Chemical composition and anti-acetylcholinesterase, nitric oxide suppressing activities of Piper betle leaves oil

Abstract

Essential oil of Piper betle leaves in Quang Nam-Da Nang do obtain via the steam distillation method with oil collection efficiency reaching 0.83%. The chemical composition of the essential oil from Piper betle leaves in Quang Nam-Da Nang is determined via the GC-MS method that includes 21 components (99.68%), among which the main components are eugenol acetate (32.33%), eugenol (24.56%), 4-allyl-1,2-diacetoxybenzene (19.8%), germacrene D (5.98%), caryophyllene (3.32%), and γ-muurolene (2.45%). The essential oil of Piper betle leaves in Quang Nam-Da Nang also showed moderate anti-acetylcholinesterase activity with IC50 (µg/mL) = 65.94±5.96 and moderate nitric oxide suppressing activity with IC50 (µg/mL) = 46.69±3.57.

Towards the universal use of DOSY as a molar mass characterization tool: temperature dependence investigations and a software tool to process diffusion coefficients

“…In our previous work, we had used 298 K (25 °C), yet others would have chosen any temperature around room temperature. Hence, we tested the outcome of the calibration for polystyrene (probably, to date, the best tested polymer for DOSY calibrations 8,10,17–23 ) in the temperature range of 273 to 313 K (0 to 40 °C) using the exact same methodology as earlier.…”

“…Overall, the above discussed temperature dependence shows that using 298 K (25 °C) as a DOSY standard temperature is a good choice, which is underpinned by many individual studies using this condition. 8,10,13,14,17–20,22,23,28 Yet, as mentioned above, polymer chemists who want to use DOSY to determine molar masses face difficulties when they want to use the methodology. Even though an individual calibration is not required, and despite the fact that the mathematical transformation is quite simple, one still needs to have a good overview on the state of the literature regarding calibration results.…”