Alkaloids from the stem barks of Scutia buxifolia Reissek (Rhamnaceae): Structures and antimicrobial evaluation.

A reinvestigation of the chemical constituents of the stem barks of Scutia buxifolia, a member of the Rhamnaceae, resulted, along with the known alkaloids scutianine C and scutianene L, in the isolation of three undescribed diastereoisomeric alkaloids - scutianine N, 27-epi-scutianine N and 3, 4, 7-tri-epi-scutianine N -, one undescribed non macrocyclic alkaloid - scutianine Q - and a neutral compound -scutianene M. Their structures were determined using extensive NMR techniques and HRMS. The absolute configurations of the stereogenic centers of the three diastereoisomeric alkaloids have been assigned by gas chromatography employing modified cyclodextrins as chiral stationary phases. Scutianine Q had its structure and stereochemistry defined by single crystal X-ray crystallographic analysis. All tested compounds showed good to moderate antibacterial activity (MICs between 1.56 and 100 µg mL-1) when evaluated in vitro against a panel of Gram-positive and Gram-negative bacteria. Some stereochemistry-activity relationships have been identified for the antibacterial activity of diastereoisomeric alkaloids against the Gram-negative bacteria Enterobacter aerogenes. The alkaloid 27-epi-scutianine N was as active as the standard antibiotic chloramphenicol (MIC = 1.56 µg mL-1), while scutianine N and 3,4,27-tris-epi-Scutianine N were inactive (>100 µg mL-1).

Pharmacological evidence favouring the traditional use of the root bark of Condalia buxifolia Reissek in the relief of pain and inflammation in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: The Condalia buxifolia root bark infusion is used in traditional medicine in Brazil as antipyretic, anti-inflammatory and against dysentery. This study was designed to investigate whether the methanolic extract of the root bark of Condalia buxifolia (MECb) exhibits antinociceptive and anti-inflammatory effects in mice. Furthermore, also was investigated the involvement of glutamatergic and opioidergic system in the antinociceptive effect induced by MECb. MATERIALS AND METHODS: The antinociceptive and anti-inflammatory effects of intra-gastric gavage (i.g.) administered MECb (10-300 mg/kg) were evaluated in mice subjected to chemical (formalin, acetic-acid, glutamate) or thermal (hot plate) models of pain. The involvement of opioid system in the antinociceptive effect of the MECb was investigated in formalin test. Furthermore, a nonspecific effect of MECb was evaluated by measuring locomotor activity and exploratory behavior in open field test. Finally, was performed a phytochemical analysis of MECb. RESULTS: The phytochemical analysis of MECb was performed through HPLC analysis showing that the alkaloid Condaline-A is the main constituent. The intragastric administration of MECb (100-300 mg/kg) significantly inhibited the nociception caused by acetic acid (48 ± 2%), inflammatory phase (49 ± 3%) and paw edema (32 ± 6) caused by formalin, and MECb (100mg/kg, i.g.) also inhibited nociception caused by glutamate (41 ± 7%). In addition, MECb (100-300 mg/kg, i.g.) increased the paw withdrawal latency in hot-plate test, without affecting the locomotor activity and exploratory behavior in open field test. Finally, the antinociceptive effects of MECb (100mg/kg, i.g.) were significantly reversed by naloxone (1mg/kg, i.p.) in the formalin test. CONCLUSION: These data show, for the first time, that MECb has significant antinociceptive and anti-inflammatory effects, which appear to be related to the inhibition of the glutamatergic system and the activation of opioid mechanism, besides present central effects. These results support the use of Condalia buxifolia in traditional medicine and demonstrate that this plant has therapeutic potential for the development of phytomedicines with antinociceptive and anti-inflammatory properties.

Efficacy of eugenol and the methanolic extract of condalia buxifolia during the transport of the silver catfish Rhamdia quelen

This study evaluated extracts of Condalia buxifolia as anesthetics for the silver catfish Rhamdia quelen. The effectiveness of eugenol and of the methanolic extract (ME) of C. buxifolia during the transport of this species was also assessed. Fish of two different weights (1.50±0.02 g and 165.70±22.50 g) were transferred to aquaria containing water with the C. buxifolia ME or with fractions obtained from the ME, such as the n-hexane, dichloromethane, ethyl acetate, n-butane and aqueous fractions, at concentrations from 0-300 °L L-1. The C. buxifolia ME in the 0.5-120 °L L-1 range caused only light sedation, and the fractions did not have an effect on the fish. In the second experiment, another group of fish was transported for 12 h in 15 plastic bags. The fish were divided into five groups: control, 1 or 2.5 °L L-1 eugenol and 25 or 50 °L L-1 C. buxifolia ME. The non-ionized ammonia levels were lower at the end of transport in the groups with the compounds than in that with water alone. Moreover, both compounds decreased the Na+, Cl-, and K+ net effluxes; therefore, their addition to the water during transport is advisable because they reduce fish mortality and ion loss.

Este estudo investigou extratos de Condalia buxifolia como anestésico para jundiá Rhamdia quelen, e também a eficiência do eugenol e do extrato metanólico (EM) de C. buxifolia para utilização durante o transporte dessa espécie. Peixes de dois diferentes pesos (1,50±0,02 g e 165,70±22,50 g) foram transferidos para aquários contendo água com o EM de C. buxifolia ou frações obtidas a partir do EM (n-hexano, acetato de diclorometano, etil n- butano e aquoso, em concentrações na faixa de 0 - 300 °L L-1. O EM de C. buxifolia em concentrações na faixa de 0,5 - 120 °L L-1 causou somente uma sedação leve e as frações não tiveram efeito. No segundo experimento outro grupo de peixes foi transportado por 12 h em 15 sacos plásticos divididos em cinco tratamentos: controle, 1 ou 2,5 °L L-1 de eugenol e 25 ou 50 °L L-1 de EM de C. buxifolia. Os níveis de amônia não-ionizada foram menores nos tratamentos com ambos compostos em relação à água (controle). Além disso, ambos compostos diminuíram os efluxos líquidos de Na+, Cl- e K+ e, portanto, sua adição na água de transporte é aconselhável, pois reduzem a mortalidade e a perda de íons dos peixes.

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 ß-hydroxy amino acid unit, which is connected to the styryl fragment via an ether bridge, ß-phenylserine, as a common ring-bonded amino acid residue. Attached to the amino group of ß-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.

Antinociceptive effects of 14-membered cyclopeptide alkaloids.

The analgesic potential of six 14-membered-ring cyclopeptide alkaloids, namely, franganine (1), discarine B (2), scutianines B (3), C (4), and D (5), and adouetine X (6), have been investigated. Among the compounds tested, only franganine (1) and adouetine X (6) produced antinociceptive effects in a mouse model of acute pain, without inducing undesirable side effects. Furthermore, compound 6 also exhibited a pronounced analgesic effect in a chronic neuropathic pain model in mice. It has been found that adouetine X (6) can decrease the activities of Ca(2+)-ATPase and Na(+)/K(+)-ATPase in vitro. Thus, the present findings have demonstrated that adouetine X (6) is a promising analgesic agent.

Triterpenoids from Gouania ulmifolia.

Two new triterpenoids, named gouanic acid A (1) and gouanic acid B (2), were isolated from the aerial parts of Gouania ulmifolia, along with six known compounds. The structures of the new compounds were determined by spectroscopic methods, mainly NMR (1D and 2D) and mass spectrometry. The new compounds did not show significant antimicrobial activities.

Cyclopeptide alkaloids from Scutia buxifolia Reiss and their antimicrobial activity.

The present study reports a cyclopeptide alkaloid, scutianine M, isolated from the methanolic root bark extract of Scutia buxifolia Reiss (Rhamnaceae) along with six known compounds, scutianines-B, -C, -D, -E, -F, and scutianene D. Its structure was established on the basis of spectroscopic analyses, including application of 2D NMR spectroscopic techniques. As part of a study of the bioactive compounds of medicinal plants from southern Brazil, we also compared the antimicrobial activity of the isolated compounds towards Gram (+), Gram (-) bacteria, and yeasts.

Cyclic peptide alkaloids from the bark of Discaria americana.

The isolation and structure determination of cyclic peptide alkaloids, discarine-M and discarine-N, along with seven known cyclic peptide alkaloids, adouetine-Y', franganine, frangulanine, discarines-A, -B, -C, and -D from the root bark of Discaria americana are described. Structures were determined spectroscopically, especially using 2D NMR spectroscopic analysis. The crude methanol extract, the basic ether extract, and the alkaloids 6 and 7 also weakly inhibited growth of gram-negative and gram-positive bacteria.