Acylphloroglucinolated Catechin and Phenylethyl Isocoumarin Derivatives from Agrimonia pilosa

Anti-Inflammatory Flavonoids from Agrimonia pilosa Ledeb: Focusing on Activity-Guided Isolation

To elucidate the anti-inflammatory properties and constituents of Agrimonia pilosa Ledeb. (A. pilosa), a comprehensive investigation was conducted employing activity-guided isolation. The anti-inflammatory effects were evaluated through an in vitro nitric oxide (NO) assay on lipopolysaccharide (LPS)-treated RAW 264.7 macrophage cells. Seven bio-active compounds with anti-inflammatory properties were successfully isolated from the butanol fraction and identified as follows: quercetin-7-O-β-d-rhamnoside (1), apigenin-7-O-β-d-glucopyranoside (2), kaempferol-7-O-β-d-glucopyranoside (3), quercetin (4), kaempferol (5), apigenin (6), and apigenin-7-O-β-d-glucuronide-6″-butylester (7). All isolated compounds showed strong NO inhibitory activity with IC50 values ranging from 1.4 to 31 µM. Compound 6 demonstrated the most potent NO inhibition. Compound 7, a rare flavonoid, was discerned as a novel anti-inflammatory agent, ascertained through its inaugural demonstration of nitric oxide inhibition. Subsequently, a comprehensive structure-activity relationship (SAR) analysis was conducted employing eight flavonoids derived from A. pilosa. The outcomes elucidated that flavones exhibit superior NO inhibitory effects compared to flavonols, and the aglycone form manifests greater potency in NO inhibition than the glycone counterpart. These results highlight A. pilosa as a promising source of effective anti-inflammatory agents and indicate its potential as a health-beneficial dietary supplement and therapeutic material.

Phenolic constituents with antibacterial activity from Eleutherine bulbosa

Eleutherine bulbosa (Mill.) Urb. is a medicinal and edible plant with various benefits for humans and animals. In this work, four new phenolic constituents (1-4), along with six known phenolic compounds (5-10) were obtained from the red bulbs of E. bulbosa. Their structures with absolute configurations were characterized by extensive spectroscopic analysis, combined with HR-ESI-MS and quantum mechanical electronic circular dichroism (ECD). Compounds 1 and 2 are novel homologous and heterodimers, respectively, featuring an unusual spiro ring system. All isolated phenolic constituents were tested for their antibacterial effects. The results revealed four phenolic compounds 1-3 and 7 showed moderate antibacterial activity against Bacillus subtilis, Staphylococcus aureus and Escherichia coli with minimum inhibitory concentration (MIC) values ranging from 15.6 to 250.0 μg/mL.

Systematic Identification of the Main Constituents from Agrimonia pilosa Ledeb. and Their Metabolites in Rats using HPLC-Q-TOF-MS/MS

Agrimonia pilosa is a perennial herbaceous flowering plant, commonly known as agrimony or hairy agrimony. The dried aerial parts of this species have been widely used for the treatment of acute diarrhea, hemostasis, and other inflammation-related diseases. However, information on the in vivo metabolism of A. pilosa constituents is limited. In this study, the phytochemical profile of A. pilosa was investigated using HPLC-Q-TOF-MS/MS combined with a nontargeted diagnostic ion network analysis strategy. An information-dependent acquisition method with multiple filters was utilized to screen possible prototypes and metabolites in complex biological matrices. Furthermore, various data-processing techniques were applied to analyze possible prototypes and their metabolites in rat plasma, feces, and urine following oral administration of A. pilosa extract. A total of 62 compounds, which belonged to five main structural classes (21 phenols, 22 flavonoids, 6 coumarins, 3 triterpenes, and 10 organic acids), were tentatively identified in A. pilosa. In addition, using our proposed stepwise method, 32 prototypes and 69 metabolites were detected in rat plasma, feces, and urine. The main metabolic pathways after the oral administration of A. pilosa extract were revealed to include methylation, dihydroxylation, demethylation, hydrolysis, sulfation, and glucuronidation. This comprehensive in vivo and in vitro identification of the possible active components in A. pilosa could provide a basis for understanding its various pharmacological activities.

Agrimonia pilosa Ledeb.: A review of its traditional uses, botany, phytochemistry, pharmacology, and toxicology

Ethnopharmacological relevance

Agrimonia pilosa Ledeb. is the dried above-ground part of dragon's tooth grass, a plant of the Rosaceae family, which is widely distributed in China, Korea, and Japan. Agrimonia pilosa Ledeb. is a herbal medicine with great scope for development and use. It is astringent and hemostatic, and it is used for treating malaria, preventing dysentery, detoxification, and as a tonic for deficiency.

Aim of the review

We summarize the traditional uses, botanical and chemical composition, extraction methods, and pharmacological and toxicological progress of Agrimonia pilosa Ledeb. and discuss the future research trends and development prospects of this plant.

Materials and methods

Information on Agrimonia pilosa Ledeb. was gathered via the Internet (China National Knowledge Infrastructure, Google Scholar, PubMed, Web of Science, SpringerLink, Wiley, Wanfang Data, and Baidu Academic). Additional information was obtained from books (Ben Cao Tu Jing, A Textual Research on the Name and Reality of Plants, Modern Practical Chinese Medicine, Zhen Nan Ben Cao) and PhD and MS dissertations.

Results

Phytochemical studies have identified more than 252 compounds from Agrimonia pilosa Ledeb., including flavonoids, volatile oils, tannins, phenols, m-benzotrienols, pentacyclic triterpenoids, isocoumarins, lignans, organic acids, and other chemical constituents. The compounds and extracts isolated from Agrimonia pilosa Ledeb. show various pharmacological activities, including anti-inflammatory, anticancer, antitumor effects, antioxidant, analgesic effects, and other pharmacological effects.

Conclusion

This review highlights the botany, phytochemistry, pharmacology, toxicology, and traditional uses of Agrimonia pilosa Ledeb., providing a basis for future research and clinical applications. Agrimonia pilosa Ledeb. has shown remarkable effectiveness in the treatment of various diseases, especially enteritis, gastric ulcers, and gastrointestinal bleeding. Most prescriptions for Agrimonia pilosa Ledeb. are empirical and lack rigorous clinical observation. For these reasons, the toxicology, standardized clinical studies, nature of active ingredients, pharmacokinetics, mechanism, and metabolism of Agrimonia pilosa Ledeb. should be deepened, especially through clinical trials, to ensure the clinical safety of its use for further research.

Unexpected Formation of 4-[(1-Carbamoyl-3-oxo-1,3-dihydro-2-benzofuran-1-yl)amino]benzoic Acid from 4-[(3-Amino-1-oxo-1H-2-benzopyran-4-yl)amino]benzoic Acid

With the aim of obtaining derivatives belonging to 2′,3′-diphenyl-3H-spiro[[2]benzofuran-1,4′-imidazole]-3,5′(3′H)-dione nucleus, we synthesized 4-[(3-amino-1-oxo-1H-2-benzopyran-4-yl)amino]benzoic acid (a 3,4-diaminoisocoumarine derivative), a known precursor of 4-[(1-carbamoyl-3-oxo-1,3-dihydro-2-benzofuran-1-yl)amino]benzoic acid (a phthalide–carboxamide-bearing system) by a novel methodology that we report here. The reaction conditions were optimized to afford the latter in 62% yield.

Agrimonia pilosa: A Phytochemical and Pharmacological Review

Agrimonia pilosa Ledeb., which belongs to Agrimonia and Rosaceae, is used in traditional Chinese medicine. It exhibits excellent medicinal properties and has been used to treat various diseases, such as tumors, trichomoniasis, vaginitis, diarrhea, and dysentery. Phytochemical studies have revealed that Agrimonia has over 100 secondary metabolites that can be categorized into six classes, i.e., flavonoids, isocoumarins, triterpenes, phloroglucinol derivatives, tannins, and organic acids. This review summarizes recently published literature on the chemical structures of 90 bioactive compounds that have been identified in A. pilosa and examines their pharmacological properties, including their antitumor, anti-inflammatory, antioxidant, antibacterial, and antidiabetic properties, as well as the potential development of parasitic resistance to these chemicals. This review highlights existing knowledge gap and serves as a basis for developing novel preparations of A. pilosa with medicinal value.

Phytochemical Profiling and Isolation of Bioactive Compounds from Leucosidea sericea (Rosaceae)

In the study, ultraperformance liquid chromatography-quadrupole time-of-flight-mass spectrometry analysis of Leucosidea sericea leaf and stem extracts led to the identification of various classes of compounds. Further chromatographic purifications resulted in the isolation of 22 compounds that consisted of a new triterpenoid named leucosidic acid A (1), an acetophenone derivative 2, a phloroglucinol derivative 3, three chromones 4-6, seven pentacyclic triterpenoids 7-13, a phytosterol glucoside 14, a flavonoid 15, and seven flavonoid glycosides 16-22. Nineteen of these compounds including the previously undescribed triterpenoid 1 are isolated for the first time from L. sericea. The structures of the isolated compounds were assigned based on their high-resolution mass spectrometry and nuclear magnetic resonance data. Some of the isolated triterpenoids were evaluated for inhibitory activity against α-amylase, α-glucosidase, and pancreatic lipase. Of the tested compounds, 1-hydroxy-2-oxopomolic acid (7) and pomolic acid (13) showed higher potency on α-glucosidase than acarbose, which is used as a positive control in this study. The two compounds inhibited α-glucosidase with IC₅₀ values of 192.1 ± 13.81 and 85.5 ± 6.87 μM, respectively.

Rugonidines A-F, Diastereomeric 1,6-Dioxa-7,9-diazaspiro[4.5]dec-7-en-8-amines from the Leaves of Alchornea rugosa

Rugonidines A-F (1-6), three pairs of novel configurationally semistable diastereomers featuring an unprecedented 1,6-dioxa-7,9-diazaspiro[4.5]dec-7-en-8-amine scaffold, were isolated from Alchornea rugosa based on MS/MS-based molecular networking analysis. Their structures were elucidated by NMR spectroscopy in combination with quantum-chemical calculations. Compounds 1-3 showed a significant increase in glucose uptake level in differentiated 3T3-L1 adipocytes using 2-deoxy-2-[(7-nitro-2,1,3-benzoxadiazol-4-yl)amino]-d-glucose (2-NBDG) as a fluorescent-tagged glucose probe.

The triterpenoids and sesquiterpenoids from the plant of Agrimonia pilosa

A phytochemistry of the whole plant of Agrimonia pilosa led to the discovery of two new nortriterpenoids, agrimonorterpenes A and B (1 and 2), together with one known triterpenoid fupenzic acid (3) and seven known sesquiterpenoids (4-10). The new structures were determined as 19α-hydroxy-2-oxo-nor-A (3)-urs-11,12-dien-28-oic acid (1) and 2, 19β-dihydroxy-3-oxo-23-noroleana-1, 4, 12-trien-28-oic acid (2) by the spectroscopic data of UV, IR, HR-ESI-MS, and NMR. Notably, the structure of 1 possessed a rare five-membered A ring. And this is the first time to discover the sesquiterpenoids (4-10) from A. pilosa. Compound 3 displayed the selective cytotoxicity against HCT116, BGC823, and HepG2 cell lines with the IC₅₀ values of 16.31 μM, 21.94 μM, and 23.40 μM, respectively.

Protective mechanisms of Agrimonia pilosa Ledeb in dextran sodium sulfate-induced colitis as determined by a network pharmacology approach

Previous studies reported that Agrimonia pilosa (AP) Ledeb possessed diverse biological activities, including anti-inflammatory, antioxidant, and anti-tumor activities. However, the effect of AP on ulcerative colitis (UC) remains unclear. In this study, we investigated the therapeutic effect and mechanisms of AP on dextran sodium sulfate (DSS)-induced colitis. The potential constituents of AP were investigated by ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS). A total of 13 compounds were recognized by UPLC-Q-TOF/MS chromatogram. Furthermore, a network pharmacology approach revealed that there are 297 candidate targets of UC and 549 common targets for the 13 active ingredients of AP. GO enrichment and KEGG pathway analysis indicated that AP might have a protective effect on UC through the nuclear factor κB (NF-κB) and nucleotide-binding oligomerization domain (NOD)-like receptor signaling pathways. Subsequent experimental validation in a DSS-induced colitis model revealed that AP alleviated the severity of DSS-induced colitis, reduced the production of proinflammatory factors, and protected against the loss of intestinal integrity. Moreover, AP inhibited the phosphorylation of NF-κB p65 and the activation of the NLRP3 inflammasome. In conclusion, AP ameliorated DSS-induced colitis through suppressing the activation of the NLRP3 inflammasome and NF-κB signaling pathways.

New dimeric phloroglucinol derivatives from Agrimonia pilosa and their hepatoprotective activities

Five new dimeric phloroglucinol derivatives, agrimones A - E (1-5), were isolated from the whole plant of Agrimonia pilosa. Their structures including absolute configurations were determined by a series of spectroscopic data (UV, IR, HR-ESI-MS, 1D and 2D NMR), complemented with the comparison of the experimental and calculated ECD spectra, and gauge-independent atomic orbital (GIAO) NMR calculations. Notably, compounds 1 and 2 represent a highly oxidized 6/6/6 tricyclic ring skeleton based on the cis-fused paraquinone and chroman. Compounds 1a, 4, and 5 exhibited moderate hepatoprotective activities against APAP-induced HepG2 cell injury at 10 μM.

The discovery of new phloroglucinol glycosides from Agrimonia pilosa and the mechanism of oxidative dearomatization of the methyl-substituted phloroglucinol derivatives

New phloroglucinol glycosides, aglycones, and oxidative dearomatized products of aglycones were discovered from Agrimonia pilosa, and the mechanism of the auto oxidative dearomatization was disclosed as a free radical chain reaction with ³O₂.

Natural isocoumarins: Structural styles and biological activities, the revelations carry on …

Isocoumarins and dihydroisocoumarins are lactonic phytochemicals plentiful in microbes and higher plants. These are an amazing small scaffolds consecrated with all types of pharmacological applications. Our previous review covered the period 2000-2016, documenting the then known natural products of this class; the current article is a critical account of discovery of known as well as undescribed structural types and pharmacological activities reported in the course of 2016-2020. The classification revealed in our previous review based on the biogenetic origin is further buttressed by discovery of new members of each class and some new structural types hitherto unknown have also been identified. Similarly, the biological activities and SAR conclusions identified were found to be valid as well, nonetheless with new accompaniments. The most recent available literature on the structural diversity and biological activity of these natural products has been included. The information documented in this article are collected from scientific journals, books, electronic search engines and scientific databases.

Phenolome of Asian Agrimony Tea (Agrimonia asiatica Juz., Rosaceae): LC-MS Profile, α-Glucosidase Inhibitory Potential and Stability

Functional beverages constitute the rapidly increasing part of the functional food section and represent an area with a wide range of products including herbal-based beverages. We carried out screening investigations of the extracts of 85 Rosaceous tea plants. Among the extracts analyzed Agrimonia asiatica herb extract demonstrated the highest inhibitory activity against the enzyme α-glucosidase (20.29 µg/mL). As a result of chromato-mass-spectrometric profiling of A. asiatica herb with high-performance liquid chromatography with photodiode array and electrospray triple quadrupole mass-spectrometric detection (HPLC-PDA-ESI-tQ-MS) 60 compounds were identified, including catechins, ellagitannins, flavones, flavonols, gallotannins, hydroxycinnamates, procyanidins, most for the very first time. The analysis of the seasonal variation of metabolites in A. asiatica herb demonstrated that the phenolic content was highest in summer samples and lower in spring and autumn. HPLC activity-based profiling was utilized to identify compounds of A. asiatica herb with the maximal α-glucosidase inhibitory activity. The most pronounced inhibition of α-glucosidase was observed for agrimoniin, while less significant results of inhibition were revealed for ellagic acid and isoquercitrin. The evaluation of phenolic content in A. asiatica herbal teas with the subsequent determination of α-glucosidase inhibiting potential was discovered. Maximum inhibition of α-glucosidase was observed for hot infusion (75.33 µg/mL) and the minimum for 30 min decoction (159.14 µg/mL). Our study demonstrated that A. asiatica herbal tea is a prospective functional beverage in which dietary intake may help to reduce blood glucose.

Secondary metabolites isolated from Agrimonia pilosa Ledeb

A pilot study on the ethanol extracts of Agrimonia pilosa found to have anti-α-glucosidase and anti-inflammatory activities. Subsequent chemical study afforded a new phenylethyl isocoumarin glycoside (1) and eight known compounds (2-9). The structure of 1 was elucidated by comprehensive spectroscopic analysis and chemical transformations. All compounds showed modest α-glucosidase inhibitory activity (IC₅₀ values ranging from 36.8 to 210.7 μM), which was lower than that of the positive control acarbose (IC₅₀=301.9 μM). Those compounds except inactive compounds 3 and 6 showed weak anti-inflammatory activity.[Formula: see text].

Increasing Structural Diversity of Natural Products by Michael Addition with ortho-Quinone Methide as the Acceptor

The active form of clavatol, ortho-quinone methide, can be generated from hydroxyclavatol in an aqueous system and used as a highly reactive intermediate for coupling with diverse natural products under very mild conditions. These include flavonoids, hydroxynaphthalenes, coumarins, xanthones, anthraquinones, phloroglucinols, phenolic acids, indole derivatives, tyrosine analogues, and quinolines. The clavatol moiety was mainly attached via C-C bonds to the ortho- or para-positions of phenolic hydroxyl/amino groups and the C2-position of the indole ring.

Exploring novel secondary metabolites from natural products using pre-processed mass spectral data

Many natural product chemists are working to identify a wide variety of novel secondary metabolites from natural materials and are eager to avoid repeatedly discovering known compounds. Here, we developed liquid chromatography/mass spectrometry (LC/MS) data-processing protocols for assessing high-throughput spectral data from natural sources and scoring the novelty of unknown metabolites from natural products. This approach automatically produces representative MS spectra (RMSs) corresponding to single secondary metabolites in natural sources. In this study, we used the RMSs of Agrimonia pilosa roots and aerial parts as models to reveal the structural similarities of their secondary metabolites and identify novel compounds, as well as isolation of three types of nine new compounds including three pilosanidin- and four pilosanol-type molecules and two 3-hydroxy-3-methylglutaryl (HMG)-conjugated chromones. Furthermore, we devised a new scoring system, the Fresh Compound Index (FCI), which grades the novelty of single secondary metabolites from a natural material using an in-house database constructed from 466 representative medicinal plants from East Asian countries. We expect that the FCIs of RMSs in a sample will help natural product chemists to discover other compounds of interest with similar chemical scaffolds or novel compounds and will provide insights relevant to the structural diversity and novelty of secondary metabolites in natural products.

Design of Chiral Bifunctional Dialkyl Sulfide Catalysts for Regio-, Diastereo-, and Enantioselective Bromolactonization

Although a wide variety of chiral organocatalysts have been developed for asymmetric transformations, effective chiral dialkyl sulfide organocatalysts remain relatively rare and under-developed, despite the potential utility of dialkyl sulfide catalysts. Herein, we report the development of chiral bifunctional dialkyl sulfide catalysts possessing a urea moiety for regio-, diastereo-, and enantioselective bromolactonization. The importance of the bifunctional design of chiral sulfide catalysts was clearly demonstrated in the present work. The roles of both the sulfide and urea moieties of the catalyst were clarified based on the results of experimental and theoretical investigation.

Morphological changes of bacterial cells upon exposure of silver-silver chloride nanoparticles synthesized using Agrimonia pilosa

Facile, eco-friendly synthesis of metal nanoparticles has been proposed as a cost effective method. In the present study, we propose the facile synthesis of silver-silver chloride (Ag-AgCl) nanoparticles (NPs) using the medicinally important Agrimonia pilosa plant extract without addition of capping or stabilizing agents. The Ag-AgCl NPs synthesis was observed at 40 °C after 10 min incubation; the synthesis of Ag-AgCl NPs was indicated by color change and confirmed by UV-vis spectroscopic peak at 454 nm. TEM analysis confirmed Ag-AgCl NPs were 10-20 nm in size and spherical, and oval in shape. Elemental composition was determined by energy dispersive X-ray analysis, and crystalline structure was confirmed by X-ray diffraction spectroscopy. Different phytocomponents present in the plant extract were analyzed by Gas Chromatography-Mass spectrometry, and the interaction of biomolecules in reduction process was analyzed by Fourier transform infrared spectroscopy studies. The synthesized Ag-AgCl NPs showed significant antibacterial efficiency, analyzed by well diffusion assay against pathogenic bacteria including Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus, Staphylococcus saprophyticus, Escherichia coli, Pseudomonas putida. Minimum inhibitory concentration and minimum bactericidal concentration were evaluated by microbroth dilution, and spread plate method, respectively. The possible mechanism of bacterial growth inhibition is due to changes in bacterial cell wall morphology that was studied by FE-SEM analysis.