Despite the historical use of plants for therapeutic purposes in Brazil, the progress in research
that justifies such pharmacological effects is still negligible in the face of the vast national
flora. With a view to indicating the Parkia platycephala species in the treatment of
Alzheimer's disease, two methods of hot extraction (hydroethanolic and sequential) of the
leaf, bark, flower and seed of this species were carried out to carry out chemical
bioprospecting (liquid chromatography “LC”, gas chromatography “GC”), determine the
antioxidant capacity (DPPH•), anticholinesterase activity (Ellman) and toxicity (Artemia
salina, Allium cepa) of these extracts. The crude extracts of the leaf (LE), bark (BE), flower
(FE) and seed (SE) of Parkia platycephala were obtained after hydroethanolic extraction at
reflux (Soxlhet), using ethanolic solution (70%) for a period of 5h. Sequential extraction
started with hexane solvent under reflux for 5h. After 12 hours of drying in a hood, the same
sample underwent a new extraction with methanolic solvent. The methodology was repeated,
to finish the extraction with ethanolic solution (70%). Thus, the methanolic and ethanolic
extracts of the leaf (LEM, LEE), bark (BEM, BEE), flower (FEM, FEE) and seed (SEM,
SEE) were obtained, respectively. The presence of tannins, flavonoids, saponins,
phytosterols/triterpenoids and alkaloids were detected in the phytochemical screening of both
methodologies. The antioxidant activity of the extracts was influenced by the methodologies,
mainly for the bark, whose BEE extract (IC50=10.69 ± 0.35 μg. mL-1) showed an antioxant
capacity superior to the rutin standard (IC50=15.85 ± 0.08μg. mL-1). The chemical
characterization of the sequential extracts indicated a diversity of compounds, evidencing urs-
12-ene and 1,2,3 benzenotriol, in leaf extracts, linoelaidic acid, (Z)-9-octadecenamide and
(Z)-7-hexadecenal, in seed extracts, trilinolein, (Z)-9-octadecenamide, in bark extracts and 3-
o-methyl-d-glucose and (methylsulfinyl)(methylthio)-methane in flower extracts. For the
crude extracts, three steroids and two triterpenoids were identified by GC-MS. Analysis by
CL-DAD revealed the presence of naringin and kaempferol in all parts of the plant, in
addition to phenolic acids (leaf, bark and flower). Among the analyzed extracts, the bark and
the seed showed the highest levels of toxicity against Artemia salina, while in relation to
Allium cepa, the seed extracts inhibited root growth from 250 μg. mL-1. Such results are
indicative of antitumor activity. Although all extracts showed potential anticholinesterase
activity, the crude seed extract and the sequential extracts of the flower stood out. We
conclude that the sequential ethanol extracts showed better results in the antioxidant (bark), of
toxicity (leaf) and anticholinesterase (flower) assays, while the crude seed extract stood out in
terms of toxicity and anticholinesterase activity.
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