Millettia isoflavonoids: a comprehensive review of structural diversity, extraction, isolation, and pharmacological properties.

There are approximately 260 known species in the genus Millettia, many of which are used in traditional medicine to treat human and other animal ailments in various parts of the world. Being in the Leguminosae (Fabaceae) family, Millettia species are rich sources of isoflavonoids. In the past three decades alone, several isoflavonoids originating from Millettia have been isolated, and their pharmacological activities have been evaluated against major diseases, such as cancer, inflammation, and diabetes. Despite such extensive research, no recent and comprehensive review of the phytochemistry and pharmacology of Millettia isoflavonoids is available. Furthermore, the structural diversity of isoflavonoids in Millettia species has rarely been reported. In this review, we comprehensively summarized the structural diversity of Millettia isoflavonoids, the methods used for their extraction and isolation protocols, and their pharmacological properties. According to the literature, 154 structurally diverse isoflavonoids were isolated and reported from the various tissues of nine well-known Millettia species. Prenylated isoflavonoids and rotenoids were the most dominant subclasses of isoflavonoids reported. Other subclasses of reported isoflavonoids include isoflavans, aglycone isoflavones, glycosylated isoflavones, geranylated isoflavonoids, phenylcoumarins, pterocarpans and coumaronochromenes. Although some isolated molecules showed promising pharmacological properties, such as anticancer, anti-inflammatory, estrogenic, and antibacterial activities, others remained untested. In general, this review highlights the potential of Millettia isoflavonoids and could improve their utilization in drug discovery and medicinal use processes. Supplementary Information: The online version contains supplementary material available at 10.1007/s11101-022-09845-w.

Polyphenol mixture of a native Korean variety of Artemisia argyi H. (Seomae mugwort) and its anti­inflammatory effects.

In the present study, a polyphenolic mixture was isolated from Seomae mugwort (SM; a native Korean variety of Artemisia argyi H.) via extraction with aqueous 70% methanol followed by the elution of ethyl acetate over a silica gel column. Each polyphenolic compound was analyzed using high­performance liquid chromatography coupled with tandem mass spectrometry, and compared with the literature. In addition to the 14 characterized components, one hydroxycinnamate, six flavonoids, and one lignan were reported for the first time, to the best our knowledge, in Artemisia argyi H. The anti­inflammatory properties of SM polyphenols were studied in lipopolysaccharide­treated RAW 264.7 macrophage cells. The SM polyphenols attenuated the activation of macrophages via the inhibition of nitric oxide production, nuclear factor­κB activation, the mRNA expression of inducible nitric oxide synthase, tumor necrosis factor α and interleukin­1ß, and the phosphorylation of mitogen­activated protein kinase. Our results suggested that SM polyphenols may have therapeutic potential for the treatment of inflammatory­related diseases.

LC-MS/MS profiling of polyphenol-enriched leaf, stem and root extracts of Korean Humulus japonicus Siebold & Zucc and determination of their antioxidant effects.

Polyphenols from ethyl acetate extracts from the leaves, stems and roots of Korean Humulus japonicus were comprehensively profiled using liquid chromatography-electrospray ionization-tandem mass spectrometry. A total of 36 polyphenols were detected, of which 26 were structurally characterized based on their [M - H]- peak, tandem mass spectrometry fragmentation pattern, UV-vis absorption and published data. Validation data provided satisfactory results for the evaluated parameters. The determination coefficients were ≥0.9812. The limits of detection and quantification were 0.017-0.573 and 0.056-1.834 mg/L, respectively, indicating good performance limits. The accuracy (expressed as percentage recovery) at 50 and 100 mg/L was 71.4-99.7 and 75.1-105.1%, with precisions (expressed as relative standard deviation) of 1.5-7.3 and 0.8-4.1%, respectively, indicating acceptable accuracy and precision values. The leaves were rich in total polyphenols (3089.9 ± 6.4 mg/kg of fresh sample) followed by the stems (1313.9 ± 6.4 mg/kg of fresh sample) and roots (655.2 ± 2.7 mg/kg of fresh sample). Antioxidant activity, determined by α,α-diphenyl-ß-picrylhydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) scavenging activity and ferric reducing antioxidant power assay, revealed the lowest EC50 value for the leaf extracts, indicating a higher scavenging activity in this tissue followed by the roots and stems. Overall, the results indicated that H. japonicus is rich in polyphenols and could be a potential alternative to Humulus lupulus (hop plant) in the brewery industry.

LC-MS/MS characterization, anti-inflammatory effects and antioxidant activities of polyphenols from different tissues of Korean Petasites japonicus (Meowi).

The Korean Petasites japonicus is a perennial plant used in folk medicine as a remedy for many diseases and popularly consumed as spring greens. Ten polyphenols were characterized from the leaves, stems and roots of this plant via high-performance liquid chromatography-tandem mass spectrometry. Individual polyphenols were quantified for the first time using calibration curves of six structurally related external standards. Validation data indicated that coefficients of determinations (R2 ) were ≥0.9702 for all standards. Recoveries measured at 50 and 100 mg/L were 80.0-91.9 and 80.3-105.3%, respectively. Precisions at these two concentration levels were 0.7-6.1 and 1.1-5.5%, respectively. The total number of identified components was largest for the leaves and smallest for the stems. The leaf and root polyphenolic extracts showed anti-inflammatory effects by inducing LPS-activated COX-2 and iNOS protein levels in mouse macrophage RAW 264.7 cells. The antioxidant capacity of the polyphenols, when evaluated for DPPH (α,α-diphenyl-ß-picrylhydrazyl)ˑ , ABTS+ [2-2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)] and superoxide radical scavenging activities, and in ferric reducing ability of plasma (FRAP) assays, was highest in the leaf and lowest in the stem. This trend suggests that the antioxidant capacities depend primarily on polyphenol concentration in each tissue. The current findings suggest that polyphenols derived from P. japonicas tissues could have potential as functional health foods.

Flavone polyphenols dominate in Thymus schimperi Ronniger: LC-ESI-MS/MS characterization and study of anti-proliferative effects of plant extract on AGS and HepG2 cancer cells.

Thymus schimperi is a highly localized and a rare plant endemic to Ethiopia. An optimized and validated high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) method was applied to characterize 23 polyphenolic compounds found in ethyl acetate extracts of the plant. From those, flavones dominated and luteolin was the major component contributing 21.83% of the total composition (or 46.05±0.59g/kg of fresh sample weight). Validation data showed a determination coefficient (R2)≥0.997. Limits of detection (LOD) and quantification (LOQ) were 0.03-0.97 and 0.11-3.23mg/L, while recovery values spiked at 5 and 50mg/L were between 70.89-115.39 and 67.65-120.19%, respectively. Except for caffeic acid and epicatechin gallate, the relative standard deviations (%RSDs) were far below 15%, showing acceptable precision values. The plant extracts inhibited cell proliferation and induced cell death in human gastric adenocarcinoma (AGS) and liver hepatocellular carcinoma (HepG2) cancer cells. This is the first report of polyphenolic components from T. schimperi being characterized using HPLC-ESI-MS/MS. Being components of many edible vegetables, fruits, and spices, the identified polyphenols suggest that T. schimperi could be a potential food with promising health benefits.

Development and validation of LC-ESI-MS/MS method for analysis of moxifloxacin and levofloxacin in serum of multidrug-resistant tuberculosis patients: Potential application as therapeutic drug monitoring tool in medical diagnosis.

Moxifloxacin (MFX) and levofloxacin (LFX), class of fluoroquinolone antibiotics, are the two most prescribed drugs to multidrug resistant tuberculosis (MDR-TB) patients. A single, sensitive and reliable LC-ESI-MS/MS method was developed and validated to simultaneously quantitate the levels of these drugs in human serum where enrofloxacin (EFX) was used as internal standard (IS). Quantification was achieved by multiple reaction monitoring of selected mass transitions from precursor ions to product ions m/z 402.2→384.2 for MFX, 362.2→318.2 for LFX, and 362.1→318.3 for EFX. Calibration curves were plotted using concentrations ranging between 0.23-1000ng/mL for MFX and 0.13-1000ng/mL for LFX, and the correlation coefficients (r(2)) were in excess of 0.999. Intra- and inert-day accuracy was ranged between 92.1-104% with mean recoveries of 96% and 95.5% for MFX and LFX, respectively and precision was <9% at all quality control concentration levels. Matrix effect analysis showed extraction efficiency of 93.0-94.6% for MFX and 90.9-99.5% for LFX. Application of the developed method to real sample analysis resulted in efficient quantification of MFX and LFX in serum samples obtained from ten MDR-TB patients. The result indicated that the method could be applied as a potential drug monitoring tool to accurately analyze MFX and LFX within a short run time.

Polyphenolic profile and antioxidant effects of various parts of Artemisia annua L.

An annual Korean weed, Artemisia annua L., has been used as a folk medicine for the treatment of a number of diseases. Remarkably, among the 32 polyphenols characterized in various parts of plant tissue, including flowers, leafs, stems and roots, 10 compounds were detected for the first time using liquid chromatography-tandem mass spectrometry (LC/MS/MS). The quantification method was validated using structurally related external standards with determination coefficients (R(2) ) ≥0.9995. The limits of detection and quantitation were 0.068-3.932 and 0.226-13.108 mg/L, respectively. The recoveries estimated at 50 and 100 mg/L ranged between 60.6-92.2 and 61.3-111%, respectively, with relative standard deviations <12%. The roots contained the largest concentration of identified components, while the flowers contained the least. The antioxidant capacity evaluated in terms of 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation-scavenging activities and reducing power was highest in the roots and lowest in the flowers. The findings are well correlated and suggest that the antioxidant capacities principally depend upon the polyphenol concentrations in each part of the plant.

The polyphenolic profiles and antioxidant effects of Agastache rugosa Kuntze (Banga) flower, leaf, stem and root.

Agastache rugosa Kuntze (Korean mint) is used as a spice and in folk medicine in East Asia. The present study identified a total of 18 polyphenols from the flower, leaf, stem and roots of this plant using high-performance liquid chromatography-tandem mass spectrometry. Fourteen of these compounds had not previously been identified in these plant tissues. Each polyphenol was validated in comparison with external calibration curves constructed using structurally related compounds, with determination coefficients >0.9993. The limits of detection and quantification were 0.092-0.650 and 0.307-2.167 mg/L, respectively. Recoveries of 61.92-116.44% were observed at two spiking levels, with 0.91-11% precision, expressed as relative standard deviation (except anthraquinone spiked at 10 mg/L). Hydroxycinnamic acid was the most abundant compound in the root, while the flowers showed the highest total flavonoid level. Antioxidant activities, determined in terms of reducing power, Fe(2+) chelating activity and the radical scavenging activities using α,α-diphenyl-ß-picrylhydrazyl and 2-2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid, increased in a concentration-dependent manner; the highest activity was identified in the stems, followed by leaves > flowers > roots. These findings indicate that A. rugosa is a good source of bioactive compounds and can be used as a functional food.

Dietary-flavonoid-rich flowers of Rumex nervosus Vahl: Liquid chromatography with electrospray ionization tandem mass spectrometry profiling and in vitro anti-inflammatory effects.

Rumex nervosus is a plant species found widely in Eastern Africa and the Arabian Peninsula. In addition to its uses in traditional medicinal, the plant shows various biological activities, such as antiviral, antibacterial, and antioxidant activity. In this study, nine flavonols, six flavones, three flavanones, and one flavanol were characterized from the flowers of R. nervosus using liquid chromatography with electrospray ionization tandem mass spectrometry and literature data. Validation data indicated that the determination coefficients (R(2) ) were ≥ 0.9914. The limits of detection and quantification were in the ranges of 0.15-1.24 and 0.50-4.13 mg/L, respectively. Recoveries at 10 and 50 mg/L were 71.1-110.2 and 65.4-115.1%, with relative standard deviations of 7.4-40.1 and 2.1-13.0%, respectively. Quercetin 3-O-rhamnoside (10) was the dominant component, contributing 30.8% of total flavonoids (1003.0 ± 26.2 mg/kg fresh flower sample), whereas luteolin 6-C-glucoside (3) was the lowest yielding compound (0.1%). The 19 flavonoids identified were characterized for the first time. In vitro anti-inflammatory studies showed that this mixture can suppress the production of inflammatory mediators, including inducible nitric oxide synthase, cyclooxygenase-2, kappa B inhibitor, and interleukin-1ß, by down-regulating the nuclear factor-kappa B and mitogen-activated protein kinases pathways. The results of this study may provide information for processing R. nervosus as a potential source of functional food.