Characteristic terpenylated coumarins from Ferula ferulaeoides as potential inhibitors on overactivation of microglia

A total of 37 characteristic terpenylated coumarins (1-25), including 17 undescribed compounds (1-5, 6a/6b, 7-10, 11a/11b-13a/13b), have been isolated from the root of Ferula ferulaeoides. Meanwhile, twelve pairs of enantiomers (6a/6b, 11a/11b-15a/15b, 17a/17b, 18a/18b, 20a/20b-22a/22b, and 25a/25b) were chirally purified. The structures of these new compounds were elucidated using HRESIMS, UV, NMR, and calculated 13C NMR with a custom DP4 + analysis. The absolute configurations of all the compounds were determined for the first time using electronic circular dichroism (ECD). Then, their inhibitory effects on nitric oxide (NO) production were evaluated with LPS-induced BV-2 microglia. Compared with the positive control minocycline (IC50 = 59.3 μM), ferulaferone B (2) exhibited stronger inhibitory potency with an IC50 value of 12.4 μM. The immunofluorescence investigation indicated that ferulaferone B (2) could inhibit Iba-1 expression in LPS-stimulated BV-2 microglia.

Sesquiterpenes and Sesquiterpene Derivatives from Ferula: Their Chemical Structures, Biosynthetic Pathways, and Biological Properties

Ferula is a genus of flowering plants known for its edible and medicinal properties. Since ancient times, many species of Ferula have been used in traditional medicine to treat various health issues across countries, such as digestive disorders, respiratory problems, and even as a remedy for headaches and toothaches. In addition, they are also used as a flavoring agent in various cuisines. As the main active ingredients in Ferula, sesquiterpenes and their derivatives, especially sesquiterpene coumarins, sesquiterpene phenylpropanoids, and sesquiterpene chromones, have attracted the attention of scientists due to the diversity of their chemical structures, as well as their extensive and promising biological properties, such as antioxidative, anti-inflammatory, antibacterial properties. However, there has not been a comprehensive review of sesquiterpenes and their derivatives from this plant. This review aims to provide an overview of the chemical structures, biosynthetic pathways, and biological properties of sesquiterpenes and sesquiterpene derivatives from Ferula, which may help guide future research directions and possible application methods for this valuable edible and medicinal plant.

Undescribed sesquiterpene coumarins from the aerial parts of Ferula sinkiangensis and their anti-inflammatory activities in lipopolysaccharide-stimulated RAW 264.7 macrophages

Eight undescribed sesquiterpene coumarins (1-8) and twenty known ones (9-28), were isolated from the aerial parts of Ferula sinkiangensis K. M. Shen. Their structures were elucidated based on the comprehensive analysis of UV, IR, HRESIMS, 1D, and 2D NMR data. The absolute configuration of 1 was determined by single crystal X-Ray diffraction, while the absolute configurations of 2-8 were determined by comparisons of experimental and calculated electrostatic circular dichroism spectra. Compound 2 is the first hydroperoxy sesquiterpene coumarin from the genus Ferula, while compound 8 has an unusual 5',8'-peroxo bridge. Griess reaction results indicated compound 18 significantly decreased nitric oxide production of the lipopolysaccharide-stimulated RAW 264.7 macrophages with an IC₅₀ value of 2.3 μM, and ELISA results revealed that compound 18 effectively inhibited tumor necrosis factor-α, interleukin (IL)-1β, and IL-6 expressions.

Neurological disorders of COVID-19: insights to applications of natural products from plants and microorganisms

In addition to the typical respiratory manifestations, various disorders including involvement of the nerve system have been detected in COVID-19 ranging from 22 to 36%. Although growing records are focusing on neurological aspects of COVID-19, the pathophysiological mechanisms and related therapeutic methods remain obscure. Considering the increased concerns of SARS-CoV-2 potential for more serious neuroinvasion conditions, the present review attempts to focus on the neuroprotective effects of natural compounds as the principle source of therapeutics inhibiting multiple steps of the SARS-CoV-2 infection cycle. The great majority of the natural products with anti-SARS-CoV-2 activity mainly inhibit the attachment, entry and gene expression rather than the replication, assembly, or release. Although microbial-derived natural products comprise 38.5% of the known natural products with neuroprotective effects following viral infection, the neuroprotective potential of the majority of microorganisms is still undiscovered. Among natural products, chrysin, huperzine A, ginsenoside Rg1, pterostilbene, and terrein have shown potent in vitro neuroprotective activity and can be promising for new or repurpose drugs for neurological complications of SARS-CoV-2.

Sesquiterpene coumarins from Ferula samarkandica Korovin and their bioactivity

Phytochemical study on the ethanolic extract of the dried roots of Ferula samarkandica Korovin led to the isolation of nine undiscribed sesquiterpene coumarins, samarcandicins A-I, along with thirteen known sesquiterpene coumarins. Their structures were characterized by detailed spectroscopic analysis including NMR and HR-ESI-MS. Mogoltacin and nevskin exhibited high inhibitory activity against MV-4-11 cell with IC₅₀ values of 3.94 ± 0.06 μM and 3.87 ± 0.10 μM, respectively, and nevskin and feshurin showed high inhibitory activity against mino cell with IC₅₀ values of 1.48 ± 0.06 μM and 7.88 ± 0.60 μM, respectively.

Sesquiterpene coumarins from Ferula sinkiangensis K.M.Shen and their cytotoxic activities

Five undescribed sesquiterpene coumarins, one undescribed coumarin derivative, and twenty-five known analogues, were isolated from the resin of Ferula sinkiangensis K.M.Shen. The planar structures and relative configurations of the undescribed compounds were determined by NMR experiment and HRESIMS data. The absolute configurations were established by Electrostatic Circular Dichroism method. Among these analogues, Sinkiangenol E showed the best cytotoxic activity against HeLa cervical cancer cells. Annexin V-FITC/PI staining indicated that Sinkiangenol E induced apoptosis in HeLa cells. Cell cycle analysis showed Sinkiangenol E arrested cell cycle at G0/G1 phase. Western blot results proved that Sinkiangenol E affected apoptosis-related and cell cycle regulation-related protein expression by activating the MAPK pathway.

Bioactive sesquiterpene coumarins from the resin of Ferula sinkiangensis targeted on over-activation of microglia

Nine undescribed (1-4, 6-10) sesquiterpene coumarins, together with a new natural one (5) and ten known ones (11-20), were isolated from the low polarity fraction of the 95% ethanol extract of the resin of Ferula sinkiangensis. Their structures were elucidated based on the comprehensive analysis of HRESIMS, 1D and 2D NMR data. The absolute configurations were determined by comparison of experimental and calculated ECD spectra. All the identified SCs were evaluated for their anti-neuroinflammatory activities in LPS-induced BV-2 cells. Ferusingensine G (8) displayed a significant inhibitory effect on nitric oxide (NO) production with an IC₅₀ value of 1.2 μM. The results suggested that natural SCs might be served as potential neuroinflammatory inhibitors.

Chinese herbal medicine Qinggongshoutao for the treatment of amnestic mild cognitive impairment: A 52-week randomized controlled trial

Introduction

This randomized, double-blind trial aimed to test effect of a Chinese herbal medicine, Qinggongshoutao (QGST) pill, on the cognition and progression of amnestic mild cognitive impairment (aMCI).

Methods

Patients with aMCI were randomly assigned to receive QGST, Ginkgo biloba extract, or placebo for 52 weeks. The primary outcome measures were progression to possible or probable Alzheimer's disease (AD) and change in Alzheimer's Disease Assessment Scale-cognitive subscale scores; secondary outcome measures included assessments for cognition and function.

Results

Total 350 patients were enrolled, possible or probable AD developed in 10. There were significant differences in the probability of progression to AD in the QGST group (1.15%) compared with placebo group (10%). There was significant difference in Alzheimer's Disease Assessment Scale-cognitive subscale scores in favor of QGST over the placebo group. Secondary outcome measure (Mini-Mental State Examination) also showed benefit in QGST at end point.

Discussion

In patients with aMCI, QGST showed lower AD progression rate than placebo at 8.85%, and may have benefit on global cognition.

Natural Inhibitors on Over-Activation of Microglia from Herbals

Neuroinflammation manifested by over-activation of microglial cells plays an essential role in neurodegenerative diseases. Short-term activation of microglia can be beneficial, but chronically activated microglia can aggravate neuronal dysfunction possibly by secreting potentially cytotoxic substances such as tumor necrosis factor-alpha (TNF-α) and nitric oxide (NO), which can result in dysfunction and death of neurons. Therefore inhibiting over-activation of microglia and the production of cytotoxic intermediates may become an effective therapeutic approach for neuroinflammation. In this paper, we review our continuous research on natural inhibitors of over-activated microglia from traditional herbals, including flavonoids, lignans, sesquiterpene coumarins, and stilbenes.

Biotransformation of 4-methylcoumarins by cambial meristematic cells of Camptotheca acuminata

Cambial meristematic cell (CMC) suspension cultures were investigated as a new biotransformation system for the first time. Four 4-methylcoumarins substrates were transformed by CMCs of Camptotheca acuminata into four corresponding products, including 4,8-dimethylcoumarin-7-O-β-d-glucopyranoside (I-1), 4,7-dimethylcoumarin-6-O-β-d-glucopyranoside (II-1), 6-hydroxy-7-methoxyl-4- methylcoumarin (III-1), and 4,7-dimethylcoumarin-5-O-β-d-glucopyranoside (IV-1), of which I-1, II-1, and IV-1 were new compounds. In addition, the biotransformation time and the amount of substrate were investigated to compare the biotransformation rate and optimize the biotransformation conditions of the four substrates in C. acuminata CMCs suspension cultures. The results suggested C. acuminata CMCs were able to select glycosylate phenolic hydroxyl groups of 4-methylcoumarins I, II, and IV, with high regio- and stereoselectivity, but no corresponding glycoside of any phenolic hydroxyl group of compound III was detected. Simultaneously, the result also showed that the C. acuminata CMCs were able to transform the 7-hydroxy groups of substrate III to its corresponding methylated products. Furthermore, the monoamine oxidase (MAO) inhibition activities of biotransformed products were evaluated, and the data showed that all the products possessed good MAO inhibition activities in vitro. In conclusion, C. acuminata CMCs could be applied to glycosylation biotransformation as a novel plant-based system due to the successful application of bioconversion of exogenous coumarins.

Cambial meristematic cell (CMC) suspension cultures were investigated as a new biotransformation system for the first time.

Sweeping-micelle to solvent stacking for the on-line preconcentration and determination of organic acids in Angelica sinensis by capillary electrophoresis

A two-step on-line preconcentration technique has been applied to the analysis of organic acids in Angelica sinensis.

An Investigation on the Quantitative Structure-Activity Relationships of the Anti-Inflammatory Activity of Diterpenoid Alkaloids

Diterpenoid alkaloids are extracted from plants. These compounds have broad biological activities, including effects on the cardiovascular system, anti-inflammatory and analgesic actions, and anti-tumor activity. The anti-inflammatory activity was determined by carrageenan-induced rat paw edema and experimental trauma in rats. The number of studies focused on the determination, quantitation and pharmacological properties of these alkaloids has increased dramatically during the past few years. In this work we built a dataset composed of 15 diterpenoid alkaloid compounds with diverse structures, of which 11 compounds were included in the training set and the remaining compounds were included in the test set. The quantitative chemistry parameters of the 15 diterpenoid alkaloids compound were calculated using the HyperChem software, and the quantitative structure-activity relationship (QSAR) of these diterpenoid alkaloid compounds were assessed in an anti-inflammation model based on half maximal effective concentration (EC₅₀) measurements obtained from rat paw edema data. The QSAR prediction model is as follows: log ( E C 50 ) = - 0.0260 × SAA + 0.0086 × SAG + 0.0011 × VOL - 0.0641 × HE - 0.2628 × LogP - 0.5594 × REF - 0.2211 × POL - 0.1964 × MASS + 0.088 × BE + 0.1398 × HF (R² = 0.981, Q² = 0.92). The validated consensus EC₅₀ for the QSAR model, developed from the rat paw edema anti-inflammation model used in this study, indicate that this model was capable of effective prediction and can be used as a reliable computational predictor of diterpenoid alkaloid activity.

Site-selective biotransformation of ursane triterpenes by Streptomyces griseus ATCC 13273

The oxidization of unactivated C–H bonds of pentacyclic triterpenes (PTs) is of great interest for the structural modification of PTs.