A caffeic acid phenethyl ester analog inhibits the proliferation of nasopharyngeal carcinoma cells via targeting epidermal growth factor receptor

A previous study reported that compound 5A, a caffeic acid phenethyl ester (CAPE) analog, exhibited obvious neuroprotective activity, in particular, compound 5A possessed higher stability and membrane permeability than CAPE. CAPE displays antitumour function; therefore, evaluating the antitumour effect of its analog with higher stability and membrane permeability is worthwhile. We first investigated the antitumour activity of compound 5A. We found that compound 5A significantly inhibited the proliferation of tumor cells and showed low cytotoxicity in normal cells. Furthermore, compound 5A was found to induce the cell cycle arrest and apoptosis of CNE2 cells. Through the prediction of SwissTargetPrediction and subsequent confirmation, epidermal growth factor receptor (EGFR) was identified as a target of compound 5A. Compound 5A also influenced the expression of genes downstream of EGFR in nasopharyngeal carcinoma (NPC) cells. Based on these findings, compound 5A inhibits the proliferation of NPC cells by targeting EGFR and may become a new candidate compound for NPC treatment.     

Responses of single olfactory receptor cells to sex pheromones in the tobacco cutworm moth, Spodoptera litura

A single olfactory receptor cell of the male tobacco cutworm moth was recorded at the basal region of the sensillum trichodeum and its response to pheromones. Low frequency impulses were recorded from the olfactory receptor to compound A alone. Stimulation with a mixed ratio (9:1) of compound A and compound B increased the frequency of impulses more than compound A alone. However, increase of compound B in the ratio (5:5, 1:9) reduced gradually the frequency of impulses. Stimulation by compound B alone was without effect.It appears that the synergistic effect probably involve mechanisms at the level of the olfactory receptor cell.     

Novel thiazonaphthalimides as efficient antitumor and DNA photocleaving agents: effects of intercalation, side chains, and substituent groups

A series of novel antitumor and DNA photocleaving agents was designed and synthesized by fusing a (substituted) thiazole ring to the naphthalimide skeletons. C1, the most active compound against A549, was about 30-fold more cytotoxic than the compound amonafide. A1, the most active compound against P388, was about 6-fold more cytotoxic than amonafide. C2, the most efficient DNA intercalator, showed the strongest DNA photocleaving activity via superoxide anion produced under UV light at 360 nm.     

Detection of silver(I) ions based on the controlled self-assembly of a perylene fluorescence probe

In the current work, we report a label-free fluorescence turn-on approach for the sensitive and selective sensing of Ag(+). A cationic perylene derivative, compound A, was used as the fluorescence probe. Compound A monomer is strongly fluorescent, and the fluorescence can be efficiently quenched through self-aggregation (self-assembly). A cytosine (C)-rich oligonucleotide, oligo-C, was employed. In the absence of Ag(+), oligo-C induced strong compound A aggregation due to electrostatic interactions in aqueous media, and very weak fluorescence signal was detected. However, in the presence of Ag(+), the specific interactions between oligo-C and Ag(+) induced hairpin structure formation of oligo-C through C-Ag(+)-C bonding interactions. Oligo-C binding to compound A aggregates was weakened; therefore, compound A monomer could be released and detected. The intensity of the fluorescence signal was directly related to the amount of Ag(+) added to the assay solution. Our method is highly sensitive-a limit of detection of 5nM was obtained-and also very selective. Ag(+) detection in complex sample mixtures was also demonstrated.     

Mechanisms of electron transfer from sulfite to horseradish peroxidase-hydroperoxide compounds.

Using a rapid-scan spectrophotometer equipped with a stopped-flow apparatus, reactions of sulfite with compounds I and II of two horseradish peroxidase isoenzymes A and C were investigated. The direct two-electron reduction of peroxidase compound I by sulfite occurred at acidic pH but the mechanism gradually changed to the two-step reduction with the intermediate formation of compound II as the pH increased. The pH at which the one- and two-electron changes occurred at the same speed was 4.5 for peroxidase A and 7.7 for peroxidase C. A new peroxidase intermediate was found in the reaction between peroxidase compound II and sulfite. The sulfite compound showed a characteristic absorption band at 850 nm and the optical spectrum was similar to that of isoporphyrins but was quite different from that of sulfhemoproteins. The rate (k) of conversion from the sulfite-compound II complex to the sulfite compound was proportional to the concentration of H+ and the log k vs. pH plot for peroxidase A moved to the acidic side by 1.1 pH unit from that for peroxidase C.     

植物生理学实验中一类偶氮化合物的分光光度检测

偶氮化合物在可见光特定波长下有最大吸收峰,但对这一特定波长认定目前仍不统一。本试验利用分光光度计法测定了偶氮化合物的特定吸收峰。结果表明：NO2-、对氨基苯磺酸（或磺胺）及α-萘胺在酸性条件下形成偶氮化合物特定吸收峰在A520nm处,并非A510nm、A530nm或A540nm。     

Endotoxic and immunobiological activities of a chemically synthesized lipid A of Helicobacter pylori strain 206-1

A synthetic lipid A of Helicobacter pylori strain 206-1 (compound HP206-1), which is similar to its natural lipid A, exhibited no or very low endotoxic activities as compared to Escherichia coli-type synthetic lipid A (compound 506). Furthermore, compound HP206-1 as well as its natural lipid A demonstrated no or very low mitogenic responses in murine spleen cell. On the other hand, compound HP206-1 showed a weaker but significant production of interleukin-8 in a gastric cancer cell line, MKN-1, in comparison with compound 506. Furthermore, compound HP206-1 exhibited induction of tumor necrosis factor-alpha production in human peripheral blood mononuclear cells and the cytokine production was clearly inhibited by mouse anti-human Toll-like receptor (TLR) 4 monoclonal antibody HTA125. Our findings indicate that the chemically synthesized lipid A, mimicking the natural lipid A portion of lipopolysaccharide from H. pylori strain 206-1, has a low endotoxic potency and immunobiological activities, and is recognized by TLR4.     

A prostaglandin oligomeric derivative inhibits activities of phospholipase and protease: a possible mechanism of membrane protection during ischemia

A prostaglandin oligomeric derivative was synthesized by alkaline treatment of prostaglandin E1. This compound protected the perfused rat heart from global ischemia. This compound was found to inhibit several lipolytic and proteolytic enzymes in vitro. When phospholipase A2 from Naja naja venom was used as an enzyme and phosphatidylcholine was used as a substrate, 50 per cent inhibition was achieved at 50 microM of the prostaglandin derivative. When trypsin and casein were used as enzyme and substrate, 50 per cent inhibition was obtained at 80 microM. A possible mechanism of beneficial effect of this compound in protecting membranes during ischemia is discussed.     

Chemical structure of peptidoglycan in Selenomonas ruminantium: cadaverine links covalently to the D-glutamic acid residue of peptidoglycan

The peptidoglycan of Selenomonas ruminantium, a strictly anaerobic bacterium, contains cadaverine (Y. Kamio, Y. Itoh, Y. Terawaki, and T. Kusano, J. Bacteriol. 145:122-128, 1981). This report describes the chemical structure of the peptidoglycan of this bacterium. The [14C]cadaverine-labeled peptidoglycan was degraded with the lytic enzymes prepared from Streptomyces albus G into three small fragments including a major fragment (band A compound). Bank A compound was composed of L-alanine, D-glutamic acid, meso-diaminopimelic acid, D-alanine, and cadaverine in the molar ratio 0.98:1.0:1.0:0.98:0.97. Diaminopimelic acid, L-alanine, and cadaverine were N-terminal residues in band A compound. When the [14C]cadaverine-labeled band A compound was subjected to partial acid hydrolysis, two peptide fragments were obtained. One of them consisted of diaminopimelic acid and D-alanine; diaminopimelic acid was the N-terminal amino acid, and the other fragment was composed of L-alanine, D-glutamic acid, and cadaverine, of which L-alanine and cadaverine were N-terminal. These results lead us to conclude that the primary peptide structure of band A compound is L-alanyl-D-glutamyl-meso-diaminopimelyl-D-alanine and that cadaverine links covalently to the D-glutamic acid residue.     

Compound 48/80 is a potent inhibitor of phospholipase C and a dual modulator of phospholipase A2 from human platelet

Compound 48/80 inhibited phosphatidylinositol-specific phospholipase C activity from human platelets. Whereas 1 microgram/ml of compound 48/80 slightly stimulated Ca2+-dependent phospholipase A2, higher concentrations led to dose-dependent inhibition of this platelet enzyme. This biphasic effect was confirmed with phospholipases A2 purified from rat liver and human synovial fluid. The aggregation of human platelets induced by ADP and PAF-acether was inhibited by compound 48/80, whereas the aggregation induced by ionophore A23187 was not modified by this compound. These results demonstrate that the inhibition of platelet aggregation by compound 48/80 is not due solely to effects on calmodulin as previously reported, but that inhibition of phospholipases and probably arachidonate mobilization may also be involved.     

臭牡丹中一个新的过氧化物

从四川眉山地区产的臭牡丹（Ｃｌｅｒｏｄｅｎｄｒｕｍ ｂｕｎｇｅｉ Ｓｔｅｕｄ．）地上部分分离到一个新的过氧化物,命名为ｂｕｎｇｅｉｎＡ。其结构通过各项波谱分析得到鉴定,这是首次从马莰草得桐属植物中分到的过氧化物。     

Larvicidal activity of Acacia nilotica extracts and isolation of D-pinitol--a bioactive carbohydrate

A low-molecular-weight, sugar-like compound other than glucose, fructose, sucrose, or myo-inositol showing lipophilic nature was isolated from the EtOH extract of Acacia nilotica. The structure of the compound was determined by spectral methods. This alicyclic polyalcohol was found to be D-pinitol (= 3-O-methyl-D-chiro-inositol; 1). The configuration of the compound was confirmed by single-crystal X-ray analysis. The compound 1 is known from Soybean, Australian mangroves, Fagonia indica, Arachis hypogaea, etc., but we have isolated this compound for the first time from the aerial parts of A. nilotica. Very few references have been cited for compound 1 for its entomological activity, and there are no reports on mosquitoes. Therefore, the crude extracts of A. nilotica were tested for its biological activity against mosquito larvae. Acetone extract at 500-ppm concentration showed chronic toxicity against Aedes aegypti and Culex quinquefasciatus IVth instar mosquito larvae. Such a biological activity has been observed for the first time for this plant. This study could be a stepping stone to a solution for destroying larval species as well as consumption of such a widely grown, problem weed, A. nilotica. This larvicidal agent, since it is derived from plant, is eco-friendly, cost effective, non-hazardous to non-target organisms and would be safe unlike commercially available insecticides.     

Effects of an extinguished CS on competition with another CS

Three experiments were conducted using a conditioned taste aversion procedure with rats to examine the effect of nonreinforced presentations of a conditioned stimulus (CS) on its ability to compete with a target stimulus for manifest conditioned responding. Two CSs (A and B) were presented in a serial compound and then paired with the unconditioned stimulus. CS A was first paired with the US and then presented without the US (i.e., extinction) prior to reinforced presentation of the AB compound. Experiment 1 showed that A was poor at competing with B for conditioned responding when given conditioning and extinction prior to reinforcement of AB relative to a group that received both A and B for the first time during compound conditioning. That is, an extinguished A stimulus allowed greater manifest acquisition to B. Experiment 2 found that extinction treatment produced a poor CR to the pretrained and extinguished CS itself following compound conditioning. Experiment 3 found that interposing a retention interval after extinction of A and prior to compound conditioning enhanced A's ability to compete with B. The results of these experiments are discussed with regard to different theories of extinction and associative competition.     

羊毛生物整理复合酶高产菌的激光选育*

采用激光对宇佐美曲霉棕色突变株W25进行诱变处理。选育到一株产酸性蛋白酶、纤维素CMC酶的复合酶生产菌L86,与出发菌株相比发酵单位酸性蛋白酶提高了42.7%、纤维素CMC酶提高了40.9%。所选育的L86经多次传代,遗传性状非常稳定。生物整理试验表明,L86复合酶比较适合用作羊毛织物生物整理用酶。     

Immunomodulation-mediated anticancer activity of a novel compound from Brugmansia suaveolens leaves

Immunomodulation activity-guided fractionation of ethanol extract of Brugmansia suaveolens leaves was carried out to isolate a novel compound SUPH036-022A (1) by co-culturing the test fraction/compound activated PBMC with MCF7 and A549 cancer cell lines. Assessment of immune markers in PBMC, and analysis of apoptosis markers and cell cycle was carried out for cancer cells. The structure of the isolated compound was elucidated by spectral analysis. Compound 1 enhanced the secretion of immune markers, IL-2 and IFN-γ, from PBMC. Further, compound 1 treated PBMC increased cell death in MCF7 and A549 cell lines and induced ROS production and mitochondrial membrane perturbation, leading to apoptosis. Flow cytometry analysis revealed; compound 1 stimulated PBMC to cause a five-fold increase in cell cycle perturbations in the sub-G1 stage of cancer cells as compared to the negative control. The compound, in the absence of PBMC, only had a weak cytotoxic activity against these cell lines. Thus, compound 1 is a novel lead for immunomodulation-mediated anticancer activity.     

Minimum frequency of compound autosomes inDrosophila melanogaster to achieve chromosomal replacement in cages

A genetic insect control technique is examined that involves the replacement of a population of individuals carrying standard chromosomes by those bearing compound autosomes, which also incorporate factors such as conditional lethal mutations for subsequent control. A variety of compound 2 and 3 lines from the fruit flyDrosophila melanogaster was tested in cages at initial compound to standard ratios that approached the unstable genetic equilibrium point. The lowest ratio that gave successful displacement of standards by compounds was 4 compounds: 1 standard. To evaluate the effciency of the various methods, a comparison is drawn between the data from the compound competition experiments and those from alternative genetic techniques for pest control.     

Synthesis of TDP-3-amino-3,4,6-trideoxy-alpha-D-xylo-hexopyranose--the immediate precursor of TDP-alpha-D-desosamine

A synthetic pathway producing the title compound starting from methyl alpha-D-glucose is described. This compound was shown to be a substrate for DesVI, an AdoMet-dependent methyltransferase which catalyzes N,N-dimethylation of the title compound to give a biological significant unusual sugar, desosamine.     

Characterization of Lipid A,A Component of Lipopolysaccharides from Selenomonas ruminantium

Lipid components of a glycolipid, formerly designated as spot A, from the cells of Selenomonas ruminantium were investigated. The basic structure of this material had been previously shown to be β-glucosaminyl-l,6-glucosamine. The major component of O- and N-acyl side chains was β-OH C_13:0 acid when the cells were grown with added valerate. Approximately 85 % of the total amide linked fatty acids was this compound. A considerable amount of C_13:2 acid was also present as a component of O-acyl fatty acids. When the cells were grown in a glucose medium containing caproate, the major fatty acid component of the spot A compound was β-OH myristic and β-OH C_13:0: acids. ¹⁴C-Valerate or ¹⁴C-caproate, supplemented to the glucose medium, was incorporated into O- and N-acyl linked fatty acid moieties of the spot A compound. It was also shown that the spot A compound was the lipid A component of lipopolysaccharides of this organism.     

Insecticidal compound isolated from Syzygium lineare Wall. (Myrtaceae) against Spodoptera litura (Lepidoptera: Noctuidae)

A new crystal compound 2,5-diacetoxy-2-benzyl-4,4,6,6-tetramethyl-1,3-cyclohexanedione was isolated from the leaves of Syzygium lineare. The insecticidal activity of the compound was assessed against fourth instar larvae of Spodoptera litura. Its activity was better than the positive control azadirachtin. The compound was responsible for growth inhibition on S. litura. It induced larval, pupal and adult deformities even at low concentration. The compound may be useful as a botanical pesticide.     

Effect of a new ultrashort betalytic agent on aconitine-induced arrhythmia

The anti-arrhythmic effect was tested on the model of aconitine-induced arrhythmia. The experiment was performed in vivo with 31 male Wistar laboratory rats. Group A was first administered aconitine and, after the onset of the first sinus rhythm disorders, the 44Bu compound was administered. Group B was first administered the 44Bu compound and only after that the aconitine. The control group was administered aconitine and saline as a replacement of the tested compound. In group A, there was a decrease in the ventricular fibrillation occurrence from 100 % to 8 % (p < 0.001) after the administration of the 44Bu compound. In the B group, the onsets of all monitored arrhythmia types were delayed by an average of 15.6 min. Ventricular rhythm occurrence was decreased from 100 to 20 %, as well as ventricular fibrillations, from 100 to 0 % (p < 0.001).