Puqiedinone, a novel 5 alpha-cevanine alkaloid from the bulbs of Fritillaria puqiensis, an antitussive traditional Chinese medicine

Cevanine-type alkaloids from the bulbs of Fritillaria unibracteata var. wabuensis and their antifibrotic activities in vitro

Steroidal alkaloids are the main bioactive components of the bulbs of Fritillaria, which have been used as traditional Chinese medicine, known as "Beimu", for the treatment of cough for thousands of years in China. Cough and dyspnea are the most common symptoms observed in patients with pulmonary fibrosis. However, the antifibrotic activity of steroidal alkaloids has not been reported yet. In this study, two previously unreported cevanine-type steroidal alkaloids (1 and 2), four previously undescribed cevanine-type alkaloid glycosides (3-6), and 19 known steroidal alkaloids (7-25) were isolated from the bulbs of Fritillaria unibracteata var. wabuensis. The structures of these compounds were elucidated by comprehensive HRESIMS and NMR spectroscopic data analysis, as well as DP4+ NMR calculations. The biological evaluation showed that compounds 2, 7-10, 14, 15, and 17 downregulated fibrotic markers induced by transforming growth factor-β (TGF-β) in MRC-5 cells. Moreover, compounds 14 and 17 dose dependently inhibited TGF-β-induced epithelial-mesenchymal transition in A549 cells, alleviated TGF-β-induced migration and proliferation of fibroblasts, and decreased the expression of fibrotic markers, fibronectin, and N-cadherin in TGF-β-induced MRC-5 cells. The research showed the potential of cevanine-type alkaloids as a class of natural antifibrotic agents.

Diastereomers of Steroidal Alkaloids with Cytotoxic Activities against Non-Small-Cell Lung Cancer from the Bulbs of Fritillaria sinica

Eleven new steroidal alkaloids, along with nine known related compounds, were isolated from the bulbs of Fritillaria sinica. Seven pairs of diastereomers were identified, including six and four 20-deoxy cevanine-type steroidal alkaloid diastereomers with molecular weights of 413 and 415, respectively. Structures were elucidated based on spectroscopic data analysis, chemical derivatization, and single-crystal X-ray diffraction analysis. Compounds 5, 9, 11, 12, 16, and 20 exhibited significant in vitro cytotoxic activity against non-small-cell lung cancer with CC50 values from 6.8 ± 3.9 to 12 ± 5 μM.

Antiplasmodial activity of the bulbs of Fritillaria cirrhosa D.Don (Syn: Fritillaria roylei Hook.): UPLC-IM-Q-TOF-MS/MS-based biochemometric approach for the identification of marker compounds

ETHNOPHARMACOLOGICAL RELEVANCE

Fritillaria cirrhosa D.Don (Syn: Fritillaria roylei Hook.) (Hindi name: Kshirakakoli) is a critically endangered Himalayan medicinal plant, well documented in Ayurveda for its therapeutic uses against various disorders such as jvara (fever), kasa (respiratory tract disease) etc. Its bulbs are also used as Szechuan-Pei-Mu for their antipyretic properties in the traditional Chinese medicine. However, despite its ethnomedicinal usage, the therapeutic use of F. cirrhosa bulbs for jvara (fever) related conditions such as malaria has remained unexplored. Hence in the context of increasing global concerns about drug-resistant malaria, it is important to investigate the antiplasmodial activity of F. cirrhosa bulbs for novel antimalarial agents.

AIM OF THE STUDY

To investigate the antiplasmodial effects of the extracts/fractions of F. cirrhosa bulbs by the biochemometric approach and to rationalize its ethnopharmacological usage for jvara (fever) related conditions such as malaria.

MATERIAL AND METHODS

This study involves the UHPLC-MS-based plant material selection, preparation, quantification, and assessment of F. cirrhosa bulb extracts against CQ-sensitive Pf 3D7 & CQ-resistant Pf INDO strains. Further, UPLC-IM-Q-TOF-MS-based biochemometric approach has been applied for the identification of marker compounds responsible for the observed antiplasmodial effects. The identified marker compounds were also assessed for their in silico ADMET properties and binding efficacy with the drug transporter Pf CRT.

RESULTS

Different F. cirrhosa bulb extracts/fractions showed promising antiplasmodial activity with IC₅₀ values 2.71-19.77 μg/mL for CQ-resistant Pf INDO strain and 1.76-21.52 μg/mL for CQ-sensitive Pf 3D7 strain. UPLC-IM-Q-TOF-MS/MS-based biochemometric analysis revealed four marker compounds i.e., peimine (m/z 432.3448), peimisine (m/z 428.3504), puqiedinone (m/z 414.3379), and puqiedine (m/z 416.3509) responsible for the observed antiplasmodial activity. The identified marker compounds showed excellent binding efficacy with Pf CRT and suitable drug-like properties in silico.

CONCLUSIONS

The study demonstrated promising antiplasmodial activity of the chloroform and alkaloid enriched fractions of F. cirrhosa bulbs and further identified the four marker compounds responsible for the promising antiplasmodial activity. These marker compounds i.e., peimine, peimisine, puqiedinone and puqiedine were identified by the biochemometric analysis as the putative antiplasmodial constituents of the F. cirrhosa bulbs. Further, in silico studies indicated the good binding affinity of the marker compounds with Pf CRT along with suitable ADMET properties. Overall, the study elucidates the antiplasmodial activity of F. cirrhosa bulbs from the western Himalayan region and provides nascent scientific evidence for their ethnopharmacological usage in jvara (fever) related conditions such as malaria.

Undescribed steroidal alkaloids from the bulbs of Fritillaria sinica

Eight undescribed steroidal alkaloid derivatives, including three cevanine-type isosteroidal alkaloids (two N-oxide glycosides and one D-ring aromatization) (1-3), one verazine-type steroidal alkaloid derivative (4), three solanidine-type steroidal alkaloid glycosides (5-7), and one veratramine-type analogue (8), along with three known compounds (9-11) were isolated from the bulbs of Fritillaria sinica. Their structures were elucidated by comprehensive analysis of spectroscopic data, acidic hydrolysis, and X-ray crystal diffractions. In the in vitro bioassay, the anti-cancer effect, anti-oxidation and anti-inflammatory activities for the isolates were evaluated at a concentration of 10 μM.

Steroidal alkaloids from the bulbs of Fritillaria unibracteata var. wabuensis and their anti-inflammatory activities

Fourteen previously undescribed steroidal alkaloids, including six jervine-type, wabujervine A-E and wabujerside A, seven cevanine-type, wabucevanine A-G, and one secolanidin-type, wabusesolanine A, along with thirteen known steroidal alkaloids, were isolated from the bulbs of Fritillaria unibracteata var. wabuensis. On the basis of comprehensive analysis of IR, HRESIMS, 1D and 2D NMR spectroscopic data, and single-crystal X-ray diffraction analyses, their structures were elucidated. In the zebrafish acute inflammatory models, nine compounds showed anti-inflammatory activity.

The phytochemical constituents and protective effect of Fritillaria hupehensis on acute lung injury

Acute lung injury (ALI), a severe respiratory disorder, frequently develops into acute respiratory distress syndrome (ARDS) without timely treatment and scores highly in terms of morbidity and mortality rates. Fritillaria hupehensis is a famous traditional Chinese medicine with antitussive, expectorant and anti-asthmatic effect. Here, the effects of F. hupehensis extracts on lipopolysaccharide (LPS)-induced ALI mice were evaluated for the first time. We showed ethyl acetate fraction (EAF) significantly reduced the leukocytes and neutrophils of bronchoalveolar lavage fluid (BALF) and the lung index as well as pro-inflammatory cytokines (TNF-α and IL-6) of lung homogenates but increasing the anti-inflammatory cytokines (IL-4 and IL-10). Additionally, the alleviation of EAF treatment on lung injury was verified through histopathological observations. Subsequent phytochemical investigation on bioactive fraction led to isolation of 17 compounds including two new, in which compounds 2, 5 and 6 exhibited better anti-inflammatory effect on LPS-induced 16 human airway epithelial (16HBE) cells model by inhibiting the production of CRP and PCT. Furthermore, compound 2 suppressed the LPS-induced upregulation of proteins containing p-p65, COX-2, Caspase-1 and IL-18. In summary, F. hupehensis alleviating LPS-induced ALI in mice may be associated with the anti-inflammatory activity of steroidal alkaloids by suppressing the NF-κB-regulated pro-inflammatory proteins.

Chemistry and bioactivities of natural steroidal alkaloids

Steroidal alkaloids possess the basic steroidal skeleton with a nitrogen atom in rings or side chains incorporated as an integral part of the molecule. They have demonstrated a wide range of biological activities, and some of them have even been developed as therapeutic drugs, such as abiraterone acetate (Zytiga^®), a blockbuster drug, which has been used for the treatment of prostate cancer. Structurally diverse natural steroidal alkaloids present a wide spectrum of biological activities, which are attractive for natural product chemistry and medicinal chemistry communities. This review comprehensively covers the structural classification, isolation and various biological activities of 697 natural steroidal alkaloids discovered from 1926 to October 2021, with 363 references being cited.

Cirrhosinones A-H, 24-hydroxy cevanine-type alkaloids from Fritillariacirrhosa

Eight undescribed isosteroidal alkaloids cirrhosinones A-H (1-8), along with six known isosteroidal alkaloids (9-14), were isolated from the bulbs of Fritillaria cirrhosa D. Don. Their structures were determined by HRESIMS and 2D NMR analysis, and their absolute configurations were established by X-ray analysis. Compounds 1-8 possessed a typical cevanine-type alkaloid skeleton with a hydroxyl group rarely substituted at C-24 and compounds 4-8 possessed rare 7α or 7β-hydroxyl groups. This was the first report of both C-7 and C-24 hydroxyl groups substituted cevanine-type alkaloids. In addition, an approach for distinguishing D/E cis and trans conformations of cevanine-type alkaloids by ¹H NMR data was developed. Moreover, the correlations between the relative configurations of 3-OH, 7-OH, 22-C, 24-OH, and 25-Me and the ¹H NMR and ¹³C NMR data were also summarized. Compounds 1-9 exhibited moderate NO inhibitory activities in LPS-stimulated BV-2 cells at the concentration of 40 μM. The acetylcholinesterase inhibitory activities of compounds 1-7 and 9-10 were also evaluated and none of them showed acetylcholinesterase inhibitory activities at the concentrations of 20-80 μM.

Steroidal alkaloids and their glycosides from the bulbs of Fritillaria unibracteata

Seven undescribed steroidal alkaloids, including two jervine-type steroidal alkaloids, fritiunibras A-B (1-2), and five cevanine-type steroidal alkaloid glycosides, fritiunibras C-G (3-7), along with six known cevanine-type steroidal alkaloids and their glycosides (8-13) were isolated from the bulbs of Fritillaria unibracteata Hsiao et K. C. Hsia. Their structures were determined by interpretation of comprehensive spectroscopic and single-crystal X-ray diffraction analysis. The absolute configurations of sugar moieties were determined by HPLC analysis and compared with standards after hydrolysis and derivatization. Furthermore, their inhibitory effects on NO production and cytotoxic activities were evaluated.

Steroidal alkaloids from the bulbs of Fritillaria pallidiflora Schrenk and their anti-inflammatory activity

Steroidal alkaloids (1-11), including one new 24-hydroxylated cevanine-type steroidal alkaloid, named yibeinone F (1), were isolated from the bulbs of Fritillaria pallidiflora Schrenk. Their structures were elucidated by analyses of extensive spectroscopic data and comparison of the NMR data with those reported previously, and the structures of compounds 1, 7 and 11 were further confirmed by X-ray single crystal diffraction analyses. The anti-inflammatory effects of all the isolated alkaloids were evaluated in LPS-activated RAW264.7 macrophages. Among them, compounds 9 (stenanzine) and 10 (hapepunine) showed significant inhibitory effects against LPS-induced NO production with IC₅₀ values of 8.04 μM and 20.85 μM, respectively. Furthermore, compound 9 effectively inhibited the release of cytokines such as interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and prostaglandin E2 (PGE₂), and suppressed the protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX2) in LPS-stimulated RAW264.7 cells. Further experiments revealed the underlying mechanism that 9 blocked LPS-induced phosphorylation and degradation of inhibitor-α of nuclear transcription factor κB (IκBα) and c-Jun N-terminal kinase (JNK) in RAW264.7 cells. Taken together, compound 9 may be a valuable candidate for the treatment of inflammatory diseases.

Metabolomics Study of Cultivated Bulbus Fritillariae Cirrhosae at Different Growth Stages using UHPLC-QTOF-MS Coupled with Multivariate Data Analysis

INTRODUCTION

Bulbus fritillariae cirrhosae (known as Chuān bèi mǔ in China, BFC) contain fritillaria steroidal alkaloids as the bioactive ingredients and are widely used as traditional Chinese medicine for the treatment of cough and phlegm. Due to limited wild resources, the cultivated species are becoming predominantly used in Chinese traditional medicine markets.

OBJECTIVE

To assess the impact of different growth stages on the alkaloids of cultivated BFC and establish a reference for quality control and guidance for appropriate harvesting practices.

METHODS

The ultra-high performance liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) metabolomic strategy was applied to determine potential chemical markers for the discrimination and quality control of cultivated BFC in different growth stages. The molecular feature extraction and multivariate statistical analysis were applied to alkaloid extraction and full metabolomic profiling of cultivated BFC for classification and marker compound characterisation.

RESULT

This approach allowed the establishment of a fast and efficient comparative multivariate analysis of the metabolite composition of 42 samples covering growth of cultivated BFC ranging in age from one to seven years old. Four alkaloid compounds were identified in cultivated BFC based on accurate mass, retention time, and MS/MS fragments. These compounds may be used as potential chemical markers for the classification and discrimination of cultivated BFC samples indifferent growth stages.

CONCLUSIONS

The proposed analytical method in combination with multivariate statistical analysis comprised a useful and powerful strategy to explore the chemical ingredients and transforming mechanisms of cultivated BFC and for quality evaluation and control. Copyright © 2018 John Wiley & Sons, Ltd.

The Veratrum and Solanum alkaloids

This survey on steroidal alkaloids of the Veratrum and Solanum family isolated between 1974 and 2014 includes 187 compounds and 197 references. New developments in the chemistry and biology of this family of natural products with a special focus on the medicinal relevance of the jervanine alkaloid cyclopamine are discussed.

Steroidal alkaloids from the bulbs of Fritillaria unibracteata

Two new steroidal alkaloids peimisine-3-O-β-D-glucopyranoside (1) and puqiedinone-3-O-β-D-glucopyranoside (3), together with three known compounds peimisine (2), puqiedinone (4), and puqiedine (5), were isolated and characterized from the bulbs of Fritillaria unibracteata. Their structures were fully elucidated by spectroscopic and chemical methods. Compound 1 showed moderate protection effect on neurotoxicity of PC12 cell lines induced by rotenone.

New steroidal alkaloids from the bulbs of Fritillaria puqiensis

Six new steroidal alkaloids, namely puqienines C-E (1-3), puqiedine (4), 3alpha-puqiedin-7-ol (5), and puqietinedione (6), along with two known steroidal alkaloids puqiedinone (7) and peimisine (8), were isolated from the bulbs of Fritillaria puqiensis G.D. Yu et G.Y. Chen (Liliaceae). Their structures were elucidated on the basis of spectroscopic analysis, including 1D and 2D NMR experiments. Among these alkaloids, 1-3 had a veratramine-type skeleton, 4, 5, 7 a cevanine-type skeleton, 6 a secosolanidine-type skeleton, and 8 a jervine-type skeleton. The existence of multiple types of steroidal skeletons, especially of relatively large amount of veratramine-type alkaloids in one species is rare in the genus Fritillaria, and the results might be of chemotaxonomic significance for this species.

Chemistry, bioactivity and geographical diversity of steroidal alkaloids from the Liliaceae family

Plants belonging to the Liliaceae family have been the topic of research in many phytochemical and pharmacological laboratories because they contain structurally complex and biologically fascinating steroidal alkaloids. This review, citing 153 references, summarises the chemistry, bioactivity and geographical diversity of steroidal alkaloids isolated from Veratrum and Fritillaria species, so as to illustrate the chemo-diversity and biological significance of these alkaloids, along with their geographical distribution where this is discernible.

Chromatographic analysis of Fritillaria isosteroidal alkaloids, the active ingredients of Beimu, the antitussive traditional Chinese medicinal herb

Bulbus Fritillariae derived from plants of various Fritillaria species is the most commonly used antitussive traditional Chinese medicinal herb and is called Beimu. Herbs derived from similar and/or different species of Fritillaria are also used in Japan and Turkey as traditional or folk medicines. Isosteroidal alkaloids are the main bioactive ingredients in Fritillaria species. As the contents and structure types of these bioactive alkaloids vary in different Fritillaria species, quality control of these active principles in herbal Beimu is very important to ensure its safe and effective clinical use. This review describes the development of chromatographic analyses for the simultaneous qualitative and quantitative determination of the main bioactive Fritillaria isosteroidal alkaloids in herbal and biological samples. The recently developed direct HPLC-evaporative light scattering detection method is the most simple, selective and sensitive assay, and is readily used as a suitable quality control method for the analysis of the active principles of herbal Beimu.

Determination of the major isosteroidal alkaloids in bulbs of Fritillaria by high-performance liquid chromatography coupled with evaporative light scattering detection

A new direct HPLC analytical method using evaporative light scattering detection coupled with a low-temperature adapter for the simultaneous determination of the major biologically active isosteroidal alkaloids in Bulbus Fritillariae, a commonly used antitussive traditional Chinese medicinal (TCM) herb, has been developed. The simultaneous separation of eight Fritillaria alkaloids was achieved on a reversed-phase C8 column with an isocratic mobile phase system consisting of acetonitrile-methanol-water (66.5:3.5:30, v/v) containing 0.006% triethylamine. This method provides good reproducibility and sensitivity for the quantification of six major isosteroidal alkaloids, namely peimissine, verticine, verticinone, imperialine, isoverticine and ebeiedine in different Fritillaria species with overall intra- and inter-day precision and accuracy of less than 11% and higher than 90%, respectively. The assay was successfully utilized to quantify the major biologically active alkaloids in five Fritillaria species. The results demonstrate that this method is simple, selective, and suitable for the quality control of this commonly used antitussive TCM herb, Bulbus Fritillariae. reserved.

Simultaneous determination of seven major isosteroidal alkaloids in bulbs of Fritillaria by gas chromatography

The present paper describes the development of a most simple, sensitive, and specific gas chromatographic method to date, for the direct determination of seven major bioactive isosteroidal alkaloids, namely ebeiedine, ebeiedinone, ebeienine, hupehenine, isoverticine, verticine, verticinone and imperialine, in Fritillaria species, a commonly used antitussive traditional Chinese medicinal (TCM) herb. In the present study, a commercially available Supelco SAC-5 capillary column (30 m x 0.25 mm, 0.25 microm) specifically designed for the analysis of steroids was utilized for the direct determination of Fritillaria alkaloids. Calibration curves were obtained by spiking authentic compounds and the internal standard (solanidine) into herbal samples prior to extraction. Extraction was conducted simply by shaking the pre-alkalized diethyl ether solution (5.0 ml) containing dried herb (0.1 g) for 2 h. All calibration curves showed good linear regressions (r2>0.995) within test ranges. The assay was reproducible and accurate with the overall intra- and inter-day variation and accuracy of less than 10% and more than 90%, respectively. The developed GC method was successfully utilized to analyze seven major bioactive alkaloids in seven Fritillaria species, and the results demonstrate that this direct GC analytical method is suitable for the quality control of this commonly used antitussive TCM herb.

Pre-column derivatization and gas chromatographic determination of alkaloids in bulbs of Fritillaria

A method of precolumn derivatization GC with FID detection was developed for a simultaneous analysis of five major steroidal alkaloids of Fritillaria species, namely ebeiedine, ebeiedinone, verticine, verticinone and imperialine. Derivatization was carried out by trimethylsilylation of the hydroxyl-containing Fritillaria alkaloids to the corresponding trimethylsilylates with trimethylsilylimidazole. Reaction conditions were optimised and the alkaloids derivatives were characterised by on-line GC-MS. The validated GC method demonstrated a good linearity at the sampling ranges used. This analytical method is simple, convenient and reproducible. The developed assay was successfully applied to the determination of the major pharmacologically active alkaloids in three commonly used antitussive Fritillaria species: F. cirrhosa, F. thunbergii and F. pallidiflora.

Prederivatization and high-performance liquid chromatographic analysis of alkaloids of bulbs of Fritillaria

A method of prederivatization and HPLC with UV detection was developed for the simultaneous analysis of five major steroidal alkaloids of the Fritillaria species: verticine, verticinone, isoverticine, ebeiedine, and ebeiedinone. Derivatization was carried out by esterification of the hydroxyl-containing Fritillaria alkaloids to the corresponding naphthoates with 1-naphthoyl chloride. Reaction conditions were optimized and the yields of the derivatization were between 94 and 100% for all test alkaloids. Derivatized alkaloids were characterized by mass spectrometry and HPLC-MS. The validated HPLC-UV method demonstrated linear UV response at the sampling ranges used, and a test limit of 1 microgram/mL was determined for all analytes. This analytical method is simple, convenient, and readily reproducible. The developed method was applied to the analysis of the major pharmacologically active alkaloids in three medicinally used Fritillaria species: F. cirrhosa, F. thunbergii, and F. hupehensis. Five major Fritillaria alkaloids were simultaneously analyzed qualitatively and quantitatively from crude extracts of each of these herbs.