RESUMEN
Potato-sunflower intercropping is a prevailing cropping system in the agricultural and pastoral ecotone in China. To precisely simulate the crop phenology in the intercropping system is of significance for the assessment and optimization of intercropping systems. In this paper, the simulation model for the development stages of sunflower and potato in monoculture and intercropping was established, based on the crop's physiological development time, and validated with the field experimental data from 2010 to 2011. A good fitness was observed between the simulated and observed values of the crop's development stages. The root mean square error (RMSE) of the development stages from sowing to emergence, emergence to flowering, flowering to mature, and from sowing to mature was 1.2, 2.9, 2.4 and 2.6 d, respectively, with the prediction error lower than 5%. The model was strong on mechanistic, explanation and adaptability, and could be applied as a good tool in the researches of crop growth and development.
Asunto(s)
Agricultura/métodos , Helianthus/crecimiento & desarrollo , Modelos Biológicos , Solanum tuberosum/crecimiento & desarrollo , Simulación por ComputadorRESUMEN
A new 8-O-4' neolignan glycoside was isolated from the stem bark of Tetracentron sinense. Its structure was elucidated as erythro 4',5',7, 9, 9'-pentahydroxy-3-methoxy 8-O-4'-neolignan 3'-O-beta-glucopyranoside on the basis of spectral evidence (MS, IR, 1D and 2D NMR).
Asunto(s)
Glucósidos/aislamiento & purificación , Glicósidos/aislamiento & purificación , Magnoliopsida/química , Extractos Vegetales/química , Medicamentos Herbarios Chinos , Glucósidos/química , Glicósidos/química , Estructura Molecular , Corteza de la Planta , Extractos Vegetales/aislamiento & purificación , Tallos de la PlantaRESUMEN
One novel neolignan (tetracentronsine; 1), one new indole alkaloid (=3-(2-hydroxyethyl)-1H-indole-5-O-beta-D-glucopyranoside; 2), and two new phenol derivatives, 3-{2-[(beta-glucopyranosyl)oxy]-4,5-(methylenedioxy)phenyl}propanoic acid (3) and methyl 3-{2-[(beta-glucopyranosyl)oxy]-4,5-(methylenedioxy)phenyl}propanoate (4), together with six known compounds were isolated from the stem bark of Tetracentron sinense. Their structures were determined by spectral analysis, including 1D- and 2D-NMR, and MS analyses. These compounds were tested for their cytotoxic activity against human leukaemia cells in vitro. Among them, compound 2, (E)-3-(4-hydroxyphenyl)-N-[2-(4-hydroxyphenyl)ethyl]prop-2-enamide (5), and maslinic acid (6) showed significant inhibitory activities against human leukaemia cells CCRF-CEM and its multidrug-resistant sub-line, CEM/ADR5000, with IC50 values in a range of 7.1 to 29.7 microM.