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Nectandra grandiflora Nees (Lauraceae) is a Brazilian native tree recognized by its durable wood and the antioxidant compounds of its leaves. Taking into account that the forest industry offers the opportunity to recover active compounds from its residues and by-products, this study identifies and underlines the potential of natural products from Nectandra grandiflora that can add value to the forest exploitation. This study shows the effect of three different extraction methods: conventional (CE), ultrasound-assisted (UAE) and microwave-assisted (MAE) on Nectandra grandiflora leaf extracts (NGLE) chemical yields, phenolic and flavonoid composition, physical characteristics as well as antioxidant and antifungal properties. Results indicate that CE achieves the highest extraction phytochemical yield (22.16%), but with similar chemical composition to that obtained by UAE and MAE. Moreover, CE also provided a superior thermal stability of NGLE. The phenolic composition of NGLE was confirmed firstly, by colorimetric assays and infrared spectra and then by chromatographic analysis, in which quercetin-3-O-rhamnoside was detected as the major compound (57.75–65.14%). Furthermore, the antioxidant capacity of the NGLE was not altered by the extraction methods, finding a high radical inhibition in all NGLE (>80% at 2 mg/mL). Regarding the antifungal activity, there was observed that NGLE possess effective bioactive compounds, which inhibit the Aspergillus niger growth. [ABSTRACT FROM AUTHOR]

Trees of the Amazon River floodplain (várzea) are subjected to regular periods of waterlogging which last up to seven months every year. The present study shows the importance of stem water storage for buffering root water uptake restrictions during water logging in different tree species which are common in this environment. With the method of Granier, total water fluxes were measured in five individuals of each of six species (Crateva benthami, Laetia colymbulosa, Nectandra amazonum, Pseudobombax munguba, Tabebuia barbata and Vitex cymosa ) with different phenologies, located in a várzea inundation forest near Manaus, Brazil. Xylem sap flux density was positively correlated with the above stand or upper canopy diurnal variation of vapour pressure deficit in all tree species under study. Increasing above stand or upper canopy vapor pressure deficit lead to an increasing sap flux density and total sap flow, and vice versa. Reduced water availability during day time was buffered by stem water which was filled up during night time. The severe physiological stress caused by anoxic conditions in the root zone was indicated by a reduction of the transpiring surfaces via leaf shedding. Stem water store could buffer water shortage during day time. [ABSTRACT FROM AUTHOR]