Preparative separation of the flavonoid fractions from Periploca forrestii Schltr. ethanol extracts using macroporous resin combined with HPLC analysis and evaluation of their biological activities

Multi-omics analysis reveals promiscuous O-glycosyltransferases involved in the diversity of flavonoid glycosides in Periploca forrestii (Apocynaceae)

Flavonoid glycosides are widespread in plants, and are of great interest owing to their diverse biological activities and effectiveness in preventing chronic diseases. Periploca forrestii, a renowned medicinal plant of the Apocynaceae family, contains diverse flavonoid glycosides and is clinically used to treat rheumatoid arthritis and traumatic injuries. However, the mechanisms underlying the biosynthesis of these flavonoid glycosides have not yet been elucidated. In this study, we used widely targeted metabolomics and full-length transcriptome sequencing to identify flavonoid diversity and biosynthetic genes in P. forrestii. A total of 120 flavonoid glycosides, including 21 C-, 96 O-, and 3 C/O-glycosides, were identified and annotated. Based on 24,123 full-length coding sequences, 99 uridine diphosphate sugar-utilizing glycosyltransferases (UGTs) were identified and classified into 14 groups. Biochemical assays revealed that four UGTs exhibited O-glycosyltransferase activity toward apigenin and luteolin. Among them, PfUGT74B4 and PfUGT92A8 were highly promiscuous and exhibited multisite O-glycosylation or consecutive glycosylation activities toward various flavonoid aglycones. These four glycosyltransferases may significantly contribute to the diversity of flavonoid glycosides in P. forrestii. Our findings provide a valuable genetic resource for further studies on P. forrestii and insights into the metabolic engineering of bioactive flavonoid glycosides.

A green and simple method for enrichment of major diterpenoids from the buds of Wikstroemia chamaedaphne with macroporous resins and their activation of latent human immunodeficiency virus activity

In this study, a green and efficient enrichment method for the four majors active diterpenoid components: pimelotide C, pimelotide A, simplexin, and 6α,7α-epoxy-5β-hydroxy-12-deoxyphorbol-13-decanoate in the buds of Wikstroemia chamaedaphne was established using macroporous resin chromatography. The adsorption and desorption rates of seven macroporous resins were compared using static tests. The D101 macroporous resin exhibited the best performance. Static and dynamic adsorption tests were performed to determine the enrichment and purification of important bioactive diterpenoids in the buds of W. chamaedaphne. Diterpenoid extracts were obtained by using D101 macroporous resin from the crude extracts of W. chamaedaphne. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis demonstrated that most of the diterpenoids were enriched in diterpenoid extracts. These results confirmed that diterpenoids in the buds of W. chamaedaphne could be enriched using macroporous resin technology, and the enriched diterpenoid extracts showed more efficient activation of the latent human immunodeficiency virus. This study provides a novel strategy for discovering efficient and low-toxicity latency-reversing agents and a potential basis for the comprehensive development and clinical application of the buds of W. chamaedaphne.

Analysis of Chemical Constituents of Miao Ethnomedicine Heiguteng Zhuifeng Huoluo Capsule (HZFC) and the Discovery of Active Substances in the Treatment of Rheumatoid Arthritis

In this study, the chemical substances of Heiguteng Zhuifeng Huoluo Capsule (HZFC) and its potential active ingredients for the treatment of rheumatoid arthritis (RA) were characterized and analyzed by medicinal chemistry combined with bioinformatics methods. Also, the potential active ingredients of HZFC against RA were verified by lipopolysaccharide (LPS)-induced macrophage activation model. The results showed that 79 chemical constituents were successfully identified, mainly including phenylpropanoids, flavonoids, and alkaloids. Among them, 13 active components were closely related to the nine core targets (FASN, ALOX5, EGFR, MMP1, CYP2D6, CNR1, AR, MAOA, and FKBP5) of HZFC in the treatment of RA. Molecular docking further proved that 13 active components had strong docking activity with 9 core targets. In the verification experiment of the LPS-induced RAW 264.7 macrophage model, the verified components (magnoflorine, N-feruloyltyramine, canadine, rutin, quercetin-3-O-glucoside, and pseudocolumbamine) all showed a clear inhibitory effect on the secretion of inflammatory factors in model cells. The above research results suggest that 13 components such as stepharanine, rutin, quercetin-3-O-glucoside, corydine methyl ether, canadine, 8-oxoepiberberine, disinomenine, deosinomenine glucoside, tuduranine, magnoflorine, isosinomenine, pseudocolumbamine, and N-feruloyltyramine may be the main active substances of HZFC in the treatment of RA.

Investigation of the Mechanism of Action of Periploca forrestii Schltr. Extract on Adjuvant Collagen Rats Based on UPLC-Q-Orbitrap-HRMS Non-Targeted Lipidomics

Periploca forrestii Schltr. (P. forrestii) is a classical medicinal plant and is commonly used in traditional medicine for the treatment of rheumatoid arthritis, soft tissue injuries, and traumatic injuries. The aim of this study was to evaluate the anti-arthritic effects of three fractions of P. forrestii alcoholic extracts (PAE), P. forrestii water extracts (PWE), and total flavonoids from P. forrestii (PTF) on Freund's complete adjuvant (FCA)-induced arthritis in rats, and to use a non-targeted lipidomic method to investigate the mechanism of action of the three fractions of P. forrestii in the treatment of rheumatoid arthritis. To assess the effectiveness of anti-rheumatoid arthritis, various indicators were measured, including joint swelling, histopathological changes in the joints, serum cytokines (tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6)), and the joint inflammatory substance prostaglandin E2 (PGE2). Finally, ultra-performance liquid chromatography-quadrupole-orbitrap-high-resolution mass spectrometry (UPLC-Q-Orbitrap-HRMS) was used to determine the non-targeted lipid histology of the collected rat serum and urine samples to investigate the possible mechanism of action. PWE, PAE, and PTF were all effective in treating FCA-induced rheumatoid arthritis. The administered groups all reduced joint swelling and lowered serum inflammatory factor levels in rats. In the screening of lipid metabolite differences between serum and urine of the rat model group and the normal group, a total of 52 different metabolites were screened, and the levels of lipid metabolites in PWE, PAE, and PTF were significantly higher than those in the normal group after administration. In addition, PWE, PAE, and PTF may have significant therapeutic effects on FCA-induced arthritis by modulating nicotinic acid, nicotinamide, and histidine metabolic pathways.

In vitro acetylcholinesterase, tyrosinase inhibitory potentials of secondary metabolites from Euphorbia schimperiana and Euphorbia balsamifera

Acetylcholinesterase, tyrosinase, and α-glucosidase inhibition activities of Euphorbia schimperiana and Euphorbia balsamifera extracts, fractions, and available pure compounds were evaluated for the first time. Acetylcholinesterase assay revealed a significant inhibitory activity of E. balsamifera total extract and n-hexane fraction with 47.7% and 43.3%, respectively, compared to the reference drug, which was 75%. The n-butanol fraction demonstrated tyrosinase inhibitory activity for E. balsamifera and E. schimperiana with 36.7% and 29.7%, respectively, compared to 60% for the reference drug. Quercetin-3-O-α-glucuronide, quercetin-3-O-β-D-glucuronide-methyl ester, quercetin-3-O-α-L-rhamnoside, 3,3′-di-O-methyl ellagic acid, 3,3′-di-O-methyl-ellagic acid-4-β-D-xylopyranoside, and 4-O-ethyl gallic acid were identified from E. schimperiana while quercetin-3-O-glucopyranoside and isoorientin were determined from E. balsamifera. The AChE inhibitory effect of pure compounds exhibited promising activity, where 4-O-ethylgallic acid demonstrated 51.1%, while the highest tyrosinase inhibition was demonstrated by isoorientin with 50.6% compared to the reference drug (60%). Finally, a molecular docking study was performed for the most promising AChE and tyrosinase inhibitors. The extracts, fractions, and isolated compounds showed no α-glucosidase inhibitory activity.

A review on traditional usages, chemical constituents and pharmacological activities of periploca forrestii schltr

ETHNOPHARMACOLOGICAL RELEVANCE

Periploca forrestii Schltr. was listed as a classical medicinal plant in "Miao medicine", which is a branch of traditional Chinese medicine (TCM). According to the theory of TCM, P. forrestii has the efficacy of relaxing tendons and activating collaterals, and dispelling wind and eliminating dampness. Hence, it was often used for the therapy of rheumatoid arthritis and traumatic injury in clinical practice.

AIMS OF THE REVIEW

This review aims to present comprehensive information for the research progress of P. forrestii. The researches on botany, traditional uses, phytochemistry, pharmacology and toxicology of the plant are summarized. We mainly focus on the phytochemical and pharmacological investigations. As a representative class of phytochemicals in P. forrestii, more attention is paid to cardiac glycosides. The insights into potential action of mechanisms and possible future studies on P. forrestii are also discussed.

MATERIALS AND METHODS

Relevant literature was acquired from scientific databases including Google Scholar, Web of Science, Scifinder, Baidu Scholar, PubMed and Chinese national knowledge infrastructure. Monographs and Chinese pharmacopoeia were also utilized as references.

RESULTS

To date, all kinds of phytochemical constituents have been isolated and identified from this plant including cardiac glycosides, steroids, terpenoids, flavonoids, phenylpropanoids, quinones, organic phenolic acids and others. Among these, cardiac glycosides were considered as the major ingredients and bioactive materials. Modern pharmacological studies demonstrated that the plant possessed extensive bioactivity, such as anti-inflammatory and analgesic effects, immunosuppressive action, wound healing activity, antioxidant, anti-tumor and, cardiotonic properties.

CONCLUSIONS

As an important medicinal plant, lots of studies have proved that P. forrestii has significant therapeutical effects, especially on rheumatoid arthritis and traumatic injury. These results provide modern scientific evidence for traditional use and contribute to the development of novel remedies for chronic diseases. However, the exact mechanism of action remains to be elucidated. Furthermore, the long-term in vivo toxicity and clinical efficacy also require in-depth exploration in the future.

A simple and effective method for the preparation of high-purity shikimic acid from chromatography wash effluent of Ginkgo biloba leaf extract by macroporous resin considering the effect of varying feed solution compositions

OBJECTIVES

The present study investigated the feasibility of preparing high-purity shikimic acid (SA) from the chromatography wash effluent of Ginkgo biloba leaf extract by macroporous resin.

METHODS

First, static/dynamic adsorption and desorption were conducted to screen out the optimal resin. Second, the key parameters of the chromatographic process were optimised with face-centred central composite design (CCD). Third, wash effluent indices were measured, different batches of wash effluent were used to prepare SA under the optimised parameters, and the effect of varying feed solution compositions on final products was investigated.

KEY FINDINGS

It was found that the final purity and recovery rate of SA prepared with ADS-21 resin were not lower than 70 and 60%, respectively, when the purity of SA in the wash effluent was higher than 21.4%. The quality of the final product can be predicted based on the properties of wash effluent.

CONCLUSIONS

The proposed method could not only provide a simple, green and promising approach for the large-scale purification of SA from wash effluent but also be used to develop process intermediate quality standards for other natural products.

Chromatographic identification of "green capping agents" extracted from Nasturtium officinale (Brassicaceae) leaves for the synthesis of MoO3 nanoparticles

A low-temperature, efficient and effective method was investigated for phytochemical hydroethanolic extraction of Nasturtium officinale (Brassicaceae). The phytocompounds of the selected plant leaves were identified by high-performance liquid chromatography, gas chromatography with mass spectroscopy, Fourier transform infrared spectroscopy, and ultraviolet-visible spectroscopy. Acetic acid, d-alanine, octodrine, decanoic acid, and cyclohexylethylamine were the major phytocompounds identified in N. officinale leaves with high similarity match and spectral purity. The reducing and stabilizing potential of the extracted phytochemicals was demonstrated by synthesizing the metal oxide nanoparticles (MoO₃ ) by treating ammonium heptamolybdate tetrahydrate (H₄ MO₇ N₆ O₂₄ .4H₂ O) aqueous complex with bioactive compounds of the leaves. The bio-synthesized MoO₃ nanoparticles were characterized by ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, energy dispersive X-ray spectroscopy, field emission-scanning electron microscopy, and gas chromatography with mass spectroscopy. Gas chromatography-mass spectroscopy identified acetic acid, d-alanine, and octodrine as stabilizing agents in the synthesis of MoO₃ nanoparticles.

Combined chromatographic strategy based on macroporous resin, high-speed counter-current chromatography and preparative HPLC for systematic separation of seven antioxidants from the fruit of Terminalia billerica

In the present study, combined chromatographic strategy based on macroporous resin, high-speed counter-current chromatography and preparative high-performance liquid chromatography for systematic separation of antioxidants from crude samples guided by high-performance liquid chromatography with 1,1-diphenyl-2-picrylhydrazyl has been successfully established. Based on this strategy, seven antioxidants including isorugosin A, _β -1,2,3,6-tetragalloyl-D-glucose, chebulinic acid, 1,2,3,4,6-penta-O-galloyl-_β -D-glucose, chebulagic acid, ethyl gallate, and gallic acid were obtained from the fruit of Terminalia billerica. First, high-performance liquid chromatography with 1,1-diphenyl-2-picrylhydrazyl experiment showed the presence of seven main antioxidants in the crude extract of the fruit of Terminalia billerica. Then, a macroporous resin column chromatography method was developed for the enrichment of these seven antioxidants. Finally, an efficient method based on high-speed counter-current chromatography and preparative high-performance liquid chromatography was developed for the separation of these antioxidants. In the selection of solvent systems, it was found that acetic acid could be a good regulator for modifying the partition coefficient values of tannins. The present study provides a reference for systematic separation of antioxidants from crude samples. Considering the general existence of antioxidants in crude samples, this combined chromatographic strategy might lead to broader application prospects.

Genus Periploca (Apocynaceae): A Review of Its Classification, Phytochemistry, Biological Activities and Toxicology

The genus Periploca belongs to the family Apocynaceae, which is composed of approximately ten species of plants according to incomplete statistics. Most of these plants serve as folk medicines with a long history, especially Periploca sepium and Periploca forrestii. The botanical classifications, chemical constituents, biological activities and toxicities of the genus Periploca were summarized in the literature from 1897 to early 2019. Though the botanical classification of this genus is controversial, these species are well-known to be rich sources of diverse and complex natural products-above all, cardiac steroids and C₂₁ pregnane steroids with special structures and obvious pharmacological activities. The various crude extracts and 314 isolated metabolites from this genus have attracted much attention in intensive biological studies, indicating that they are equipped with cardiotonic, anti-inflammatory, immunosuppressive, antitumor, antimicrobial, antioxidant, insecticidal and other properties. It is noteworthy that some cardiac glycosides showed hepatotoxicity and cardiotoxicity at certain doses. Therefore, in view of the medical and agricultural value of the genus Periploca, in-depth investigations of the pharmacology in vivo, the mechanisms of biological actions, and the pharmacokinetics of the active ingredients should be carried out in the future. Moreover, in order to ensure the safety of clinical medication, the potential toxicities of cardiac glycosides or other compounds should also be paid attention. This systematic review provides an important reference base for applied research on pharmaceuticals and pesticides from this genus.