechanism in most eukaryotic cells. Ras targets Raf/MEK/ERK cascade by integrating and transmitting extracellular signals from growth factor receptors to Raf, leading to the propagation of signals to modulate a serious of cellular survival events. Apoptosis signal-regulating kinasel (ASK1) serves as a general mediator of cell death because it is responsive to a variety of death signals. In this study, we found that H-Ras interacted with ASK1 to cause the inhibition of both ASK1 activity and ASK1-induced apoptosis in vivo, which was reversed only partially by addition of RafS621A, an antagonist of Raf, whereas MEK inhibitor, PD98059, and PI3K inhibitor, LY294002, did not disturb the inhibitory effect of H-Ras on ASK-1-induced apoptosis. Furthermore, by means of immunoprecipitate and kinase assays, we demonstrated that the interaction between H-Ras and ASK1 as well as the inhibition of ASK1 activity were dependent on the binding activity of H-Ras. These results suggest that a novel mechanism may be involved in H-Rasmediated cell survival in addition to the well established MEK/ERK and PI3K/Akt kinase-dependent enhancement of cell survival.

Migration-associated secretion of melanoma inhibitory activity at the cell rear is supported by KCa3.1 potassium channels

Malignant melanoma, characterized by invasive local growth and early formation of metastases, is the most aggressive type of skin cancer. Melanoma inhibitory activity （MIA）, secreted by malignant melanoma cells, interacts with the cell adhesion receptors, integrins a4131 and 05131, facilitating cell detachment and promoting formation of me- tastases. In the present study, we demonstrate that MIA secretion is confined to the rear end of migrating cells, while in non-migrating cells MIA accumulates in the actin cortex. MIA protein takes a conventional secretory pathway including coat protein complex I （COPI）- and coat protein complex II （COPII）-dependent protein transport to the cell periphery, where its final release depends on intracellular Ca2＋ ions. Interestingly, the Ca2＋-activated K＋-channel, subfamily N, member 4 （KCa3.1）, known to be active at the rear end of migrating cells, was found to support MIA secretion. Secretion was diminished by the specific KCa3.1 channel inhibitor TRAM-34 and by expression of dominant- negative mutants of the channel. In summary, we have elucidated the migration-associated transport of MIA protein to the cell rear and also disclosed a new mechanism by which KCa3.1 potassium channels promote cell migration.

Inhibitory activity of an extract from a marine bacterium Halomonas sp.HSB07 against the red-tide microalga Gymnodinium sp.(Pyrrophyta)

In recent years,red tides occurred frequently in coastal areas worldwide.Various methods based on the use of clay,copper sulfate,and bacteria have been successful in controlling red tides to some extent.As a new defensive agent,marine microorganisms are important sources of compounds with potent inhibitory bioactivities against red-tide microalgae,such as Gymnodinium sp.(Pyrrophyta).In this study,we isolated a marine bacterium,HSB07,from seawater collected from Hongsha Bay,Sanya,South China Sea.Based on its 16S rRNA gene sequence and biochemical characteristics,the isolated strain HSB07 was identified as a member of the genus Halomonas.A crude ethyl acetate extract of strain HSB07 showed moderate inhibition activity against Gymnodinium sp.in a bioactive prescreening experiment.The extract was further separated into fractions A,B,and C by silica gel column chromatography.Fractions B and C showed strong inhibition activities against Gymnodinium.This is the first report of inhibitory activity of secondary metabolites of a Halomonas bacterium against a red-tide-causing microalga.

Effect of Lime Nitrogen on the Transformation of Ureain Soils

Laboratory incubation experiment was conducted to study the effect of lime nitrogen(LN) on transfor-mation of iirea-N in three paddy soils. The results showed that LN had an inhibitory effect on urease activityin these soils especially in the first 5 days, and that in the first 20 days of incubation, the amount of NH-Nderived from urea was lower in the soil with LN than in the soil without LN. While after 30 days the ainountof NH-N was higher in the mature haplic paddy soil developed on Quaternary red clay(MHPS) with LNthan that in the soil without LN. The amonnt of NH_3-N volatilized was decreased in the earlier stage andincreased in the later stage of incubation in the MHPS by the addition of LN.

In vitro study of immunosuppressive effect of apoptotic cells

Recent studies revealed that apoptotic cells are actively involved in immunosuppression and anti-inflammation. After being phagocytosed by macrophages, apoptotic cells can actively regulate cytokines secretion from lipopolysaccharide （LPS）-stimulated macrophages, in which the secretion of immunosuppressive cytokines such as interleukin-10 （1L-10） is increased while the pro-inflammatory cytokines such as tumor necrosis factor-alpha （TNFα）, interleukin-lbeta （IL-1β） and leukin-8 （IL-8） are suppressed. In this paper, we first present evidence that phagocytosed apoptotic cells regulate cytokine secretion of LPS-stimulated macrophages, but also inhibit the activation of T lymphocytes stimulated by ConA. These data suggest that apoptotic cells can alter the biological behavior of macrophages which gain immunosuppressive property.

Extraction and PTP1B inhibitory activity of bromophenols from the marine red alga Symphyocladia latiuscula

Previously, we had characterized several structurally interesting brominated phenols from the marine red alga Symphyocladia latiuscula collected from various sites. However, Phytochemical investigations on this species collected from the Weihai coastline of Shandong Province remains blank. Therefore, we characterized the chemical constituents of individuals of this species collected from the region. Eight bromophenols were isolated and identified. Using detailed spectroscopic techniques and comparisons with published data, these compounds were identified as 2,3-dibromo-4,5-dihydroxybenzyl methyl ether (1), 3,5-dibromo-4-hydroxybenzoic acid (2), 2,3,6-tribromo-4,5-dihydroxymethylbenzene (3), 2,3,6-tribromo-4,5-dihydroxybenzaldehyde (4), 2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether (5), bis(2,3,6-tribromo-4,5-dihydroxyphenyl)methane (6), 1,2-bis(2,3,6-tribromo-4,5-dihydroxyphenyl)-ethane (7), and 1-(2,3,6-tribromo-4,5-dihydroxybenzyl)-pyrrolidin-2-one (8). Among these compounds, 1 and 2 were isolated for the first time from S. latiuscula. Each compound was evaluated on the ability to inhibit protein tyrosine phosphatase 1B (PTP1B), which is a potential therapeutic target in the treatment of type 2 diabetes. Bromophenols 5, 6, and 7 showed strong activities with IC50 values of 3.9, 4.3, and 3.5 μmol/L, respectively. This study provides further evidence that bromophenols are predominant among the chemical constituents of Symphyocladia, and that some of these compounds may be candidates for the development of anti-diabetes drugs.