Aporphine alkaloids from Piper erecticaule and acetylcholinesterase inhibitory activity / Alcaloides de aporfina obtenida de Piper erecticaule y actividad inhibitoria de la acetilcolinesterasa

Chemical constituents and biological activities of the aerial parts of Piper erecticaule C.DC. have been studied for the first time. Fractionation and purification of the extracts afforded aristolactam AII (1), aristolactam BII (2), piperolactam A (3), piperolactam C (4), piperolactam D (5), together with terpenoids of ß-sitosterol, ß-sitostenone, taraxerol, and lupeol. The structures of these compounds were obtained by analysis of their spectroscopic data, as well as the comparison with that of reported data. Acetylcholinesterase inhibitory activity revealed that compounds 1 and 3 showed strong AChE inhibitory effects with the percentage inhibition of 75.8% and 74.8%, respectively.

Se estudiaron por primera vez los constituyentes químicos y actividad biológica de las partes aéreas de Piper erecticaule C.DC. El fraccionamiento y la purificación de los extractos proporcionaron aristolactama AII (1), aristolactama BII (2), piperolactama A (3), piperolactama C (4), piperolactama D (5), junto con terpenoides de ß-sitosterol, ß-sitostenona, taraxerol, y el lupeol. Las estructuras de estos compuestos se obtuvieron mediante el análisis de sus datos espectroscópicos, así como mediante la comparación con datos ya informados. La actividad inhibidora de la acetilcolinesterasa reveló que los compuestos 1 y 3 mostraron un potente efecto inhibidor de la AChE con un porcentaje de inhibición del 75.8% y 74.8%, respectivamente.

Anticholinesterase and Anti-inflammatory Constituents from Beilschmiedia pulverulenta Kosterm

Phytochemical investigation from the stem bark of Beilschmiedia pulverulenta resulted in the isolation of five lignans, (+)-yangambin (1), (+)-sesartemin (2), (+)-excelsin (3), (+)-sesamin (4), and (+)-syringaresinol (5), together with lupeol (6), lupenone (7), β-sitosterol (8), and β-sitostenone (9). Their structures were established by the analysis of their spectroscopic (1D and 2D NMR) and spectrometric (MS) data, as well as by comparison with those reported in the literature. The isolated lignans were tested for their anticholinesterase (AChE: acetylcholine esterase and BChE: butyryl cholineesterase) and anti-inflammatory (COX-2: cyclooxygenase-2 and LOX: lipoxygenase) activities. All the isolated lignans (1 – 5) exhibited significant inhibition activities in AChE/BChE and COX-2/LOX assays with IC50 values ranging from 168.8 – 504.2 µM and 21.0 – 59.4 µM, respectively.

Chemical composition of Piper stylosum Miq. and Piper ribesioides Wall.essential oils, and their antioxidant, antimicrobial and tyrosinaseinhibition activities / Composición química de los aceites esenciales de Piper stylosum Miq. y Piper ribosoides Wall. y sus actividadesantioxidantes, antimicrobiana y de inhibición de la tirosinasa

Chemical compositions of P. stylosum and P. ribesioides essential oils, and their antioxidant, antimicrobial and tyrosinase inhibition activities were determined. GC and GC–MS analysis of essential oils from leaves and stems of P. stylosum resulted in the identification of 50 (89.2 percent) and 45 (88.8 percent) components, respectively. The major components were aromadendrene (leaves 26.6 percent; stems 18.8 percent), sabinene (leaves 13.8 percent; stems 6.7 percent) and beta-caryophyllene (leaves 11.5 percent; stems 17.9 percent). A total of 60 (87.0 percent) and 39 (82.9 percent) components were identified from leaves and stems of P. ribesioides, respectively. The most abundant components were beta-caryophyllene (leaves 20.0 percent; stems 14.4 percent), camphene (leaves 16.3 percent; stems 12.3 percent) and delta-cadinene (leaves 4.4 percent; stems 7.8 percent). Antioxidant activity using DPPH and total phenolic content were tested for essential oils. However, the essential oils showed low antioxidant activity and phenolic content, compared to BHT. Studies of tyrosinase inhibition showed that the essential oils of P. ribesioides leaves had the highest inhibition (30.0 percent), although were lower than the control (kojic acid 81.8 percent). The evaluation of antimicrobial activities revealed that P. ribesioides essential oils showed strong activity against Bacillus cereus and Staphylococcus aureus, both with MIC value 62.5 micrograms/mL.

Se determinaron las composiciones químicas, las actividades antioxidante y antimicrobiana, y el contenido total de fenoles de los aceites esenciales de P. stylosum y P. ribesioides. El análisis GC y GC-MS de los aceites esenciaales de hojas y tallos de P. stylosum permitió la identificación de 50 (89.2 por ciento) y 45 (88.8 por ciento) de components, respectivamente. Los principales componentes fueron aromadendreno (hojas 26.6 por ciento; tallos 18.8 por ciento), sabineno (hojas 13.8 por ciento; tallos 6.7 por ciento) y beta-cariofileno (hoja 11.5 por ciento; tallo 17.9 por ciento). Se identificaron 60 (87.0 por ciento) y 39 (82.9 por ciento) components en los aceites esenciales de hojas y tallos de P. ribesioides. Los componentes más abundantes fueron beta-cariofileno (hojas 20.0 por ciento; tallos 14.4 por ciento), canfeno (hojas 16.3 por ciento; tallos 12.3 por ciento) y delta-cadineno (hojas 4.4 por ciento; tallos 7.8 por ciento). Los aceites esenciales se ensayaron para determinar sus actividades antioxidantes con DPPH y el contenido de fenoles totales. Para los aceites esenciales obtenidos se determinaron valores bajos en la actividad antioxidante con DPPH y el contenido total de fenoles, en comparación con BHT. Sin embargo, los ensayos de inhibición de tirosinasa most raron que el aceite esencial de las hojas de P. ribesioides presento la mayor inhibición (30.0 por ciento), aunque mas baja que el compuesto control (Àcido Kójico, 81.8 por ciento). Para el aceite esencial de P. ribesioides se determinó una MIC 62.5 mg/mL contra Bacillus cereus y Staphylococcus aureus.