RESUMEN

The genus Clinanthus Herb. is found in the Andes Region (South America), mainly in Peru, Ecuador, and Bolivia. These plants belong to the Amaryllidaceae family, specifically the Amaryllidoideae subfamily, which presents an exclusive group of alkaloids known as Amaryllidaceae alkaloids that show important structural diversity and pharmacological properties. It is possible to find some publications in the literature regarding the botanical aspects of Clinanthus species, although there is little information available about their chemical and biological activities. The aim of this work was to obtain the alkaloid profile and the anti-cholinesterase activity of four different samples of Clinanthus collected in South America: Clinanthus sp., Clinanthus incarnatus, and Clinanthus variegatus. The alkaloid extract of each sample was analyzed by gas chromatography coupled with mass spectrometry (GC-MS), and their potential against the enzymes acetyl- and butyrylcholinesterase were evaluated. Thirteen alkaloids have been identified among these species, while six unidentified structures have also been detected in these plants. The alkaloid extract of the C. variegatus samples showed the highest structural diversity as well as the best activity against AChE, which was likely due to the presence of the alkaloid sanguinine. The results suggest this genus as a possible interesting new source of Amaryllidaceae alkaloids, which could contribute to the development of new medicines.

Asunto(s)

Alcaloides , Alcaloides de Amaryllidaceae , Amaryllidaceae , Alcaloides de Amaryllidaceae/farmacología , Butirilcolinesterasa/química , Amaryllidaceae/química , Alcaloides/química , Inhibidores de la Colinesterasa/química , Extractos Vegetales/farmacología , Extractos Vegetales/química , América del Sur

RESUMEN

The Libellus de Medicinalibus Indorum Herbis (Booklet of Indian Medicinal Plants) is the first book of medicinal plants written in the American continent. It was first published in 1939 as 'An Aztec Herbal'. One of the depicted plants is Huetzcanixochitl (laughing flower) interpreted as Zephyranthes fosteri (Amaryllidaceae). No chemical or pharmacological studies are reported for this species; so, we decide to investigate it. The GC/MS of the bulbs and aerial parts extracts indicated that they contain Amaryllidaceae alkaloids, among them: lycorine, 3-O-acetylpowelline, and norlycoramine. An unknown major alkaloid was isolated and identified by 1 H, 13 C-NMR and MS, as 3'-demethoxy-6-epimesembranol (1). The methanolic extract, the alkaloid fraction, and compound 1 inhibited acetylcholinesterase in vitro. Mesembrine alkaloids are found in Sceletium species (Aizoaceae). Several are known as serotonin recapture inhibitors and have been proposed as potential antidepressant drugs. The presence of 1 suggests that Z. fosteri was probably used in pre-Columbian times in Mexico as a 'stimulant and euphoriant', alike Sceletium tortuosum by several ethnic groups in South Africa.

Asunto(s)

Alcaloides/farmacología , Amaryllidaceae/química , Inhibidores de la Colinesterasa/farmacología , Fitoquímicos/farmacología , Plantas Medicinales/química , Acetilcolinesterasa/metabolismo , Alcaloides/química , Alcaloides/aislamiento & purificación , Animales , Inhibidores de la Colinesterasa/química , Inhibidores de la Colinesterasa/aislamiento & purificación , Relación Dosis-Respuesta a Droga , Electrophorus , México , Estructura Molecular , Fitoquímicos/química , Fitoquímicos/aislamiento & purificación , Estereoisomerismo , Relación Estructura-Actividad

RESUMEN

The extracts of 14 Julianaceae and 5 Clusiaceae species growing in Mexico were tested in vitro (50 µg/mL) against Mycobacterium tuberculosis H37Rv and HIV reverse transcriptase (HIV-RT). The Julianaceae bark and leaf extracts inhibited M. tuberculosis (>84.67%) and HIV-RT (<49.89%). The Clusiaceae leaves extracts also inhibited both targets (>58.3% and >67.6%), respectively. The IC50 values for six selected extracts and their cytotoxicity (50 µg/mL) to human macrophages were then determined. Amphipterygium glaucum, A. molle, and A. simplicifolium fairly inhibited M. tuberculosis with IC50 of 1.87-2.35 µg/mL; but their IC50 against HIV-RT was 59.25-97.83 µg/mL. Calophyllum brasiliense, Vismia baccifera, and Vismia mexicana effect on M. tuberculosis was noteworthy (IC50 3.02-3.64 µg/mL) and also inhibited RT-HIV (IC50 26.24-35.17 µg/mL). These 6 extracts (50 µg/mL) presented low toxicity to macrophages (<23.8%). The HPLC profiles of A. glaucum, A. molle, and A. simplicifolium indicated that their antimycobacterial activity cannot be related to masticadienonic, 3α, or 3ß-hydromasticadienonic acids, suggesting that other compounds may be responsible for the observed activity or this might be a synergy result. The anti-HIV-RT and antimycobacterial activities induced by C. brasiliense can be attributed to the content of calanolides A, B, as well as soulatrolide.