Linarin, a Glycosylated Flavonoid, with Potential Therapeutic Attributes: A Comprehensive Review

Many flavonoids, as eminent phenolic compounds, have been commercialized and consumed as dietary supplements due to their incredible human health benefits. In the present study, a bioactive flavone glycoside linarin (LN) was designated to comprehensively overview its phytochemical and biological properties. LN has been characterized abundantly in the Cirsium, Micromeria, and Buddleja species belonging to Asteraceae, Lamiaceae, and Scrophulariaceae families, respectively. Biological assessments exhibited promising activities of LN, particularly, the remedial effects on central nervous system (CNS) disorders, whereas the remarkable sleep enhancing and sedative effects as well as AChE (acetylcholinesterase) inhibitory activity were highlighted. Of note, LN has indicated promising anti osteoblast proliferation and differentiation, thus a bone formation effect. Further biological and pharmacological assessments of LN and its optimized semi-synthetic derivatives, specifically its therapeutic characteristics on osteoarthritis and osteoporosis, might lead to uncovering potential drug candidates.

New Flavone C-Glycosides from Scleranthus perennis and Their Anti-Collagenase Activity

Three new flavone glycosides, one known flavone glycoside, and the phenolic derivative apiopaenonside were isolated and identified from the ethyl acetate fraction of the aerial parts of Scleranthus perennis. The planar structures were elucidated through extensive analysis of UV-Vis, IR, and 1H NMR and 13C NMR spectral data, including the 2D techniques COSY, HSQC, and HMBC, as well as ESI mass spectrometry. The isolated compounds were established as 5,7,3′-trihydroxy-4′-acetoxyflavone-8-C-β-d-xylopyranoside-2′′-O-glucoside (1), 5,7,3′-trihydroxy-4′-methoxyflavone-8-C-β-d-xylopyranoside-2′′-O-glucoside (2), 5,7-dihydroxy-3′-methoxy-4′-acetoxyflavone-8-C-β-d-xylopyranoside-2′′-O-glucoside (3), 5,7-dihydroxy-3′-methoxy-4′-acetoxyflavone-8-C-β-d-xylopyranoside-2′′-O-(4′′′-acetoxy)-glucoside (4), and apiopaenonside (5). Moreover, all isolated compounds were evaluated for anti-collagenase activity. All compounds exhibited moderate inhibitory activity with IC50 values ranging from 36.06 to 70.24 µM.

Protective Effect of Baicalin against Clostridioides difficile Infection in Mice

This study investigated the prophylactic and therapeutic efficacies of baicalin (BC), a plant-derived flavone glycoside, in reducing the severity of Clostridioides difficile infection (CDI) in a mouse model. In the prophylactic trial, C57BL/6 mice were provided with BC (0, 11, and 22 mg/L in drinking water) from 12 days before C. difficile challenge through the end of the experiment, whereas BC administration started day 1 post challenge in the therapeutic trial. Both challenge and control groups were infected with 106 CFU/mL of hypervirulent C. difficile BAA 1803 spores or sterile PBS, and the clinical and diarrheal scores were recorded for 10 days post challenge. On day 2 post challenge, fecal and tissue samples were collected from mice prophylactically administered with BC for microbiome and histopathologic analysis. Both prophylactic and therapeutic supplementation of BC significantly reduced the severity of colonic lesions and improved CDI clinical progression and outcome compared with control (p < 0.05). Microbiome analysis revealed a significant increase in Gammaproteobacteria and reduction in the abundance of protective microbiota (Firmicutes) in antibiotic-treated and C. difficile-infected mice compared with controls (p < 0.05). However, baicalin supplementation favorably altered the microbiome composition, as revealed by an increased abundance in beneficial bacteria, especially Lachnospiraceae and Akkermansia. Our results warrant follow-up investigations on the use of BC as an adjunct to antibiotic therapy to control gut dysbiosis and reduce C. difficile infection in humans.

Characterization of glucosyltransferase and glucuronosyltransferase family members reveals how major flavone glycoside accumulate in the root of Scutellaria baicalensis

Flavonoid glycosides extracted from roots of Scutellaria baicalensis exhibit strong pharmaceutical effect in antitumor, antioxidative, anti-inflammatory, and antiviral activity. UDP glycosyltransferase family members are responsible for the transfer of a glycosyl moiety from UDP sugars to a wide range of acceptor flavonoids. Here, we report the phylogenetic analysis, tissue-specific expression and biochemical characterization of 10 glucosyltrasferases (SbUGTs) and 6 glucuronosyltransferases (SbUGATs) based on the recently released genome of S. baicalensis. These results reveal that the high expression level and affinity to substrate of SbUGAT4 make baicalin become the richest flavonoid glycoside in the root of S. baicalensis.

Chemical Constituents of the Whole Plant of Verbena hastata and Their Inhibitory Activity Against the Production of AGEs

Two iridoid glycosides (1 and 2), 3 phenolic glycosides (3–5), 1 flavone glycoside (6), 3 biflavonoids (7–9), 1 flavone (10), 2 triterpenes (11 and 12), 1 sterol (13), and 1 naphthoquinone derivative (14) were isolated from the whole plant of Verbena hastata (Verbenaceae). Compounds 3-13 were isolated from V. hastata for the first time. Compound 14 is undescribed in the literature. Incubation of glyceraldehyde and collagen either with phenolic glycosides (3), (4), or (5) or with biflavonoid (8) inhibited the production of advanced glycation end products, with IC50 values of 6.3, 6.4, 6.2, and 6.8 mM, respectively. Aminoguanidine, which was used as a positive control, had an IC50 value of 10.2 mM.

Pharmacognostical, Phytochemical and Pharmacological profile of Colebrookea oppositifolia Smith

Colebrookea oppositifolia commonly known as ‘Bhaman’ is distributed throughout India from the Himalayas down to Deccan. The plant is used traditionally as such as dermatitis, dysentery, fever, headache, peptic ulcer, haemostatic, wounds, as anti-fertility agent, fungicide, and the roots of the plant has been most widely used for the treatment of epilepsy.. Medicinally, it has been proven to possess various pharmacological activities like treating corneal opacity or conjunctivitis, sore eyes due to its anti-inflammatory properties, cardioprotective, hepatoprotective, anti-inflammatory, antihelmintic, antifungal, antioxidant, antimicrobial, antinociceptive, cytotoxic activity, anticonvulsant, antiulcer, antimicrobial, anti-fertility, antipyretic and insecticide. Further, studies reveal the presence of various phytochemical constituents mainly flavone glycosides viz. chrysin, negletein, landenein; leaves contain 5,6,7- tri-methoxyflavone, 5,6,7,4'-tetramethoxyflavone, acteoside, and quercetin in the bark; root contains stearic, palmitic, oleic acids, triacontanol, flavone glycoside echioidin, 5,6,7-trimethoxyflavone and 4',5,6,7- tetra methoxy flavone; sugars and vitamins have also been isolated from this plant. These studies reveal that Colebrookea oppositifolia is a source of medicinally active compounds and have various pharmacological effects; hence, this drug encourage finding its new therapeutic uses. Keywords: Colebrookea oppositifolia, wound healing, anticonvulsant, Lamiaceae

Antibacterial Activity of a New Flavone Glycoside from the Stems of Holmskioldia sanguinea Retz.

A new flavone glycoside was isolated from ethanolic extract of stem parts of Holmskioldia sanguinea Retz. Its structure was characterized as 3,4′-dihydroxy-5,7-dimethoxyflavone-3-O-β-Dgalactopyranosyl(1→4)-O-β-D-arabinopyranosyl-4′-O-α-L-rhamnopyranoside (1) by colour reactions, chemical degradation and spectroscopic analysis. Antibacterial activity of compound 1 was evaluated against various Gram positive and Gram negative bacteria showing a significant effects.

A New Flavone Glycoside From Lumnitzera littorea with In Vitro α-Glucosidase Inhibitory Activity

A new flavone glycoside, lumnitzerone (1), was isolated from leaves of Lumnitzera littorea, together with 9 known flavonoids. Their structures were elucidated by spectroscopic (one-dimensional, two-dimensional nuclear magnetic resonance) and high-resolution mass spectrometry analysis, and comparison with literature data. Extracts and all isolated compounds were evaluated for α-glucosidase inhibitory activity; all the extracts and most of the isolated compounds exhibited better activities than the positive control acarbose.

Chemical Constituents From Phalaenopsis Hybrids and Their Bioactivities

One new flavone glycoside and 11 known compounds were characterized from the methanolic extracts of Dtps. Tinny Ribbon × Dtps. Plum Rose ( Phalaenopsis hybrids) by nuclear magnetic resonance and mass spectrometric analyses. In addition, the major pigment constituents 1 to 3 were examined for their antioxidant and antityrosinase activities. The experimental results indicated that the Phalaenopsis flower extracts were potential for developing new cosmetic products.