Ionara I. Dalcol

Antimicrobial activity of Schinus lentiscifolius (Anacardiaceae).

ETHNOPHARMACOLOGICAL RELEVANCE Schinus lentiscifolius Marchand (syn. Schinus weinmannifolius Engl) is a plant native to Rio Grande do Sul (Southern Brazil) and has been used in Brazilian traditional medicine as antiseptic and antimicrobial for the treatment of many different health problems as well as to treat leucorrhea and to assist in ulcer and wound healing. Although it is a plant widely used by the population, there are no studies proving this popular use. MATERIAL AND METHODS The crude aqueous extract, the crude neutral methanol extract, fractions prepared from this extract (n-hexane, ethyl acetate, and n-butanol), pure compounds isolated from these fractions, and derivatives were investigated in vitro for antimicrobial activities against five Gram positive bacteria: Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus saprophyticus, Streptococcus pyogenes, three Gram negative bacteria: Escherichia coli, Pseudomonas aeruginosa, and Shigella sonnei, and four yeasts: Candida albicans, Candida tropicalis, Cryptococcus neoformans, and Saccharomyces cerevisiae. The isolated compound moronic acid, which is the most active, was tested against a range of other bacteria such as two Gram positive bacteria, namely, Bacillus cereus, Enterococcus spp, and six Gram negative bacteria, namely, Burkholderia cepacia, Providencia stuartii, Morganella morganii, Enterobacter cloacae, Enterobacter aerogenes, and Proteus mirabilis. RESULTS The leaf aqueous extract (decoction) of Schinus lentiscifolius showed a broad spectrum of antibacterial activity, ranging from 125 to 250 μg/ml (MIC) against the tested bacteria and fungi. The n-hexane extract, despite being very little active against bacteria, showed an excellent antifungal activity, especially against Candida albicans (MIC=25 μg/ml), Candida tropicalis (MIC=15.5 μg/ml), and Cryptococcus neoformans, (MIC=15.5 μg/ml). From the acetate fraction (the most active against bacteria), compounds 1-6 were isolated: nonadecanol (1), moronic acid (2), gallic acid methyl ester (3), gallic acid (4), quercetin (5) and quercitrin (6). The minimal inhibitory concentration (MIC) of moronic acid between 1.5 and 3 μg/ml against most of the tested bacteria shows that it is one of the metabolites responsible for the antibacterial activity of Schinus lentiscifolius. CONCLUSION The antimicrobial activity and some constituents of Schinus lentiscifolius are reported for the first time. The results of the present study provide scientific basis for the popular use of Schinus lentiscifolius for a number of different health problems.

Cyclopeptide alkaloids from Scutia buxifolia Reiss

Scutianene E (1), 3,4,28-tris-epi-scutiaene E (2), 28-epi-scutianene E (3) and scutianene L (4), four neutral cyclopeptide alkaloids, were isolated from Scutia buxifolia Reiss, together with four known cyclopeptide alkaloids, scutianines B, C, D and E. Scutianenes 1-3 are diastereoisomeric compounds, with 3-hydroxyleucine as a β-hydroxy amino acid unit, which is connected to the styryl fragment via an ether bridge, β-phenylserine, as a common ring-bonded amino acid residue. Attached to the amino group of β-hydroxyamino acid is a side chain [trans-CH=CH-Ph]. The structures of the peptides were elucidated by means of spectroscopic analysis, including extensive 2D NMR studies. The stereochemistry for the diastereomeric 3,4,28-tris-epi-scutiaene E and 28-epi-scutianene E was confirmed by X-ray diffraction analysis of their O-acetyl derivatives.

Composition and antimicrobial activity of the essential oil from Aloysia sellowii

The essential oils obtained from aerial parts of Aloysia sellowii from two different collection locations Southern Brazil (A and B), were analyzed by GC, GC/MS, and chiral phase gas chromatography (CPGC). It was identified 48 compounds representing ca 93% and 91% of the oils of samples A and B, respectively. Besides them 1,8-Cineole, b-pinene, sabinene, and b-(Z)-santalol were the major components. In a preliminary biological screening the samples of essential oils of A. sellowii displayed strong activity in the brine shrimp lethality assay (LC50 = 2.85 µg mL-1) as well as antimicrobial activity against Gram-positive and Gram-negative microorganisms and two yeasts (MIC 1.7-16 mg mL-1).

Chemical Composition and Antimicrobial Activity of the Volatile Oil from Baccharis articulate (Lam.) Pers.

Abstract The essential oil obtained from aerial parts of Baccharis articulata (Lam.) Pers. from Rio Grande do Sul, Southern Brazil, was analyzed by GC, GC/MS, and chiral phase gas chromatography (CPGC). Twenty-nine compounds representing ca 86.1 % of the oil were identified. The main compounds in the oil were β-pinene (39.0%), cis—-guaiene (9.8%), γ-muurolene (5.8%), limonene (4.8%), α—pinene (4.5%), α—gurjunene (4.4%) and spathulenol (4.2%). The antimicrobial activity of the oil was evaluated against seven microorganisms using the broth microdilution method. The oil displayed antimicrobial activity against Gram-positive and Gram-negative microorganisms (MIC=2.5 mg/mL).

Structure-activity relationship of benzophenanthridine alkaloids from Zanthoxylum rhoifolium having antimicrobial activity.

Zanthoxylum rhoifolium (Rutaceae) is a plant alkaloid that grows in South America and has been used in Brazilian traditional medicine for the treatment of different health problems. The present study was designed to evaluate the antimicrobial activity of the steam bark crude methanol extract, fractions, and pure alkaloids of Z. rhoifolium. Its stem bark extracts exhibited a broad spectrum of antimicrobial activity, ranging from 12.5 to 100 µg/mL using bioautography method, and from 125 to 500 µg/mL in the microdilution bioassay. From the dichloromethane basic fraction, three furoquinoline alkaloids (1–3), and nine benzophenanthridine alkaloids (4–12) were isolated and the antimicrobial activity of the benzophenanthridine alkaloids is discussed in terms of structure-activity relationships. The alkaloid with the widest spectrum of activity was chelerythrine (10), followed by avicine (12) and dihydrochelerythrine (4). The minimal inhibitory concentrations of chelerythrine, of 1.50 µg/mL for all bacteria tested, and between 3.12 and 6.25 µg/mL for the yeast tested, show this compound to be a more powerful antimicrobial agent when compared with the other active alkaloids isolated from Z. rhoifolium. To verify the potential importance of the methylenedioxy group (ring A) of these alkaloids, chelerythrine was selected to represent the remainder of the benzophenanthridine alkaloids isolated in this work and was subjected to a demethylation reaction giving derivative 14. Compared to chelerythrine, the derivative (14) was less active against the tested bacteria and fungi. Kinetic measurements of the bacteriolytic activities of chelerythrine against the bacteria Bacillus subtilis (Gram-positive) and Escherichia coli (Gram-negative) were determined by optical density based on real time assay, suggesting that its mechanism of action is not bacteriolytic. The present study did not detect hemolytic effects of chelerythrine on erythrocytes and found a protective effect considering the decrease in TBARS and AOPP (advanced oxidized protein products) levels when compared to the control group.

Chemical composition and antimicrobial activity of the essential oil from Aeolanthus suaveolens Mart. ex Spreng

The essential oils from leaves (sample A) and flowers (sample B) of Aeolanthus suaveolens Mart. ex Spreng were obtained by hydrodistillation and analyzed by GC, GC-MS, and chiral phase gas chromatography (CPGC). Six compounds have been identified from the essential oils, representing ca 94.3 and 93% of the oils corresponding to samples A and B, respectively. The major constituents of samples A and B essential oils were respectively, linalool (34.2%/34.9%), (-)-massoialactone (25.9%/17.0%) and (E)-b-farnesene (25.4%/29.1%). The enantiomeric distribution of the monoterpene linalool was established by analysis on heptakis- (6-O-methyl-2,3-di-O-pentyl)-b-cyclodextrin capillary column. The antimicrobial activity of the essential oil from leaves and isolated compounds was also evaluated.

Chemical composition and evaluation of prolyl oligopeptidase and acetylcholinesterase inhibitory activities of Leonurus Sibiricus L. from Brazil

Abstract Chemical investigation of the aerial parts of Leonurus sibiricus L. used in Brazilian folk medicine led to the identification of the following constituents: the labdane-type diterpenoid leojaponin, the phytosterols β-sitosterol and β-sitosterol glucoside and the alkaloid leonurine. The crude extracts obtained from methanol and methanol/1% HCl and pure compounds isolated from L. sibirius were investigated as acetylcholinesterase (AChE) and prolyl oligopeptidase (POP) inhibitors. Extracts obtained by maceration were active against POP (53–58%), but showed weak activity against AChE. The isolated leojaponin and leonurine were evaluated as POP inhibitors.

Inhibitory Effect of Verbascoside Isolated from Buddleja brasiliensis Jacq. ex Spreng on Prolyl Oligopeptidase Activity

The phenylpropanoid glycoside verbascoside [2‐(3,4‐dihydroxyphenylethyl)‐1‐O‐α‐l‐rhamnopyranosyl‐(1→3)‐β‐d‐(4‐O‐caffeyl)‐glucopyranoside] (1) has been isolated as the main constituent of the crude extract of Buddleja brasiliensis Jacq. ex Spreng from Southern Brazil. The crude extract, main fractions and the compound 1 were evaluated for inhibition of the enzymes acetylcholinesterase (AChE), dipeptidyl peptidase‐IV (DPP‐IV) and prolyl oligopeptidase (POP). Compound 1 showed weak activity against DPP‐IV with an IC50 >> 150 µm and was inactive against AChE, with a pMIQ determined by bioautography of 9.6. In contrast, 1 displayed significant inhibition of POP in a dose‐dependent manner with an IC50 value of 1.3 ± 0.2 µm, similar to the positive control, baicalin, with a POP IC50 of 12 ± 3 µm. Copyright

Phytochemical analysis of bark from Helietta apiculata Benth and antimicrobial activities

Extraction and characterization of natural products from the bark of the trunk of Helietta apiculata Benth (Rutaceae) afforded nine alkaloids, eight furoquinoline and one quinolone, limonine, three cinnamic acid derivatives, three neolignans, tetracosanoic acid, six coumarins, of which apiculin A and apiculin B (neolignans), and tanizin (coumarin) are previously undescribed compounds. The structures of all compounds were determined by spectroscopic methods, and the crystal structures of two of the newly undescribed compounds, apiculin A and apiculin B, were determined by X-ray analysis. Extracts and pure compounds isolated from Helietta apiculata showed promising antimicrobial activities.

Lanostane-type triterpenes from the fungal endophyte Scleroderma UFSMSc1 (Persoon) Fries.

Two lanostane triterpenoids (sclerodols A and B) were isolated from the culture of the Eucalyptus grandis derived from the endophyte Scleroderma UFSM Sc1(Persoon) Fries together with three known compounds: one related triterpenoid lanosta-8,23-dien-3β,25-diol, the disaccharide α,β-trehalose, and the sugar alcohol mannitol. Their structures were elucidated on the basis of 2D NMR, HRME, and single-crystal X-ray diffraction data. The methanol crude extract and the isolated lanostane triterpenoids showed promising anticandidal activities.