Kadsuracoccinic acids A-C, ring-A seco-lanostane triterpenes from Kadsura coccinea and their effects on embryonic cell division of Xenopus laevis

Insights into Arsenic Secondary Metabolism in Actinomycetes from the Structure and Biosynthesis of Bisenarsan

The unique bioactivities of arsenic-containing secondary metabolites have been revealed recently, but studies on arsenic secondary metabolism in microorganisms have been extremely limited. Here, we focused on the organoarsenic metabolite with an unknown chemical structure, named bisenarsan, produced by well-studied model actinomycetes and elucidated its structure by combining feeding of the putative biosynthetic precursor (2-hydroxyethyl)arsonic acid to Streptomyces lividans 1326 and detailed NMR analyses. Bisenarsan is the first characterized actinomycete-derived arsenic secondary metabolite and may function as a prototoxin form of an antibacterial agent or be a detoxification product of inorganic arsenic species. We also verified the previously proposed genes responsible for bisenarsan biosynthesis, especially the (2-hydroxyethyl)arsonic acid moiety. Notably, we suggest that a C-As bond in bisenarsan is formed by the intramolecular rearrangement of a pentavalent arsenic species (arsenoenolpyruvate) by the cofactor-independent phosphoglycerate mutase homologue BsnN, that is entirely distinct from the conventional biological C-As bond formation through As-alkylation of trivalent arsenic species by S-adenosylmethionine-dependent enzymes. Our findings will speed up the development of arsenic natural product biosynthesis.

Effects of simulated in vitro gastrointestinal digestion on antioxidant activities and potential bioaccessibility of phenolic compounds from K. coccinea fruits

The changes of bioactive substances in peels and sarcocarps of three different varieties of Kadsura coccinea (Dahong, Fenhong, and Zihei) were evaluated by an in vitro simulation model. In this study, three varieties of K. coccinea fruits were digested in vitro to compare the changes and differences in antioxidant activity (DPPH, ABTS, FRAP) and bioaccessibility. The results showed that before digestion the highest content of total phenolics (TPC) (2.265 ± 0.127 mg GAE/g DW) and the highest content of flavonoids contents (TFC) (10.379 ± 0.093 mg GAE/g DW) were found in Fenhong fruit. The highest release of TPC and TFC after simulated gastric digestion was observed in the Dahong and Zihei sarcocarp, which increased by 98.7 and 20%, respectively. During oral and intestinal digestion, the content of bioactive compounds showed a decreasing trend. The radical scavenging ability of 1, 1-diphenyl-2-picrylhydrazyl (DPPH), [2,2-azino-bis(3-ethylbenzothiazoline) (ABTS)] sulfonic acid free radical scavenging ability, and ferric ion reducing antioxidant power (FRAP) results showed that the antioxidant capacity of K. coccinea fruits increased most significantly (26.9∼181%) in gastric digestion stage and then decreased after intestinal digestion stage. The recoveries of TPC and TFC were all increased after whole simulated digestion, as well as their bioaccessibility in sarcocarps was higher than those in peels, especially for the bioaccessibility of TPC and TFC in Dahong reached 50.53 and 48.19%, respectively. These results indicated that the peel and sarcocarp of K. coccinea had good antioxidant activity, with high bioaccessibility of phenolics could be a promising antioxidant source for the food industry.

Anti-RAFLS Triterpenoids and Hepatoprotective Lignans From the Leaves of Tujia Ethnomedicine Kadsura heteroclita (Xuetong)

A pair of 3,4-seco-cycloartane triterpenoid isomers with a rare peroxy bridge, namely, xuetonins A and B (1 and 2), four new lignans xuetonlignans A–D (3–6), a new sesquiterpene xuetonpene (7), and a new natural product xuetonin C (8), along with 43 known compounds, were obtained from the leaves of Tujia ethnomedicine, Kadsura heteroclita. Their structures and configurations were determined with the help of a combination of 1D- and 2D-NMR, HRESIMS spectra, electronic circular dichroism (ECD), and X-ray diffraction data. Compounds 2, 10, 13–15, and 17–19 showed moderate-to-potent activity against rheumatoid arthritis fibroblast-like synoviocytes (RAFLS) with IC₅₀ values of 19.81 ± 0.26, 12.73 ± 0.29, 5.70 ± 0.24, 9.25 ± 0.79, 5.66 ± 0.52, 11.91 ± 0.44, 13.22 ± 0.27, and 15.94 ± 0.36 μM, respectively. Furthermore, compounds 22, 25, and 31 exhibited significant hepatoprotective effects against N-acetyl-p-aminophenol (APAP)–induced toxicity in HepG2 cells at 10 μM, and the cell viability increased by 12.93, 25.23, and 13.91%, respectively, compared with that in the model group (cf. bicyclol, 12.60%).

Triterpenoids From Kadsura coccinea With Their Anti-inflammatory and Inhibited Proliferation of Rheumatoid Arthritis-Fibroblastoid Synovial Cells Activities

One new 3,4-seco-17,13-friedo-lanostane triterpenoid heilaohuacid A (1), one new 3,4-seco-17,14-friedo-lanostane triterpenoid heilaohuacid B (2), five new 3,4-seco-lanostane triterpenoids heilaohuacids C-D (3–4) and heilaohumethylesters A-C (7–9), one new 3,4-seco-cycloartane triterpenoid heilaohuacid E (5), and one new intact-lanostane triterpenoid heilaohuacid F (6), together with twenty-two known analogues (10–31), were isolated from heilaohu. Their structures were determined using HR-ESI-MS data, 1D and 2D NMR spectra, ¹³C NMR calculations, and electronic circular dichroism (ECD) calculations. Heilaohuacids A and B (1 and 2) contain a 3,4-seco ring A and unprecedented migration of Me-18 from C-13 to C-17 or C-14 to C-18. This type of lanostane triterpenoid derivatives was rarely reported so far. More importantly, all compounds against inflammatory cytokines IL-6 and TNF-α levels on LPS-induced RAW 264.7 macrophages were evaluated, and compounds 4 and 31 significantly inhibited the release level of IL-6 with IC₅₀ values of 8.15 and 9.86 μM, respectively. Meanwhile, compounds 17, 18, and 31 significantly inhibited proliferation of rheumatoid arthritis-fibroblastoid synovial (RA-FLS) cells in vitro with IC₅₀ values of 7.52, 8.85, and 7.97 μM, respectively.

Chemical Composition and Biological Activities of Essential Oils from the Leaves, Stems, and Roots of Kadsura coccinea

The chemical composition and biological activities of the essential oils from the leaves, stems, and roots of Kadsura coccinea (K. coccinea) were investigated. The essential oils were extracted by hydro distillation and analyzed by gas chromatography mass spectrometry (GC-MS) and gas chromatography with flame ionization detector (GC-FID). Antioxidant activities of the essential oils were examined with DPPH radical scavenging assay, ABTS cation radical scavenging assay, and ferric reducing antioxidant power assay. Antimicrobial activities were evaluated by determining minimum inhibitory concentrations (MIC) and minimum microbiocidal concentrations (MMC). Acetylcholinesterase and butyrylcholinesterase inhibitory activity of the essential oils were also tested. A total of 46, 44, and 47 components were identified in the leaf, stem, and root oils, representing 95.66%, 97.35%, and 92.72% of total composition, respectively. The major compounds of three essential oils were α-pinene (16.60-42.02%), β-pinene (10.03-18.82%), camphene (1.56-10.95%), borneol (0.50-7.71%), δ-cadinene (1.52-7.06%), and β-elemene (1.86-4.45%). The essential oils were found to have weak antioxidant activities and cholinesterase inhibition activities. The essential oils showed more inhibitory effects against Staphylococcus aureus (S. aureus) than those of other strains. The highest antimicrobial activity was observed in the root oil against S. aureus, with MIC of 0.78 mg/mL. Therefore, K. coccinea essential oils might be considered as a natural antibacterial agent against S. aureus with potential application in food and pharmaceutical industries.

Anti-gastric cancer activity and mechanism of natural compound "Heilaohulignan C" isolated from Kadsura coccinea

In this research, we analyzed the antitumor activity of one new compound Heilaohulignan C (B-6) on the human gastric carcinoma cells. MTT, cell migration, Calcein AM/Propidium Iodide (PI), and flow cytometry in BGC-823 cell line (gastric tumor). Western blot was utilized to distinguish the protein level. Xenografts nude mice were used for in vivo anticancer analysis. H&E staining and laboratory investigation was accomplished for toxicity study. MTT test demonstrated the cytotoxicity of BGC-823 cells, Calcein AM/Propidium Iodide (PI) examine indicated increment dead cells proportion with a high dose of B-6, Flow cytometry (FACS) measure showed that B-6 influenced gastric cancer cells by initiating apoptosis. Western blot analysis confirmed that (B-6) decrease the level of Bcl-2 and increase the level of p53, Bax, and cleaved Caspase-3, this confirms that the B-6 doing the apoptosis through caspase and cytochrome C apoptotic pathways. Also, B-6 particularly decline the tumor volume and tumor size in the xenograft mice. H&E staining additionally supports that B-6 does not have any toxic impact on the normal tissues. This research supports that B-6 have pharmacological activity against gastric cancer, by p53 and mitochondrial dependent apoptotic pathway, and have no toxicity on normal tissues.

Calendula officinalis Triterpenoid Saponins Impact the Immune Recognition of Proteins in Parasitic Nematodes

The influence of triterpenoid saponins on subcellular morphological changes in the cells of parasitic nematodes remains poorly understood. Our study examines the effect of oleanolic acid glucuronides from marigold (Calendula officinalis) on the possible modification of immunogenic proteins from infective Heligmosomoides polygyrus bakeri larvae (L3). Our findings indicate that the triterpenoid saponins alter the subcellular morphology of the larvae and prevent recognition of nematode-specific proteins by rabbit immune-IgG. TEM ultrastructure and HPLC analysis showed that microtubule and cytoskeleton fibres were fragmented by saponin treatment. MASCOT bioinformatic analysis revealed that in larvae exposed to saponins, the immune epitopes of their proteins altered. Several mitochondrial and cytoskeleton proteins involved in signalling and cellular processes were downregulated or degraded. As possible candidates, the following set of recognised proteins may play a key role in the immunogenicity of larvae: beta-tubulin isotype, alpha-tubulin, myosin, paramyosin isoform-1, actin, disorganized muscle protein-1, ATP-synthase, beta subunit, carboxyl transferase domain protein, glutamate dehydrogenase, enolase (phosphopyruvate hydratase), fructose-bisphosphate aldolase 2, tropomyosin, arginine kinase or putative chaperone protein DnaK, and galactoside-binding lectin. Data are available via ProteomeXchange with identifier PXD024205.

Discovery of cyclooxygenase-2 inhibitors from Kadsura coccinea by affinity ultrafiltration mass spectrometry and the anti-inflammatory activity

The medicinal plant Kadsura coccinea distributing in South China, was widely used for reducing inflammation and relieving pain. Previous study in our laboratory had proved the significant therapeutic effects of K. coccinea extract on adjuvant arthritis rats. To explore the responsible components and possible mechanisms, an AUF-HPLC-Q-TOF/ MS method was employed for screening and characterizing COX-2 ligands from K. coccinea stems for the first time. Meanwhile, the molecular docking was performed to simulate the binding modes for ligands and COX-2, the cell-free enzyme activity assay was applied to verify the direct COX-2 inhibition of potential inhibitors, and the cell-based study on COX-2 expression was to evaluate the anti-inflammatory effect of (+)-Anwulignan. As a result, the potential COX-2 inhibitor (+)-Anwulignan significantly suppressing COX-2 expressions in LPS signaling pathways might be a good candidate for anti-inflammation and analgesia. In conclusion, AUF mass spectrometry combining the molecular docking and bioassays in vitro was an efficient approach for discovering enzyme inhibitors from traditional herbs.

Kadsura coccinea: A rich source of structurally diverse and biologically important compounds

Kadsura coccinea belongs to medicinally important genus Kadsura from the Schisandraceae family. It has been used in traditional Chinese medicine (TCM) for the treatment of rheumatoid arthritis and gastroenteric disorders. The initial phytochemical work focused on the identification of some structurally novel and diverse natural products, which turned the attention of many researchers towards this plant. Thus far, 202 compounds have been reported in this plant. Lignans and terpenoids were found as the main chemical constituents of this plant. Some of the triterpenoids and sesquiterpenoids with novel structures are of particular interest for natural product researchers. The isolated compounds of this plant have shown different bioactivities including anti-tumor, anti-HIV, anti-inflammatory, nitric oxide (NO) production inhibitory and other pharmacological effects. This review systematically summarizes all the phytochemical and pharmacological work done so far on K. coccinea, and can be used as a reference for future research on this plant.

Chemical constituents from the roots of Kadsura coccinea with their protein tyrosine phosphatase 1B and acetylcholinesterase inhibitory activities

Kadsura coccinea (Lem.) A. C. Smith has been used as a tonic, decongestant, and digestive agent. The roots are also employed in traditional medicine to treat chronic enteritis, acute gastritis, duodenal ulcers, rheumatic pain in bone, and traumatic injuries. In the present study, we have described the biological evaluation of constituents from the roots of K. coccinea with PTP1B and AChE inhibitory activities for the first time in literature. A new compound (1), kadcoccilactone T, and 24 known ones (2‒25) were isolated and identified using spectroscopic methods. All the isolates were examined for PTP1B and AChE inhibitory activities. Compounds 4 and 8 expressed strong PTP1B inhibition with IC₅₀ values of 1.57 ± 0.11 and 3.99 ± 1.08 μM, respectively. Apparently, these compounds were further studied for PTP1B enzyme kinetic analysis. The result indicated that compounds 4 and 8 exhibited mixed-type inhibition with the Κ_i values of 4.97 and 3.26 µM, respectively.

A naturally occuring triterpene saponin ardisiacrispin B displayed cytotoxic effects in multi-factorial drug resistant cancer cells via ferroptotic and apoptotic cell death

INTRODUCTION

Multidrug resistance of cancer cells constitutes a serious problem in chemotherapy and a challenging issue in the discovery of new cytotoxic drugs. Many saponins are known to display anti-cancer effects. In this study, the cytotoxicity and the modes of action of a naturally occuring oleanane-type tritepene saponin, ardisiacrispin B isolated from the fruit of Ardisia kivuensis Taton (Myrsinaceae) was evaluated on a panel of 9 cancer cell lines including various sensitive and drug-resistant phenotypes.

METHODS

Resazurin reduction assay was used to evaluate cytotoxicity and ferroptotic cell death of samples; caspase-Glo assay was used to detect the activation of caspases in CCRF-CEM leukemia cells. Flow cytometry was used for cell cycle analysis and detection of apoptotic cells by annexin V/PI staining, analysis of mitochondrial membrane potential (MMP) and measurement of reactive oxygen species (ROS).

RESULTS

Ardisiacrispin B displayed significant cytotoxic effects in the 9 tested cancer cell lines with IC₅₀ values below 10 µM. The IC₅₀ values ranges were 1.20 µM (towards leukemia CCRF-CEM cells) to 6.76 µM [against heptocarcinoma HepG2 cells] for ardisiacrispin B and 0.02 µM (against CCRF-CEM cells) to 122.96 µM (against resistant CEM/ADR5000 leukemia cells) for doxorubicin. Collateral sensitivity of resistant HCT116p53^-/- colon adenocarcinoma cells to ardisiacripsin B was observed. Ardisiacrispin B induced apoptosis in CCRF-CEM cells via activation of inititator caspases 8 and 9 and effector caspase 3/7, alteration of MMP and increase in ROS production. Ferroptosis also contributed to the cytotoxicity of ardisiacrispin B.

CONCLUSIONS

The studied oleanane-type triterpene saponin is a good cytotoxic molecule that deserve more detailed exploration in the future, to develop novel cytotoxic drugs to combat both sensitive and drug-resistant cancers.

Chemical Compounds in Natural Medicines That Affect Macropharges and Adipocyte Cells

Macrophages play major roles in inflammation, immunity and host defense mechanisms. Once activated they produce and release cytokines, oxygen and nitrogen species, and eicosanoids. The best characterized stimuli to induce the transcription of genes encoding pro-inflammatory proteins in macrophages in vitro is bacterial lipopolysaccharide (LPS). LPS could be used alone or in combination with recombinant mouse interferon-γ (IFN-γ). Such stimulation results in cytokine release and the synthesis of enzymes such as cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). The nitric oxide (NO) radical is known to play a central role in inflammatory and immune reactions for self-protection. However, the excessive production of NO may lead to tissue damage. In inflammatory diseases such as rheumatoid arthritis, excessive NO production by activated macrophages has been observed. Adipose tissue is composed of various cell types such as mature adipocytes, preadipocytes, fibroblasts, endothelial cells, vascular cells, and macrophages. Recent studies indicate that obesity is associated with low-grade chronic inflammation of adipose tissues, and that such inflammation is one of the potential mechanisms leading to the insulin resistance. It has been demonstrated that obese adipose tissue is characterized by the increased infiltration of macrophages. Therefore, we attempted to identify natural anti-inflammatory compounds that not only inhibit the secretion of NO from RAW 264.7 cells, but also inhibit triglyceride accumulation in 3T3-L1 adipocytes. This review describes the NO prpduction inhibitory activity or the TG accumulation inhibitory activity of the compounds obtained from 18 plants and a fungi that have been used as traditional medicines.

Pharmacokinetic study of ardisiacrispin A in rat plasma after intravenous administration by UPLC-MS/MS

In this work, a sensitive and selective UPLC-MS/MS method for determination of ardisiacrispin A in rat plasma was developed. Cyasterone used as an internal standard (IS) and protein precipitation by acetonitrile-methanol (9:1, v/v) was used to prepare samples. Chromatographic separation was achieved on a UPLC BEH C₁₈ column (2.1 × 100 mm, 1.7 μm) with 0.1% formic acid and acetonitrile as the mobile phase with gradient elution. An electrospray ionization source was applied and operated in positive ion mode; multiple reaction monitoring mode was used for quantification using target fragment ions m/z 1083.5 → 407.1 for ardisiacrispin A and m/z 521.3 → 485.2 for IS. Calibration plots were linear throughout the range 5-2000 ng/mL for ardisiacrispin A in rat plasma. Mean recoveries of ardisiacrispin A in rat plasma ranged from 80.4 to 92.6%. The values of RSD of intra- and inter-day precision were both <11%. The accuracy of the method was between 97.3 and 105.6%. The method was successfully applied to pharmacokinetic study of ardisiacrispin A after intravenous administration in rats.

Unusual cycloartane triterpenoids from Kadsura ananosma

Five 3,4-seco-cycloartane triterpenoids were isolated from the stems of Kadsura ananosma, two of which had rearranged 5/6 consecutive carbocycle rings C/D (trivially named ananosins A (1) and B (2)), one had a migrated CH3-18 (named ananosins C (3)), and two were analogs, ananosins D (4) and E (5). Their structures were characterized by comprehensive spectroscopic analysis, especially using 2D NMR spectra. A biogenetic pathway to 1 was proposed. These 5 compounds, together with 5 known analogs isolated from the same origin, were evaluated for their cytotoxicity against HL-60, SMMC-7721, A-549, PANC-1, and SK-BR-3 human cancer cells, but were inactive.

Triterpenoids from the Schisandraceae family: an update

Plants from the Schisandraceae family produce architecturally interesting triterpenoids, including lanostanes, cycloartanes, and schinortriterpenoids. This review focuses on their structures, classifications, biogenetic pathways, syntheses, and bioactivities (from February 2008 to May 2014).

Genus Kadsura, a good source with considerable characteristic chemical constituents and potential bioactivities

In China, the plants of genus Kadsura had been used as the folk medicines for a long time and showed good effect of activating blood and dissolving stasis, promoting qi circulation to relieve pain, dispelling wind and eliminating dampness. The bioactivities of genus Kadsura were attributed to the existence of its characteristic chemical constituents. This review systematically summarized the traditional efficacy and medicinal application of genus Kadsura in China, chemical constituents and bioactivities of the plants of genus Kadsura. And, lignans and triterpenoids were the main bioactive constituents, which exhibited good anti-HIV, anti-tumor, anti-hepatitis, anti-oxidant, anti-platelet aggregation activities and neuroprotective effect etc. Moreover, some structure-activity relationships mining would greatly enrich the opportunity of finding new and promising lead compounds and promote the reasonable development and utilization of the plants of genus Kadsura.

Triterpenes from Kadsura coccinea

In vitro anti-allergic screening of medicinal herbal extracts revealed that the 80% acetone extract of the rhizome of Kadsura coccinea inhibited nitric oxide (NO) production in a lipopolysaccharide (LPS) and recombinant mouse interferon-γ (IFN-γ) activated murine macrophage like cell line, RAW264.7. Further fractionation of the EtOAc extract led to the isolation of one new 3,4-seco-lanostane type triterpene named kadsuracoccin acid A (1) together with two known triterpenes anwuweizonic acid (2) and neokadsuranic acid B (3). Compounds 1−3 did not exhibit any inhibitory activities for NO production and IFN-γ activation.

Triterpenes from the fungus Poria cocos and their inhibitory activity on nitric oxide production in mouse macrophages via blockade of activating protein-1 pathway

Two new triterpenes, 29-hydroxydehydrotumulosic acid (1) and 29-hydroxydehydropachymic acid (2), together with six known compounds, dehydropachymic acid (3), dehydrotumulosic acid (4), 29-hydroxypolyporenic acid C (5), polyporenic acid C (6), tumulosic acid (7), and pachymic acid (8), were isolated from the dried sclerotia of Poria cocos. In the in vitro bioassays, these isolated compounds reduced, in a dose-dependent manner, nitric oxide (NO) production from lipopolysaccharide (LPS)-induced RAW 264.7 cells, with compounds 5 and 6, the IC(50) values of which were 16.8±2.7 and 18.2±3.3 μM, respectively, exhibiting the greatest inhibition activity. Further Western blot analysis conducted on cells pre-treated with compounds 5 and 6, and luciferase assays on activator protein 1-dependent gene expression revealed that the inhibited NO release was attributed to the reduced expression of iNOs (=inducible NO synthase) enzymes, which might be regulated via the blockade of activator protein-1 signaling pathway.

Ardisia: health-promoting properties and toxicity of phytochemicals and extracts

Ardisia species (Myrsinaceae) are found throughout tropical and subtropical regions of the world. Traditional medicinal uses attributed to Ardisia include alleviation of liver cancer, swelling, rheumatism, earache, cough, fever, diarrhea, broken bones, dysmenorrhea, respiratory tract infections, traumatic injuries, inflammation, pain, snake and insect bites, birth complications and to improve general blood circulation, among others. Ardisia species are rich in polyphenols, triterpenoid saponins, isocoumarins, quinones and alkylphenols. A summary of the uses, potential health benefits, adverse reactions and important bioactive phytochemicals isolated from the Ardisia species is presented. Future research needs to include more toxicological studies, more comprehensive chemical characterization of extracts, bioavailability, extract standardization, investigation of possible herb-drug interactions, plant improvement with regards to bioactivity and composition, and additional human and animal studies to confirm the health-promoting properties claimed for Ardisia species. The information presented here exemplifies the potential of Ardisia species as a source of chemotherapeutic, chemo-modulating and/or chemopreventive agents.

Cytotoxic triterpene dilactones from the stems of Kadsura ananosma

Six new triterpene dilactones with a rare rearranged pentacyclic skeleton, longipedlactones K-P (1-6), and seven known analogues (7-13) were isolated from the stems of Kadsura ananosma. Compound 1 was found to possess a unique peroxide bridge between C-1 and C-9 in rings A and B. The structures of these new compounds were established on the basis of spectroscopic data analysis, especially of their 2D NMR spectra. In the evaluation of the in vitro cytotoxicity of these compounds against a small panel of human cancer cell lines, compounds 3, 7, 9, and 13 were found to be the most potent against HL-60 acute leukemia cell.

Triterpenoids

This review covers the isolation and structure determination of triterpenoids including squalene derivatives, protostanes, lanostanes, holostanes, cycloartanes, dammaranes, euphanes, tirucallanes, tetranortriterpenoids, lupanes, oleananes, friedelanes, ursanes, hopanes, isomalabaricanes and saponins; 574 references are cited.