Diseases caused by intestinal parasites such as protozoa represent a worldwide problem mainly for developing countries. From morbidity in different groups of people to cases of mortality in children and/or immunocompromised patients. In addition to the above, there is growing resistance to the drugs used in the treatment of these diseases, as well as undesirable side effects in patients. Therefore, there is an interest in the search for new alternatives for the base and/or development of new drugs with antiparasitic activities without harmful effects. In this sense, natural products offer to be a diverse source of compounds with biological activities. In this work, we describe the isolation and elucidation by 1D and 2D NMR spectroscopy of three cyclopeptides obtained from seeds of A. diversifolia Saff.: cherimolacyclopeptide D (1), squamin D (2), and squamin C (3). The fractions enriched in cyclopeptides, as well as a pure compound (1), showed antiprotozoal activity against E. hystolitica Schaudinn and Giardia lamblia Kunstler in vitro assays, with values of IC₅₀ = 3.49 and 5.39 μg mL⁻¹, respectively. The molecular docking study revealed that 1 has a strong interaction with targets used, including aldose reductase and PFOR enzymes. The antiprotozoal activity of cherimolacyclopeptide D is reported for the first time in this study.

Introducción: Schinus molle L. (Anacardiaceae), conocido como pirul en México, es una especie rica en aceite esencial en hojas y frutos.Objetivo: Caracterizar el perfil fitoquímico de aceite esencial obtenido de hojas de S. molle mediante dos sistemas de destilación y distintos tiempos de extracción.Materiales y métodos: Se utilizó un destilador discontinuo Rayleigh de escala intermedia para extraer aceite esencial de hojas de S. molle colectadas en la región central de México. El producto obtenido a distintos tiempos se caracterizó mediante cromatografía de gases y espectrometría de masas (GC-MS). El perfil fitoquímico se comparó con extracto obtenido en aparato Clevenger.Resultados y discusión: El destilador Rayleigh tuvo mayor capacidad de extracción, pero el rendimiento fue 0.6 % menor (P = 0.05) que con el aparato Clevenger a los 120 min. En total se encontraron 37 compuestos, de los cuales 31 estuvieron presentes en el extracto obtenido con destilador Rayleigh, cinco fueron compuestos de baja concentración y uno, catalogado como sesquiterpeno oxigenado, tuvo alta concentración (10.25 %) en el aceite esencial. Con mayor tiempo de extracción, los sesquiterpenos incrementaron y los sesquiterpenos oxigenados disminuyeron. El aceite esencial tuvo presencia mayoritaria de monoterpenos hidrogenados, principalmente de α-felandreno (21.20-28.57 %), limoneno + β-felandreno (19.07-27.78 %), canfeno (3.32-9.93 %), α-pineno (5.74-8.56 %), β-mirceno (2.95-6.91 %) y β-pineno (1.31-3.55 %).Conclusiones: La caracterización del procedimiento de extracción y del perfil químico del aceite esencial de S. molle puede favorecer el aprovechamiento de esta especie.

The genus Annona is scarcely investigated for its neuropharmacological and toxicological activities, especially regarding its seeds. To explore the effects on the central nervous system (CNS) and the acute toxicity (LD₅₀) of the polar extracts and fractions obtained from the A. macroprophyllata seeds, their potential as a possible source of anxiolytic drugs was evaluated. After determining LD₅₀, one or two doses were selected to evaluate the neuronal activity using electrocorticographic (ECoG) recordings, and the anxiolytic-like behavior in mice treated with the crude extracts or some of their fractions was assessed in the experimental models of anxiety, such as the open-field, hole-board, and plus-maze tests. Phytochemical analysis was carried out to identify the most abundant constituents, whose possible mechanism of action was also evaluated by in silico analysis. Results showed CNS depressant activity associated with an anxiolytic-like behavior, in which cherimolacyclopeptide D and squamins C and D were identified. According to a docking analysis, the inhibitory receptors GABA_A and 5-HT_1A of serotonin are possible mechanisms of action involved in the anxiolytic-like effects of these cyclopeptides, which, in conclusion, might be potential molecules for anxiety therapy.

Giardiasis is a parasitic disease for which there is a growing need to develop new therapeutic alternatives due to the adverse effects associated with first-line treatments such as metronidazole and the increasing emergence of resistant strains. In this study, the in vitro antigiardial activity of three quassinoids, chaparrin (1), amarolide (2), and chaparrinone (3), isolated from the stems of Castela tortuosa Liebm., was evaluated. The compounds were obtained from the methanolic extract through fractionation and chromatographic purification, and their antigiardial activity was determined against Giardia lamblia trophozoites. In addition, in silico studies were conducted to evaluate their physicochemical, pharmacokinetic, and toxicological properties, as well as molecular docking studies against actin, aldose reductase (ARL), and pyruvate: ferredoxin oxidoreductase (PFOR). Chaparrinone (3) exhibited the highest antigiardial activity, with an IC₅₀ 18.98 μg mL⁻¹, whereas chaparrin (1) and amarolide (3) showed lower activity. Amarolide (2) exhibited the highest binding affinities toward the molecular targets, while chaparrin (1) showed the most favorable overall toxicological/ADME profile. Taken together, these findings highlight chaparrinone (3) as a quassinoid of interest for the development of new antigiardial agents and support the need for further enzymatic, pharmacokinetic, and in vivo studies to more precisely determine its therapeutic potential.