Extraction, Quantification, and Ftir Characterization of Bark Tannins of Four Forest Species Grown in Northeast Brazil

Abstract

Condensed tannins are chemical compounds derived from the secondary metabolism of plants. They are of particular interest due to their broad range of technological uses and applications. The objective of this study was to extract, quantify, and characterize by Fourier-transform infrared spectroscopy (FTIR) the bark tannins of four forest species grown in Northeast Brazil: Acacia mangium, Azadirachta indica, Mimosa tenuiflora, and Mimosa caesalpiniifolia. Bark samples were collected from 5 trees of each species grown in a five-year-old forest stand. Samples were collected, grounded, and submitted to extraction with hot water, then measured to determine total solids content (TSC), Stiasny number (SN), and condensed tannins content (CTC). FTIR spectra were acquired from tannin samples fixed in potassium bromide pellets. Among the four species, M. tenuiflora presented the highest CTC, equal to 23.4%, and the purest crude hot-water extract with SN of 91.27%. Based on FTIR characterization, tannins from M. caesalpiniifolia, A. indica, and A. mangium barks were classified as proanthocyanidins and those from M. tenuiflora bark as prodelphinidins.

EFFECT OF THINNING ON VOLUMES OF BIOMASS AND BARK TANNINS CONTENT OF Mimosa caesalpiniifolia BENTH. TREES

“…There was no statistical diff erence between the experimental treatments T1 and T2 for TSC and CTC (Table 6). Assessing the TSC in M. caesalpiniifolia bark from 5-year-old trees, Marques et al (2021) determined a value for TSC of 9.18%, close to the values found here for T1 and T2 of 8.57 and 7.12% respectively. TSC corresponds to the hotwater-soluble extractives from the bark, while CTC indicates the content of extractable tannins in each material.…”

“…We found a statistical diff erence between the experimental treatments T1 and T2, with the highest value found for the extracts from the bark of the non-thinned plot (T2), 73.31%. However, this value is lower than that of Marques et al (2021), 91.27%. When subjected to stressful situations, plants show alteration in the production of secondary metabolites as a defense mechanism (Isah, 2019).…”

“…Other properties, such as high wood density, higher calorifi c value, and contents of volatile matter and ash, allow the species to be used for energy generation (Santos et al, 2013;Batista et al, 2020). Besides these features, M. caesalpiniifolia has a good capacity for regeneration after harvesting (Podadera et al, 2015), and its bark has a high content of condensed tannins (Marques et al, 2021). Gonçalves et al (2010) determined that, on average, bark corresponds to 7.5% of the harvested trunk.…”

Environmentally Friendly Extraction from Picea Abies Bark as an Approach to Accessing Valuable Antioxidants in Biorefineries

“…The presence of peaks between 1200 cm −1 and 1350 cm −1 indicates that phenolic and anthocyanic compounds are contained in the samples. This was clearly pointed out by Marques [41].…”

Phytochemical characterization by GC-MS and in vitro evaluation of antiproliferative and antimigratory studies of Leucas aspera leaf extracts on MDA-MB-231 cell line

“…3 , Table 4 ). In previous studies, FT-IR analysis revealed that the alkaloids exhibited NH stretching, phenols and flavonoids had OH stretching (Devi and Battu, 2019 ), saponins had C=O stretching (Bajad and Pardeshi, 2016 ), tannins possess C=C stretching (Marques, 2021 ). The outcomes of the current study revealed that dichloromethane and ethyl acetate extracts of L. aspera have alkaloids, flavonoids, phenols, saponins, and tannins, whereas the hexane extract of L. aspera showed the presence of alkaloids and tannins and these are in correlation with previous studies of Das et al ( 2011 ), Vasudha et al ( 2019 ).…”