Alicia Mariel Agnese

The essential oil of Senecio graveolens (Compositae): chemical composition and antimicrobial activity tests.

The chemical composition of the essential oil obtained from Senecio graveolens (Compositae) was analyzed by GLC-MS and the components identified were: isovaleraldehyde, alpha-pinene, alpha-phellandrene, alpha-terpinene, p-cymene, sabinene, gamma-terpinene, 1-methyl-4-isopropenylbenzene, terpinolene, terpinen-4-ol, piperitenone, alpha- and beta-eudesmol. The investigation by the agar-well diffusion method of the antimicrobial activity of the essential oil proved that it has antibacterial effects on Micrococcus luteus ATCC 9341, oxacillin-sensitive and oxacillin-resistant Staphylococcus aureus, as well as antifungal effects on clinically isolated Candida albicans. The minimal inhibitory concentration (MIC) values for M. luteus, oxacillin-sensitive S. aureus and C. albicans were 8.73, 10.91 and 2.13 x 10(-2) mg/ml, respectively. The antimicrobial activity related to known antibiotics was calculated. These results would be compatible with a potential concentration-dependent selectivity of antifungal effect of S. graveolens essential oil. Minimal bactericidal concentration (MBC) is above 87.3 mg/ml. Thus the MBC:MIC ratio would be clearly higher than 1 (above 8), indicating a bacteriostatic effect of the essential oil.

Adesmia aegiceras: antimicrobial activity and chemical study.

The antimicrobial activity of the ethanolic extract of Adesmia aegiceras was studied by the agar-well diffusion method. Antibacterial activity against Micrococcus luteus and eight pathogenic bacterial strains as well as antifungal activity against Candida albicans, was detected. Bacterial and fungal strains exhibited similar concentration-response curves (EC50 and Rmax values) and similar MIC. The MBC/MIC was about 8. These data would indicate the potential usefulness of the A. aegiceras extract as a microbiostatic, antiseptic or disinfectant agent. Furthermore, chemical study of the bioactive alcoholic extract was performed, which revealed quercetin, isorhamnetin-3-rutinoside, isovitexin, pinitol and chlorogenic acid as its main components.

CHEMOTAXONOMIC FEATURES IN ARGENTINIAN SPECIES OF FLAVERIA (COMPOSITAE)

Abstract The presence of thiophene derivatives in Flaveria bidentis and Flaveria bidentis var. angustifolia has been investigated to expand on the existing chemical information on both taxa. Alpha-terthienyl and 5- (3-buten-1-ynyl)- 2,2′-bithienyl were found in the roots and aerial parts of F. bidentis, whereas in F. bidentis var. angustifolia α-terthienyl was found only in the roots. These results, in conjunction with the different patterns of sulphated flavonoids present in each one of these entities, reinforce the differentiation, based on exomorphological features, of Argentinian Flaveria into two species: F. bidentis and F. haumanii (formerly F. bidentis var. angustifolia).

Study of the interaction of Huperzia saururus Lycopodium alkaloids with the acetylcholinesterase enzyme.

In the present study, we describe and compare the binding modes of three Lycopodium alkaloids (sauroine, 6-hydroxylycopodine and sauroxine; isolated from Huperzia saururus) and huperzine A with the enzyme acetylcholinesterase. Refinement and rescoring of the docking poses (obtained with different programs) with an all atom force field helped to improve the quality of the protein-ligand complexes. Molecular dynamics simulations were performed to investigate the complexes and the alkaloids binding modes. The combination of the latter two methodologies indicated that binding in the active site is favored for the active compounds. On the other hand, similar binding energies in both the active and the peripheral sites were obtained for sauroine, thus explaining its experimentally determined lack of activity. MM-GBSA predicted the order of binding energies in agreement with the experimental IC50 values.

Two new alkamides from roots of Acmella decumbens

From the roots of Acmella decumbens (Sm) R.K. Jansen three compounds belonging to the alkamide family were isolated: (2E, 4E)-N-hydroxiphenylethyl-2,4-decadien-9-inamide (1); (4E, 6E)-N-isobutyl-4,6-undecen-10-inamide; (2) and (2Z)-N-phenylethyl-2-nonane-6,8-diinamide (3). The structures were determined by means of IR, MS, 1H NMR, 13C NMR, DEPT 135 and COSY. Compounds 1 and 2 are reported for the first time, while 3 was previously isolated from Spilanthes acmella L.

Huperzia saururus Lam. Trevis. (Lycopodiaceae) facilitates ejaculation in spinal cord transected male rats.

ETHNOPHARMACOLOGICAL RELEVANCE Huperzia saururus (Lam.) Trevis. has an extensive ethnopharmacological use, mainly because of its aphrodisiac properties. The species is consumed as decoctions or infusions in traditional medicine. The purpose of the present research was to determine if Huperzia saururus is able to increase sexual potency by evaluating the ejaculatory response, in the presence of a decoction in spinal cord transected male rats. MATERIALS AND METHODS The fictive ejaculation model to record the rhythmic contractions of the bulbospongiosus muscles that accompany ejaculation as an indicator of ejaculation occurrence was used. Sexually experienced male Wistar rats were used. The activation of the fictive ejaculation by the i.v. administration of a decoction was tested, as well as the effects of the oxytocinergic, cholinergic, adrenergic and nitrergic antagonism upon the pro-ejaculatory activity of Huperzia saururus. RESULTS Decoction (3µg/animal) was able to activate the fictive ejaculation in spinal male rats, producing a statistically significant diminution on the latency of discharge parameter and a statistically significant augment for the number of discharges. Moreover, when sequential treatments using antagonists plus decoction were administered, the effects produced showed that prazosin prevent the pro-ejaculatory effect of the decoction and that the four antagonists assayed blocked the facilitatory effect of Huperzia saururus since the facilitation in the latency of response was prevented, and the number of discharges was reduced. Together these findings support the notion that the decoction exerts an aphrodisiac effect influencing the ejaculatory potency which is partially mediated by oxytocinergic, cholinergic, adrenergic and nitrergic spinal mechanisms. CONCLUSION In agreement to the ethnopharmacological uses, Huperzia saururus decoction has aphrodisiac properties by influence on the ejaculatory potency.

Mass spectrometry studies of lycodine‐type Lycopodium alkaloids: sauroxine and N‐demethylsauroxine

RATIONALE Sauroxine and N-demethylsauroxine are lycodine-type Lycopodium alkaloids. In recent years, Lycopodium alkaloids have gained significant interest due to their unique skeletal characteristics as well as due to their acetylcholinesterase activity. It is known that drugs that inhibit acetylcholinesterase can be used to treat the early stages of Alzheimers disease. METHODS Sauroxine and N-demethylsauroxine were isolated from the aerial parts of Huperzia saururus (Lam.) Trevis. Electron ionization mass spectrometry (EI-MS) (low resolution) and collision-induced dissociation tandem mass spectrometry (CID-MS/MS) fragmentation was conducted using an ion trap, GCQ Plus mass spectrometer with MS/MS. Electron ionization high-resolution mass spectrometry (EI-HRMS) was performed in a magnetic sector mass spectrometer (Micromass VG). RESULTS Using GC/EI-CID-MS/MS we obtained different fragmentation routes that connect all the ionic populations. In addition, the use of EI-HRMS allowed us to measure the exact masses of all the fragment ions, and, with all this information gathered, we tried to establish a fragmentation scheme concordant with the ascendant and descendant species. CONCLUSIONS The mass spectrometry studies presented in this work complete our mass studies of Lycopodium alkaloids. The mass spectrometry work presented has been very useful to confirm the structures as well as to support the biogenetic relationships between the lycodine-type Lycopodium alkaloids: sauroxine and N-demethylsauroxine.

Amino acid content and acetylcholinesterase inhibition of Huperzia saururus infusion and decoction

Abstract Context. Huperzia saururus (Lam.) Trevis. (Lycopodiaceae), an autochthonous plant species in Argentina, is used as a memory improver in traditional medicine. It was studied for this reason and the purified alkaloid extract did show significant activity on learning and memory. The species is mostly consumed in the form of infusions and decoctions. Objectives: To evaluate the activity of the H. saururus infusion and decoction as inhibitors of acetylcholinesterase (AChE) and to determine the amino acid content in both extracts. Material and methods: Infusion and decoction were purified by ionic exchange chromatography and analyzed by high-performance liquid chromatography HPLC-UV, and the AChE inhibition of these extracts was evaluated by using the Ellman method. Results: Both infusion and decoction exerted strong AChE inhibitory activities (IC50 = 7.2 ± 0.4 and 22.7 ± 5.6 μg/mL, respectively). Among nine amino acids, arginine (Arg) was identified in a concentration greater than 9 mg/100 g of dried aerial parts in both extracts. Discussion and conclusion: This high content of Arg could be considered a contributing factor to the activity on memory previously demonstrated for the H. saururus alkaloid extract, since Arg is implicated indirectly in mnemonic processes as a precursor in nitric oxide synthesis. Thus, the central effect of H. saururus could involve two different mechanisms, the cholinergic mechanism and the nitric oxide pathway.

Sauroxine reduces memory retention in rats and impairs hippocampal long-term potentiation generation

In the present paper it was investigated the role of sauroxine, an alkaloid of Phlegmariurus saururus, as a modulator of some types of learning and memory, considering the potential nootropic properties previously reported for the alkaloid extract and the main alkaloid sauroine. Sauroxine was isolated by means of an alkaline extraction, purified by several chromatographic techniques, and assayed in electrophysiological experiments on rat hippocampus slices, tending towards the elicitation of the long-term potentiation (LTP) phenomena. It was also studied the effects of intrahippocampal administration of sauroxine on memory retention in vivo using a Step-down test. Being the bio distribution of a drug an important parameter to be considered, the concentration of sauroxine in rat brain was determined by GLC-MS. Sauroxine blocked LTP generation at both doses used, 3.65 and 3.610-2μM. In the behavioral test, the animals injected with this alkaloid (3.6510-3nmol) exhibited a significant decrease on memory retention compared with control animals. It was also showed that sauroxine reached the brain (3.435μg/g tissue), after an intraperitoneal injection, displaying its ability to cross the blood-brain barrier. Thus, sauroxine demonstrated to exert an inhibition on these mnemonic phenomena. The effect here established for 1 is defeated by other constituents according to the excellent results obtained for P. saururus alkaloid extract as well as for the isolated alkaloid sauroine.