Artemisians A–D (1–4), the first examples of [4 + 2] Diels–Alder type adducts presumably biosynthesized from a rare 1, 10-4, 5-diseco-guaianolide and a guaianolide diene, along with their possible precursor 5, were isolated from the traditional Chinese medicine Artemisia argyi. The structures of 1–4 were elucidated by extensive spectroscopic analyses and calculated electronic circular dichroism. Compound 2, with an IC50 value of 3.21 μM, exhibited significant antiproliferative activity via apoptosis induction and G2/M arrest in MDA-MB-468 cells.

Targeting signal transducer and activator of transcription 3 (STAT3) is a potential anticancer strategy. However, STAT3 inhibitors with good selectivity and bioavailability are rare. The aim of this study was to discover selective direct STAT3 inhibitors with good druglikeness. By the advanced multiple ligand simultaneous docking (AMLSD) method, compound 9 was designed as an orally bioavailable STAT3 inhibitor that presented superior druggability and selectivity compared with other representative STAT3 inhibitors. 9 directly and selectively inhibited the pY705 site of STAT3 with an affinity (Ki) of 440 nM. The IC50 of 9 for MDA-MB-231 breast cancer cells was 184-fold lower than its IC50 for MCF-10A normal breast epithelial cells. 9 in vivo induced significant antitumor responses (better than gefitinib), and its therapeutic index should be over 100, indicating good safety of 9.

One new indoloditerpene, 6,7-dehydropaxilline (1), one new indole-diketopiperazine, spirotryprostatin F (2), and one new 13-membered macrolide, N-demethylmelearoride A (3), as well as 8 known alkaloids (4–11), were isolated from the solid cultures of the endophytic fungus, Penicillium brefeldianum. The structures and absolute configurations of compounds 1-3 were elucidated by comprehensive spectroscopic analysis and the circular dichroism (CD) exciton chirality method. All the metablites were evaluated for their cytotoxic activites against three human tumor cell lines. Compound 2 exhibited cytotoxicities against HepG2 and MDA-MB-231 cells with IC50 values of 14.1 μmol/L and 35.5 μmol/L, respectively. Compound 3 showed moderate activity against HepG2 cells with IC50 values of 36.6 μmol/L.Three new (1–3) and 8 known alkaloids were isolated from the cultures of an endophytic fungus Penicillium brefeldianum. The circular dichroism (CD) exciton chirality method was used to determine the absolute configurations of 1 and 2. These metablites showed different cytotoxic activites to three human tumor cell lines.Download high-res image (147KB)Download full-size image

Walsuronoid B is a limonoid compound extracted from Walsura robusta. Previous studies have shown that limonoid compounds possess anti-cancer potential, although the molecular mechanism of this activity remains elusive. In this study, we demonstrated for the first time that walsuronoid B inhibited cell proliferation in several human cancer lines. Liver cancer cells (HepG2 and Bel-7402) were chosen for their high sensitivity to walsuronoid B. Walsuronoid B induced cell death through G2/M phase arrest and apoptosis and induced the accumulation of autophagosomes through the suppression of mTOR signaling, which serves as a cell survival mechanism and prevents cell death. We further examined the molecular mechanisms and found that walsuronoid B-induced dysfunction of the mitochondria and lysosomes rather than the endoplasmic reticulum contributed to its cell death effect. Walsuronoid B enhanced the generation of hydrogen peroxide, nitric oxide and superoxide anion radical, resulting in elevated levels of reactive oxygen species (ROS). In addition, ROS induced by walsuronoid B upregulated p53 levels; conversely, p53 stimulated ROS. These results suggested that ROS and p53 reciprocally promoted each other’s production and cooperated to induce liver cancer cell death. We found that the induction of ROS and p53 significantly triggered G2/M phase arrest and mitochondrial and lysosomal apoptosis. Finally, walsuronoid B suppressed tumor growth in vivo with few side effects. In summary, our findings demonstrated that walsuronoid B caused G2/M phase arrest and induced mitochondrial and lysosomal apoptosis through the ROS/p53 signaling pathway in human liver cancer cells in vitro and in vivo.Download high-res image (74KB)Download full-size image

•We isolated four new Δ7, 9(11) stigmastane-type steroid saponins from an African medicinal plant, Vernonia amygdalina.•These compounds possessed highly oxidized side chains.•We report that these compounds possess anti-inflammatory activities.Vernoamyosides A–D (1–4), four new Δ7, 9(11) stigmastane-type steroid saponins were isolated from the dried leaves of an African medicinal plant Vernonia amygdalina Delile (Asteraceae). Their structures were determined by a combination of spectroscopic analyses (HR-ESI–MS, 1D/2D NMR) and by chemical methods. These four new compounds possessed highly oxidized side chains (C-20–C-29), and formed complex ring systems in 2–4. The inhibitory effects on NO production in lipopolysaccharide-activated RAW264.7 macrophages of these new compounds were tested.

•Five new 18,19-secoursane triterpene derivatives were isolated from Rubus lambertianus.•The 18,19-secoursane triterpenes are rarely found previously.•Seven compounds could protect HUVECs against oxidative damage.•This is first report of phytochemical research on R. lambertianus.Two new 18,19-secoursane triterpenes and three triterpene glucosides, together with twelve known compounds, were isolated from the aerial parts of Rubus lambertianus Ser. The structures of the new compounds were determined by spectroscopic analyses (HR-ESI-MS, 1D/2D NMR). The protective effects of compounds 1–17 on high glucose-induced oxidative stress injury in human umbilical vein endothelial cells (HUVECs) were evaluated using cell viability assay. Compounds 1, 2, 7, 10, 12, 15 and 17 significantly attenuated high glucose-induced oxidative damage on HUVECs at the concentration of 3.10 μM.

•A novel UFLC-ESI–MS/MS quantitation method was developed.•Gastrodin and HBA were firstly simultaneously determined in dog plasma.•Pharmacokinetics behaviors of the two analytes in dog were studied.A simple, sensitive and reliable ultra fast liquid chromatography-electrospray ionization–tandem mass spectrometry (UFLC-ESI–MS/MS) method was developed for simultaneously quantifying gastrodin (p-hydroxy-methyl-phenol-β-d-glucoside) and its metabolite p-hydroxybenzyl alcohol (HBA) in dog plasma. Separation was performed on an ultra fast liquid chromatography (UFLC) system. Detection was carried out on a tandem mass spectrometry (MS/MS) in multiple reaction monitoring (MRM) mode via an electrospray ionization (ESI) interface. MRM mode of precursor–product ion transitions was used for gastrodin, HBA and the internal standard (IS, bergeninum) at m/z 285.0 → 123.0, 123.0 → 105.0 and 326.9 → 192.2, respectively. The lower limits of quantification (LLOQ) of this method for both gastrodin and HBA were 1 ng/mL, with their linear concentration ranging from 0.001 to 10 μg/mL. The methods were validated for selectivity, calibration curves, accuracy and precision, extraction recoveries, matrix effects, carry-over, cross talk, dilution integrity, stability and incurred sample reanalysis (ISR). Using this validated method, pharmacokinetic behaviors of gastrodin and HBA after intragastric administration (ig) of gastrodin to dogs were studied for the first time.

Aphagranols A (1) and B (2), a pair of isomers with a novel limonoid carbon skeleton, were isolated from the fruits of Aphanamixis grandifolia. Their structures were determined by spectroscopic analyses and further confirmed by their unique acetylated derivative aphagranol C (3). The possible equilibrium system of the enol interconversion was presented using the polarizable continuum model (PCM). The absolute configuration of 3 was established via experimental and calculated ECD spectra comparison. The γ-lactone moiety in ring A system was first found in this class of limonoids.

A strategy of ultra performance liquid chromatography-quadrupole-time of flight-mass spectrometry (UPLC-Q-TOF-MS) coupled to recycling preparative HPLC was utilized to sensitively detect the minor constituents and preparatively isolate coumarin isomers from the petroleum ether extract of Peucedanum praeruptorum roots. UPLC-Q-TOF-MS was achieved on an Agilent ZORBAX Extend C-18 analytical column (50 mm × 2.1 mm i.d. 1.8 μm) using methanol:H2O as the mobile phase, and three pairs of coumarin isomers with similar polarity were detected. Then recycling preparative HPLC was successfully used in one step for the isolation and purification of these six compounds with optimized mobile phases (methanol: H2O, 73:27, 81:19, 78:22, v/v). The structures of six coumarins including three new coumarins named praeruptorin (F–H) (1, 3 and 6) were identified by spectroscopic analysis.

•Six partially acylated pentasaccharide resin glycosides were isolated from Ipomoea cairica.•The absolute configuration of the aglycone was established as 11S by Mosher’s method.•The monosaccharides of cairicosides A–F were proved by GC–MS.•The cytotoxic activities of the pentasaccharide resin glycosides were evaluated in vitro.Six partially acylated pentasaccharide resin glycosides, cairicosides A–F, were isolated from the aerial parts of Ipomoea cairica. These compounds were characterized as a group of macrolactones of simonic acid A, partially acylated with different organic acids. The lactonization site of 11S-hydroxyhexadecanoic acid (jalapinolic acid) was bound to the second saccharide moiety at C-3 in cairicosides A–E, while at C-2 in cairicoside F. Structures were established by spectroscopic and chemical methods. Compounds cairicosides A–E exhibited moderate cytotoxicity against a small panel of human tumor cell lines with IC50 values in the range of 4.28–14.31 μM.From the aerial parts of Ipomoea cairica, six pentasaccharide resin glycosides, cairicosides A–F, were isolated. The absolute configuration of aglycone was established as S by Mosher’s method. The monosaccharides of Cairicoside A–F were proved by GC–MS. Cairicosides A–E were tested for cytotoxic activity against five tumor cell lines (MCF-7, Hela, SGC-7901, Hep-G2, and A549) in vitro.

A rare 16β-H steroidal alkaloid saponin (1), an avenacoside-type saponin (2), two steroidal saponins (4, 5), one revised-structure steroidal saponin (3) and six known compounds (6–11) were isolated from aerial parts of Solanum surattense Burm. f. Their structures were established on the basis of physical data, as well as by using spectroscopic (HRESIMS, 1D and 2D NMR), and chemical analysis methods. Compounds 1 and 11 showed cytotoxicity against A549 cell line with IC50 values of 20.3 and 15.7 μM, respectively.Graphical abstractSteroidal and steroidal alkaloid glycosides, together with seven known compounds, were isolated from the aerial parts of Solanum surattense Burm. f. Their structures were determined by spectroscopic methods.Research highlights► Eleven saponins (1–11) were isolated from Solanum surattense. ► Their structures were characterized on the basis of spectroscopic analysis. ► All compounds were evaluated for their cytotoxicities. ► Compounds 1 and 11 showed cytotoxicity against the A549.

•Four new limonoids were isolated from the seeds of Chukrasia tabularis A. Juss.•1 and 2 were classified as C-15 enolic acyl phragmalin-type limonoid orthoesters.•The absolute configurations of 1 and 2 were determined by CD spectrum analyses.Two new C-15 enolic acyl phragmalin-type limonoid orthoesters (1-2) which possessed a C-15-propionyl phragmalin skeleton and two new mexicanolide-type limonoids (3-4) were isolated from the ethanol extract of seeds of Chukrasia tabularis A. Juss. Their structures were established on the basis of spectroscopic analyses and electronic circular dichroism (ECD) exciton chirality method. Additionally, all of the compounds were screened against three human tumor cell lines MCF-7, SMMC-7721, and U2OS.Four limonoids were isolated from the seeds of Chukrasia tabularis A. Juss. Two new C-15 enolic ancyl phragmalin-type limonoid orthoesters and two new mexicanolide-type limonoids were determined by NMR, HRESIMS, and CD spectra.Download high-res image (137KB)Download full-size image

•Developmental toxicity and neurotoxicity of matrine and sophocarpine were examined.•Both drugs induced teratogenic and lethal effects to zebrafish embryos.•They significantly altered spontaneous movement and inhibited swimming behavior.•The low EC50 for swimming behavior indicate a neurotoxic potential of both drugs.Matrine and sophocarpine are two major matrine-type alkaloids included in the traditional Chinese medicine (TCM) Kushen (the root of Sophora flavescens Ait.). They have been widely used clinically in China, however with few reports concerning their potential toxicities. This study investigated the developmental toxicity and neurotoxicity of matrine and sophocarpine on zebrafish embryos/larvae from 0 to 96/120 h post fertilization (hpf). Both drugs displayed teratogenic and lethal effects with the EC50 and LC50 values at 145 and 240 mg/L for matrine and 87.1 and 166 mg/L for sophocarpine, respectively. Exposure of matrine and sophocarpine significantly altered spontaneous movement and inhibited swimming performance at concentrations below those causing lethality and malformations, indicating a neurotoxic potential of both drugs. The results are in agreement with most mammalian studies and clinical observations.Download full-size image

•Alopecurone B enhances doxorubicin toxicity in MG-63 doxorubicin-resistance cells.•Alopecurone B increases doxorubicin-induced apoptosis at non-toxic concentration.•Alopecurone B suppresses P-glycoprotein in MG-63 doxorubicin-resistance cell line.•Alopecurone B can reverse drug resistance by inhibiting NF-kappaB signaling.Doxorubicin (DOX) was first used in osteosarcoma in the early 1970s as a first-line antineoplastic drug. However, the occurrence of drug resistance in chemotherapeutic treatment has greatly restricted its use. When resistance to DOX treatment occurs, osteosarcoma may become not only resistant to the drug originally administered but also to a wide variety of structurally and mechanistically unrelated drugs. Thus, there is an urgent need to find ways of reversing DOX chemotherapy resistance in osteosarcoma. Plant-derived agents have great potential in preventing the onset of the carcinogenic process and enhancing the efficacy of conventional antitumor drugs. Alopecurone B (ALOB), a flavonoid, is isolated from Traditional Chinese Medicine Sophora alopecuroides L., and is reported to have potent inhibitory effect on multidrug resistance associated protein 1. In this study, a DOX-resistant osteosarcoma cell line (MG-63/DOX) was established by increasing the concentration gradient of DOX in a stepwise manner. MTT assay, flow cytometry analysis, dual-luciferase reporter gene assay, quantitative real-time polymerase chain reaction and Western blot analysis were applied to investigate the reversing effect of ALOB and its underlying mechanisms. The results indicated that ALOB mediated the resistance of MG-63/DOX cells to DOX by inhibiting P-glycoprotein function, transcription and expression. Besides, ALOB also enhanced the sensitivity of MG-63/DOX cells to other conventional chemotherapeutic drugs. Cell viability assay confirmed the reversing activity of ALOB. Furthermore, ALOB increased DOX-induced apoptosis at nontoxic concentration. In addition, ALOB showed inhibitory effect on NF-κB transcription in a DOX-independent manner. Furthermore, NF-κB signaling was suppressed by ALOB in an IKK-dependent manner. These studies not only demonstrate that ALOB is a potential agent for reversal of drug resistant cancers, but also testify that ALOB reverses multidrug resistance by inhibiting P-glycoprotein via NF-κB signaling.Download high-res image (174KB)Download full-size image

BackgroundPolyphyllin I (PPI), a bioactive phytochemical isolated from the rhizoma of Paris polyphyllin, exerts preclinical anticancer efficacy in various cancer models. However, the effects of PPI on regulatory human hepatocellular carcinoma (HCC) cell proliferation and its underlying mechanisms remain unknown.PurposeThis study investigated the antiproliferation effect of PPI on HCC cells and its underlying mechanisms.MethodsCell viability was measured by MTT assay. Cell death, apoptosis and acidic vesicular organelles (AVOs) formation were determined by flow cytometry. Protein levels were analyzed by Western blot analysis.ResultsPPI induced apoptosis through the caspase-dependent pathway and activated autophagy through the PI3K/AKT/mTOR pathway. Blockade of autophagy by pharmacological inhibitors or RNA interference enhanced the cytotoxicity and antiproliferation effects of PPI. Moreover, chloroquine (CQ) enhanced the antiproliferation effect of PPI on HCC cells via the caspase-dependent apoptosis pathway by inhibiting protective autophagy. Therefore, the combination therapy of CQ and PPI exhibited synergistic effects on HCC cells compared with CQ or PPI alone.ConclusionThe current findings strongly indicate that PPI can induce protective autophagy in HCC cells, thereby providing a novel target in potentiating the anticancer effects of PPI and other chemotherapeutic drugs in liver cancer treatment. Moreover, the combination therapy of CQ and PPI is an effective and promising candidate to be further developed as therapeutic agents in the treatment of liver cancer.Download high-res image (203KB)Download full-size image