Polarity Directed Appraisal of Pharmacological Potential and HPLC-DAD Based Phytochemical Profiling of Polygonum glabrum Willd

The present study was designed to evaluate polarity-dependent extraction efficiency and pharmacological profiling of Polygonum glabrum Willd. Crude extracts of leaves, roots, stems, and seeds, prepared from solvents of varying polarities, were subjected to phytochemical, antioxidant, antibacterial, antifungal, antidiabetic, and cytotoxicity assays. Maximum extraction yield (20.0% w/w) was observed in the case of an acetone:methanol (AC:M) root extract. Distilled water:methanol (W:M) leaves extract showed maximum phenolic contents. Maximum flavonoid content and free radical scavenging potential were found in methanolic (M) seed extract. HPLC-DAD quantification displayed the manifestation of substantial quantities of quercetin, rutin, gallic acid, quercetin, catechin, and kaempferol in various extracts. The highest ascorbic acid equivalent total antioxidant capacity and reducing power potential was found in distilled water roots and W:M leaf extracts, respectively. Chloroform (C) seeds extract produced a maximum zone of inhibition against Salmonella typhimurium. Promising protein kinase inhibition and antifungal activity against Mucor sp. were demonstrated by C leaf extract. AC:M leaves extract exhibited significant cytotoxic capability against brine shrimp larvae and α-amylase inhibition. Present results suggest that the nature of pharmacological responses depends upon the polarity of extraction solvents and parts of the plant used. P. glabrum can be considered as a potential candidate for the isolation of bioactive compounds with profound therapeutic importance.

Effects of Different Extracting Solvents on Non-Phenolic Phytochemical Profiles of Selected Nigerian Spices and Spice-treated Foods

The aim of this research was to investigate the impact of extraction solvents on the non-phenolic phytochemical profiles of selected spices (Ocimum viride, Monodora myristica, Monodora tenuifolia and Tetrapleura tetraptera) and spice-treated foods in southern part of Nigeria. The spice samples were processed into powder for antioxidant screening. The spice extracts were obtained from the samples using 5 extracting solvents [distilled water, 95 % methanol, acetone / hexane (1:1 v/v), n-hexane / methanol / acetone (2:1:1, v/v/v) and acetone / water / acetic acid (70:29.5:0.5, v/v/v)]. Water extracts were obtained from beef, pork and fluted pumpkin leaves. The alkaloid, saponin, oxalate and phytate components of the spice extracts and the spice-treated foods were evaluated using standard methods. The laboratory analyses were performed at analytical laboratory, National Centre for Energy Research and Development, University of Nigeria, Nsukka during the 3rd quarter of 2020. The percentage yield of the extracts were low (0.32 - 0.96 %) and varied widely among extracting solvents, spices and spice-treated foods. M. myristica and T. tetrpleura had the highest yield, 0.96, in methanol extracts. Phytochemical contents differed significantly (p < 0.05) among spices, extracts of the same spice and among spice-treated foods. Spices had high contents of oxalate (2.0 – 7.0 mg/100 g), alkaloid (0.8 – 5.76 mg/100 g) and phytate (2.14 – 3.88 mg/100 g) but relatively low content of saponin (0.03 – 0.736 mg/100g). Methanol alone or in combination with other solvents extracted higher amounts of phytochemicals (0.96 %) than other solvent mixtures from the spices. Phytochemical contents of spice-treated foods were in the order: vegetable > rice > pork > beef.

Pulicaria laciniata (Coss and Kral): Effects of Different Extraction Solvents on Phytochemical Screening and Antioxidant Activity

This study aims to investigate phytochemical constituents of Pulicaria laciniata extracts and determine their antioxidant activity using three methods; Phosphomolybdate, Reducing Power, and Metal Chelating. The phytochemical investigation showed various secondary metabolites such as Phenols, Glycosides, Flavonoids, Alkaloids, Tannins, and Terpenoids. The N-butanol extract exhibited the highest antioxidant activity comparing with the other extract in all methods (0.51 and 0.65 mg/ml as A0.5 values of Phosphomolybdate, reducing power) and (1.65mg/ml for IC50 value of metal-chelating). In contrast, all the extracts showed week activity against the metal-chelating method.

A metabolomics approach to evaluate the effect of lyophilization versus oven drying on the chemical composition of plant extracts

Lyophilization is the “gold standard” for drying plant extracts, which is important in preserving their quality and extending their shelf-life. Compared to other methods of drying plant extracts, lyophilization is costlier due to equipment, material and operational expenses. An alternative method is post-extraction oven-drying, but the effects of this process on extract quality are unknown. In this study, crude extracts from Arthrocnemum macrostachyum shoots were compared using three post-extraction drying methods (lyophilization and oven drying at 40 and 60 °C) and two extraction solvents (water and aqueous 50% ethanol). Untargeted metabolomics coupled with chemometrics analysis revealed that post extraction oven-drying resulted in the loss of up to 27% of molecular features when compared to lyophilization in water extracts only. In contrast, only 3% of molecular features were lost in aqueous 50% ethanol extracts when subjected to oven drying. That is to say, ethanol used as a solvent has a stabilizing effect on metabolites and enhances their resistance to thermal transformation in the oven. Collectively, oven-drying of extracts was as effective as lyophilization in preserving metabolites in extracts only when 50% ethanol was used as a solvent. The results presented in this paper demonstrate the value of selecting solvent-appropriate post-extraction drying methods.