GC/MS-Based Fingerprinting Reveals Two Chemotypes in the Leaf Essential Oils from Magnolia grandiflora Trees within The Urban Forestry of a Colombian Andean Plateau.

Magnolia grandiflora is an aromatic plant widely distributed around the world. In Colombia, and more specifically in Bogotá, M. grandiflora has been introduced as part of urban forestry programs, and their specimens are therefore subjected to several environments. Nevertheless, there are no previous studies on the chemical composition of such plants. Hence, the characterization of the essential oil from 20 specimens of M. grandiflora from Bogotá, Colombia, by GC/MS was carried out here. Two different chemotypes were found. While one was characterized by monoterpenes α-pinene, ß-pinene, and limonene, the other contained mainly sesquiterpenes ß-elemene, bicyclogermacrene, and germacrene D. Multivariate statistical analyses confirmed their existence and helped to identify variations within and between chemotypes. Furthermore, differential expression of genes encoding the terpene synthases Mg25 and Mg17 could arguably be responsible for the characteristic compositions of both chemotypes, as suggested by rational biosynthetic analysis of the most contrasting metabolites.

Validation of PM10 and PM2.5 early alert in Bogotá, Colombia, through the modeling software WRF-CHEM.

Air quality data from Bogotá, Colombia, show high levels of particulate matter (PM), which often generate respiratory problems to the population and a high economic cost to the government. Since 2016, air quality in the city of Bogotá has been measured through the Bogota Air Quality Index (IBOCA) which works as an indicator of environmental risk due to air pollution. However, available technological tools in Bogotá are not enough to generate early alerts due to PM10 and PM2.5. Currently, alerts are only announced once the measured PM values exceed a certain standard (e.g., 37 µ g/m3), but not with enough anticipation to efficiently protect the population. It is necessary to develop an early air quality alert in Bogotá, in order to provide information that improves risk management protocols in the capital district. The purpose of this investigation is to validate the corrective alert presented on the 14th and 15th of February of 2019, through the WRF-Chem model under different weather conditions, using three different setups of the model to simulate PM10 and PM2.5 concentrations during two different climatic seasons and different resolutions. The results of this article generate a validation of two configurations of the model that can be used for the Environmental Secretary of the District (SDA) forecasts in Bogotá, Colombia, in order to contribute to the prediction of pollution events produced by PM10 and PM2.5 as a tool for an early alert system (EAS) at least 24 h in advance.