Experimental and computational study on anti-gastric cancer activity and mechanism of evodiamine derivatives.

Introduction: Human topoisomerase 1 (TOP1) is an important target of various anticancer compounds. The design and discovery of inhibitors targeting TOP1 are of great significance for the development of anticancer drugs. Evodiamine and thieno [2,3-d] pyridine hybrids show potential antitumor activity. Herein, the anti-gastric cancer activities of these hybrids were investigated. Methods: The inhibitory effects of different concentrations of ten evodiamine derivatives on the gastric cancer cell line SGC-7901 were assessed using a methyl thiazolyl tetrazolium assay. Compounds EVO-1 and EVO-6 strongly inhibited gastric cancer cell proliferation, with inhibition rates of 81.17% ± 5.08% and 80.92% ± 2.75%, respectively. To discover the relationship between the structure and activity of these two derivatives, density functional theory was used to investigate their optimized geometries, natural population charges, frontier molecular orbitals, and molecular electrostatic potentials. To clarify their anti-gastric cancer mechanisms, molecular docking, molecular dynamics simulations, and binding free energy calculations were performed against TOP1. Results: The results demonstrated that these compounds could intercalate into the cleaved DNA-binding site to form a TOP1-DNA-ligand ternary complex, and the ligand remained secure at the cleaved DNA-binding site to form a stable ternary complex. As the binding free energy of compound EVO-1 with TOP1 (-38.33 kcal·mol-1) was lower than that of compound EVO-6 (-33.25 kcal·mol-1), compound EVO-1 could be a more potent anti-gastric cancer agent than compound EVO-6. Discussion: Thus, compound EVO-1 could be a promising anti-gastric cancer drug candidate. This study may facilitate the design and development of novel TOP1 inhibitors.

ent-8(14),15-Pimaradiene-2ß,19-diol, a diterpene from Aleuritopteris albofusca, inhibits growth and induces protective autophagy in hepatocellular carcinoma cells.

A new pimarane-type diterpene, ent-8(14),15-pimaradiene-2ß,19-diol (JXE-23), was isolated from the fern plant Aleuritopteris albofusca by our previous work; however, the biological activity of this diterpene remains unclear. In the present study, the anti-cancer potential of JXE-23 in various cancer cells was investigated. Among MCF-7 breast cancer cells, A549 lung cancer cells, and HepG2 liver cancer cells, JXE-23 displayed significant cytotoxicity to HepG2 cells with an IC50 value of 17.20 ± 1.73 µM, while showing no obvious toxicity in normal hepatocytes HL7702. JXE-23 inhibited cell growth and colony formation in HepG2 cells. A cell cycle distribution analysis showed that JXE-23 caused G2/M cell cycle arrest. Besides, JXE-23 also suppressed the migration of HepG2 cells. Interestingly, an increase of light chain 3 II (LC3II) and Beclin 1 and a decrease of P62 have occurred in JXE-23-treated cells, as well as the formation of GFP-LC3 dots, indicative of autophagy induction by JXE-23. When combined with autophagy inhibitor 3-methyladenine and chloroquine, the cell viability was significantly reduced, suggesting that JXE-23 triggered protective autophagy in hepatoma cells. Further study showed that JXE-23 inactivated the CIP2A/p-AKT/c-Myc signaling axis in HepG2 cells. Our data provided evidence that JXE-23 inhibited cell growth, arrested cells at the G2/M phase, and induced protective autophagy in HepG2 hepatocellular carcinoma cells. JXE-23 may be a potential lead compound for anti-cancer drug development, and autophagy inhibitor treatment may provide an effective strategy for improving its anti-cancer effect.

Discovery of a Pimaradiene that Decreases Viability of MDA-MB-468 Cells Through Inhibition of EGFR Signaling Pathway.

Triple-negative breast cancer (TNBC) is characterized by strong invasiveness, high relapse rates, and poor overall survival. It occurs in approximately 15-20 % of all breast cancer cases. Natural compounds are a promising option for managing breast cancer. ent-8(14),15-Pimaradiene-2ß,19-diol (JXE-23), is a pimaradiene isolated from the fern Aleuritopteris albofusca. However, the effects and molecular mechanisms of JXE-23 on cancer cells are still unknown. Thus, this study was designed to determine the potential of JXE-23 for its anticancer properties in TNBC cells. JXE-23 was evaluated for its antiproliferative activity in vitro against human breast cancer cell lines, and showed selectively cytotoxic activity against MDA-MB-468, an EGFR-overexpressing TNBC cancer cell line, with an IC50 value of 1.17±0.04 µM. Moreover, mechanistic investigations indicated that JXE-23 was significantly capable of inhibiting cell proliferation and viability in MDA-MB-468 cells. In addition, JXE-23 exerted an anticancer effect against MDA-MB-468 cells via restraining cell migration in a dose-dependent mode. Moreover, after treatment with JXE-23, the protein expressions of pEGFR, pERK, pAkt and p-p70S6K were significantly reduced in MDA-MB-468 cells. The results underscored that JXE-23 could be a potential lead compound for the treatment of EGFR-overexpressing TNBC cells.

Anti-inflammatory activities of several diterpenoids isolated from Hemionitis albofusca.

Hemionitis albofusca (Baker) Christenh is a plant that grows in various regions of China. Although it is not recognized as a traditional medicine, it is often mistakenly labelled and used as Aleuritopteris argentea (S. G. Gmél.) Fée to alleviate menstruation-related issues. Recently, several diterpenoids such as ent-16-oxo-17-norkauran-19-oic acid (Compound A), 14-oxy-7ß,20-dihydroxycyath-12,18-diene (Compound B), ent-8(14),15-pimaradiene-2ß,19-diol (Compound C), ent-kaurane-16-ene-2ß,18α-diol (Compound D), ent-kaurane-2ß,16α,18α-triol (Compound E), and onychiol B have been extracted from H. albofusca. In this study, we investigated the anti-inflammatory activity of these diterpenes. We confirmed that compounds A ~ D suppressed the amount of cellular NO production by inhibiting the expression and transcription of iNOS protein. They also significantly inhibited the expression and transcription of inflammatory factors TNF-α and IL-6. Additionally, Compounds A and C suppressed the activation of the NF-κB signaling pathway and inhibited the phosphorylation level of p38, ultimately down-regulating inflammation. Compound B suppressed the activation of the NF-κB signaling pathway, while Compound D inhibited the phosphorylation level of p38 and down-regulated the activation of the p38 MAPK signaling pathway. In a word, our investigation supports the potential application of natural diterpenes as lead compounds for developing anti-inflammatory agents.

Identification of an Alepterolic Acid Derivative as a Potent Anti-Breast-Cancer Agent via Inhibition of the Akt/p70S6K Signaling Pathway.

Alepterolic acid is a diterpene occurring in the fern Aleuritopteris argentea with potential biological activity that warrants further structural modification. In the present work, sixteen alepterolic acid derivatives were synthesized and evaluated for their anticancer activities. Among them, N-[m-(trifluoromethoxy)phenyl] alepterolamide displayed comparable activity (IC50 =4.20±0.21 µM) in MCF-7 cells. Moreover, mechanistic investigations indicated this compound was significantly capable of diminishing cell proliferation and viability of MCF-7 cells. After treatment with N-[m-(trifluoromethoxy)phenyl] alepterolamide, a significant increase in cleaved caspase-9, cleaved caspase-3, cleaved poly (ADP-ribose) polymerase (PARP) and Bax/Bcl2 ratio were observed in MCF-7 cells, leading to caspase-dependent apoptotic pathways. Further studies showed this compound promoted cellular apoptosis and inhibited migration in MCF-7 cells via modulation of the Akt/p70S6K signaling pathway. All these results revealed the potential of N-[m-(trifluoromethoxy)phenyl] alepterolamide as an appealing therapeutic drug candidate for breast cancer.

Synthesis and Evaluation of Piperazine-Tethered Derivatives of Alepterolic Acid as Anticancer Agents.

Alepterolic acid is a natural diterpenoid isolated from Aleuritopteris argentea with potential anti-cancer activity. In this study, alepterolic acid was modified to construct a series of arylformyl piperazinyl derivatives (3a-3p). The synthesized derivatives were fully characterized with HRMS, NMR, and IR. Four compounds with inhibition rate higher than 30 % at 10 µM (3f, 3n, 3g and 3k) were further measured to obtain the IC50 values against four cancer cell lines, including hepatoma cell lines HepG2, lung cancer cell lines A549, estrogen receptor-positive cell lines MCF7, and triple-negative breast cancer (TNBC) cell lines MDA-MB-231 by MTT assay. It was found that these compounds were more effective to HepG2 and MDA-MB-231 cells, while less toxic to A549 and MCF7 cells, and compound 3n as the most toxic derivatve against MDA-MB-231 cell lines, with IC50 value of 5.55±0.56 µM. Trypan blue staining and colony formation assay showed that compound 3n inhibited the growth of MDA-MB-231 cells and prevented colony formation. Hoechst staining, flow cytometry and western blot analysis revealed that compound 3n induced caspase-dependent apoptosis in MDA-MB-231 cells. Conclusively, compound 3n was demonstrated to be a potential anti-cancer lead compound for further investigation.

Onychiol B attenuates lipopolysaccharide-induced inflammation via MAPK/NF-κB pathways and acute lung injury in vivo.

Acute lung injury (ALI) is a devastating respiratory disorder characterized by rapid alveolar injury, uncontrolled inflammatory response, etc. Onychiol B is a cyathane diterpene originally isolated from fern plants. In this study, onychiol B can inhibit the production and secretion of pro-inflammatory cytokines such as NO, iNOS, IL-6 and TNF-α in LPS-stimulated RAW264.7 cells by restraining the NF-κB and the p38 MAPK pathway. In addition, it prevents the production of ROS and reduces the loss of mitochondrial membrane potential in LPS-stimulated RAW264.7 cells. Furthermore, in the acute lung injury mouse model induced by LPS injected into the trachea, onychiol B alleviates pulmonary edema, reverses inflammatory mediator TNF-α, IL-6, and IL-ß secretion in lung. In general, our data show that significant anti-ALI effects of onychiol B would render it a potential candidate for the treatment of inflammatory diseases.

Ethoxysanguinarine Induces Apoptosis, Inhibits Metastasis and Sensitizes cells to Docetaxel in Breast Cancer Cells through Inhibition of Hakai.

Ethoxysanguinarine (ESG) is a benzophenanthridine alkaloid extracted from plants of Papaveraceae family, such as Macleaya cordata (Willd) R. Br. The anti-cancer activity of ESG has been rarely reported. In this study, we investigated the anti-breast cancer effect of ESG and its underlying mechanism. MTT assay and flow cytometry analysis showed that ESG inhibited the viability and induced apoptosis in MCF7 and MDA-MB-231 human breast cancer cells. Western blot revealed that ESG triggered intrinsic and extrinsic apoptotic pathways, as evidenced by the activation of caspase-8, caspase-9 and caspase-3. ESG attenuated breast cancer cell migration and invasion through Hakai/E-cadherin/N-cadherin. Moreover, Hakai knockdown sensitized ESG-triggered viability and motility inhibition, suggesting that Hakai mediated the anti-breast cancer effect of ESG. In addition, ESG potentiated the anti-cancer activity of docetaxel (DTX) in breast cancer cells. Overall, our findings demonstrate that ESG exhibits outstanding pro-apoptosis and anti-metastasis effects on breast cancer via a mechanism related to Hakai-related signaling pathway.

Bridging Integrator 3 (BIN3) Downregulation Predicts a Poor Prognosis in Patients with Esophagus Carcinoma: A Study based on TCGA Data.

BACKGROUND: Bridging integrator 3 (BIN3) has been reported to play a key role in certain tumors. Nevertheless, little is known about the role and clinical value of BIN3 in esophagus carcinoma (ESCA). This study aimed to investigate the pathological and prognostic role of BIN3 in ESCA patients. METHODS: Genes significantly correlated with the prognosis of ESCA patients were screened and identified by comprehensive analysis of differentially expressed genes associated with overall survival (OS), disease-specific survival (DSS) and progression-free interval (PFI) in ESCA. The expression of BIN3, pathological features correlation and subgroup overall survival analysis were performed using The Cancer Genome Atlas (TCGA) and GTEx databases. Moreover, the potential signaling pathways in which BIN3 was involved were analyzed by GO-KEGG enrichment analysis and gene set enrichment analysis (GSEA). Immune infiltrates correlation of BIN3 in ESCA was performed by TIMER and ssGSEA. The influence of BIN3 on epithelial-mesenchymal transition (EMT) was validated by western blot. RESULTS: There were two differentially expressed genes related to the prognosis of ESCA patients, which were identified from three gene clusters associated with overall survival (OS), diseasespecific survival (DSS) and progression-free interval (PFI) in ESCA patients. The BIN3 mRNA level was found to be significantly decreased in ESCA compared to normal tissues (p < 0.05). The decreased expression of BIN3 in ESCA was significantly correlated with the clinical stage (p = 0.015), T stage (p < 0.05), histological type (p < 0.001), age (p < 0.05) and gender (p < 0.05). ESCA patients with high BIN3 expression were observed to be correlated with T stage (T3 & T4), age (＜＝60), gender (male), primary therapy outcome (PD) and columnar metaplasia (No) of favorable OS. GO-KEGG enrichment analysis revealed that BIN3 was involved in endocytosis. GSEA showed that several pathways were enriched in BIN3, such as O linked glycosylation of mucins, PID HNF3B pathway, biocarta TFF pathway, WP pregnane X receptor pathway, reactome regulation of beta cell development, WP Urea cycle and associated pathways and others. BIN3 was significantly related to the infiltration level of T cells (p < 0.001), Tregs (p < 0.001), B cells (p < 0.001), NK cells (p < 0.001), and macrophage M2 (p < 0.001). In addition, BIN3 overexpression inhibited N-cadherin expression and promoted E-cadherin expression in ESCA cell lines TE-1. CONCLUSION: These results suggest that BIN3 might be a potential prognostic biomarker in ESCA. BIN3 functions as a tumor-suppressor role in ESCA, which is significantly associated with the immune infiltration of ESCA.

Celastrol inhibits the migration and invasion and enhances the anti-cancer effects of docetaxel in human triple-negative breast cancer cells.

The molecular mechanism of anti-metastatic effect of celastrol is not fully understood in breast cancer cells. Herein, we investigated the activity and molecular mechanism of celastrol in triple-negative breast cancer (TNBC) cells, which is a more aggressive subtype of breast cancer. The results of wound healing assay and trans-well assay revealed that celastrol inhibited cell migration and invasion under sub-cytotoxic concentrations in MDA-MB-231 and MDA-MB-468 TNBC cells. Molecular data showed that the effect of celastrol on TNBC cells might be mediated via up-regulation of E-cadherin, a key protein involved in epithelial-mesenchymal transition (EMT). In addition, Hakai, an E3 ligase responsible for E-cadherin complex ubiquitination and degradation, was down-regulated under celastrol treatment. Hakai partially contributed to celastrol-induced anti-invasive effect. In addition, celastrol and docetaxel could synergistically inhibit growth and metastasis of MDA-MB-231 cells. Our results showing anti-migratory/anti-invasive effects of celastrol and associated mechanisms provide new evidence for the development of celastrol as a potential anti-metastatic compound against highly aggressive breast cancer, and celastrol in combination with docetaxel might potentially be used as a novel regimen for the treatment of TNBC.

Antibacterial effect of Cu2O/TiO2 photocatalytic composite on Pseudomonas marginalis pv. marginalis.

Cu2O/TiO2 visible-light photocatalytic composite was successfully synthesized by supercritical solvothermal route. Cu2O/TiO2 presented excellent bacterial inactivation activity for Pseudomonas marginalis pv. marginalis, which was related to the concentration of bacteria and the antibacterial time. The highest sterilization ratio reached up to 100% when the bacteria was treated with 80 µg/mL of Cu2O/TiO2 photocatalytic composite for 80 min, which could be further proved by the damage of integrity and shrink of the cell membrane in transmission electron microscopy (TEM) image. When the bacterial concentration was 1 × 105 CFU/mL, the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined as 16 and 32 µg/mL by agar dilution, respectively. Meanwhile, the production of reactive oxygen species (ROS), glutathione reductase (GR) and glutathione (GSH) of Pseudomonas marginalis pv. marginalis treated by Cu2O/TiO2 were determined by DCFH-DA, DTNB and kinetic method, respectively, to evaluate the anti-oxidation capacity of bacteria cell. The enzyme activity of peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) in bacteria treated with Cu2O/TiO2 were measured to further confirm the overproduction of ROS. Cu2O/TiO2 was demonstrated as the excellent visible-light photocatalyst for efficiently killing Pseudomonas marginalis pv. marginalis with the low dosage. Finally, the Cu2O/TiO2 composite photocatalytic material was applied to cucumber seedlings based on field experimental, and its inhibitory effect in practical application was judged by measuring the morphology, enzyme activity and resistance index of cucumber plants. It is of great significance to the practical application as a suitable and powerful antibacterial agent for Pseudomonas marginalis pv. marginalis and other bacteria.

A novel 8-hydroxyquinoline derivative induces breast cancer cell death through paraptosis and apoptosis.

Chemotherapy represents one of the main conventional therapies for breast cancer. However, tumor cells develop mechanisms to evade chemotherapeutic-induced apoptosis. Thus, it is of great significance to induce non-apoptotic cell death modes, such as paraptosis, in breast cancer. Herein, a novel 8-hydroxyquinoline derivative, 5,7-dibromo-8-(methoxymethoxy)-2-methylquinoline (HQ-11), was obtained and its potential anti-breast cancer mechanisms were investigated. Our results showed that extensive cytoplasmic vacuoles derived from the endoplasmic reticulum (ER) and mitochondria were appeared in MCF7 and MDA-MB-231 breast cancer cells by HQ-11 incubation, and pretreatment of cycloheximide was able to inhibit this vacuolation and HQ-11-induced cell death, showing the characteristics of paraptosis. ER stress was involved in HQ-11-caused paraptosis evidenced by the increase of glucose-regulated protein 78, C/EBP homologous protein and polyubiquitinated proteins. Molecular docking analysis revealed a favorable binding mode of HQ-11 in the active site of the chymotrypsin-like ß5 subunit of the proteasome, indicative of proteasome dysfunction under HQ-11 treatment, which might result in further aggravated ER stress. Furthermore, treatment of HQ-11 resulted in increased phosphorylation of extracellular signal-regulated kinase (ERK) and c-Jun NH2-terminal kinase, and inhibition of ERK with U0126 significantly attenuated HQ-11-induced ER stress and paraptosis. In addition, exposure to HQ-11 also caused apoptosis in breast cancer cells partially through activation of ERK pathway. All these results conclusively indicate that HQ-11 triggers two distinct cell death modes via inhibition of proteasome and activation of ERK pathway in breast cancer cells, providing a promising candidate in future anti-breast cancer therapy.

Hydnocarpin D attenuates lipopolysaccharide-induced acute lung injury via MAPK/NF-κB and Keap1/Nrf2/HO-1 pathway.

BACKGROUND: Acute lung injury (ALI) is a complex pulmonary destructive disease with limited therapeutic approaches. Hydnocarpin D (HD) is a flavonolignan isolated from Hydnocarpus wightiana which possesses antioxidant and anti-inflammatory properties. However, whether HD has beneficial effects on ALI as well as its underlying mechanism remains to be elucidated. PURPOSE: This study evaluated the protective effect of HD in ALI and the underlying molecular mechanisms. METHODS: In vivo, the role of HD on lipopolysaccharide (LPS)-induced ALI in mice was tested by determination of neutrophil infiltration, levels of inflammatory cytokines, lung histology and edema, vascular and alveolar barrier disruption. In vitro, murine macrophage RAW 264.7 cells were used to investigate the molecular mechanisms RESULTS: Administration of HD protected mice against LPS-induced ALI, including ameliorating the histological alterations in the lung tissues, and decreasing lung edema, protein content of bronchoalveolar lavage fluid, infiltration of inflammatory cell and secretion of cytokines. Moreover, HD blocked the phosphorylation of TLR-4, NF-κB, and ERK in LPS-induced lung injury. In vitro, HD inhibited LPS-induced oxidative stress and inflammation in RAW 264.7 cells, which largely depend upon the upregulation of antioxidant defensive Nrf2 pathway, thereby suppressing LPS-activated proinflammatory mediator secretion, NLRP3 inflammasome, and MAPK/NF-κB signaling pathway. CONCLUSION: HD attenuates oxidative stress and inflammation against LPS-induced ALI via MAPK/NF-κB and Keap1/Nrf2/HO-1 pathway, and is a promising novel therapeutic candidate for ALI.

Synthesis and biological evaluation of cytotoxic activity of novel podophyllotoxin derivatives incorporating piperazinyl-cinnamic amide moieties.

Podophyllotoxin, as a natural lignan isolated from the dried rhizomes and roots of several plant species of Podophyllum family, exhibits potent activity of interfering polymerization of tubulin and causes cancer cell apoptosis. Structure-activity relationship research revealed that modification at 4-position was tolerable for its potency. In the present study, podophyllotoxin derivatives incorporating piperazinyl-cinnamic amide moieties at 4-position were designed and synthesized. Their structures were confirmed by 1H NMR, 13C NMR, and mass spectral data. ADMET analysis proposed that these compounds had a good distribution and high clearance profile with little toxicity. The cytotoxicity of these derivatives was evaluated against four human cancer cell lines (MCF-7, A549, HeLa and PC-3) by MTT assay. Among all the compounds, compound 6e exhibited the best anti-proliferative properties with an IC50 = 0.08 ± 0.01 µM against MCF-7 cancer cell line. Further cellular mechanism studies by cell colony formation, mitochondrial membrane potential assay, nuclear morphology analysis and western blot confirmed that compound 6e could inhibit cancer cell proliferation and induce mitochondria-associated apoptosis in MCF-7 cells. Meanwhile, immunofluorescence assay revealed that compound 6e could apparently disrupt tubulin network in MCF-7 cells, and molecular docking further supported that compound 6e was able to bind into the colchicine site of tubulin. The above results might lay a foundation for further investigation for drug discovery based on podophyllotoxin.

Adiantic acid, a new unsaturated fatty acid with a cyclopropane moiety from Adiantum flabellulatum L.

Phytochemical investigation of Adiantum flabellulatum L. led to the isolation of four natural compounds, including a novel unsaturated fatty acid with a cyclopropane moiety, i.e. (S,E)-7-(2-octylcyclopropylidene)heptanoic acid (1), together with three known compounds, isoadiantol B (2), stigmast-4-en-6ß-ol-3-one (3), ß-sitosterol (4). Compound 3 was isolated from the A. flabellulatum L. for the first time. The structure of 1 was elucidated following a comprehensive analysis of spectroscopic analyses including MS, 1 D and 2 D NMR, and by a mass spectrometry experiment of the dimethyl disulfide (DMDS) adduct, while the known compounds were identified by comparisons with those reported in the literature. Enzyme evaluation of 1 indicated this compound possesses anti- protein tyrosine phosphatase (PTP1B) activity with an IC50 value of 6.99 ± 0.41 µM in vitro.

A novel nickel-modified nano-magnetite for isolation of histidine-tagged proteins expressed in Escherichia coli.

Nano-magnetite with superparamagnetism could be coated by some organic compounds or by nano Au or Pt via surface modifications with multi-step reactions for the applications of isolating histidine-tagged (His-tagged) proteins. Introducing active sites of binding histidine onto the surface of nano-magnetite was the ultimate task. However, multi-step treatments might result in departure of the coatings from the surface of the nano-magnetite, which led to loss of active sites. In this work, we reported a convenient and efficient way of treating nano-magnetites and applied them in isolating His-tagged proteins. Carboxylates were introduced on the surface of home-made nano-magnetite directly via ultrasonic mixing with sodium bitartrate rather than complicated surface modifications, which was proved by thermogravimetric analyses. Ni2+ was, therefore, caught by the carboxylates of the coating via the coordinate interaction, demonstrated by X-ray photoelectron spectra. The coated magnetic nanoparticles with the bonded Ni2+ were successfully employed to selectively bind and separate recombinant His-tagged proteins directly from the mixture of Escherichia coli cell lysate, and showed wonderful affinity for His-tagged proteins with the saturated adsorption amount being 556 mg g-1. Additionally, such functionalized nano-magnetite manifested the excellent recyclability in isolating His-tagged proteins.

Structural Modification of Sylibin to Derivatives of Sylibin/Hydnocarpin D/Silandrin, and Evaluation of their Cytotoxicity against Cancer Cells.

BACKGROUND: Flavonolignans like silybin, hydnocarpin, and siliandrin are a group of natural compounds combining the structural moieties of flavonoid and phenylpropanoid (lignan). Hydnocarpin and silandrin have been less explored because of their trace occurrence in nature. OBJECTIVE: The present study aimed at chemical conversion of silybin to hydnocarpin and siliandrin. Another objective was to synthesize a series of amide derivatives and biologically evaluate them with regard to their anti-cancer effects. METHODS: In order to selectively convert silybin to 23-iodo silybin, 23-iodo hydnocarpin D and 23- iodo isosilandrin, the ratio of Ph3P, imidazole and molecular iodine was meticulously adjusted. These three iodide compounds were converted into amide compounds by chemical transformation. MTT method was applied to evaluate their anti-cancer potency. The binding affinity to related proteins was calculated by molecular docking. RESULTS: A total of 45 new amido-derivatives were synthesized and structurally characterized by NMR and HRMS. Some of them showed moderate to good antiproliferative potency against cancer cells. The activity of compound 10j was further testified by colony formation assay and molecular docking. CONCLUSION: The synthesis of 23-iodo silybin, 23-iodo hydnocarpin D and 23-iodo isosilandrin from silybin was successfully accomplished by one simple iodination reaction. Some of the amide derivatives of sylibin/hydnocarpin D /silandrin exhibited a remarkable inhibitory effect of proliferation on cancer cells compared to silybin. These results would pave the way for further investigation on the derivatives of flavonolignans for the treatment of cancer.

Inhibitory effect of hydnocarpin D on T-cell acute lymphoblastic leukemia via induction of autophagy-dependent ferroptosis.

Hydnocarpin D (HD) is a bioactive flavonolignan compound that possesses promising anti-tumor activity, although the mechanism is not fully understood. Using T cell acute lymphoblastic leukemia (T-ALL) cell lines Jurkat and Molt-4 as model system, we found that HD suppressed T-ALL proliferation in vitro, via induction of cell cycle arrest and subsequent apoptosis. Furthermore, HD increased the LC3-II levels and the formation of autophagolysosome vacuoles, both of which are markers for autophagy. The inhibition of autophagy by either knockdown of ATG5/7 or pre-treatment of 3-MA partially rescued HD-induced apoptosis, thus suggesting that autophagy enhanced the efficacy of HD. Interestingly, this cytotoxic autophagy triggered ferroptosis, as evidenced by the accumulation of lipid ROS and decrease of GSH and GPX4, while inhibition of autophagy impeded ferroptotic cell death. Our study suggests that HD triggers multiple cell death processes and is an interesting compound that should be evaluated in future preclinical studies.

LFZ-4-46, a tetrahydroisoquinoline derivative, induces apoptosis and cell cycle arrest via induction of DNA damage and activation of MAPKs pathway in cancer cells.

LFZ-4-46, that is [2-hydroxy-1-phenyl-1,5,6,10b-tetrahydropyrazolo(5,1-a) isoquinolin-3(2H)-yl](phenyl) methanone, a tetrahydroisoquinoline derivative with a pyrazolidine moiety, was synthetically prepared. The anti-cancer mechanism of the compound has not been clarified yet. In this study, the anticancer effects and potential mechanisms of LFZ-4-46 on human breast and prostate cancer cells were explored. (a) 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazoliumbromide assay was first performed to detect the effects of LFZ-4-46 on the viability of human cancer cells. (b) Comet assay was utilized to evaluate DNA damage. (c) Cell cycle, apoptosis and mitochondrial membrane potential were detected by flow cytometry. (d) The expression of relative proteins was detected by western blotting assay. LFZ-4-46 significantly inhibited the viability of cancer cells in a time- and dose-dependent manner and had no obviously inhibitory effect on the viability of mammary epithelial MCF-10A cells. Mechanistic studies demonstrated that LFZ-4-46-induced cell apoptosis and cycle arrest were mediated by DNA damage. It caused DNA damage through activating γ-H2AX and breaking DNA strands. Further studies showed that mitogen-activated protein kinasess pathway was involved in these activated several key molecular events. Finally, LFZ-4-46 showed a potent antitumor effect in vivo. These results suggest that LFZ-4-46 may be a potential lead compound for the treatment of breast and prostate cancer.

Nickel-Catalyzed Asymmetric Addition of Aromatic Halides to Ketones: Highly Enantioselective Synthesis of Chiral 2,3-Dihydrobenzofurans Containing a Tertiary Alcohol.

A highly enantioselective and straightforward synthetic procedure to chiral 3-hydroxy-2,3-dihydrobenzofurans has been developed by nickel/bisoxazoline-catalyzed intramolecular asymmetric addition of aryl halides to unactivated ketones, giving 2,3-dihydrobenzofurans with a chiral tertiary alcohol at the C-3 position in good yields and excellent enantioselectivities (up to 92% yield and 98% ee). The gram-scale reaction also proceeded smoothly without a loss of yield and enantioselectivity.