Antimicrobial activity of Brazilian propolis extracts against rumen bacteria in vitro

The antimicrobial activity of three Brazilian propolis extracts was evaluated on bacterial strains representing major rumen functional groups. The extracts were prepared using different concentrations of propolis and alcohol, resulting in different phenolic compositions. The propolis extracts inhibited the growth of Fibrobacter succinogenes S85, Ruminococcus flavefaciens FD-1, Ruminococcus albus 7, Butyrivibrio fibrisolvens D1, Prevotella albensis M384, Peptostreptococcus sp. D1, Clostridium aminophilum F and Streptococcus bovis Pearl11, while R. albus 20, Prevotella bryantii B₁4 and Ruminobacter amylophilus H18 were resistant to all the extracts. The inhibited strains showed also different sensitivity to propolis; the hyper-ammonia-producing bacteria (C. aminophilum F and Peptostreptococcus sp. D1) being the most sensitive. Inhibition of hyper-ammonia-producing bacteria by propolis would be beneficial to the animal. The extract containing the lowest amount of phenolic compounds (LLOS C3) showed the lowest antimicrobial activity against all the bacteria. The major phenolic compounds identified in the propolis extracts (naringenin, chrysin, caffeic acid, p-coumaric acid and Artepillin C) were also evaluated on four sensitive strains. Only naringenin showed inhibitory effect against all strains, suggesting that naringenin is one of the components participating to the antibacterial activity of propolis.     

Freon 11 Extraction of Volatile Metabolites Formed by Certain Lactic Acid Bacteria

The volatile metabolites formed by 18 lactic acid bacteria, representing three genera, were extracted from a complex medium by using a Freon 11 extraction method. The Freon extracts were then analyzed by capillary gas chromatography, and certain extracts were analyzed by gas chromatography-mass spectrometry. A total of 35 major peaks, of which 20 were positively identified, were used to differentiate between the various strains. On the basis of the results obtained, it was possible to differentiate between the members of the genera Lactobacillus, Pediococcus, and Leuconostoc, as well as between various species within the genus Leuconostoc. Of the 10 Leuconostoc oenos strains included in this study, 9 yielded similar results, but it was still possible to differentiate between the various strains. L. oenos B66 differed from the other L. oenos strains. Use of the Freon 11 extraction technique to determine volatile metabolites formed by lactic acid bacteria was shown to be highly reproducible and of great value. Furthermore, certain compounds not previously known to be formed by lactic acid bacteria were found.     

Insect growth inhibition by tocotrienols and hydroquinones from Roldana barba-johannis

The methanol extract from the aerial parts of Roldana barba-johannis (Asteraceae) afforded sargachromenol, sargahydroquinoic acid, and sargaquinoic acid. These natural products and their corresponding acetylated and methylated derivatives showed insecticidal and insect growth regulatory activities against the Fall Armyworm [Spodoptera frugiperda J.E. Smith, (Lepidoptera: Noctuidae)], an important insect pest of corn. The most active compounds were sargachromenol and its acetylated derivative; sargahydroquinoic acid and its acetylated derivative; and a mixture of sargachromenol, sargahydroquinoic acid, and sargaquinoic acid (6:3:1) and the acetylated form of this mixture. All these compounds and mixtures had significant inhibitory effects between 5.0 and 20.0 ppm in diets. Most compounds were insecticidal to larvae, with lethal doses between 20 and 35 ppm. In addition, these substances also demonstrated scavenging properties toward 2,2-diphenyl-1-picrylhydrazyl radical in TLC autographic and spectrophotometric assays. These compounds appear to have selective effects on the pre-emergence metabolism of the insect. The results from these compounds were fully comparable in activity to those known natural insect growth inhibitors such as gedunin and methanol extracts of Cedrela salvadorensis and Yucca periculosa. These substances may be useful as natural insecticidal agents.     

Differential pathogenicity of two entomopathogenic bacteria,Photorhabdus temperata subsp. temperata and Xenorhabdus nematophila against the red flour beetle,Tribolium castaneum

Two entomopathogenic bacteria, Photorhabdus temperata subsp. temperata (Ptt) and Xenorhabdus nematophila (Xn), are symbiotically associated with the nematodes, Heterorhabdis megidis and Steinernema carpocapsae, respectively. There is little information on natural host ranges of the nematodes, but a significant difference in pathogenicity was observed between these two bacteria against the red flour beetle, Tribolium castaneum, in which Ptt exhibited more than six times higher pathogenicity than Xn. The pathogenic difference was not due to their inhibitory effect on phospholipase A₂ activity that is required for expression of immune response of T. castaneum. The culture broths of both bacterial species had insecticidal activities when injected into the hemocoel. When the bacterial culture broths were fractionated into aqueous and organic extracts, most insecticidal activity remained in the aqueous extracts. The aqueous extracts of two bacteria contained proteins which showed different profiles.     

Agro-waste derived compounds (flax and black seed peels): Toxicological effect against the West Nile virus vector,Culex pipiens L. with special reference to GC–MS analysis

The development of different approaches to use agricultural residues as a source of high value-added products, become a must, especially after the problems emerged due to their accumulation. This contribution demonstrates the potential of agricultural residues, Linuim usitatissium (flax seed) and Nigella sativa (black seed) peels, as raw materials for the production of bioactive products, botanical insecticides, against Cx. pipiens, with deep analysis to their chemical constituents by gas chromatography-mass spectrometry, the larvicidal efficacies of the three crude extracts (methylene chloride, petroleum ether and methanol 70%) from the two plant waste peels were evaluated for the first time against the late third instar larvae of Cx. pipiens. Results indicated different lethal doses in larvae depending on the efficacy of organic solvent used. For both compounds methanol 70% extracts produced the highest dry yield. The most efficient solvent is petroleum ether in case of both flax and Black seed peels. Petroleum ether extract exhibited the highest toxicity against Cx. pipiens with an LC50 of 69.6383 ppm. The same results for black seed indicated that petroleum ether was the most efficient against Cx. pipiens with an LC50 of 40.7748 ppm. The study revealed for the first time the type of phytochemical constituents presents in peels of flax and black seeds using GC–MS analysis which revealed twenty-eight constituents among extracts of flax and black seed peels ranging from to 58.8711% to 99.99% of the total extracts. GC–MS profiling showed that a five constituents, 9-2-Methyl-Z, Z-3, 13 octadecadienol (terpenoid), 9,17-Octadecadienal, (Z)-, Nonanoic acid, 9-oxo-, methyl ester, 9,12-Octadecadienoic acid Z,Z and Octasiloxane, 1,1,3,3,5,5,7,7,9,9,11,11,13,13,15,15-hexadecamethyl- have insecticidal activity beside many other biological activities as recorded from a variety of botanical extracts. While the constituents like Hexadecanoic acid, methyl ester and cis-9-Hexadecenal, both of them are larvicidal, cis-Vaccenic acid and 9-Oxononanoic acid showing only an insecticidal activity beside Undecanoic acid the mosquito repellent. The other six constituents Linoelaidic acid, Oleic Acid, Z-2-Octadecen-1-ol, 1-Methoxy-3-hydroxymethylheptane, Cis-11,14–Eicosadieonic acid-methyl ester and Heptasiloxane, 1,1,3,3,5,5,7,7,9,9,11,11,13,13-tetradecamethyl- are constituents of other plant extracts which showed as a whole an insecticidal activity.     

Agro-waste derived compounds (flax and black seed peels): Toxicological effect against the West Nile virus vector,Culex pipiens L. with special reference to GC–MS analysis

The development of different approaches to use agricultural residues as a source of high value-added products, become a must, especially after the problems emerged due to their accumulation. This contribution demonstrates the potential of agricultural residues, Linuim usitatissium (flax seed) and Nigella sativa (black seed) peels, as raw materials for the production of bioactive products, botanical insecticides, against Cx. pipiens, with deep analysis to their chemical constituents by gas chromatography-mass spectrometry, the larvicidal efficacies of the three crude extracts (methylene chloride, petroleum ether and methanol 70%) from the two plant waste peels were evaluated for the first time against the late third instar larvae of Cx. pipiens. Results indicated different lethal doses in larvae depending on the efficacy of organic solvent used. For both compounds methanol 70% extracts produced the highest dry yield. The most efficient solvent is petroleum ether in case of both flax and Black seed peels. Petroleum ether extract exhibited the highest toxicity against Cx. pipiens with an LC50 of 69.6383 ppm. The same results for black seed indicated that petroleum ether was the most efficient against Cx. pipiens with an LC50 of 40.7748 ppm. The study revealed for the first time the type of phytochemical constituents presents in peels of flax and black seeds using GC–MS analysis which revealed twenty-eight constituents among extracts of flax and black seed peels ranging from to 58.8711% to 99.99% of the total extracts. GC–MS profiling showed that a five constituents, 9-2-Methyl-Z, Z-3, 13 octadecadienol (terpenoid), 9,17-Octadecadienal, (Z)-, Nonanoic acid, 9-oxo-, methyl ester, 9,12-Octadecadienoic acid Z,Z and Octasiloxane, 1,1,3,3,5,5,7,7,9,9,11,11,13,13,15,15-hexadecamethyl- have insecticidal activity beside many other biological activities as recorded from a variety of botanical extracts. While the constituents like Hexadecanoic acid, methyl ester and cis-9-Hexadecenal, both of them are larvicidal, cis-Vaccenic acid and 9-Oxononanoic acid showing only an insecticidal activity beside Undecanoic acid the mosquito repellent. The other six constituents Linoelaidic acid, Oleic Acid, Z-2-Octadecen-1-ol, 1-Methoxy-3-hydroxymethylheptane, Cis-11,14–Eicosadieonic acid-methyl ester and Heptasiloxane, 1,1,3,3,5,5,7,7,9,9,11,11,13,13-tetradecamethyl- are constituents of other plant extracts which showed as a whole an insecticidal activity.     

Novel aromatic polyketides from soil <Emphasis Type="Italic">Streptomyces</Emphasis> spp.: purification,characterization and bioactivity studies

Aromatic polyketides are important therapeutic compounds which include front line antibiotics and anticancer drugs. Since most of the aromatic polyketides are known to be produced by soil dwelling Streptomyces, 54 Streptomyces strains were isolated from the soil samples. Five isolates, R1, B1, R3, R5 and Y8 were found to be potent aromatic polyketide producers and were identified by 16S rRNA gene sequencing as Streptomyces spectabilis, Streptomyces olivaceus, Streptomyces purpurascens, Streptomyces coeruleorubidus and Streptomyces lavendofoliae respectively. Their sequences have been deposited in the GenBank under the accession numbers KF468818, KF681280, KF395224, KF527511 and KF681281 respectively. The Streptomyces strains were cultivated in the media following critically optimised culture conditions. The resulting broth extracts were fractionated on a silica gel column and preparative TLC to obtain pure compounds. The pure compounds were tested for bioactivity and the most potent compound from each isolate was identified by UV–Vis, IR and NMR spectroscopic methods. Isolated S. spectabilis (R1), yielded one potent compound identified as dihydrodaunomycin with an MIC of 4 µg/ml against Bacillus cereus and an IC₅₀ value of 24 µM against HeLa. S. olivaceus (B1), yielded a comparatively less potent compound, elloramycin. S. purpurascens (R3) yielded three compounds, rhodomycin, epelmycin and obelmycin. The most potent compound was rhodomycin with an MIC of 2 µg/ml against B. cereus and IC₅₀ of 15 µM against HeLa. S. coeruleorubidus (R5), yielded daunomycin showing an IC₅₀ of 10 µM and also exhibiting antimetastatic properties against HeLa. S. lavendofoliae (Y8), yielded a novel aclacinomycin analogue with IC₅₀ value of 2.9 µM and potent antimetastatic properties at 1 µM concentration against HeLa. The study focuses on the characterization of aromatic polyketides from soil Streptomyces spp., which can serve as potential candidates for development of chemotherapeutic drugs in future.     

Insecticidal activity of five Chinese medicinal plants against Plutella xylostella L. larvae

Twenty-five extracts of five Chinese medicinal plant species were screened for insecticidal activity against the diamondback moth, Plutella xylostella L., larvae by a leaf dipping bioassay method. The ethyl acetate, ethanol, and acetone extracts of Veratrum nigrum L. root and rhizome, the ethyl acetate extract of Phytolacca americana L. root, and the petroleum ether extract of Pseudolarix kaempferi Gord. root bark were effective against P. xylostella. Among them, the ethyl acetate extract of V. nigrum showed the strongest insecticidal activity against the second and third instar larvae of P. xylostella, with LC₅₀ values of 225 and 335 ppm, respectively. The other extracts gave little or no insecticidal activity against P. xylostella. These results indicated that V. nigrum may be a promising naturally occurring agent for P. xylostella larval control, and that the organic solvent used for plant extraction can affect its insecticidal activity.     

Wax D from Different Bovine Strains of Mycobacterium

Wax D_P, a peptido-glycolipid found in extracts of Mycobacterium tuberculosis var. hominis, was not found in extracts of three strains of still-grown M. tuberculosis var. bovis (BCG, Marmorek and Dupray). However, extracts from three other bovine strains (Behring, LA and BB) did yield waxes D_P, and these did not differ as to their molar ratios of alanine/glutamic acid/diaminopimelic acid from human waxes D_P.     

Potential of natural phenolic antioxidant compounds from Bersama abyssinica (Meliathacea) for treatment of chronic diseases

Chronic diseases including cardiovascular, diabetes and cancer persist for a long time in the course of treatment affecting health and are currently the cause of many deaths. In most cases, the treatment of chronic infectious diseases especially Tuberculosis relies on conventional drugs which are currently becoming fruitless due to drug resistance and unpredicted complications in course of treatment. However, herbal medicines have for a long time been used in prevention and treatment of chronic diseases including asthma and heart diseases in Africa. In this study, we extracted metabolites and screened for active compounds with potential free radical scavenging and pharmacological activities from Bersama abyssinica, the plant commonly used in traditional medicine in Tanzania. B. abyssinica root, stembark and leaf were air dried, sequentially extracted in various solvents including petroleum ether, dichloromethane, ethylacetate and methanol to yield extracts and fractions. The extracts and fractions were tested for the presence of several metabolites and antioxidant activity. The analysis of chemical compounds from resultant extracts was done by GC–MS for non-polar factions and LC-MS/MC for moderate polar extracts.High amount of phenolic acid, flavonoids and tannin were identified in ethylacetate fraction compared to ethanol, dichloromethane and petroleum ether. The GC–MS analysis of petroleum ether extract of B. abyssinica stem back yielded twelve (12) compounds with varying composition. The most abundant compounds were 2-Butenoic acid, 3-methyl-, ethyl ester comprising 33.8%, n-Hexadecanoic acid comprising 16.7% and Ethanolpentamethyl- yielded in 16.7%.The LC-MS/MS analysis of Ethyl acetate fractions yielded 20 compounds including; Mangiferin and Isoquercitin were abundant in leaves, stembark and roots. Lastly, ethyl vanillate was identified in both roots and leaves whereas Quercitrin and 7,8-Dimethoxycoumarin were found in stembark and root.These findings indicated that B. abyssinica is rich in phenolic compounds ranging from phenolic acids, flavonoids and coumarin that possess high antioxidant and pharmacological properties potential for treatment of chronic diseases.     

Comparative Analysis of the Biological Activity and Chromatographic Profiles of the Extracts of <Emphasis Type="Italic">Beauveria bassiana</Emphasis> and <Emphasis Type="Italic">B. pseudobassiana</Emphasis> Cultures Grown on Different Nutrient Substrates

Soil, enodphytic, and insect-pathogenic micromycetes of the genus Beauveria are widespread in nature and are important producers on mycoinsecticides, enzymes, and pharmacologically usable and toxic compounds. The goal of the work was to determine chemodiagnostic approaches to differentiation of Beauveria cryptic species using the strains B. bassiana BBL and B. pseudobassiana BCu22 by comparing their toxicological properties (insecticidal, antimicrobial, phytotoxic, cytotoxic, and esterase-inhibition activity) and metabolite profiles (TLC and HPLC/DAD patterns) of the extracts from the cultures of these fungi growing on different loose substrates, on solid and liquid media. It was shown that when the strains were cultured in liquid media (SDAY and Adámek medium) and on solid substrates (millet and Czapek agar medium), they could be differentiated by the extract yield and chromatographic profiles, as well as by their insecticidal, antifungal, and cytotoxic activity. Thus, antifungal properties were more pronounced in B. pseudobassiana BCu22 grown in liquid Adámek and SDAY media, while cytotoxic properties were more notable in B. bassiana BBL grown in Adámek medium and on millet. Insecticidal properties of the extracts from these cultures varied depending on the substrate composition. Since the extracts of the studied fungi exhibited a broad spectrum of biological activity, the toxic properties of Beauveria spp. should be considered in the course of assessment of safety of these fungi as bioinsecticides.     

Sequence Analysis of Insecticidal Genes from Xenorhabdus nematophilus PMFI296

Three strains of Xenorhabdus nematophilus showed insecticidal activity when fed to Pieris brassicae (cabbage white butterfly) larvae. From one of these strains (X. nematophilus PMFI296) a cosmid genome library was prepared in Escherichia coli and screened for oral insecticidal activity. Two overlapping cosmid clones were shown to encode insecticidal proteins, which had activity when expressed in E. coli (50% lethal concentration [LC₅₀] of 2 to 6 μg of total protein/g of diet). The complete sequence of one cosmid (cHRIM1) was obtained. On cHRIM1, five genes (xptA1, -A2, -B1, -C1, and -D1) showed homology with up to 49% identity to insecticidal toxins identified in Photorhabdus luminescens, and also a smaller gene (chi) showed homology to a putative chitinase gene (38% identity). Transposon mutagenesis of the cosmid insert indicated that the genes xptA2, xptD1, and chi were not important for the expression of insecticidal activity toward P. brassicae. One gene (xptA1) was found to be central for the expression of activity, and the genes xptB1 and xptC1 were needed for full activity. The location of these genes together on the chromosome and therefore present on a single cosmid insert probably accounted for the detection of insecticidal activity in this E. coli clone. Although multiple genes may be needed for full activity, E. coli cells expressing the xptA1 gene from the bacteriophage lambda P_L promoter were shown to have insecticidal activity (LC₅₀ of 112 μg of total protein/g of diet). This is contrary to the toxin genes identified in P. luminescens, which were not insecticidal when expressed individually in E. coli. High-level gene expression and the use of a sensitive insect may have aided in the detection of insecticidal activity in the E. coli clone expressing xptA1. The location of these toxin genes and the chitinase gene and the presence of mobile elements (insertion sequence) and tRNA genes on cHRIM1 indicates that this region of DNA represents a pathogenicity island on the genome of X. nematophilus PMFI296.     

The alleged occurrence of adrenalin in the mealworm

Wense has reported the isolation of crystalline adrenalin from larvae of the beetle Tenebrio molitor. An attempt to repeat his procedures failed to yield any evidence of adrenalin. Analysis of mealworm extracts by paper chromatography and colorimetric means also yielded no indication of adrenalin, though adrenalin added to mealworms can be detected by these procedures in amounts less than 1 mg. per 100 gm. Mealworm extracts reveal on the paper chromatogram the presence of two other orthodiphenols, neither of which appears to be dopa but which may be 3,4-dihydroxyphenyllactic acid and 3,4-dihydroxyphenylacetic acid, compounds recently isolated elsewhere from this organism.     

Production of 3-nitropropionic acid by endophytic fungus Phomopsis longicolla isolated from Trichilia elegans A. JUSS ssp. elegans and evaluation of biological activity

The compound 3-nitropropionic acid is a potent neurotoxic agent in animals and well-known as a potent inhibitor of Mycobacterium tuberculosis. In this research, we were able to extract this compound from the endophytic fungus, Phomopsis longicolla (FJ62759), isolated from Trichilia elegans A. JUSS ssp. elegans. The aim of this study was the isolation of secondary metabolites produced by P. longicolla, the chemical identification of these compounds and evaluation of their antimicrobial and insecticidal activity. To accomplish these goals, the fungus was cultured in BD broth for 25 days without agitation at 28 °C, and then the broth was separated from the mycelium. The supernatant was partitioned with dichloromethane (CH₂Cl₂), ethyl acetate (EtOAc), and butanol (BuOH) solvents resulting in 3 extracts. However, only the EtOAc extract was used for fractionation and chemical identification because it had the greatest mass. After common chromatographic procedures, the fractions were analyzed by nuclear magnetic resonance to elucidate the chemical components. This procedure resulted in the identification of 3-nitropropionic acid in the D fraction. Evaluation of the insecticidal and antimicrobial activity of this compound has been accomplished, and the results indicate good inhibition of the citrus pathogen Guignardia citricarpa and cocoa pathogen Moniliophthora perniciosa and slight inhibition of the human bacterial pathogens Micrococcus luteus, Salmonella typhi and slight inhibition of phytopathogenic bacteria Xanthomonas axonopodis pv. phaseoli. The evaluation of insecticide activity did not show mortality of the Diatraea saccharalis larvae by the metabolite 3-nitropropionic acid in the D fraction. The results suggest that P. longicolla is a bioactive metabolic producing endophytic fungus with biotechnological properties.     

Antibacterial and cytotoxic activities of extracts from (Tunisian)Rhamnus alaternus (Rhamnaceae)

The petroleum ether, chloroformic, ethyl acetate, methanolic, Total Oligomers Flavonoids (TOF) enriched extracts, water extract as well as its fractions A₁, A₂, A₃ obtained from aerial parts ofRhamnus alaternus, a Tunisian-Mediterranean medicinal species, were investigated for the contents of phenolic compounds, cytotoxic activity against the K562 human chronic myelogenous leukaemia cell line and L1210 leukaemia murine cells and for antibacterial activity against Gram positive and Gram negative bacterial reference strains. A pronounced cytotoxic effect on both the cell lines was shown in the TOF, ethyl acetate, methanolic, aqueous extracts and A₂ fraction, with respectively IC₅₀ values 75, 232, 298, 606 and 571 μg/ml on K562 cells and 198, 176, 767, 560 and 614 μg/ml on L1210 cell line. Significant activity against bacterial reference strains:Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Salmonella enteritidis andSalmonella typhimurium was shown with ethyl acetate, TOF extracts and A2 fraction. The antimicrobial and cytotoxic activities showed byR. alatemus depended on the chemical composition of the tested extracts.     

Isolation and Characterization of Antidermatophytic Bioactive Molecules from Piper longum L. Leaves

Piper longum L. (Piperaceae) commonly known as “long pepper” is a well known medicinal plant in ayurveda. Different parts of this plant, such as root, seed, fruit, whole plant etc. are used traditionally in various ailments. Here we have investigated the antidermatophytic activity of sequentially extracted petroleum ether, chloroform, methanol and water extracts from P. longum leaf against Trichophytonmentagrophytes, T. rubrum, T. tonsurans, Microsporum fulvum and M. gypseum. Better activity of chloroform and methanol extracts was observed. The chloroform extract was selected for further study and the MIC value was recorded as 5.0 mg ml⁻¹ against the test organisms. In the chloroform extract, tannins and phenolic compounds were detected. Further activity-guided fractionation of chloroform extract by silica gel column chromatography yielded nine major fractions. Among these, fraction-1, 4, 5 and 7 showed higher antidermatophytic activity. Fraction-4 on further purification by repeated column chromatography yielded a potential antidermatophytic fraction showing MIC value of 0.625 mg ml⁻¹ against T. mentagrophytes and T. rubrum as determined by broth microdilution method. The major compounds were identified as 1,2-benzenedicarboxylic acid, bis(2-ethylhexyl) ester (C₂₄H₃₈O₄] (41.45 %), 2,2-dimethoxybutane (C₆H₁₄O₂] (13.6 %) and β-myrcene (C₁₀H₁₆) (6.75 %) based on GC–MS data.     

Drimanes from Drimys brasiliensis with leishmanicidal and antimalarial activity

This paper evaluates CHCl₃ and CH₃OH extracts of the stem bark, branches and leaves of Drimys brasiliensis and drimane sesquiterpenes isolated from the stem bark against strains of Leishmania amazonensis and Leishmania braziliensis promastigotes and Plasmodium falciparum trophozoites. All of the extracts and compounds were tested in cell lines in comparison with reference standards and cell viability was determined by the XTT method. The CHCl₃ and CH₃OH extracts from the stem bark and branches yielded promising results against two strains of Leishmania, with 50% inhibitory concentrations (IC₅₀ ) values ranging from 39-100 µg/mL. The CHCl₃ extract of the stem bark returned IC₅₀ values of 39 and 40.6 µg/mL for L. amazonensis and L. braziliensis, respectively. The drimanes were relatively effective: 1-β-(p-coumaroyloxy)-polygodial produced IC₅₀ values of 5.55 and 2.52 µM for L. amazonensis and L. braziliensis, respectively, compared with 1-β-(p-methoxycinnamoyl)-polygodial, which produced respective IC₅₀ values of 15.85 and 17.80 µM. The CHCl₃ extract demonstrated activity (IC₅₀ of 3.0 µg/mL) against P. falciparum. The IC₅₀ values of 1-β-(p-cumaroyloxyl)-polygodial and 1-β-(p-methoxycinnamoyl)-polygodial were 1.01 and 4.87 µM, respectively, for the trophozoite strain. Therefore, the results suggest that D. brasiliensis is a promising plant from which to obtain new and effective antiparasitic agents.     

Cytotoxic,antimicrobial activities,AChE and BChE inhibitory effects of compounds from Tanacetum chiliophyllum (Fisch. & Mey.) Schultz Bip. var. oligocephalum (D.C.) Sosn. and T. chiliophyllum (Fisch. & Mey.) Schultz Bip. var. monocephalum Grierson

Tanacetum L. species traditionally used for insecticidal purposes as well as in folk medicine for their antitumor, antimicrobial, antifungal activities. In our previous study a novel sesquiterpene lactone and triterpene lactone together with 12 known flavonoids, coumarin and a triterpene were isolated from T. chiliophyllum var. oligocephalum and T. chiliophyllum var. monocephalum extracts which have insecticidal and antimicrobial activity. In this study, cytotoxic, antimicrobial activities and acetylcholinesterase (AChE), butyrylcholinesterase (BChE) inhibitory effects of pure compounds isolated from these plants were investigated. The tested compounds showed AChE and BChE inhibition which ranged between 7.20–80.37% and 9.19%–76.99% respectively. The highest AChE and BChE inhibition was observed for ulubelenolide which afforded 80.37% and 76.99% inhibition respectively. The cytotoxic effect of the compounds ranged between 22.34–49.77 μg/mL IC₅₀ values. Highest cytotoxic activity was observed against MCF-7 and HEK 293 cell line by 5–hydroxy-3′,4′,7-trimethoxy flavone and 5-hydroxy-3′,4′,6,7-tetramethoxyflavone that produced 25.80 ± 0.17 and 22.34 ± 0.70 IC₅₀ values respectively. Compounds eupatilin, cirsilineol, 5–hydroxy-3′,4′,7-trimethoxy flavone and ulubelenolide showed significant antimicrobial effect on C. albicans with 7.8 μg/mL MIC. The new compound ulubelenolide afforded high AChE and BChE inhibition as well as high antifungal activity. In our opinion activity of this substance should be evaluated further against other fungal species.     

Bioactive chemical constituents of Caesalpinia bonduc (Fabaceae)

Phytochemical studies on the ethanolic extracts of Caesalpinia bonduc (Fabaceae) yielded two new homoisoflavonoids, caesalpinianone, and 6-O-methylcaesalpinianone along with five known natural products, namely, hematoxylol, stereochenol A, 6′-O-acetylloganic acid, 4′-O-acetylloganic acid, and 2-O-β-d-glucosyloxy-4-methoxybenzenepropanoic acid. Structures of these compounds were elucidated with the aid of extensive NMR spectral studies. All of these compounds exhibited different levels of glutathione S-transferase (GST) inhibitory and antifungal activities.     

Two octopine dehydrogenases in crown-gall tumor tissue

Extracts from four crown-gall tumor tissue culture lines, originally induced by two octopine-type strains of Agrobacterium on three plant species, converted l-arginine-[5-³H] to a compound which co-migrated with octopine on electrophoresis. Synthesis showed dependence on added pyruvate and reduced pyridine nucleotide. Both NADH and NADPH were active and mixtures of the two coenzymes, when tested with Vinca strain W1 tumor extracts, were more effective than either coenzyme at comparable concentrations. Addition of an NADH-consuming enzyme system to reaction mixtures containing NADPH had little effect on this activity. Products formed by Vinca rosea strain W1 tumor extracts and Phaseolus vulgaris strain B6 tumor extracts in reaction mixtures containing pyruvate plus NADH or NADPH co-eluted with unlabeled octopine on ion exchange chromatography. The product from the Vinca reaction mixtures co-migrated with an octopine standard in three TLC systems. Permanganate treatment of the enzymatically formed tritiated product and of unlabeled octopine gave compounds with R_f, similar to arginine and γ-guanidinobutyric acid, the products expected from permanganate degradation of octopine. The Vinca W1 extracts catalyzed the oxidative cleavage of octopine, with the formation of arginine, in the presence of NAD or NADP. Two octopine dehydrogenases were concluded to be present in these tissues, one dependent on NAD, the second on NADP.