Two novel furan derivatives from Phellinus linteus with anti-complement activity

Two novel stereoisomers of furan derivatives, phellinusfurans A (1) and B (2), were isolated from the fruiting body of Phellinus linteus. Their structures were elucidated by spectroscopic analysis. Compounds 1 and 2 exhibited significant anti-complement activity with IC50 values of 33.6 and 33.7 microM, respectively, in inhibiting the hemolytic activity of human serum against erythrocytes.     

Analysis of sialyltransferase-like proteins from Oryza sativa

Sialic acids are widely distributed among living creatures, from bacteria to mammals, but it has been commonly accepted that they do not exist in plants. However, with the progress of genome analyses, putative gene homologs of animal sialyltransferases have been detected in the genome of some plants. In this study, we cloned three genes from Oryza sativa (Japanese rice) that encode sialyltransferase-like proteins, designated OsSTLP1, 2, and 3, and analyzed the enzymatic activity of the proteins. OsSTLP1, 2, and 3 consist of 393, 396, and 384 amino acids, respectively, and each contains sequences similar to the sialyl motifs that are highly conserved among animal sialyltransferases. The recombinant soluble forms of OsSTLPs produced by COS-7 cells were analyzed for sialyltransferase-like activity. OsSTLP1 exhibited such activity toward the oligosaccharide Galbeta1,4GlcNAc and such glycoproteins as asialofetuin, alpha1-acid glycoprotein, and asialo-alpha1-acid glycoprotein; OsSTLP3 exhibited similar activity toward asialofetuin; and OsSTLP2 exhibited no sialyltransferase-like activity. The sialic acid transferred by OsSTLP1 or 3 was linked to galactose of Galbeta1,4GlcNAc through alpha2,6-linkage. This is the first report of plant proteins having sialyltransferase-like activity.     

Immunosuppressive activity in buffalo placenta

Immunosuppressive activity in buffalo placenta was evaluated by measuring proliferation of lymphocytes in presence of phytohaemagglutinin (PHA) alone or PHA plus placental proteins. The immunosuppressive activity was dose-dependent over the protein concentration range of 10-50 micrograms/ml. Proteins from both cotyledon and non-cotyledon portions of placenta exhibited immunosuppressive activity. Fractions obtained with 0-40, 40-60 and 60-80% saturated ammonium sulphate exhibited 70, 73 and 75% suppression, respectively. PBS-soluble placental proteins were resolved on G-100 column into three peaks that exhibited 69 (peak 1), 55 (peak 2) and 73% (peak 3) suppression. Exogenously added interleukin-1 (IL-1) failed to reverse the suppression caused by buffalo placental proteins.     

Biological evaluation of curcumin and related diarylheptanoids

Nine derivatives of three natural diarylheptanoids, curcumin, demethoxycurcumin and bisdemethoxycurcumin, were prepared. Their antioxidant, free radical scavenging, nitric oxide (NO) inhibitory and cytotoxic activities were evaluated and compared with those of the respective natural compounds. Curcumin (1), demethoxycurcumin (2), demethyldemethoxy-curcumin (C3), diacetyldemethoxycurcumin (AC2) and triacetyldemethylcurcumin (AC5) exhibited higher antioxidant activity than quercetin while products from demethylation of 1 and 2 exhibited higher free radical scavenging activity. Compounds AC2 and AC5 were found to be most active in inhibiting breast cancer cells (MCF-7) proliferation with IC50 values of 6.7 and 3.6 microM, respectively. The activity of AC2 is almost doubled and of AC5 almost tripled as compared to curcumin. Their selectivity towards different cell lines is also more noticeable. Compounds AC2 and AC5 also showed increased activity against a human prostate cancer cell line (DU-145) and non-small lung cancer cell line (NCI-H460) with IC50 values of 20.4, 16.3 and 18.3, 10.7 microM, respectively.     

Naphthalene Derivatives and Quinones from Ventilago denticulata and Their Nitric Oxide Radical Scavenging,Antioxidant, Cytotoxic,Antibacterial, and Phosphodiesterase Inhibitory Activities

New naphthalene derivatives ( 1 and 2 ) and a new isomer ( 3 ) of ventilagolin, together with known anthraquinones, chrysophanol ( 4 ), physcion or emodin 3‐methyl ether ( 5 ), and emodin ( 6 ), were isolated from vines of Ventilago denticulata. The isolated compounds exhibited cytotoxic activity with IC₅₀ values of 1.15 – 40.54 μg/ml. Compounds 1 – 3 selectively exhibited weak antibacterial activity (MIC values of 200.0 – 400.0 μg/ml), while emodin ( 6 ) displayed moderate antibacterial activity with MIC value of 25.0 μg/ml. The isolated compounds showed nitric oxide and DPPH radical scavenging activities. Compounds 1 – 3 and 6 exhibited weak xanthine oxidase inhibitory activity, while emodin ( 6 ) acted as an aromatase inhibitor with the IC₅₀ value of 10.1 μm . Compounds 1 and 2 exhibited phosphodiesterase 5 inhibitory activity with IC₅₀ values of 8.28 μm and 6.48 μm , respectively.     

Purification and Characterization of Two Forms of Glutamine Synthetase from the Pedicel Region of Maize (Zea mays L.) Kernels

Maize (Zea mays L.) kernel pedicels, including vascular tissues, pedicel parenchyma, placento-chalazal tissue, and the surrounding pericarp, contained two forms of glutamine synthetase (EC 6.3.1.2), separable by anion exchange chromatography under mildly acidic conditions. The earlier-eluting activity (GS_p1), but not the later-eluting activity (GS_p2), was chromatographically distinct from the maize leaf and root glutamine synthetases. The level of GS_p1 activity changed in a developmentally dependent manner while GS_p2 activity was constitutive. GS_p1 and GS_p2 exhibited distinct ratios of transferase to hydroxylamine-dependent synthetase activities (5 and 23, respectively), which did not change with kernel age. Purified pedicel glutamine synthetases had native relative molecular masses of 340,000, while the subunit relative molecular masses differed slightly at 38,900 and 40,500 for GS_p1 and GS_p2, respectively. Both GS forms required free Mg²⁺ with apparent K_ms = 2.0 and 0.19 millimolar for GS_p1 and GS_p2, respectively. GS_p1 had an apparent K_m for glutamate of 35 millimolar and exhibited substrate inhibition at glutamate concentrations greater than 90 millimolar. In contrast, GS_p2 exhibited simple Michaelis-Menten kinetics for glutamate with a K_m value of 3.4 millimolar. Both isozymes exhibited positive cooperativity for ammonia, with S_0.5 values of 100 and 45 micromolar, respectively. GS_p1 appears to be a unique, kernel-specific form of plant glutamine synthetase. Possible functions for the pedicel GS isozymes in kernel nitrogen metabolism are discussed.     

Syntheses of C(18) dibenzocyclooctadiene lignan derivatives as anti-HBsAg and anti-HBeAg agents

(+)-Gomisin K(3) (1) and kadsurarin (2) were isolated from Schizandra arisanensis and Kadsura matsudai, respectively, and a series of C(18) dibenzocyclooctadiene lignan analogues (5-20) derived from 1 and 2 were synthesized. Esterified derivatives of 1 and 2 were evaluated for inhibitory activity against human type B hepatitis with surface antigen (HBsAg) and e antigen (HBeAg). Most of the analogues (5-8, 10, 12-13) derived from 1 exhibited higher anti-HBsAg effects and lower toxicity, and 6, 7, 8 and 12 also showed higher anti-HBeAg activity. Among these active C(18) dibenzocyclooctadiene lignan analogues, the lignan with a but-3-enoyl group (6) exhibited the most active inhibition.     

Isolation, purification and characterization of xylanasefrom Staphylococcus sp. SG-13 and its application in biobleaching of kraft pulp

A haloalkalophilic Staphylococcus sp. SG-13 produced an alkalistable xylanase in wheat bran medium. A 12-fold purification was achieved by using standard purification techniques. The purified xylanase exhibited a dual pH optima of 7.5 and 9.2. The optimum temperature for enzyme activity was 50 degrees C. The enzyme was stable at 50 degrees C for more than 4 h. The xylanase exhibited Km and Vmax values of 4 mg ml-1, 90 micromol min-1 per mg for birchwood xylan and 7 mg ml-1, 55 micromol min-1 per mg for oatspelt xylan, respectively. The substrate binding affinity of xylanase was more for oatspelt xylan but birchwood xylan was hydrolysed more rapidly. The xylanase activity was stimulated by Fe2+, Ni2+, Cu2+ and dithiothreitol up to 60% and was strongly inhibited in the presence of Co2+, Hg2+, Pb2+, phenyl methane sulphonyl fluoride, ethylenediaminetetraacetic acid, and acetic anhydride up to 100%. The xylanase dose of 1.8 U g-1 moisture free pulp, exhibited bleach boosting of kraft pulps optimally at pH 9.5-10.0 and 50 degrees C after 4 h of reaction time. Pretreatment of pulp with xylanase and its subsequent treatment with 8% hypochlorite, reduced the kappa number by 30%, enhanced the brightness and viscosity by 11% and 1.8%, respectively, and improved the paper properties such as tensile strength and burst factor up to 10% and 17%, respectively.     

Synthesis and antibacterial activity of new carbapenems containing isoxazole moiety

The synthesis and biological activity of a series of new 1beta-methylcarbapenems 1a-g containing 5'-isoxazolopyrrolidin-3'-ylthio derivatives as C-2 side chain are described. Most compounds exhibited potent and well-balanced antibacterial activity as well as high stability to DHP-I comparable to that of meropenem. 1e and 1c showed the best combination of antibacterial activity and stability to DHP-I, respectively.     

Possible correlation between levansucrase production and probiotic activity of <Emphasis Type="Italic">Bacillus</Emphasis> sp. isolated from honey and honey bee

Five bacterial isolates from honey and bee gut were selected based on their high levansucrase activity and levan yield which were strongly positively correlated. All isolates showed good tolerance to temperature up to 70?°C, to NaCl up to 3 M and to 0.1% H₂O₂. They maintained over 59 and 64% survival at pH 9.0 and 2.0 respectively, but showed varying tolerance to 0.1% bile salts and pancreatic enzymes. Most isolates were susceptible to widely used antibiotics, but demonstrated diverse antimicrobial activity. Non hemolytic isolates were identified on the basis of 16S rRNA sequencing as Bacillus subtilis HMNig-2 and B. subtilis MENO2 with 97% homology. They exhibited promising probiotic characteristics and achieved highest levansucrase activity of 94.1 and 81.5 U/mL respectively. Both exhibited highest biofilm formation ability in static microtiter plate assay. Also, they achieved 34 and 26% adhesion respectively to Caco-2cells and had highest free radical scavenging activity of 30.8 and 26.2% respectively. The levans of the two isolates showed good antimicrobial activity against some pathogens and exhibited positive prebiotic effect (prebiotic index >1) with Lactobacillus casei and Lactobacillus reuteri. Results suggest a correlation between levansucrase production, levan yield and pre-probiotic activities of the studied strains.     

Synthesis and antimycobacterial evaluation of certain fluoroquinolone derivatives

A number of fluoroquinolone derivatives were synthesized and evaluated for antimycobacterial activity. Preliminary results are (1) for 1-aryl fluoroquinolones, 1-(4-nitrophenyl) derivatives were inactive while their 1-(2-fluoro-4-nitrophenyl) counterparts were active anti-TB agents (3a vs 4a; 3b vs 4b) indicated the fluoro substituent at C-2 position is important. For the 1-(2-fluoro-4-nitrophenyl)quinolones, 7-piperidinyl derivative 4a and 7-(3,5-dimethylpiperazinyl) derivative 4e, which exhibited 97% and 98% inhibition, respectively, were more active than their 7-morpholinyl, 7-(4-methylpiperazinyl) and 7-piperazinyl congeners, 4b,4c and 4d, respectively. In addition, 7-[4-(8-hydroxyquinolin-2-ylmethyl)piperazin-1-yl] derivative 9d exhibited 44% inhibition on the growth of Mycobacterium tuberculosis while its 7-(4-methylpiperazin-1-yl) counterpart 3c was inactive implied the metal-chelating 8-hydroxyquinoline moiety was capable of enhancing the anti-TB activity, (2) for the bifunctional fluoroquinolone-hydroxyquinoline complexes, ciprofloxacin and ofloxacine derivatives, which exhibited the same anti-TB activity (98% inhibition), are more potent than norfloxacin counterpart, which in turn is more potent than 1-aryl congeners (9b, 9c>9a>9d, 9e).     

Nitrogenase proteins from Gluconacetobacter diazotrophicus, a sugarcane-colonizing bacterium

Gluconacetobacter diazotrophicus Pal-5 grew well and expressed nitrogenase activity in the absence of NH4+ and at initial O2 concentrations greater than 5% in the culture atmosphere. G. diazotrophicus nitrogenase consisted of two components, Gd1 and Gd2, which were difficult to separate but were purified individually to homogeneity. Their compositions were very similar to those of Azotobacter vinelandii nitrogenase, however, all subunits were slightly smaller in size. The purified Gd1 protein contained a 12:1 Fe/Mo ratio as compared to 14:1 found for Av1 purified in parallel. Both Gd2 and Av2 contained 3.9 Fe atoms per molecule. Dithionite-reduced Gd1 exhibited EPR features at g=3.69, 3.96, and 4.16 compared with 3.64 and 4.27 for Av1. Gd2 gave an S=1/2 EPR signal identical to that of Av2. A Gd1 maximum specific activity of 1600 nmol H2 (min mg of protein)(-1) was obtained when complemented with either Gd2 or Av2, however, more Av2 was required. Gd2 had specific activities of 600 and 1100 nmol H2 (min mg protein)(-1) when complemented with Av1 and Gd1, respectively. The purified G. diazotrophicus nitrogenase exhibited a narrowed pH range for effective catalysis compared to the A. vinelandii nitrogenase, however, both exhibited maximum specific activity at about pH 7. The Gd-nitrogenase was more sensitive to ionic strength than the Av-nitrogenase.     

Synthesis and biological evaluation of novel 1'-branched and spironucleoside analogues

Novel anomeric spironucleosides and 1'-cyano-2',3'-didehydro-2',3'-dideoxyuridine, a structural analogue of known anti-HIV agents, were prepared by nucleophilic addition of organolithium reagents to 1'-cyano-2'-deoxy- and 1'-cyano-2'-deoxy-2'beta-bromo-uridine derivatives, respectively. The yield and distribution of products depended on the reaction conditions, which were studied in detail. Although none of the compounds exhibited antiviral activity, two compounds displayed cytostatic activity against both murine leukemia and human T-lymphocyte cells.     

Synthesis, anti-inflammatory and analgesic activities evaluation of some mono, bi and tricyclic pyrimidine derivatives

3-Aminobenzonitrile and 2-amino-4-phenyl thiazole on condensation with 4-isothiocyanato-4-methyl pentane-2-one gave condensed monocyclic pyrimidine derivatives 1 and 2, 3, respectively. Condensation of 3-aminopropyl imidazole with 3-isothiocyantobutanal gave condensed monocyclic pyrimidine derivative 4. Bicyclic pyrimidine derivatives 5a and 5b have been synthesized by the condensation of diaminomaleonitrile with 4-isothiocyanto-4-methylpentane-2-one and 3-isothiocyanatobutanal, respectively. Condensation of 4-isothiocyanato-4-methyl pentane-2-one with 2,3-diaminopropionic acid hydrochloride yielded another bicyclic compound 7. 4-Isothiocyanato-4-methyl pentane-2-one, 3-isothiocyanatobutanal and 4-isothiocyanatobutan-2-one on condensation with 2-amino-4-nitro phenol gave tricyclic pyrimidine derivatives 8a, 8b and 8c, respectively. Structures of all the synthesized pyrimidine derivatives are supported by correct IR, 1H NMR and mass spectral data. The anti-inflammatory activity evaluation was carried out using carrageenin-induced paw oedema assay, and compounds 1, 3 and 5b exhibited good anti-inflammatory activity, that is, 27.9, 34.5 and 34.3% at 50 mg/kg po, respectively. Analgesic activity evaluation was carried out using phenylquinone writhing assay and compounds 5a, 5b and 8b showed good analgesic activity, that is, 50, 70 and 50% at 50 mg/kg po, respectively.     

酸渣树中一个新的黄烷类化合物

从酸渣树(Carapaguianensis Aubl.)枝条的乙醇提取物中首次分离到7个化合物,通过波谱方法鉴定,它们分别是:()-epicatechin-3-O-(3",5"-di-O-methyl)gallate(1)、(-)-catechin(2)、sciadopitysin(3)、cl eomi scosin B(4)、photogedunin(5)、chi socheton compound F(6)和odoratone(7).其中,化合物1为新黄烷类化合物,2～7为首次从该植物中分离得到.补充了化合物5的13C-NMR谱数据.活性测定显示,化合物7对大菜粉蝶(Pieris brassicae)三龄幼虫具有较强的杀虫活性,化合物2有一定的活性,而正丁醇部分只有很弱的活性.     

Estrogen- and Antiestrogen-responsiveness of HEC1A Endometrial Adenocarcinoma Cells in Culture

HEC1A endometrial cancer cells express the wild-type form of the estrogen receptor (ER) and 17β-estradiol (E2) induces proliferation of these cells. In contrast, tamoxifen only causes a minimal increase (<20%) in cell proliferation. In HEC1A cells transiently transfected with the C3-Luc plasmid derived from the complement C3 gene, both E2 and tamoxifen exhibited ER agonist activity and tamoxifen was also a partial antagonist for this response. The relative ER agonist/antagonist activities of E2, tamoxifen and ICI 182,780 were also investigated in HEC1A1 cells transiently transfected with two E2-responsive plasmids, pCATHD-CAT and pCKB-CAT which contain 5′-promoter inserts from the cathepsin D and creatine kinase B genes, respectively. The results showed that E2 and tamoxifen induced reporter gene activity in cells transiently transfected with both constructs. ICI 182,780 exhibited partial ER agonist activity only in cells transiently transfected with pCKB-CAT and antagonized E2-induced reporter gene activity using both the CKB- and CATHD-derived constructs. These results demonstrate that HEC1A endometrial cancer cells are E2-responsive and represent a useful cell culture model for understanding hormone/antihormone-induced endometrial cell responses.     

Different responses between diploid and tetraploid H1 embryonic stem cells appeared during long-term culturing in L15F10 medium without leukemia inhibitory factor

To examine the alteration in cellular characteristics of polyploid embryonic stem (ES) cells during long-term culturing without leukemia inhibitory factor (LIF), mouse diploid and tetraploid H-1 (ES) cells (2H1 and 4H1 cells, respectively) were cultured without LIF for approximately 5 months. 2H1 and 4H1 cells were adapted to the medium without LIF by decreasing the concentration for several passages, and they were denoted as 2H1(?) and 4H1(?) cells, respectively. DNA content of 4H1(?) cells decreased gradually in the early stage, increased abruptly in the second stage, and then was maintained for a long time. 4H1(?) cells exhibited longer doubling time and equivalent phase fraction compared with those of 2H1(?) cells. The G? phase fractions of 2H1(?) and 4H1(?) cells were increased compared with that of 2H1 cells. Cellular morphology and pluripotency were maintained in 4H1(?) cells but not in 2H1(?) cells. 2H1(?) cells showed a cell population consisting of several kinds of cells, and they lost alkaline phosphatase activity, suggesting that the cells had differentiated. 4H1(?) cells, however, exhibited alkaline phosphatase activity and formed teratocarcinoma in mouse abdomen, suggesting that the cells maintained their pluripotency in the medium without LIF.     

Anti-Helicobacter pylori activity of derivatives of the phthalide-containing antibacterial agents spirolaxine methyl ether, CJ-12,954, CJ-13,013, CJ-13,102, CJ-13,104, CJ-13,108 and CJ-13,015

The naturally occurring phthalide-containing antibiotics spirolaxine methyl ether, CJ-12,954, CJ-13,013, CJ-13,015, CJ-13,102, CJ-13,103, CJ-13,104 and CJ-13,108, have been reported to exhibit anti-H. pylori activity. However, the exact stereochemistry of spirolaxine methyl ether, CJ-12,954 or CJ-13,013, contributing to this observed activity has not been confirmed. The anti-H. pylori activity of several analogues of spirolaxine methyl ether, CJ-12,954 and CJ-13,013 of defined stereochemistry together with the anti-H. pylori activity of several indole analogues of the simpler phthalide-containing antibiotics CJ-13,102, CJ-13,104, CJ-13,108 and CJ-13,015 is reported herein. A 1:1 mixture of spiroacetals 5b and 6b in which the phthalide substituent exhibited (3R)-stereochemistry was sixty times more active than the corresponding 1:1 mixture of spiroacetals with (3S)-stereochemistry. Notably, the unnatural (2'S)-diastereomer of spirolaxine methyl ether exhibited more potent anti-H. pylori activity than the natural product spirolaxine methyl ether. The 4,6-dimethoxyindoles 9, 10, 11 and 13 were all found to be less active than their parent compounds 1, 2, 3 and 4, respectively. Chain-shortened 4,6-dimethoxyindole analogue 12 of CJ-13,108 3 and 4,6-dimethoxyindole-spiroacetal 13 exhibited weak anti-H. pylori activity thus providing future opportunity for drug discovery programs.     

In vitro cytotoxic activity of Salsola oppositifolia Desf. (Amaranthaceae) in a panel of tumour cell lines

The aim of the present study was to evaluate for the first time the in vitro cytotoxic activity of fractions and isolated flavonols from Salsola oppositifolia Desf. (Amaranthaceae). The n-hexane fraction demonstrated an effective cytotoxic activity on the large lung carcinoma and amelanotic melanoma cell lines with IC50 values of 19.1 microg/ml and 24.4 microg/ml, respectively. Also the dichloromethane fraction exhibited cytotoxic activity against COR-L23 (IC50 30.4 microg/ml) and C32 (IC50 33.2 microg/ml) cells, while the EtOAc fraction demonstrated a selective cytotoxic activity against MCF-7 cells (IC50 67.9 microg/ml). The major active constituents of this fraction were isorhamnetin-3-O-glucoside (1) and isorhamnetin-3-O-rutinoside (2), which showed an interesting activity against the cell line MCF-7 with IC50 values of 18.2 and 25.2 microg/ml, respectively. Compound 2 exhibited a strong activity against the hormone-dependent prostate carcinoma LNCaP cell line with an IC50 of 20.5 microg/ml. Constituents of S. oppositifolia were identified by GC-MS and NMR analyses.     

Synthesis, characterization, antiamoebic activity and cytotoxicity of new pyrazolo[3, 4-d]pyrimidine-6-one derivatives

A new series of pyrazolo[3,4-d]pyrimidine-6-one derivatives (2a-2j) were prepared by using the Biginelli multicomponent cyclocondensation of 3-methyl-1-phenyl-1H-pyrazol-5(4H)-one (1a), different aromatic aldehydes, and urea with a catalytic amount of HCl at reflux temperature. These compounds were characterized by IR, (1)H NMR, (13)C NMR, and Mass spectral data. In vitro antiamoebic activity was performed against HM1:IMSS strain of Entamoeba histolytica. The results showed that the compounds 2b, 2i, and 2j with IC(50) values of 0.37 μM, 0.04 μM, and 0.06 μM, respectively, exhibited better antiamoebic activity than the standard drug metronidazole (IC(50)?=?1.33 μM). The toxicological studies of these compounds on human breast cancer MCF-7 cell line showed that the compounds 2b, 2i, and 2j exhibited >80% viability at the concentration range of 1.56-50 μM.