Oluwaseun Ruth Alara

Parameter study, antioxidant activities, morphological and functional characteristics in microwave extraction of medicinal oleoresins from black and white pepper

ABSTRACT The study investigated the effects of extraction parameters on the yield, antioxidant activities, morphological and functional group characteristics of black and white pepper oleoresin extracts. Optimized oleoresin yields of 5.64 and 8.72 w/w% were obtained as black and white pepper extracts, respectively. Moreover, from the antioxidant assay, the concentration of black and white pepper extracts required to scavenge half of stable DPPH radicals were 94.92 and 107.57 µg/ml, respectively. From the complementary antioxidant assay; the concentration of black and white pepper extracts required to scavenge half of the stable ABTS free radicals were 82.36 and 94.71 µg/ml, respectively. This indicated that extracts from white pepper exhibited higher antioxidant capacity than the black pepper extracts. The results from the untargeted compositional GC-MS analysis identified a total of 23 and 31 bioactive compounds in black and white oleoresin extracts, respectively. This study, therefore, revealed the potential of microwave extraction in obtaining high-quality extracts.

Metabolic profiling of flavonoids, saponins, alkaloids, and terpenoids in the extract from Vernonia cinerea leaf using LC-Q-TOF-MS

Abstract The leaves of Vernonia cinerea are widely used for medicinal purposes. Although, different studies have reported on the biological activities of the plant extracts whereas the tentative assignment of secondary metabolites that include flavonoids, saponins, alkaloids, and terpenoids had not been reported. Thus, this study tentatively assigned the flavonoids, saponins, alkaloids, and terpenoids in the extract of V. cinerea leaves that are mainly responsible for the reported activities. Liquid chromatography-mass spectrometry quadrupole time of flight (LC-Q-TOF-MS) analysis was employed in the assignments. The results obtained showed that a total number of 221 compounds were tentatively assigned in the extract of V. cinerea leaves which include 64 flavonoids, 13 saponins, 36 alkaloids, and 108 terpenoids. These phytochemicals can further be isolated, purified, characterized, and quantified due to their importance. Graphical Abstract

Data article on elemental and metabolomic-based alkaloidal composition in black pepper oleoresin using a positive ESI-mode LC-QToF and ICP-mass spectroscopy

This paper contains data from the elemental and phytochemical profiling of black pepper oleoresin extracts using the LC–MS QToF and ICP-MS analysis. In recent years studies have shown the medicinal properties of extracts from these two cultivars of Piper nigrum. The medicinal properties are attributed to the presence of many secondary metabolites and mineral element in them. The phytochemical profiling was conducted using a Liquid Chromatography equipped with an electrospray time-of-flight mass spectrometer detectors. The mass spectrometer was equipped with an electrospray ionization sources operated in positive ion mode. The alkaloid compounds in the optimized black pepper extract were tentatively characterized in accordance with their ions׳ mass fragmentation.