[Chemical constituents from Clitocybe clavipes and their antitumor activities].

This paper aimed to study the chemical constituents from Clitocybe clavipes. Silica gel, ODS, Sephadex LH-20, and semi-p reparative HPLC were employed to separate the ethanol extract of C. clavipes. Six compounds were identified by ~1H-NMR, ~(13)CNMR,and ESI-MS as clavilactone L(1), clavilactone A(2), clavilactone B(3), clavilactone E(4), clavilactone H(5), and clav ilactone I(6). Among them, compound 1 was a new meroterpenoid with a 10-membered carbocycle connected to a hydroquinone. Theantitumor activities of compounds 1-6 were determined by the methyl thiazolyl tetrazolium(MTT) ass ay. The results showed that compounds 1-6 exerted inhibitory effects on the proliferation of human gastric cancer cells(MGC-803),human non-small cell lung cancer cells(A549), and cervical cancer cells(HeLa). Compound 1 exhibited significant inhibitory activity against MGC-803 cells, with the half maximal inhibitory concentration(IC_(50)) of 11. 76 µmol·L~(-1).

Three new triterpenoid glycosides from Aronia melanocarpa (Michx.) Elliott.

Three new triterpenoid glycosides, 2α,3α,23,24-tetrahydroxyurs-12,19- dien-oic acid 28-O-ß- D -glucopyranoside (1), 2α,3ß,23,24-tetrahydroxyurs-12, 19(29) -dien-28-oic acid 28-O-ß- D -glucopyranoside (2), and 2α,3ß,23,24-tetrahydroxyurs-12, 18-dien-28-oic acid 28-O-ß- D -glucopyranoside (3) were isolated from Aronia melanocarpa (Michx.) Elliott. Their structures were elucidated by extensive spectroscopic methods. All the isolated compounds displayed moderate inhibitory activity against nitric oxide production in macrophages.

Three new compounds with their anti-glioma effects from the roots of Arnebia guttata Bunge.

Three new compounds, arneatas A-C (1-3), together with three known compounds (4-6) were isolated from the roots of Arnebia guttata Bunge. The structures were established on the basis of extensive spectroscopic data including NMR and HRESIMS. All the new compounds (1-3) were tested for their cytotoxic activity against two glioma cell lines (U118-MG and U373-MG) in vitro after treatment for 48 h. Compound 1 exhibited moderate cytotoxic activity against U118-MG and U373-MG glioma cell lines, with IC50 values of 10.4 and 17.5 µM, respectively.

Faecalibacterium prausnitzii Attenuates CKD via Butyrate-Renal GPR43 Axis.

BACKGROUND: Despite available clinical management strategies, chronic kidney disease (CKD) is associated with severe morbidity and mortality worldwide, which beckons new solutions. Host-microbial interactions with a depletion of Faecalibacterium prausnitzii in CKD are reported. However, the mechanisms about if and how F prausnitzii can be used as a probiotic to treat CKD remains unknown. METHODS: We evaluated the microbial compositions in 2 independent CKD populations for any potential probiotic. Next, we investigated if supplementation of such probiotic in a mouse CKD model can restore gut-renal homeostasis as monitored by its effects on suppression on renal inflammation, improvement in gut permeability and renal function. Last, we investigated the molecular mechanisms underlying the probiotic-induced beneficial outcomes. RESULTS: We observed significant depletion of Faecalibacterium in the patients with CKD in both Western (n=283) and Eastern populations (n=75). Supplementation of F prausnitzii to CKD mice reduced renal dysfunction, renal inflammation, and lowered the serum levels of various uremic toxins. These are coupled with improved gut microbial ecology and intestinal integrity. Moreover, we demonstrated that the beneficial effects in kidney induced by F prausnitzii-derived butyrate were through the GPR (G protein-coupled receptor)-43. CONCLUSIONS: Using a mouse CKD model, we uncovered a novel beneficial role of F prausnitzii in the restoration of renal function in CKD, which is, at least in part, attributed to the butyrate-mediated GPR-43 signaling in the kidney. Our study provides the necessary foundation to harness the therapeutic potential of F prausnitzii for ameliorating CKD.

Abietane-Type Diterpenoids From Nepeta bracteata Benth. and Their Anti-Inflammatory Activity.

Terpenes possess a wide range of structural features and pharmaceutical activities and are promising for drug candidates. With the aim to find bioactive terpene molecules, eight new compounds were isolated from the medicinal plant Nepeta bracteata Benth., including seven new abietane-type diterpenoids (1-7), along with a new ursane-type triterpenoid (8). The structures of compounds 1-8 were elucidated through the detailed spectroscopic analyses of their 1D and 2D NMR and MS data, and the absolute configurations of compounds 1-7 were determined by comparing their experimental and calculated ECD spectra. Compound 1 was a novel degraded carbon diterpene with the disappearing of methyl signal at C-19, while compound 7 possessed a new norabietane-type diterpenoid carbon skeleton with the presence of five-membered lactone arising from ring rearrangement. The anti-inflammatory of all obtained isolates were evaluated on lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and the results of anti-inflammatory activity screening showed that compared with the LPS model group, all compounds were significantly down-regulation the TNF-α inflammatory factor at the specific concentration, except for compound 6.

Cadinane-type sesquiterpenoid dimeric diastereomers hibisceusones A-C from infected stems of Hibiscus tiliaceus with cytotoxic activity against triple-negative breast cancer cells.

Three new cadinane-type sesquiterpenoid dimeric diastereomers (1-3) named hibisceusones A-C were obtained from the infected stems of Hibiscus tiliaceus. The structures were determined by NMR spectroscopy and MS techniques, and the absolute configurations were assigned by ECD and single-crystal X-ray diffraction techniques. Compounds 1-3 are diastereomers, and contain a 1,4-dioxane ring linearly fused to different cadinane-type polycyclic skeletons. This is the first time that such a structure has been identified in natural products. Compounds 1-3 exhibited cytotoxic activities, and 2 showed a significantly high anti-triple-negative breast cancer (TNBC) effect. The anti-cancer effect of compound 2 was 3-4 fold higher than that of 1 and 3. The anti-cancer effect was generated via the induction of the apoptosis of the MDA-MB-231 cells by inhibiting the PI3Kα pathway.

Chloramphenicol-activated electro-chemiluminescent behavior of BNQDs-Ru(phen)32+ system for ultra-sensitive sensing of chloramphenicol in pharmaceutical and milk samples.

To improve the sensitivity for electro-chemiluminescent (ECL) detection of chloramphenicol (CAP), a common broad-spectrum antibiotic, boron nitride quantum dots (BNQDs) were prepared with excellent photoelectric property and low toxicity. After its structure and electrochemical property were investigated in detail, it was noted that the ECL signal of Ru(Phen)32+could be strengthened by the proposed BNQDs, which was further activated by ten's times in the presence of CAP. Under the optimized conditions, there was an excellent linear relationship between ΔECL and lgcCAPin a wide linear range from 1.0 × 10-10to 1.0 × 10-6mol l-1CAP. The detection limit was super-low to be 3.3 × 10-11mol l-1(S/N = 3). When applied for CAP detection in real pharmaceutical and food samples, the recoveries were between 97.8% and 105.7% with R.S.D. less than 3.3%. A possible CAP-activated ECL mechanism of BNQDs-Ru(phen)32+was also proposed. This work will offer a great potential for efficient monitoring of CAP pollution and clinical diagnosing of CAP-related diseases in future.

Chloramphenicol-activated electro-chemiluminescent behavior of BNQDs-Ru(phen)32+ system for ultra-sensitive sensing of chloramphenicol in pharmaceutical and milk samples.

To improve the sensitivity for electro-chemiluminescent (ECL) detection of chloramphenicol (CAP), a common broad-spectrum antibiotic, boron nitride quantum dots (BNQDs) were prepared with excellent photoelectric property and low toxicity. After its structure and electrochemical property were investigated in detail, it was noted that the ECL signal of Ru(Phen)32+ could be strengthened by the proposed BNQDs, which was further activated by ten's times in the presence of CAP. Under the optimized conditions, there was an excellent linear relationship between △ECL and lgcCAP in a wide linear range from 1.0×10-10 to 1.0×10-6 mol/L CAP. The detection limit was super-low to be 3.3×10-11 mol/L (S/N=3). When applied for CAP detection in real pharmaceutical and food samples, the recoveries were between 97.8 and 105.7 % with R.S.D. less than 3.3%. A possible CAP-activated ECL mechanism of BNQDs-Ru(phen)32+ was also proposed. This work will offer a great potential for efficient monitoring of CAP pollution and clinical diagnosing of CAP-related diseases in future.

Cadinane-Type Sesquiterpenoids with Cytotoxic Activity from the Infected Stems of the Semi-mangrove Hibiscus tiliaceus.

Eight new cadinane sesquiterpenoids (1-8), along with two known compounds (9 and 10), were isolated from infected stems of the semi-mangrove plant, Hibiscus tiliaceus. The structures of compounds 1-8 were elucidated through the analysis of their 1D and 2D NMR and MS data, and their absolute configurations were determined by comparing their experimental and calculated ECD spectra and by single-crystal X-ray diffraction. The two confused known compounds (9 and 10) were resolved using single-crystal X-ray crystallography. Compounds 1-3 have novel norsesquiterpene carbon skeletons arising from a ring contraction rearrangement. All obtained isolates were evaluated against the HepG2 and Huh7 cell lines, and compounds 1b, 2b, 4, 6, and 8 showed cytotoxic activity toward both cell lines, with IC50 values ranging from 3.5 to 6.8 µM.

Design and Development of Autotaxin Inhibitors.

Autotaxin (ATX) is the only enzyme of the ecto-nucleotide pyrophosphatase/phosphodiesterase (ENPP2) family with lysophospholipase D (lysoPLD) activity, which is mainly responsible for the hydrolysis of extracellular lysophosphatidylcholine (LPC) into lysophosphatidic acid (LPA). LPA can induce various responses, such as cell proliferation, migration, and cytokine production, through six G protein-coupled receptors (LPA1-6). This signaling pathway is associated with metabolic and inflammatory disorder, and inhibiting this pathway has a positive effect on the treatment of related diseases, while ATX, as an important role in the production of LPA, has been shown to be associated with the occurrence and metastasis of tumors, fibrosis and cardiovascular diseases. From mimics of ATX natural lipid substrates to the rational design of small molecule inhibitors, ATX inhibitors have made rapid progress in structural diversity and design over the past 20 years, and three drugs, GLPG1690, BBT-877, and BLD-0409, have entered clinical trials. In this paper, we will review the structure of ATX inhibitors from the perspective of the transformation of design ideas, discuss the advantages and disadvantages of each inhibitor type, and put forward prospects for the development of ATX inhibitors in the future.

A Review on Phytochemicals of the Genus Maytenus and Their Bioactive Studies.

The genus Maytenus is a member of the Celastraceae family, of which several species have long been used in traditional medicine. Between 1976 and 2021, nearly 270 new compounds have been isolated and elucidated from the genus Maytenus. Among these, maytansine and its homologues are extremely rare in nature. Owing to its unique skeleton and remarkable bioactivities, maytansine has attracted many synthetic endeavors in order to construct its core structure. In this paper, the current status of the past 45 years of research on Maytenus, with respect to its chemical and biological activities are discussed. The chemical research includes its structural classification into triterpenoids, sesquiterpenes and alkaloids, along with several chemical synthesis methods of maytansine or maytansine fragments. The biological activity research includes activities, such as anti-tumor, anti-bacterial and anti-inflammatory activities, as well as HIV inhibition, which can provide a theoretical basis for the better development and utilization of the Maytenus.

Amino acid ester-coupled caffeoylquinic acid derivatives as potential hypolipidemic agents: synthesis and biological evaluation.

Pandanus tectorius (L.) Parkins. (PTPs) is rich in caffeoylquinic acids and amino acids, especially some essential amino acids, such as valine, phenylalanine, and so forth. A series of novel amino acid ester-coupled caffeoylquinic acid derivatives have been designed and synthesized. Biological evaluation suggested that some amino acid ester-coupled derivatives exhibited varying degrees of lipid-lowering effects on oleic acid-elicited lipid accumulation in HepG2 liver cells. Particularly, derivatives 6c, 6d, 6e and 6f exhibited comparable potential lipid-lowering effect with the positive control simvastatin and chlorogenic acid. Further studies on the mechanism of 6c, 6d, 6e and 6f revealed that the lipid-lowering effects were related to their regulation of TG levels and mRNA levels of lipometabolic-modulating genes, and merit further investigation.

Recent advances in natural anti-HIV triterpenoids and analogs.

The human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) epidemic is one of the world's most serious health challenges. Although combination antiretroviral therapy provides effective viral suppression, current medicines used against HIV cannot completely eradicate the infectious disease and often have associated toxicities and severe side effects in addition to causing drug resistance. Therefore, the continued development of new antiviral agents with diverse structures and novel mechanisms of action remains a vital need for the management of HIV/AIDS. Natural products are an important source of drug discovery, and certain triterpenes and their analogs have demonstrated potential as pharmaceutical precursors for the treatment of HIV. Over the past decade, natural triterpenoids and analogs have been extensively studied to find new anti-HIV drugs. This review discusses the anti-HIV triterpenoids and analogs reported during the period of 2009-2019. The article includes not only a comprehensive review of the recent anti-HIV agent development from the perspective of medicinal chemistry, but also discusses structure-activity relationship analyses of the described triterpenoids.

Natural Nitrogenous Sesquiterpenoids and Their Bioactivity: A Review.

Nitrogenous sesquiterpenoids fromnatural sourcesare rare, so unsurprisingly neither the potentially valuable bioactivity nor thebroad structural diversity of nitrogenous sesquiterpenoids has been reviewed before. This report covers the progressduring the decade from 2010 to February 2020 on the isolation, identification, and bioactivity of 391 nitrogen-containing natural sesquiterpenes from terrestrial plant, marine organisms, and microorganisms. This complete and in-depth reviewshouldbe helpful for discovering and developing new drugs of medicinal valuerelated to natural nitrogenous sesquiterpenoids.

Five New Cucurbitane-Type Triterpenoid Glycosides from the Rhizomes of Hemsleya penxianensis with Cytotoxic Activities.

Five new cucurbitane-typetriterpenoid glycosides, named Xuedanoside F-J (1-5), were obtained from the rhizomes of Hemsleya penxianensis (Xue dan), which belongs to the family of Cucurbitaceae. These new compounds were elucidated byspectroscopic analysis, including 1D, 2D NMR, and HR-ESI-MS spectra. Additionally, all the isolates were evaluated for cytotoxicity against three human cancer cell lines (Hela, MCF-7, and A-549) with the IC50 ranging from 2.25 to 49.44 µM in vitro with treatment 48 h and showed low cytotoxicity in human normal liver L-02 cells (IC50 > 50 µM). Compound 5 showed the most significant cytotoxic activity with the IC50 value of 2.25, 4.72, and 5.33 µM in 48 h, respectively.

Synthesis and In Vitro Evaluation of Caffeoylquinic Acid Derivatives as Potential Hypolipidemic Agents.

A series of novel caffeoylquinic acid derivatives of chlorogenic acid have been designed and synthesized. Biological evaluation indicated that several synthesized derivatives exhibited moderate to good lipid-lowering effects on oleic acid-elicited lipid accumulation in HepG2 liver cells. Particularly, derivatives 3d, 3g, 4c and 4d exhibited more potential lipid-lowering effect than the positive control simvastatin and chlorogenic acid. Further studies on the mechanism of 3d, 3g, 4c and 4d revealed that the lipid-lowering effects were related to their regulation of TG levels and merit further investigation.

The clickable activity-based probe of anti-apoptotic calenduloside E.

CONTEXT: Calenduloside E (CE), one of the primary natural products found in Aralia elata (Miq.) Seem. (Araliaceae), possesses prominent anti-apoptotic potential. A previous study found that one of the anti-apoptotic CE targets is heat shock protein 90 AB1 (Hsp90AB1) by probe CE-P, while the other targets of CE still need to be identified with more efficient probes. OBJECTIVE: This study investigates CE analogue (CEA) as one clickable activity-based probe for use in exploring anti-apoptotic CE targets. MATERIALS AND METHODS: Pretreatment of HUVECs with CEA (1.25 µM) for 8 hr, followed by ox-LDL stimulation for 24 h. Flow cytometry analysis and JC-1 staining assays were performed The kinetic constant measurements were tested by the Biacore T200, CM5 Sensor Chip which was activated by using sulpho-NHS/EDC. Ligands were dissolved and injected with a concentration of 12.5, 6.25, 3.125, 1.56, 0.78 and 0 µM. RESULTS: CEA was confirmed to possess an anti-apoptotic effect. The probable targets of CE/CEA were calculated, and as one of the higher scores proteins (Fit values: 0.88/0.86), Hsp90 properly got our attention. Molecular modelling study showed that both CE and CEA could bind to Hsp90 with the similar interaction, and the docking scores (S value) were -7.61 and -7.33. SPR assay provided more evidence to prove that CEA can interact with Hsp90 with the KD value 11.7 µM. DISCUSSION AND CONCLUSIONS: Our results suggest that clickable probe CEA could alleviate ox-LDL induced apoptosis by a similar mechanism of anti-apoptotic CE, and afforded the possibility of identifying additional anti-apoptotic targets of CE.

A new bis-γ-pyrone polypropionate from a marine pulmonate mollusc Onchidium struma.

A new bis-γ-pyrone polypropionate compound onchidione II (1), together with three known compounds, was isolated from a marine pulmonate mollusc Onchidium struma, collected at Hainan Island of China. The structure of new compound was determined by extensive spectroscopic analyses including IR, 1D and 2D NMR techniques, and chemical methods. Compounds 1-4 were evaluated for their cytotoxicity against human tumor cell lines HepG-2, A549, and MCF-2. The results showed that compounds 1 and 2 were moderate cytotoxic against HepG-2, A549, and MCF-2 cell lines, with IC50 values from 13.2 to 22.4 µM.

A new cadinane sesquiterpenoid glucoside with cytotoxicity from Abelmoschus sagittifolius.

A new cadinane sesquiterpenoid glucoside, 2ß,7,3-trihydroxycalamenene 3-O-ß-d-glucoside (1) together with six known compounds, N-(p-trans-coumaroyl)-N-methyl tyramine (2), Cleomiscosin A (3), 9,12,13-trihydroxy-10,15-heptadecadienoic acid (4), Cytochalasin B (5), Marmesinin (6) and N-(p-trans-coumaroyl) tyramine (7) were obtained from the stem bark of Abelmoschus sagittifolius. The new structure of compound 1 was elucidated by analysing its 1H and 13C-NMR, 1H-1H COSY, HSQC, HMBC, NOESY and HR-ESI-MS spectra. Compounds 1-7 showed moderate cytotoxicity against Hela and HepG-2 human cancer cell lines.

[A new naphthalene derivative from bulbs of Eleutherine americana].

A new naphthalene derivative and three known compounds were isolated from the petroleum ether extract of the bulbs of Eleutherine americana by using various chromatographic techniques, such as column chromatography over silica gel and semi-preparative HPLC. Their structures were elucidated by spectroscopic date (MS, UV, IR, NMR), which were identified as eleutherol B (1), 4,8-dihydroxy-3-methoxy-1-methylanthraquinone-2-carboxylic acid methyl ester (2), 8-hydroxy-3,4-dimethoxy-1-methylanthraquinone-2-carboxylic acid methyl ester (3), and isoeleutherine (4). Compound 1 is a new compound. The diastolic blood vessels activity of compound 1 and 2 were potent, reaching 82.5% and 85.3% at the concentration of 10 µmol·L⁻¹, which were basically the same as that of the positive drug tanshinone ⅡA.