Investigation of 5-nitrofuran derivatives: synthesis, antibacterial activity, and quantitative structure-activity relationships.

Three sets of antibacterial nitrofuran derivatives [set I, 5-R-substituted (Z)-2-(5-nitrofuran-2-ylmethylene)-3(2H)-benzofuranones (R = OCH(3), H, CH(3), C(2)H(5), nC(3)H(7), Cl, Br, CN, and NO(2)) and their 2-hydroxyphenyl and 2-acetoxyphenyl analogues; set II, 5-R-substituted (E)-1-(2-hydroxyphenyl)-3-(5-nitrofuryl)-2-propen-1-ones (R = H, CH(3), C(2)H(5), Cl, and NO(2)); and set III, 5-R-substituted (E)-1-(2-acetoxyphenyl)-3-(5-nitrofuryl)-2-propen-1-ones (R = H, CH(3); C(2)H(5), Cl, and NO(2))] were prepared and tested against a Gram-positive (Staphylococcus aureus, strain ATCC-25923) and a Gram-negative bacterium (Caulobacter crescentus, strain NA 1000). QSAR equations derived for the IC(50) values against both bacteria show negative contributions of two terms: an electronic one, expressed either by sigma, the Hammett substituent constant, or by E, the cyclic voltametric reduction potential. Another term described by an indicator variable, I(abs), is assigned the value of 0 for set I compounds and the value of 1 for sets II and III. No important contribution of the hydrophobic factor was found. For the three sets, the QSAR regressions suggest that the same structural features describe the activities for both bacteria and that, although reduction is a necessary step, it should not be the determining one. These results agree with those found for the QSAR of 5-nitroimidazole analogues.

Antifungal polysulphides from Petiveria alliacea L.

Bioactivity-directed fractionation of the CH(2)Cl(2)/MeOH (2:1, v/v) extract of the roots of Petiveria alliacea, using mutant yeast strains of Saccharomyces cerevisiae and fungi Cladosporium cladosporioides and C. sphaerospermum led to the isolation of dipropyl disulphide (1), dibenzyl sulphide (2), dibenzyl disulphide (3), dibenzyl trisulphide (4), dibenzyl tetrasulphide (5), benzylhydroxymethyl sulphide (6) and di(benzyltrithio) methane (7). Of these, 5-7 are new compounds and this is the first report of the natural occurrence of 2 and 3.

nor-Lignans from the leaves of Styrax ferrugineus (Styracaceae) with antibacterial and antifungal activity.

Chemical examination of the leaves of Styrax ferrugineus yielded 5-[3''-(beta-D-glucopyranosyloxy)propyl]-7-methoxy-2-(3',4'-dimethoxyphenyl) benzofuran, along with the known nor-lignans 5-(3''-hydroxypropyl)-7-methoxy-2-(3',4'-methylenedioxyphenyl) benzofuran, 5-(3''-hydroxypropyl)-7-methoxy-2-(3',4'-dimethoxyphenyl)benzofuran, 5-[3''-(beta-D-glucopyranosyloxy)propyl]-7-methoxy-2-(3',4'-methylenedioxyphenyl)benzofuran and the lignan, dihydrodehydrodiconiferyl alcohol. All arylpropanoids isolated showed antibacterial and antifungal activities. The structures of the isolates were established by spectroscopic analysis.

Synthesis of new (4-alkylamino-4'-fluoro)-diphenyl sulphones with potential biological activity.

In the present work, we report the synthesis and characterization of five (4-alkylalmino-4'-fluoro)-diphenyl sulphones, four of which have not been described before. In a preliminary evaluation of their biological activity, these products showed no effect on several Gram-positive and Gram-negative bacteria and yeasts.

Antimitotic action of extracts of Petiveria alliacea on sea urchin egg development.

The hydroethanol extract of the roots of Petiveria alliacea L. (Phytolaccaceae) has been investigated previously as an antitumor agent against mouse Ehrlich ascites. The extract and its methanol, butanol and ether fractions exhibited an antimitotic effect on sea urchin egg development. The aqueous fraction did not produce inhibition of cell cleavage. At the first cleavage the inhibition, at the lowest concentration (10 micrograms/ml), produced by the ether fraction was 42%, whereas the inhibition produced by the total extract and by the other fractions was only 5 to 10% showing that the ether fraction was the most active. Even at higher concentrations the butanol and methanol fractions inhibit the cleavage about 30%. At the first cleavage, the ED50 of the hydroethanol extract and of the ether fraction were 45.02 and 12.40 micrograms/ml, respectively. Furthermore, in the second cleavage, the hydroethanol extract was about twice as potent as the methanol or butanol fractions (ED50 of 22.40, 44.80 and 54.10 micrograms/ml, respectively).

Antimitotic action of extracts of Petiveria alliacea on sea urchin egg development

The hydroethanol extract of the roots of Petiveria alliacea L. (Phytolaccaceae) has been investigated previously as an antitumor agent against mouse Ehrlich ascites. The extract and its methanol, butanol and ether fractions exhibited an antimitotic effect on sea urchin egg development. The aqueous fraction did not produce inhibition of cell cleavage. At the first cleavage the inhibition, at the lowest concentration (10 micrograms/ml), produced by the ether fraction was 42 per cent , whereas the inhibition produced by the total extract and by the other fractions was only 5 to 10 per cent showing that the ether fraction was the most active. Even at higher concentrations the butanol and methanol fractions inhibit the cleavage about 30 per cent . At the first cleavage, the ED50 of the hydroethanol extract and of the ether fraction were 45.02 and 12.40 micrograms/ml, respectively. Furthermore, in the second cleavage, the hydroethanol extract was about twice as potent as the methanol or butanol fractions (ED50 of 22.40, 44.80 and 54.10 micrograms/ml, respectively)

In vitro antifungal activity of essential oils obtained from officinal plants against dermatophytes.

Thirteen essential oils were isolated from officinal plants and tested in vitro against dermatophyte strains isolated from patients with dermatophytosis. Of the tested oils, those obtained from Cinnamomum zeylanicum, Ocimum gratissimum, Cymbopogon citratus, Eugenia uniflora and Alpinia speciosa were found to be the most active, inhibiting 80% of the dermatophyte strains tested and producing inhibition zones more than 10 mm in diameter.

Antihistamine activity of Bryophyllum calycinum.

1. The juice obtained by pressing the leaves of Bryophyllum calycinum (Crassulaceae) exhibited histamine-blocking activity. 2. The juice contains flavonoid compounds, carbohydrates and mineral salts. A flavonoid fraction (fraction B) obtained by partitioning the juice between n-butanol and water contained the substance responsible for the antihistamine activity. 3. When assayed on the isolated guinea pig ileum, 50 mg/ml juice and 0.15 mg/ml fraction B produced parallel and concentration-dependent rightward displacement of the concentration-response curve to histamine (EC50 (FL): 1.30 (0.26-5.28) x 10(-7) M, 15.80 (5.90-23.30) x 10(-7) M, 12.50 (7.62-14.90) x 10(-7) M, in the absence and presence of 50 mg/ml juice and 12 mg/ml fraction B, respectively) apparently in a competitive manner. The antagonism was specific for histamine, i.e., did not modify the response to acetylcholine, KCl and BaCl2 and was reversible upon washing. Vascular permeability responses of rats to intracutaneous 1.0, 5.0 or 10.0 micrograms histamine were decreased by about 20-25% in animals pretreated with 4 ml/kg of juice or with 12 mg/kg fraction B. The juice (4 ml/kg) protected guinea pigs from death by asphyxia induced by 5 mg histamine and the protection lasted at least 1 h. 4. However, since the juice was ineffective in protecting the gastric mucosa from histamine-induced ulceration, we conclude that the antihistamine effect of the juice and fraction B was produced by blockade of H1 and not H2 receptors.

Antihistamine activity of Bryophyllum, calycinum

The juice obtained by pressing the leaves of Bryphyllum calycinum (Crassulaceae) exhibited histamine-blocking activity. The juice contains flavonoid compounds, carbohydrates and mineral salts. A flavonoid fraction (fraction B) obtained by partioning the juice between n-butanol and water contained the substance responsible for the antihistamine activity. When assayed on the isolated guinea pig ileum, 50 mg/ml juice and 0.15 mg/ml fraction B produced parallel and concentration-dependent rightward displacement of the concentration-response curve to histamine (EC50 (FL): 1.30 (0.26-5.28) x 10-7 M, 15.80 (5.90 -23.30) x 10-7 M, 12.50 (7.62 -14.90) x 10-7 M, in the absence and presence of 50 mg/ml juice and 12 mg/ml fraction B, respectively) apparently in a competitive manner. The antagonism was specific for histamine, i. e., did not modify the response to acetylcholine, KCl and BaCl2 and was reversible upon washing. Vascular permeability responses of rats to intracutaneous 1.0, 5.0 or 10.0 ug histamine were decreased by about 20-25% in animals pretreated with 4 ml/kg of juice or with 12 mg/kg fraction B. The juice (4 ml/kg) protected guinea pigs from death by asphyxia induced 5 mg histamine and the protection lasted at least at 1 h. However, since the juice was ineffective in protecting the gastric mucosa from histamine-induced ulceration, we conclude that the antihistaminic effect of the juice and fraction B was produced by blockade of H1 and not H2 receptors

Antimicrobial activity of kaurenoic acid derivatives substituted on carbon-15.

The antibacterial and antifungic activities of two kaurenic acids, ent kaurenoic acid and cinnamoylgrandifloric acid isolated from a hexane extract of aerial parts of Mikania laevigata, were investigated and compared with the activities of other kaurenic acid derivatives substituted on carbon-15. Only acetylgrandifloric acid (ent-kaur-16-en-15 alpha-acetyloxy-19-oic) and its epimer xylopic acid (ent-kaur-16-en-15 beta-acetyloxy-19-oic) displayed significant antibacterial activity at concentrations greater than or equal to 250 micrograms/ml, the 15 alpha epimer being the most active.

Antimicrobial activity pf kaurenoic acid derivatives substituted on carbon-15

The antibacterial and antifungic activities of two kaurenic acids, ent kaurenoic acid and cinnamoylgrandifloric acid isolated from a hexane extract of aerial parts of Mikania laevigata, were investigated and compared with the activities of other kaurenic acid-derivatives substituted on carbon-15. Only acetylgrandifloric acid (en-kaur-16-en-15 alfa-acetyloxy-19-oic) and its epimer xylopic acid (ent-kaur-16-4n-15 beta-acetyloxy-19-oic) displayed significant antibacterial activity at concentrations >=250 microng/ml., the 15 alfa epimer being the most active

In vitro study of the antibiotic activity of diterpenes.

The antibiotic activity of 16 diterpenes and of 2 phenanthrene derivatives of diterpene origin, isolated from Brazilian plants was investigated against bacteria, yeasts, dermatophytes and aflatoxin-producing fungi. Eight of the compounds were completely inactive. None showed inhibitory activity against the Gram-negative bacteria assayed or against the Aspergillus species. The phenanthrene derivatives, chemically very similar to phytoalexins isolated from orchids, were especially active.

In vitro study of the antibiotic activity of diterpenes

The antibiotic activity of 16 diterpenes and of 2 phenanthrehene derivatives of diterpene origin, isolated from Brazilian plants was investigated against bacteria, yeasts, dermatophytes and aflatoxin-producing fung. Eight of the compounds were completely inactive. None showed inhibitory activity against the Gram-negative bacteria assaywed or aginst the Aspergillus species. The phenanthrene derivatives, chemically very simular to phytoalexins isolated from orchids, were especially active

Aspectos basicos das linhagens celulares mais utilizadas. / Culture characteristics of some cell lines

Sao apresentados alguns aspectos basicos das linhagens celulares mais utilizadas nos nossos laboratorios de pesquisas. Quatro linhagens de origem humana e tres linhagens de origem animal sao descritas quanto a sua obtencao, meio de congelamento, meio de cultura, caracteristicas de crescimento e morfologia

(2E,4E)-N-isobutyl-9-piperonyl-nona-2,4-dienoic amide from Ottonia anisum.

Roots and stems of Ottonia anisum contain besides 1-butyl-3,4-methylenedioxybenzene and piperovatine, the novel (2E,4E)-N-isobutyl-9-piperonyl-nona-2,4-dienoic amide.

Ocotea quixos, American cinnamon.

Among the three South American Lauraceae with cinnamon odours, Ocotea quixos Lam. is distinguished with the richest historical legacy. Cinnamaldehyde, its odoriferous principle, occurs besides o-methoxycinnamaldehyde, cinnamic acid and methyl cinnamate in the fruit calyx. In contradistinction, 1-nitro-2-phenylethane is responsible for the cinnamon odour of bark and leaves of Aniba canelilla (H..B.K.) Mez and Ocotea pretiosa (Nees) Mez.