Alkaloids of Phaedranassa dubia (Kunth) J.F. Macbr. and Phaedranassa brevifolia Meerow (Amaryllidaceae) from Ecuador and its cholinesterase-inhibitory activity.

Alzheimer's disease is considered the most common cause of dementia and, in an increasingly aging population worldwide, the quest for treatment is a priority. Amaryllidaceae alkaloids are of main interest because of their cholinesterase inhibition potential, which is the main palliative treatment available for this disease. We evaluated the alkaloidal profile and the in vitro inhibitory activity on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) of bulb alkaloid extract of Phaedranassa dubia and Phaedranassa brevifolia collected in Ecuador. Using gas chromatography coupled to mass spectrometry (GC-MS), we identified typical Amaryllidaceae alkaloids in these species, highlighting the presence of lycorine-type alkaloids in P. dubia and haemanthamine/crinine-type in P. brevifolia. The species P. dubia and P. brevifolia showed inhibitory activities against AChE (IC50 values of 25.48 ± 0.39 and 3.45 ± 0.29 µg.mL-1, respectively) and BuChE (IC50 values of 114.96 ± 4.94 and 58.89 ± 0.55 µg.mL-1, respectively). Computational experiments allowed us to understand the interactions of the alkaloids identified in these samples toward the active sites of AChE and BuChE. In silico, some alkaloids detected in these Amaryllidaceae species presented higher estimated binding free energy toward BuChE than galanthamine. This is the first study about the alkaloid profile and biological potential of P. brevifolia species.

Estrogenic and chemopreventive activities of xanthones and flavones of Syngonanthus (Eriocaulaceae).

The possible benefits of some bioactive flavones and xanthones present in plants of the genus Syngonanthus prompted us to screen them for estrogenic activity. However, scientific research has shown that such substances may have undesirable properties, such as mutagenicity, carcinogenicity and toxicity, which restrict their use as therapeutic agents. Hence, the aim of this study was to assess the estrogenicity and mutagenic and antimutagenic properties. We used recombinant yeast assay (RYA), with the strain BY4741 of Saccharomyces cerevisiae, and Ames test, with strains TA100, TA98, TA97a and TA102 of Salmonella typhimirium, to evaluate estrogenicity, mutagenicity and antimutagenicity of methanolic extracts of Syngonanthus dealbatus (S.d.), Syngonanthus macrolepsis (S.m.), Syngonanthus nitens (S.n.) and Syngonanthus suberosus (S.s.), and of 9 compounds isolated from them (1=luteolin, 2=mix of A-1,3,6-trihydroxy-2-methoxyxanthone and B-1,3,6-trihydroxy-2,5-dimethoxyxanthone, 3=1,5,7-trihydroxy-3,6-dimethoxyxanthone, 4=1,3,6,8-tetrahydroxy-2,5-dimethoxyxanthone, 5=1,3,6,8-tetrahydroxy-5-methoxyxanthone, 6=7-methoxyluteolin-8-C-ß-glucopyranoside, 7=7-methoxyluteolin-6-C-ß-glucopyranoside, 8=7,3'-dimethoxyluteolin-6-C-ß-glucopyranoside and 9=6-hydroxyluteolin). The results indicated the estrogenic potential of the S. nitens methanol extract and four of its isolated xanthones, which exhibited, respectively, 14.74±1.63 nM; 19.54±6.61; 7.20±0.37; 6.71±1.02 e 10.01±4.26 nM of estradiol-equivalents (EEQ). None of the extracts or isolated compounds showed mutagenicity in any of the test strains and all of them showed antimutagenic potential, in particular preventing mutations caused by aflatoxin B1 (AFB1) and benzo[a]pyrene (B[a]P). The results show that the xanthones, only isolated from the methanol extract of S. nitens capitula, probably were the responsible for its estrogenic activity and could be useful as phytoestrogens, providing a new opportunity to develop hormonal agents. In addition, flavones and xanthones could also be used as a new antimutagenic agent. Since, the mutagens are involved in the initiation and promotion of several human diseases, including cancer, the significance of novel bioactive phytocompounds in counteracting these pro-mutagenic and carcinogenic effects is now gaining credence.

Phytochemical study guided by the myorelaxant activity of the crude extract, fractions and constituent from stem bark of Hymenaea courbaril L.

ETHNOPHARMACOLOGICAL RELEVANCE: Hymenaea courbaril L. (Caesalpinoideae) is used in Brazilian folk medicine to treat anemia, kidney problems, sore throat and other dysfunctions of the respiratory system, such as bronchitis and asthma, although such properties are yet to be scientifically validated. AIM OF THE STUDY: In order to give a scientific basis to support the traditional use of Hymenaea courbaril, this study was designed to evaluate antioxidant, myorelaxant and anti-inflammatory properties of the ethanol extract from stem bark and its fractions. The myorelaxant effect of astilbin, a flavonoid isolated from the bioactive ethyl acetate fraction (EAF), has also been evaluated. MATERIAL AND METHODS: In the present study ethanol extract from stem bark (EEHC) and fractions were analyzed using bioassay-guided fractionation. The following activities were investigated: antioxidant by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, myorelaxant on rat tracheal smooth muscle, and anti-inflammatory using ovalbumin-induced leukocytosis and airway hyperresponsiveness in rats. RESULTS: The results of the present investigation show that the whole extract of Hymenaea courbaril and some of its fractions strongly scavenged DPPH radical. The extract showed myorelaxant activity on rat trachea, being EAF its highest efficient fraction. Bio-guided study allowed the isolation of astilbin, a well-known flavonoid. The activity induced by this compound indicates that it may be partly responsible for the myorelaxant effect of EAF. EAF reduced contractions that depended on divalent cation inflow through voltage-operated Ca(2+) channels (VOCCs) or receptor-operated Ca(2+) channels (ROCCs), but it was more potent to inhibit VOCC- than ROCC-dependent contraction induced by Ca(2+) addition in ACh-enriched Ca(2+)-free medium. Oral pretreatment of antigen-challenged animals with EAF prevented airway hyperresponsiveness on KCl-induced contraction and reduced the number of total white cells, particularly eosinophils and neutrophils in bronchoalveolar lavage. CONCLUSIONS: This study provided scientific basis that Hymenaea courbaril presents potential antioxidant, myorelaxant and anti-inflammatory actions, which support its use in folk medicine to treat inflammatory airway diseases.

Antimicrobial activity of copper (II) complex with 1,2-bis [(1,3-diphenylpyrazol-4-yl)methyl] diaminoethane / Antimicrobial activity of copper (II) complex with 1,2-bis [(1,3-diphenylpyrazol-4-yl)methyl] diaminoethane

Background: Multi-resistant strains multiply daily, populate farms, hospitals and other ecological niches around the world, and cause serious infections in animals and humans, often leading to a fatal outcome. Researchers of all profiles are investigating intensively to fi nd new substances with antimicrobial activity. In the period between 1981 and 2002, 163 new chemical compounds were approved for use as drugs. Synthesized compounds have become much more interesting than the natural ones in the production of new antimicrobial agents. Some of these synthesized compounds are Copper (II) complex. The antimicrobial properties of copper were known in ancient Egypt (2000 BC), where it was used to sterilize water and wounds. Copper is still interesting for todays research. Materials, Methods & Results: Antimicrobial activity was tested using a microdilution method according to Clinical and Laboratory Standards Institute. The percentage of surviving bacteria was calculated in comparison to the number of bacteria placed in each well. Based on these results, using the Excel software package from Microsoft Office 2007, graphs were generated that showed the percentage of surviving bacteria depending on the corresponding effective concentrations of the tested substance. The function, which was used to approximate the experimental results, was determined using the Power Trendline supp

Background: Multi-resistant strains multiply daily, populate farms, hospitals and other ecological niches around the world, and cause serious infections in animals and humans, often leading to a fatal outcome. Researchers of all profiles are investigating intensively to fi nd new substances with antimicrobial activity. In the period between 1981 and 2002, 163 new chemical compounds were approved for use as drugs. Synthesized compounds have become much more interesting than the natural ones in the production of new antimicrobial agents. Some of these synthesized compounds are Copper (II) complex. The antimicrobial properties of copper were known in ancient Egypt (2000 BC), where it was used to sterilize water and wounds. Copper is still interesting for todays research. Materials, Methods & Results: Antimicrobial activity was tested using a microdilution method according to Clinical and Laboratory Standards Institute. The percentage of surviving bacteria was calculated in comparison to the number of bacteria placed in each well. Based on these results, using the Excel software package from Microsoft Office 2007, graphs were generated that showed the percentage of surviving bacteria depending on the corresponding effective concentrations of the tested substance. The function, which was used to approximate the experimental results, was determined using the Power Trendline supp

Antimicrobial activity of copper (ii) complex with 1, 2-bis [(1, 3-diphenylpyrazol-4-yl)methyl] diaminoethane

Background: Multi-resistant strains multiply daily, populate farms, hospitals and other ecological niches around the world, and cause serious infections in animals and humans, often leading to a fatal outcome. Researchers of all profiles are investigating intensively to find new substances with antimicrobial activity. In the period between 1981 and 2002, 163 new chemical compounds were approved for use as drugs. Synthesized compounds have become much more interesting than the natural ones in the production of new antimicrobial agents. Some of these synthesized compounds are Copper (II) complex. The antimicrobial properties of copper were known in ancient Egypt (2000 BC), where it was used to sterilize water and wounds. Copper is still interesting for today's research. Materials, Methods & Results: Antimicrobial activity was tested using a microdilution method according to Clinical and Laboratory Standards Institute. The percentage of surviving bacteria was calculated in comparison to the number of bacteria placed in each well. Based on these results, using the Excel software package from Microsoft Office 2007, graphs were generated that showed the percentage of surviving bacteria depending on the corresponding effective concentrations of the tested substance. The function, which was used to approximate the experimental results, was determined using the Power Trendline supplement from the Microsoft Excel program. Cytotoxicity (growth inhibition) was evaluated by tetrazolium colorimetric MTT assay, after exposure of cells to the tested compound for 48 h. Inhibition of growth was expressed as a percentage of cytotoxicity and calculated according to the following equation: (1-A test/A control) x 100. MBC99.9 and MIC99 of the test substance were lowest for Arcanobacterium haemolyticum being 0.2 mg/L and 0.0054 mg/L, respectively. The highest values were obtained for Arcanobacterium pyogenes and methicillin-resistant Staphylococcus aureus (MRSA) 488.002 mg/L and 20.2 mg/L. MIC80 for all four strains ranged from 0.00002 to 0.0023 mg/L. Measured values for MIC99 are 0.00545 mg/L for A. haemolyticum, 0.0443199 mg/L for R. equi, 0.0520712 mg/L for S. aureus and 2.36378 mg/L for A. pyogenes. Values for MIC99.9 ranged from 0.236134 to 488,002 mg/L. Most of the MIC values obtained in this study are significantly lower than those reported by other researchers. The values we obtained were lower as compared to MIC values for standard antibiotics, which were considered acceptable by the relevant institutions. This speaks in favor of a stronger antibacterial effect of our tested substances. In regards to cytotoxicity, the obtained MIC80 doses were lower than toxic, whereas MIC90 could be classified as low-toxic (less than 0.0625 µM), except of Arcanobacterium pyogenes only. According to the IC50 values, the compound Cu (L) Br2·MeOH was 6.4-fold and 4.8-fold more potent against HCT116 cells compared to normal lung fi broblasts and SW620 cells, respectively. Discussion: Copper (II) complex with an arylpyrazole ligand exhibits strong antibacterial properties, and it shows bacteriostatic effect at concentrations where there is no cytotoxic effect in normal human cells. The emergence of multi-resistant strains of pathogenic bacteria is a growing problem worldwide. Therefore, each new compound with potential antimicrobial activity, especially if it is not cytotoxic in effective dosage, deserves the attention of the scientific community. In this paper, we presented a newly synthesized substance with such properties.

Antimicrobial activity of copper (II) complex with 1,2-bis [(1,3-diphenylpyrazol-4-yl)methyl] diaminoethane / Antimicrobial activity of copper (II) complex with 1,2-bis [(1,3-diphenylpyrazol-4-yl)methyl] diaminoethane

Background: Multi-resistant strains multiply daily, populate farms, hospitals and other ecological niches around the world, and cause serious infections in animals and humans, often leading to a fatal outcome. Researchers of all profiles are investigating intensively to fi nd new substances with antimicrobial activity. In the period between 1981 and 2002, 163 new chemical compounds were approved for use as drugs. Synthesized compounds have become much more interesting than the natural ones in the production of new antimicrobial agents. Some of these synthesized compounds are Copper (II) complex. The antimicrobial properties of copper were known in ancient Egypt (2000 BC), where it was used to sterilize water and wounds. Copper is still interesting for todays research. Materials, Methods & Results: Antimicrobial activity was tested using a microdilution method according to Clinical and Laboratory Standards Institute. The percentage of surviving bacteria was calculated in comparison to the number of bacteria placed in each well. Based on these results, using the Excel software package from Microsoft Office 2007, graphs were generated that showed the percentage of surviving bacteria depending on the corresponding effective concentrations of the tested substance. The function, which was used to approximate the experimental results, was determined using the Power Trendline supp

Background: Multi-resistant strains multiply daily, populate farms, hospitals and other ecological niches around the world, and cause serious infections in animals and humans, often leading to a fatal outcome. Researchers of all profiles are investigating intensively to fi nd new substances with antimicrobial activity. In the period between 1981 and 2002, 163 new chemical compounds were approved for use as drugs. Synthesized compounds have become much more interesting than the natural ones in the production of new antimicrobial agents. Some of these synthesized compounds are Copper (II) complex. The antimicrobial properties of copper were known in ancient Egypt (2000 BC), where it was used to sterilize water and wounds. Copper is still interesting for todays research. Materials, Methods & Results: Antimicrobial activity was tested using a microdilution method according to Clinical and Laboratory Standards Institute. The percentage of surviving bacteria was calculated in comparison to the number of bacteria placed in each well. Based on these results, using the Excel software package from Microsoft Office 2007, graphs were generated that showed the percentage of surviving bacteria depending on the corresponding effective concentrations of the tested substance. The function, which was used to approximate the experimental results, was determined using the Power Trendline supp

Acción biocida de plantas de Piper tuberculatum Jacq. sobre Diatraea saccharalis (Lepidóptera, Pyralidae)

En el presente trabajo evaluamos la acción biocida sobre larvas del III estadío de Diatraea saccharalis, usando extractos acuoso, diclorometano-metanol (DCM:MeOH, 2:1) y alcohólico (EtOH, 96%) de hojas, tallos y espigas maduras (con frutos y semillas) de Piper tuberculatum, en larvas del III estadío. El método de inoculación del extracto, previamente eluido con agua destilada, fue de aplicación tópica en el mesotorax de las larvas. Solamente los extractos DCM:MeOH y EtOH de espigas maduras y extracto DCM:MeOH de plantas in vitro mostraron niveles significativos de mortalidad larval. El mayor efecto tóxico correspondió a extractos de espigas maduras respecto a plantas in vitro y a extracto EtOH respecto a extracto DCM:MeOH, tal como lo expresan los resultados de las concentraciones letales a 50% (CL50) y 90% (CL90), en 72 h de exposición. Así tenemos que en el caso de espigas maduras fue: CL50 (0,11 mg/mL con EtOH y 0,16 mg/mL con DCM:MeOH) y CL90 (0,35 mg/mL con EtOH y 0,55 mg/mL con DCM:MeOH); en el caso de plantas in vitro, unicamente con DCM:MeOH, fue: CL50 0,39 mg/mL y CL90 2,62 mg/mL. Los resultados de las rectas valores probitos-mortalidad expresaron la misma tendencia.

The biocid action of DCM:MeOH (2:1), EtOH and aqueous extracts of leaves, stems and mature spikes (with fruits and seeds) of field plants and DCM:MeOH (2:1) extract of in vitro plants of Piper tuberculatum on III larval stage of Diatraea saccharalis was evaluated. The method was by inoculating the previously eluted extract with distillate water as topic applications on the larval mesothorax. Only DCM:MeOH and EtOH extracts of mature spikes and DCM:MeOH extract of in vitro plants showed significant levels of larval mortality. The corresponding highest toxic effect was (a) for mature spikes respect to in vitro plants and (b) EtOH extract respect to DCM:MeOH extract, according to the results showed for the lethal concentration to 50% (LC50) and 90% (LC90), in 72 hours of exposure. Thus, in the case of mature spikes was: LC50 0,11 mg/mL with EtOH and 0,16 mg/mL with DCM:MeOH) and LC90 (0,35 mg/mL with EtOH and 0,55 mg/mL with DCM:MeOH); and, in the case of in vitro plants, only with DCM:MeOH extract, was: LC50 0,39 mg/mL and LC90 2,62 mg/mL. The results of probit values-mortality lines showed the same tendency.