Lignan glycosides from Fritillaria verticillata Willd. and their anti-inflammatory activities.

Three undescribed lignan glycosides, echiunines E-G (1-3), as well as eight known compounds (4-11) were isolated from Fritillaria verticillata Willd. Among them, compounds 1-3 were a series of lignan glycosides reported for the first time from genus Fritillaria. Their structures were elucidated by analyses of extensive spectroscopic data and comparison of the NMR data with those reported previously, the absolute configuration of compounds were further confirmed by calculated ECD method. The NO release inhibitory effects of compounds were evaluated in LPS-activated RAW264.7 macrophages. Compounds 7-8 showed inhibitory acitivities in a dose-dependent manner.

Recent advances in medicinal chemistry of oleanolic acid derivatives.

Oleanolic acid (OA), a ubiquitous pentacyclic oleanane-type triterpene isolated from edible and medicinal plants, exhibits a wide spectrum of pharmacological activities and tremendous therapeutic potential. However, the undesirable pharmacokinetic properties limit its application and development. Numerous researches on structural modifications of OA have been carried out to overcome this limitation and improve its pharmacokinetic and therapeutic properties. This review aims to compile and summarize the recent progresses in the medicinal chemistry of OA derivatives, especially on structure-activity relationship in the last few years (2010-2021). It gives insights into the rational design of bioactive derivatives from OA scaffold as promising therapeutic agents.

A novel strategy by integrating chemical profiling, molecular networking, chemical isolation, and activity evaluation to target isolation of potential anti-ACE2 candidates in Forsythiae Fructus.

BACKGROUND: Traditional Chinese medicine (TCM) is regarded as a large database containing hundreds to thousands of chemical constituents that can be further developed as clinical drugs, such as artemisinin in Artemisia annua. However, effectively exploring novel candidates is still a challenge faced by researchers. PURPOSE: In this work, an integrated strategy combining chemical profiling, molecular networking, chemical isolation, and activity evaluation (CMCA strategy) was proposed and applied to systematically characterize and screen novel candidates, and Forsythiae fructus (FF) was used as an example. STUDY DESIGN: It contained four parts. First, the chemical compounds in FF were detected by ultra-high-performance liquid chromatography-mass spectrometry (UPLC/Q-TOF MS) with data-dependent acquisition, and further, the targeted compounds were screened out based on an in-house database. In the meantime, the representative MS/MS fragmentation behaviors of different chemical structure types were summarized. Second, homologous constituents were grouped and organized based on feature-guided molecular networking, and the nontargeted components with homologous mass fragmentation behaviors were characterized. Third, the novel compounds were isolated and unambiguously identified by nuclear magnetic resonance (NMR). Finally, the anti-angiotensin-converting enzyme 2 (ACE2) activities of isolated chemical constituents were further evaluated by in vitro experiments. RESULTS: A total of 278 compounds were profiled in FF, including 151 targeted compounds and 127 nontargeted compounds. Among them, 16 were unambitiously identified by comparison with reference standards. Moreover, 25 were classified into potential novel compounds. Two novel compounds were unambiguously identified by using conventional chromatographic methods, and they were named phillyrigeninside D (peak 254) and forsythenside O (peak 155). Furthermore, the ACE2 activity of the compounds in FF was evaluated by modern pharmacological methods, and among them, suspensaside A was confirmed to present obvious anti-ACE2 activity. CONCLUSION: Our work provides meaningful information for revealing potential FF candidates for the treatment of COVID-19, along with new insight for exploring novel candidates from complex systems.

Novel glutamic acid derivatives from the bulbs of Fritillaria verticillate Willd and their antitumor activities.

Four previously undescribed glutamic acid derivatives, verticillamines A-D (1-4), together with six known compounds (5-10) were isolated from the bulbs of Fritillaria verticillate Willd. The structures of (1-10) were established on the basis of UV, IR, MS, 1D and 2D NMR, and the absolute configurations of compounds (1-4) were determined by calculated ECD methods. Among them, compounds (1-3) were rare 2-methyl-γ-lactam alkaloid derivatives. Moreover, both γ-lactam alkaloids (1-5) and pyrrolidine alkaloids (6-7) were discovered in Fritillaria for the first time. Compound 8 exhibited moderate cytotoxic activities against A2780 and HepG 2 cells, with IC50 values of 11.7 ± 5.2 µM and 25.6 ± 2.8 µM.

Iridoid, phenylethanoid and flavonoid glycosides from Forsythia suspensa.

As part of our continuing efforts to explore bioactive compounds from natural resources, a new iridoid glycoside, adoxosidic acid-6'-oleuroperic ester (1), together with one known phenylethanoid glycoside (2) and two known flavonoid glycosides (3-4) were isolated from the fruit of Forsythia suspensa. The structure of the new compound (1) was elucidated through 1D and 2D NMR spectroscopic data and HR-ESIMS. Interestingly, compound 1 was a monoterpene ester of one iridoid glycoside. Compounds 2-4 were identified as calceolarioside A (2), kaempferol-3-O-rutinoside (3), kampferol-3-O-robinobioside (4) on the basis of NMR spectroscopic data analyses and comparison with the data reported in the literature. The antiviral activity aganisist influenza A (H5N1) virus of compound 1 was studied as well.

Seven new guanacastane-type diterpenoids from the fungus Verticillium dahliae.

Seven new guanacastane-type diterpenoids, namely dahlianes E-K (1-7), and three known ones (8-10) were isolated from the cultures of the fungus Verticillium dahliae. Their structures were established by extensive spectroscopic data analysis along with Rh2(OCOCF3)4- and Mo2(OAc)4-induced electronic circular dichroism (ECD) experiment. Dahliane G showed an 80-fold potentiation effect on the sensitization of doxorubicin at the concentration of 15 µM when screening the reversal activity on doxorubicin-resistant human breast cancer cells (MCF-7/DOX).

Two new C21 steroidal glycosides isolated from Cynanchum komarovii.

The present study was designed to further investigate the C21 steroidal glycosides in Cynanchum plants. Two new steroidal glycosides based on a 13, 14:14, 15-disecopregnane-type aglycone, komaroside P (1) and komaroside Q (2), together with three known compounds (3-5) were isolated from the whole herbs of Cynanchum komarovii. The aglycones of compounds 1 and 2 were two new disecopregnane. Their structures were elucidated on the basis of 1D, 2D NMR spectroscopic data and acid hydrolysis. All the compounds (1-5) showed potent inhibitory activities against human leukemia cell lines (HL-60) with IC50 values ranging from 16.6 to 26.3 µmol·L-1, compared to the positive control 5-fluorouracil (6.4 µmol·L-1).

Triterpenoids from Euphorbia maculata and Their Anti-Inflammatory Effects.

Euphorbia maculata is a medicinal plant of the Euphorbiaceae family, which can produce anti-inflammatory and cancer chemopreventive agents of triterpenoids. The present study reports on the bioactive triterpenoids of this plant. Two new lanostane-type triterpenoids, named (3S,4S,7S,9R)-4-methyl-3,7-dihydroxy-7(8→9) abeo-lanost-24(28)-en-8-one (1) and 24-hydroperoxylanost-7,25-dien-3ß-ol (2), together with 15 known triterpene derivatives, were isolated from Euphorbia maculata. The structures of the new compounds were determined on the basis of extensive spectroscopic data (UV, MS, ¹H and 13C-NMR, and 2D NMR) analysis. All tetracyclic triterpenoids (1⁻11) were evaluated for their anti-inflammatory effects in the test of TPA-induced inflammation (1 µg/ear) in mice. The triterpenes exhibited significant anti-inflammatory activities.

Racemic indole alkaloids from the seeds of Peganum harmala.

Five pairs of new 2-oxoindole alkaloids, (±)-peganumalines A-E (1-5), and a new indole alkaloid, peganumaline F (6), along with two known analogues, were isolated from the seeds of Peganum harmala. Their structures and absolute configurations were elucidated through spectroscopic analyses and quantum chemistry calculations. Notably, (±)-peganumalines A (1) represent a pair of rare 2-oxoindole dimeric alkaloid enantiomer with the hitherto unknown carbon skeleton. All isolates were tested for antiproliferative and antibacterial activities.

Isolation and structure elucidation of a new compound from the fungus Aspergillus flavipes PJ03-11.

A new diphenyl ether 3-methylpentyl-2, 4-dichloroasterrate (2), along with a known diphenyl ether butyl 2, 4-dichloroasterrate (1) were isolated from the metabolites of a wetland fungus Aspergillus flavipes. PJ03-11. The structures of 1 and 2 were determined by extensive NMR and HR-ESI-MS experiments. Compounds 1 and 2 showed weak cytotoxic activity, but both of them showed no antimicrobial activity.

Metabolic Profiling Analysis of the Alleviation Effect of Treatment with Baicalin on Cinnabar Induced Toxicity in Rats Urine and Serum.

Objectives: Baicalin is the main bioactive flavonoid constituent isolated from Scutellaria baicalensis Georgi. The mechanisms of protection of liver remain unclear. In this study, 1H NMR-based metabonomics approach has been used to investigate the alleviation effect of Baicalin. Method:1H NMR metabolomics analyses of urine and serum from rats, was performed to illuminate the alleviation effect of Baicalin on mineral medicine (cinnabar)-induced liver and kidney toxicity. Results: The metabolic profiles of groups receiving Baicalin at a dose of 80 mg/kg were remarkably different from cinnabar, and meanwhile, the level of endogenous metabolites returned to normal compared to group cinnabar. PLS-DA scores plots demonstrated that the variation tendency of control and Baicalein are apart from Cinnabar. The metabolic profiles of group Baicalein were similar to those of group control. Statistics results were confirmed by the histopathological examination and biochemical assay. Conclusion: Baicalin have the alleviation effect to the liver and kidney damage induced by cinnabar. The Baicalin could regulate endogenous metabolites associated with the energy metabolism, choline metabolism, amino acid metabolism, and gut flora.

Two new phenolic glycosides isolated from the fruits of Citrus aurantium.

The present study was designed to investigate the chemical constituents of the fruit of Citrus aurantium L.. The compounds were isolated and purified by various chromatographic techniques, and their structures were elucidated on the basis of physicochemical properties and spectral data. Two new phenolic glycosides (compounds 1 and 2) were obtained and identified as 1-O-3, 5-dihydroxyphenyl-(6-O-4-hydroxybenzoyl)-ß-D-glucopyranoside (1) and 1-O-3, 5-dihydroxyphenyl-(6-O-3-methoxy-4-hydroxy benzoyl)-ß-D-glucopyranoside (2), respectively.

Structurally Diverse Alkaloids from the Seeds of Peganum harmala.

Investigation of the alkaloids from Peganum harmala seeds yielded two pairs of unique racemic pyrroloindole alkaloids, (±)-peganines A-B (1-2); two rare thiazole derivatives, peganumals A-B (3-4); six new ß-carboline alkaloids, pegaharmines F-K (5-10); and 12 known analogues. Their structures, including stereochemistry, were elucidated through spectroscopic analyses, quantum chemistry calculations, and single-crystal X-ray diffraction. Notably, the incorporation of pyrrole and indole moieties in peganines A-B, thiazole fragments in peganumals A-B, and a C-1 α,ß-unsaturated ester motif in pegaharmine F (5) are all rare, and their presence in the genus Peganum were demonstrated for the first time. All isolates were tested for antiproliferative activities against the HL-60, PC-3, and SGC-7901 cancer cell lines, and compounds 9, 11, 12, and 13 exhibited moderate cytotoxicity against HL-60 cancer cell lines with IC50 values in the range of 4.36-9.25 µM.

Identification of antioxidant activity of two new aromatic ring butyrolactone derivatives from Dictamnus dasycarpus Turcz.

The present study carried out a phytochemical investigation on the root barks of Dictamnus dasycarpus Turcz, leading to the isolation and characterization of two new aromatic ring butyrolactone derivatives, dasycarpusphenol acid A (1) and dasycarpusphenol acid B (2). Their structures were elucidated by using spectroscopic techniques and HR-FAB-MS. Compounds 1 and 2 exhibited antioxidant activity, with their IC50 values being 28.95 and 41.76 mg·mL-1, respectively.

A Series of ß-Carboline Alkaloids from the Seeds of Peganum harmala Show G-Quadruplex Interactions.

In this study, we screened 17 medicinal plants for binding activity to G-quadruplex d(TTGGGTT)4 by (1)H NMR spectroscopy and found that the crude extract of Peganum harmala L. seeds showed the most potential binding activity. Subsequently, (1)H NMR- and bioassay-guided isolation of the extract of P. harmala L. was performed to obtain four pairs of partially racemized ß-carboline alkaloids, pegaharmines A-D (1-4). Their structures and absolute configurations were determined by extensive NMR analyses, X-ray crystallography, ECD calculations, and CD exciton chirality approaches. Interestingly, pegaharmine D (4), which showed the strongest G-quadruplex interaction, exhibited significant cytotoxic activity against three cancer cell lines. This work contributed a practical strategy for the discovery of novel G-quadruplex ligands from natural products and provided potential insights for using ß-carboline alkaloids as anticancer lead compounds specifically targeting G-quadruplexes.

A new sesquiterpene lactone glycoside and a new quinic acid methyl ester from Patrinia villosa.

A new sesquiterpene lactone glycoside (1) and a new quinic acid methyl ester (2) were isolated from Patrinia villosa, together with another two known compounds chlorogenic acid n-butyl ester (3), 3, 4-di-O-caffeoylquinic acid methyl ester (4). Their structures were established using 1D/2D-NMR spectroscopy, mass spectrometry, and comparing with spectroscopic data reported in the literature.

[¹H-NMR-based metabonomics on chemical component groups with toxicity alleviation effect to Realgar in Niuhuang Jiedu tablet].

To study the chemical component groups with toxicity alleviation effect to Realgar in Niuhuang Jiedu tablet based on ¹H-NMR metabonomics. Twenty-four male Wistar rats were divided into four groups： control group, R group (treated with Realgar), RRSPG group (treated with Realgar, the root and rhizoma of Rheum palmatum, the root of Scutellaria baicalensis, the root of Platycodon grandiflorum and the root and rhizoma of Glycyrrhiza uralensis) and RC group (treated with total anthraquinones from the root and rhizoma of R. palmatum, total flavonoids from the root of S. baicalensis, total saponins from the root of P. grandiflorum, total flavonoids and saponins from the root and rhizoma of G. uralensis). Based on ¹H-NMR spectra of urine and serum from rats, PLS-DA was performed to identify different metabolic profiles.The metabolic profiles of R group were different from that of control group, while the metabolic profiles of RC group were almost similar to control group.Total anthraquinones from the root and rhizoma of R. palmatum, total flavonoids from the root of S. baicalensis, total saponins from the root of P. grandiflorum, total flavonoids and saponins from the root and rhizoma of G. uralensis regulated energy, choline and amino acid metabolism and gut flora disorder affected by realgar's toxicity.

[Chemical constituents from Barringtonia racemosa].

To investigate the chemical constituents from Barringtonia racemosa, twelve compounds were isolated by chromatography methods and identified as 3ß-p-E-coumaroymaslinic acid (1), cis-careaborin (2), careaborin (3), maslinic acid (4), 2α, 3ß, 19α-trihydroxyolean-12-ene-24, 28-dioic acid (5), 3ß-p-Z-coumaroylcorosolic acid (6), corosolic acid (7), 1α, 2α, 3ß, 19α-tetrahydroxyurs-12-en-28-oic acid (8), 19α-hydroxyl ursolic acid (9), 3α, 19α-dihydroxyurs-12-en-24, 28-dioic acid (10), tormentic acid (11), 3-hydroxy-7, 22-dien-ergosterol（12） by the NMR and MS data analysis. Among them, compounds 1-4,7-12 were obtained from the genus Barringtonia for the first time. All the compounds didn't show nocytotoxic activity against MCF-7 and A549 cell lines (IC50>50 mg•L⁻¹).

Isolation and identification of two new compounds from marine-derived fungus Acremonium fusidioides RZ01.

Two new compounds, (22E)-25-carboxy-8ß,14ß-epoxy-4α,5α-dihydroxyergosta-2,22-dien-7-one (1) and fusidione (3), along with two known compounds, 5α,8α-epidioxy ergosta-6,22-diene-3ß-ol (2) and microperfuranone (4), were isolated from the fermentation products of the marine-sourced fungus Acremonium fusidioides RZ01. The structures of compounds 1 and 3 were elucidated by extensive spectroscopic methods, especially 2D NMR, and their absolute configurations were suggested on the basis of the circular dichroism spectral analysis and the NOESY data. Both new compounds showed inhibitory activity against HL-60 cells with IC50 values being16.6 and 44.9 µmol·L-1, respectively.

Quinolone and indole alkaloids from the fruits of Euodia rutaecarpa and their cytotoxicity against two human cancer cell lines.

Four quinolone alkaloids (1-4) and three indole alkaloids (20-22), together with 30 known alkaloids (5-19, 23-37), were isolated from the fruits of Euodia rutaecarpa. Their structures were established by spectroscopic analyses. The in vitro cytotoxic activities of these alkaloids against leukaemia HL-60 and prostate cancer PC-3 cell lines were evaluated.