Supervised Statistical Learning Prediction of Soybean Varieties and Cultivation Sites Using Rapid UPLC-MS Separation, Method Validation, and Targeted Metabolomic Analysis of 31 Phenolic Compounds in the Leaves

Soybean (Glycine max; SB) leaf (SL) is an abundant non-conventional edible resource that possesses value-adding bioactive compounds. We predicted the attributes of SB based on the metabolomes of an SL using targeted metabolomics. The SB was planted in two cities, and SLs were regularly obtained from the SB plant. Nine flavonol glycosides were purified from SLs, and a validated simultaneous quantification method was used to establish rapid separation by ultrahigh-performance liquid chromatography-mass detection. Changes in 31 targeted compounds were monitored, and the compounds were discriminated by various supervised machine learning (ML) models. Isoflavones, quercetin derivatives, and flavonol derivatives were discriminators for cultivation days, varieties, and cultivation sites, respectively, using the combined criteria of supervised ML models. The neural model exhibited higher prediction power of the factors with high fitness and low misclassification rates while other models showed lower. We propose that a set of phytochemicals of SL is a useful predictor for discriminating characteristics of edible plants.

Baicalein, 7,8-Dihydroxyflavone and Myricetin as Potent Inhibitors of Human Ornithine Decarboxylase

Background: Human ornithine decarboxylase (ODC) is a well-known oncogene, and the discovery of ODC enzyme inhibitors is a beneficial strategy for cancer therapy and prevention. Methods: We examined the inhibitory effects of a variety of flavone and flavonol derivatives on ODC enzymatic activity, and performed in silico molecular docking of baicalein, 7,8-dihydroxyflavone and myricetin to the whole dimer of human ODC to investigate the possible binding site of these compounds on ODC. We also examined the cytotoxic effects of these compounds with cell-based studies. Results: Baicalein, 7,8-dihydroxyflavone and myricetin exhibited significant ODC suppression activity with IC50 values of 0.88 µM, 2.54 µM, and 7.3 µM, respectively, which were much lower than that of the active-site irreversible inhibitor α-DL-difluoromethylornithine (IC50, the half maximal inhibitory concentration, of approximately 100 µM). Kinetic studies and molecular docking simulations suggested that baicalein, and 7,8-dihydroxyflavone act as noncompetitive inhibitors that are hydrogen-bonded to the region near the active site pocket in the dimer interface of the enzyme. Baicalein and myricetin suppress cell growth and induce cellular apoptosis, and both of these compounds suppress the ODC-evoked anti-apoptosis of cells. Conclusions: Therefore, we suggest that the flavone or flavonol derivatives baicalein, 7,8-dihydroxyflavone, and myricetin are potent chemopreventive and chemotherapeutic agents that target ODC.

Hepatoprotective Effects of Standardized Extracts from an Ancient Italian Apple Variety (Mela Rosa dei Monti Sibillini) against Carbon Tetrachloride (CCl4)-Induced Hepatotoxicity in Rats

The aim of this research was to examine the effect of the hydroalcoholic extracts from the peel (APE) and pulp (APP) of a traditional apple cultivar from central Italy (Mela Rosa dei Monti Sibillini) on CCl4-induced hepatotoxicity in rats. Phytoconstituents were determined by liquid chromatography–mass spectrometry (LC-MS) analysis showing an abundance of proanthocyanidins and flavonol derivatives together with the presence of annurcoic acid in APE. Wistar rats received APE/APP (30 mg/kg oral administration) for three days before CCl4 injection (2 mL/kg intraperitoneal once on the third day). Treatment with both APE and APP prior to CCl4 injection significantly decreased the serum levels of aspartate aminotransferase (AST), alkaline phosphatase (ALP) and alanine aminotransferase (ALT) compared to the CCl4 group. Besides, pretreatment with APE reversed the CCl4 effects on superoxide dismutase (SOD), myeloperoxidase (MPO), tumor necrosis factor-α (TNF-α) and interleukin-1beta (IL-1β) levels in liver tissue in rats and reduced tissue damage as shown in hematoxylin and eosin staining. These results showed that this ancient Italian apple is worthy of use in nutraceuticals and dietary supplements to prevent and/or protect against liver disorders.

RP-HPLC Estimation of Flavonol Derivatives and Phenolic Acids in Capsicum annuum L. and their Correlation with In Vitro Anti-Inflammatory Activity

Background: Flavonol derivative and phenolic acids derived from the plants function as free radical scavengers, reducing agents, and quenchers for the formation of singlet oxygen. Flavonoids and phenolic constituents also play an important role in various human diseases and disorders primarily through modulation of inflammatory responses. Objective: To estimate the Flavonol Derivatives (FD) and phenolic acids (PA) in Capsicum annuum (CA) and other important phytochemicals having an anti-inflammatory effect. Method: In the present study, FD and PA were estimated in CA and in vitro anti-inflammatory activity (pilot study) was determined and correlation was established. Results: The results were found to be significant using RP-HPLC. FD and PA were found to be 0.0659±0.0058 and 0.0862±0.0.0134 mg/gram dry weight, respectively. For in vitro anti-inflammatory activity, the inhibition of albumin denaturation and antiproteinase activity was found to be maximum in Quercetin (QE) with 98.230±1.589% and 59.906±1.529%, respectively. Heat-induced hemolysis of erythrocytes was found to be maximum in salicylic acid (SA) (71.830±2.838%). Hypotonicity-induced hemolysis showed significant activity with QE (76.770±3.475%). Lipoxygenase and cyclooxygenase inhibition was found to be maximum in QE with 56.930±4.069% and 61.660±3.135%, respectively. Conclusion: A strong positive correlation of 0.9 was observed between the extract of CA and standard QE and SA against the anti-inflammatory activity. Therefore, the role of FD and PA has been postulated to be an active phytochemical of CA accountable for its anti-inflammatory activity. However further work is desirable to fully elucidate the phytochemicals responsible for their anti-inflammatory activity and to develop better herbal drug formulations.

Phytochemicals in leaves of Cotoneaster mongolica, their antioxidative, and acetylcholinesterase inhibitory activity

The phytochemicals in the leaves of Cotoneaster mongolica Pojark, as well as their antioxidant and acetylcholinesterase (AChE) inhibitory activity were studied. The methanol extract of the leaves showed acetylcholinesterase inhibitory activity (IC50, 32.61 ± 0.51 μg/mL). The n-butanol fraction of this extract exhibited DPPH radical scavenging (IC50, 55.70 ± 0.15 μg/mL) and AChE inhibitory activity (IC50, 72.50 ± 0.60 μg/mL). From the n-butanol fraction quercetin (1), hyperoside (2), kaempferol-5-O-β-D-glucopyranoside (3), sissotrin (4), ursolic acid (5), corosolic acid (6), euscaphic acid (7), prunasin (8), (2R)-mandeloyl-β-D-glucopyranose (9), (Z)-3-hexenyl-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside (10), benzyl-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside (11) and arbutin (12) have been isolated and identified. Hyperoside, one of the major constituents among the isolated compounds, was active in both tested assays. Flavonol derivatives could provide the activity of this plant species.

Extractives of Cercidiphyllum japonicum twigs: isolation and structural elucidation of a new galloylflavonol glycoside, anomeric tannins and flavonoids

Cercidiphyllum japonicumis a deciduous tree that grows in East Asia, where its raw extracts have long been used in folk medicnes to treat various disorders or diseases. In the current work, extracts fromC. japonicumtwigs were studied for the first time. Seven individual compounds were isolated from the extracts, including a new galloylflavonol glycoside, namely 8-methoxykaempferol-4′-O-galloyl-3-O-α-L-rhamnopyranoside (VII), and six known phenolics [two anomeric galloyltannins (3,4,6-tri-O-galloyl-β-D-glucopyranoside (I) and 2,2′,5-tri-O-galloyl-α/β-D-hamamelose (III)), one anomeric ellagictannin, pedunculagin (II), one flavonol, kaempferol (V) and two flavonol derivatives (kaempferol-3-O-α-L-rhamnopyranoside (IV) and 8-methoxykaempferol (VI))]. Structural elucidation ofI–VIIwas conducted mainly on the basis of their spectroscopic [ultraviolet (UV), infrared (IR), nuclear magnetic resonance (NMR), mass spectrometry (MS)] and physicochemical analysis, as well as by comparison of the analytical data with those in the literature. CompoundsI,II,IVandVIhave not yet been reported in the genusCercidiphyllum.CompoundVII, a previously undescribed flavonoid, was isolated and elucidated in this work for the first time.

Antioxidant Activity of Myrtus communis L. and Myrtus nivellei Batt. & Trab. Extracts: A Brief Review

Myrtus communis L. (myrtle) and Myrtus nivellei Batt. & Trab. (Saharan myrtle) have been used in folk medicine for alleviating some ailments. M. communis is largely distributed in the Mediterranean Basin, whereas M. nivellei is confined in specific zones of the central Saharan mountains. The chemical composition and antioxidant activity of berry and leaf extracts isolated from myrtle are deeply documented, whereas those isolated from Saharan myrtle extracts are less studied. In both species, the major groups of constituents include gallic acid derivatives, flavonols, flavonol derivatives, and hydroxybenzoic acids. In coloured berries, anthocyanins are also present. In M. nivellei extracts are reported for some compounds not described in M. communis so far: 2-hydroxy-1,8-cineole-β-d-glucopyranoside, 2-hydroxy-1,8-cineole 2-O-α-l-arabinofuranosyl (1→6)-β-d-glucopyranoside, rugosin A, and rugosin B. Berries and leaves extracts of both species had antioxidant activity. Comparative studies of the antioxidant activity between leaf and berry myrtle extracts revealed that leaf extracts are best antioxidants, which can be assigned to the galloyl derivatives, flavonols, and flavonols derivatives, although the ratio of these groups of compounds might also have an important role in the antioxidant activity. The anthocyanins present in myrtle berries seem to possess weak antioxidant activity. The antioxidant activity of sample extracts depended on various factors: harvesting time, storage, extraction solvent, extraction type, and plant part used, among other factors. Leaf extracts of myrtle revealed to possess anti-inflammatory activity in several models used. This property has been attributed either to the flavonoids and/or hydrolysable tannins, nevertheless nonprenylated acylphloroglucinols (e.g., myrtucommulone and semimyrtucommulone) have also revealed a remarkable role in that activity. The biological activities of myrtle extracts found so far may direct its use towards for stabilizing complex lipid systems, as prebiotic in food formulations, and as novel therapeutic for the management of inflammation.