Antioxidant Properties and Stability of Geissospermum Reticulatum Tinctures: Lag Phase ESR and Chemometric Analysis

Abstract

Geissospermum species are widely used in folk medicine in the Amazon region. This study was conducted to determine total phenolic and flavonoid contents of three tinctures of Geissospermum reticulatum barks from Peruvian Amazon and correlate these contents to the antioxidant activities and stability. Total content of phenolic compounds (from 694.91 to 1430.67 mg GAE/kg) and flavonoids (575.23-815.65 mg CAE/kg) were found by spectrophotometric methods. The obtained values were interpreted by artificial neural networks to describe the most beneficial conditions for tinctures. All tinctures have demonstrated the maximum of total flavonoid between 14 and 20 weeks of maceration, whereas the maximum of total flavonoid was between 25 and 30. The highest antioxidant properties were exhibited by tinctures in 3 different tests (ferric reducing ability of plasma, DPPH-ESR, oxygen radical absorbance capacity) after 35 weeks of maceration. The principal component analysis was employed to relate contents and properties. Results from the lag phase with α-(4-pyridyl-1-oxide)-N-tert-butylnitrone (POBN) spin trap studies at 60• C demonstrated that the stability of tinctures were related to total phenolic content. Thus, samples with 550-800 mg GAE/kg were more stable than those with higher total phenolic contents. The most beneficial conditions for bark tinctures depend on aimed final products, e.g. maximum of polyphenols or flavonoids and long-term stability. Further studies about content and storage conditions are needed.

Harvest time affects antioxidant capacity, total polyphenol and flavonoid content of Polish St John’s wort’s (Hypericum perforatum L.) flowers

“…This work aims to study the seasonal variation of TP and TF content and antioxidant properties in various H. perforatum L. extracts obtained from both air-dried and lyophilized flowering tops. The antioxidant properties were studied with DPPH, ORAC and FRAP tests, which in combination with chemometric methods, are widely used to screen medicinal herbs 27 .…”

Profile of Bioactive Components and Antioxidant Activity of Aronia melanocarpa Fruits at Various Stages of Their Growth, Using Chemometric Methods

“…The chokeberry samples were gathered from three distinct regions of Poland and over two consecutive seasons. To establish a correlation between the sample's content and properties, principal component analysis (PCA) was employed, a method which has been utilized in other studies [14,15]. An assessment of PCA was conducted among all the tested samples and variables.…”

Geissospermiculatine, a New Alkaloid from Geissospermum reticulatum Bark

“…However, in recent decades, little progress has been made in the characterization of the compounds from the Geissospermum genus. In fact, among 12 species, only six ( G. argenteum, G. fuscum, G. leave, G. reticulatum, G. sericeum, and G. urceolatum ) have been studied phytochemically [ 1 , 3 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. Specifically, it has been reported that these trees are a rich source of indole alkaloids [ 1 , 3 ].…”