Anthraquinones from the Aerial Parts of Rubia cordifolia with Their NO Inhibitory and Antibacterial Activities.

The present study aimed to identify the composition of the aerial parts of Rubia cordifolia L. A chemical investigation on the EtOAc extracts from the aerial parts of Rubia cordifolia resulted in the isolation of four new anthraquinones, namely Cordifoquinone A-D (1-4), along with 16 known anthraquinones. Their structures were elucidated on the basis of NMR and HR-ESIMS data. All isolates were assessed for their inhibitory effects on NO production in LPS-stimulated RAW 264.7 macrophage cells. Compounds 1, 3 and 10 exhibited significant inhibitory activities with IC50 values of 14.05, 23.48 and 29.23 µmol·L-1, respectively. Their antibacterial activities of four bacteria, Escherichia coli (ATCC 25922), Staphylococcus aureus subsp. aureus (ATCC 29213), Salmonella enterica subsp. enterica (ATCC 14028) and Pseudomonas aeruginosa (ATCC 27853), were also evaluated. Our results indicated that the antibacterial activity of these compounds is inactive.

Synthesis, antitumor activity, and molecular docking of (-)-epigallocatechin-3-gallate-4ß-triazolopodophyllotoxin conjugates.

Two new (-)-epigallocatechin-3-gallate-4ß-triazolopodophyllotoxin conjugates (7 and 8) were synthesized and evaluated for biological activity. Compound 8 showed highly potent anticancer activity against A-549 cell line with IC50 of 2.16 ± 1.02 µM, which displayed the highest selectivity index value (SI = 14.5) in A-549 cells. Molecular docking indicated that compound 8 could bind with the active site of Top-II. Therefore, compound 8 might be a promising candidate for further development.

Novel dual-color drug screening model for GLUT4 translocation in adipocytes.

Insulin-responsive glucose transporter type 4 (GLUT4) translocation plays a major role in controlling glucose uptake in adipose tissue and muscle, maintaining homeostasis and preventing hyperglycemia. Screening for chemicals enhancing GLUT4 translocation is an approach for identifying hits of drug development for type 2 diabetes. Here we developed a novel functional dual-color probe, pHluorin-GLUT4-mOrange2, and constructed 3T3-L1 adipocytes based screening system to simply and efficiently screen new compounds stimulating GLUT4 translocation. Based on this system, we successfully identified a few hits facilitating GLUT4 translocation. In conclusion, we developed an easy-to-apply dual color GLUT4 probe to monitor GLUT4 translocation in insulin-responsive cells, which could be alternatively employed to high-throughput screen compounds regulating GLUT4 translocation and glucose uptake, even to dissect GLTU4 approaching, docking and fusion with the plasma membrane (PM), and to reveal relevant molecular mechanisms involved in these steps as expected.

The mortality risk factor of community acquired pneumonia patients with chronic obstructive pulmonary disease: a retrospective cohort study.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is one of the most common comorbidities in community acquired pneumonia (CAP) patients. We aimed to investigate the characteristics and mortality risk factors of COPD patients hospitalized with CAP. METHODS: A retrospective cohort study was conducted at Shanghai Pulmonary Hospital and Shanghai Dahua Hospital. Clinical and demographic data in patients diagnosed with CAP were collected between January 2015 and June 2016. Logistic regression analysis was performed to screen mortality risk factors of COPD patients hospitalized with CAP. RESULTS: Of the total 520 CAP patients, 230 (44.2%) patients had been diagnosed comorbid with COPD (COPD-CAP). CAP patients comorbid with COPD patients had higher rate of need for ICU admission (18.3% vs 13.1%) and need for NIMV (26.1% vs 1.4%) than without COPD (nCOPD-CAP). The PSI, CURB-65 and APACHE-II scores in COPD-CAP patients were higher than that in nCOPD-CAP patients (95 vs 79, P < 0.001; 1 vs 1, P < 0.001; 13 vs 8, P < 0.001, respectively). Logistic regression analysis indicated that aspiration, D-dimer > 2.0 µg/mL and CURB-65 ≥ 3 were risk factors associated with in-hospital mortality ((odd ratio) OR = 5.678, OR = 4.268, OR = 20.764, respectively) in COPD-CAP patients. The risk factors associated with 60-day mortality in COPD-CAP patients were comorbid with coronary heart disease, aspiration, need for NIMV (non-invasive mechanical ventilation) and CURB-65 ≥ 3 (OR = 5.206, OR = 7.921, OR = 3.974, OR = 18.002, respectively). CONCLUSIONS: COPD patients hospitalized with CAP had higher rate of need for NIMV, need for ICU admission and severity scores than those without COPD. Aspiration, D-dimer > 2.0 µg/mL, comorbid with coronary heart disease, need for NIMV and CURB-65 ≥ 3 were mortality risk factors in CAP patients comorbid with COPD.

RACK1 is required for adipogenesis.

Adipose tissue plays a critical role in metabolic diseases and the maintenance of energy homeostasis. RACK1 has been identified as an adaptor protein involved in multiple intracellular signal transduction pathways and diseases. However, whether it regulates adipogenesis remains unknown. Here, we reported that RACK1 is expressed in 3T3-L1 cells and murine white adipose tissue and that RACK1 knockdown by shRNA profoundly suppressed adipogenesis by reducing the expression of PPAR-γ and C/EBP-ß. Depletion of RACK1 increased ß-catenin protein levels and activated Wnt signaling. Furthermore, RACK1 knockdown also suppressed the PI3K-Akt-mTOR-S6K signaling pathway by reducing the PI3K p85α, pAkt T473, and S6K p70. Taken together, these results demonstrate that RACK1 is a novel factor required for adipocyte differentiation by emerging Wnt/ß-catenin signaling and PI3K-Akt-mTOR-S6K signaling pathway(s).

Epitaxial self-assembly of binary molecular components into branched nanowire heterostructures for photonic applications.

We report a sequential epitaxial growth to prepare organic branched nanowire heterostructures (BNwHs) consisting of a microribbon trunk of 1,4-dimethoxy-2,5-di[4'-(cyano)styryl]benzene (COPV) with multiple nanowire branches of 2,4,5-triphenylimidazole (TPI) in a one-pot solution synthesis. The synthesis involves a seeded-growth process, where COPV microribbons are grown first as a trunk followed by a seeded-growth of TPI nanowire branches at the pregrown trunk surfaces. Selected area electron diffraction characterizations reveal that multiple hydrogen-bonding interactions between TPI and COPV components play an essential role in the epitaxial growth as a result of the structural matching between COPV and TPI crystals. A multichannel optical router was successfully realized on the basis of the passive waveguides of COPV green photoluminescence (PL) along TPI nanowire branches in a single organic BNwH.

Whispering-gallery-mode microlaser based on self-assembled organic single-crystalline hexagonal microdisks.

Whispering-gallery-mode (WGM) resonators of semiconductor microdisks have been applied for achieving low-threshold and narrow-linewidth microlasers, but require sophisticated top-down processing technology. Organic single-crystalline hexagonal microdisks (HMDs) of p-distyrylbenzene (DSB) self-assembled from solution can function as WGM microresonators with a cavity quality factor (Q) of 210. Both multiple- and single-mode lasing had been achieved using DSB HMDs with an edge length of 4.3 and 1.2 µm, respectively. These organic microdisks fabricated by bottom-up self-assembly approach may offer potential applications as low-threshold microlaser sources for photonic circuit integration.

Chemical constituents from the aerial parts of Rubia cordifolia L. with their NO inhibitory activity.

A new naphthoquinone derivative (1) together with twenty-three known compounds (2-24), were isolated from the aerial parts of Rubia cordifolia L. Their structures were elucidated on the basis of NMR and HR-ESIMS data. Compounds 1-13 were assessed for their inhibitory effects on NO production in LPS-stimulated RAW 264.7 macrophage cells. Compounds 2-6 exhibited significant inhibitory activities with IC50 values of 21.37, 13.81, 24.56, 20.32, and 30.08 µmol·L-1, respectively.

Bio-guided isolation of anti-inflammatory compounds from Tilia tuan Szyszyl. flowers via in vitro and in silico study.

ETHNOPHARMACOLOGICAL RELEVANCE: Tilia tuan Szyszyl. is a perennial arboreal plant renowned for its medicinal and economic significance. All the roots, stems, leaves, flowers, and fruits have been used medicinally by the folk Bai and Yi people in Yunnan province, China, to treat inflammation, rheumatism and pain for a long time. The detailed chemical constituents and their anti-inflammatory mechanisms remain unexplored. AIM OF THE STUDY: The objective of this study was to investigate the main anti-inflammatory constituents of T. tuan flowers through bio-guided isolation and to evaluate their anti-inflammatory effects relevant to its traditional medicinal use. MATERIAL AND METHODS: Bio-guided isolation was conducted on the extract of T. tuan flowers using a combination of column chromatography and preparative HPLC. The structures were established by a combination of extensive spectroscopic analyses and single-crystal X-ray diffraction analysis. The anti-inflammatory activity in vitro was evaluated by measuring the inhibition of nitric oxide (NO) production in LPS-stimulated RAW 264.7 cells. TNF-α and IL-6 levels were evaluated by ELISA. The expression of COX-2 and NF-κB was assayed via western blotting, and in-silico molecular docking was conducted to explore the potential mechanism. RESULTS: Twenty-two compounds, including ten flavonoids (1-10), seven phenylpropanoids (11-17), three triterpenoids (19-21), one sterol glucoside 18, and one glyceride 22, were identified from T. tuan flowers for the first time. Among them, 1 is a new compound. It is noted that 1, 5, 7, 8, 10, 17, and 22 exhibited remarkable anti-inflammatory activity against NO production with a range of 5.2-34.5 µM, superior to the positive control L-NMMA. Moreover, the new compound 1 inhibited significantly inflammatory factors IL-6 and TNF-α. CONCLUSION: The results show that flavonoids including the new one and the phenyl-propanoid are the primary active constituents of T. tuan flowers, responsible for its ethno-pharmacological uses on osteoarthritis and rheumatism. T. tuan flowers could be a promising therapeutic agent to modulate inflammatory diseases.

Flavonoids from the fruits of Phyllanthus acidus (L.) Skeels with anti-α-glucosidase activity.

Eleven flavonoids including one new flavonol glycoside, quercetin-3-O-(2-α-L-rhamnopyranosyl)-ß-D-glucuronopyranosyl methyl ester (1), were isolated for the first time from the fruits of Phyllanthus acidus (L.) Skeels (Phyllanthaceae). Their structures were determined by extensive spectroscopic data. The known flavonoids, quercetin-3-O-ß-D-glucuronide methyl ester (3), quercetin-3-O-(2''-α-L-rhamnopyranosyl-6''-O-α-L-rhamno pyranosyl)-ß-D-glucopyranoside (5), myricetin (9), and 6-methoxy-naringenin (11) were isolated for the first time from the genus Phyllanthus. Flavonoids 4, 6 and 9 (IC50 = 6.01, 6.32, and 7.84 µM, respectively) showed stronger α-glucosidase inhibitory activities than the positive control, acarbose (IC50 = 306.45 µM). The fruits of P. acidus might be further developed as an anti-diabetic food supplement.

Sequential stabilization of RNF220 by RLIM and ZC4H2 during cerebellum development and Shh-group medulloblastoma progression.

Sonic hedgehog (Shh) signaling is essential for the proliferation of cerebellar granule neuron progenitors (CGNPs), and its misregulation is linked to various disorders, including cerebellar cancer medulloblastoma (MB). During vertebrate neural development, RNF220, a ubiquitin E3 ligase, is involved in spinal cord patterning by modulating the subcellular location of glioma-associated oncogene homologs (Glis) through ubiquitination. RNF220 is also required for full activation of Shh signaling during cerebellum development in an epigenetic manner through targeting embryonic ectoderm development. ZC4H2 was reported to be involved in spinal cord patterning by acting as an RNF220 stabilizer. Here, we provided evidence to show that ZC4H2 is also required for full activation of Shh signaling in CGNP and MB progression by stabilizing RNF220. In addition, we found that the ubiquitin E3 ligase RING finger LIM domain-binding protein (RLIM) is responsible for ZC4H2 stabilization via direct ubiquitination, through which RNF220 is also thus stabilized. RLIM is a direct target of Shh signaling and is also required for full activation of Shh signaling in CGNP and MB cell proliferation. We further provided clinical evidence to show that the RLIM‒ZC4H2‒RNF220 cascade is involved in Shh-group MB progression. Disease-causative human RLIM and ZC4H2 mutations affect their interaction and regulation. Therefore, our study sheds light on the regulation of Shh signaling during cerebellar development and MB progression and provides insights into neural disorders caused by RLIM or ZC4H2 mutations.

Hepatic RACK1 deletion disturbs lipid and glucose homeostasis independently of insulin resistance.

Receptor for activated C kinase 1 (RACK1) is a versatile protein involved in multiple biological processes. In a previous study by Zhao et al., hepatic RACK1 deletion in mice led to an inhibition of autophagy, blocked autophagy-dependent lipolysis, and caused steatosis. Using the same mouse model (RACK1hep-/-), we revealed new roles of RACK1 in maintaining bile acid homeostasis and hepatic glucose uptake, which further affected circulatory lipid and glucose levels. To be specific, even under hepatic steatosis, the plasma lipids were generally reduced in RACK1hep-/- mouse, which was due to the suppression of intestinal lipid absorption. Accordingly, a decrease in total bile acid level was found in RACK1hep-/- livers, gallbladders, and small intestine tissues, and specific decrease of 12-hydroxylated bile acids was detected by liquid chromatography-mass spectrometry. Consistently, reduced expression of CYP8B1 was found. A decrease in hepatic glycogen storage was also observed, which might be due to the inhibited glucose uptake by GLUT2 insufficiency. Interestingly, RACK1-KO-inducing hepatic steatosis did not raise insulin resistance (IR) nor IR-inducing factors like endoplasmic reticulum stress and inflammation. In summary, this study uncovers that hepatic RACK1 might be required in maintaining bile acid homeostasis and glucose uptake in hepatocytes. This study also provides an additional case of hepatic steatosis disassociation with insulin resistance.

Isolation and identification of SiCOL5, which is involved in photoperiod response, based on the quantitative trait locus mapping of Setaria italica.

Foxtail millet (Setaria italica) is a versatile grain and fodder crop grown in arid and semi-arid regions. It is an especially important crop for combating malnutrition in certain poverty-stricken areas of the world. Photoperiod sensitivity is a major constraint to the distribution and utilization of foxtail millet germplasm resources. Foxtail millet may be suitable as a model species for studying the photoperiod sensitivity of C4 crops. However, the genetic basis of the photoperiod response of foxtail millet remains poorly studied. To detect the genetic basis of photoperiod sensitivity-related traits, a recombinant inbred line (RIL) population consisting of 313 lines derived from a cross between the spring-sown cultivar "Longgu 3" and the summer-sown cultivar "Canggu 3" was established. The RIL population was genotyped using whole-genome re-sequencing and was phenotyped in four environments. A high-density genetic linkage map was constructed with an average distance between adjacent markers of 0.69 cM. A total of 21 quantitative trait loci (QTLs) were identified by composite interval mapping, and 116 candidate genes were predicted according to gene annotations and variations between parents, among which three genes were considered important candidate genes by the integration and overall consideration of the results from gene annotation, SNP and indel analysis, cis-element analysis, and the expression pattern of different genes in different varieties, which have different photoperiod sensitivities. A putative candidate gene, SiCOL5, was isolated based on QTL mapping analysis. The expression of SiCOL5 was sensitive to photoperiod and was regulated by biological rhythm-related genes. Function analysis suggested that SiCOL5 positively regulated flowering time. Yeast two-hybrid and bimolecular fluorescence complementation assays showed that SiCOL5 was capable of interacting with SiNF-YA1 in the nucleus.

Multiple in vitro biological effects of phenolic compounds from Terminalia chebula var. tomentella.

ETHNOPHARMACOLOGICAL RELEVANCE: Terminalia chebula (TC), a well-known Indian Ayurvedic medicine introduced into China in the Sui and Tang Dynasties, has been recorded and used medicinally as Fructus Chebulae, together with its variety tomentella (TCT) in the Chinese Pharmacopoeia. They have been also used commonly for the treatment of diabetes mellitus by Tibetan medicine. AIM OF THE STUDY: To investigate the main bioactive and therapeutic principles in the fruits of TCT, based on the extensive evaluation of their anti-inflammatory and hypoglycemic activities. MATERIALS AND METHODS: The TCT fresh fruits were analyzed by HPLC and separated further by column chromatography and preparative HPLC. The isolated compounds were identified by extensive spectroscopic analyses, including 1D/2D NMR, MS, UV, IR and ECD. Anti-inflammatory activity was evaluated by inhibition of NO production in RAW264.7 cells. The specific iNOS (PDB ID: 3E7G) structure was prepared by Discovery Studio 4.0, and the molecular docking simulation was performed on GOLD (version 5.2.2). Hypoglycemic activity was measured using the substrate solution of 4-nitrophenyl-α-d-glucopyranoside enzyme and buffer solution. RESULTS: The HPLC analysis method of polyphenols in the fruits of TCT was established, and 13 main chromatographic peaks were identified, including six hydrolyzable tannins (2, 4-7, 10-11), three simple phenols (12-14), and one oleanane pentacyclic triterpene, arjungenin. Extensive chromatographic separation of TCT fresh fruits yielded 14 compounds, including one new natural hydrolyzable tannin, 2,3-(S)-HHDP-6-O-galloyl-d-glucose (1). The known compounds were identified as 10 hydrolyzable tannins (2-11) and three simple phenols (12-14). Compounds 10 (IC50 = 36.43 ± 0.21 µM), 11 (IC50 = 42.28 ± 0.09 µM) displayed stronger NO inhibitory activity than the positive control L-NMMA (IC50 = 42.34 ± 0.66 µM), while 2, 4, and 9 showed moderate inhibitory activity against NO production. Further molecular docking simulation of specific iNOS on 10 and 11, as well as five previously isolated lignans 15-19 showed that there were no obvious rules between docking results and the in vitro NO inhibitory activity for hydrolyzable tannins (10 and 11), while the mechanism of anti-inflammatory activity for lignans was related to the substitution of conjugated aldehyde groups. Moreover, most of the hydrolyzable tannins (1-2, 4-5, 9-11) and simple phenol (12) displayed stronger inhibitory effects on α-glucosidase than the positive control, quercetin (IC50 = 6.118 ± 0.071 µM), with IC50 values ranging from 0.079 to 16.494 µM. Among these bioactive isolates, the hydrolyzable tannins 2, 4-5, and 9-11, and simple phenol 12 are major chemical components in TCT fruit. CONCLUSIONS: The results showed that lignans and hydrolyzed tannins are the main active ingredients of TCT fruits, responsible for the traditional treatment of sore throat and cough. Moreover, hydrolyzed tannins and simple phenolic compounds with potential hypoglycemic activity are closely related to the ethno-pharmacological uses of TCT fruits on diabetes in Tibetan medicine.

High-Throughput In Vitro Gene Expression Profile to Screen of Natural Herbals for Breast Cancer Treatment.

Breast cancer has surpassed lung cancer as the most commonly diagnosed cancer in women worldwide. Some therapeutic drugs and approaches could cause side effects and weaken the immune system. The combination of conventional therapies and traditional Chinese medicine (TCM) significantly improves treatment efficacy in breast cancer. However, the chemical composition and underlying anti-tumor mechanisms of TCM still need to be investigated. The primary aim of this study is to provide unique insights to screen the natural components for breast cancer therapy using high-throughput transcriptome analysis. Differentially expressed genes were identified based on two conditions: single samples and groups were classified according to their pharmaceutical effect. Subsequently, the sample treated with E. cochinchinensis Lour. generated the most significant DEGs set, including 1,459 DEGs, 805 upregulated and 654 downregulated. Similarly, group 3 treatment contained the most DEGs (414 DEGs, 311 upregulated and 103 downregulated). KEGG pathway analyses showed five significant pathways associated with the inflammatory and metastasis processes in cancer, which include the TNF, IL-17, NF-kappa B, MAPK signaling pathways, and transcriptional misregulation in cancer. Samples were classified into 13 groups based on their pharmaceutical effects. The results of the KEGG pathway analyses remained consistent with signal samples; group 3 presents a high significance. A total of 21 genes were significantly regulated in these five pathways, interestingly, IL6, TNFAIP3, and BRIC3 were enriched on at least two pathways, seven genes (FOSL1, S100A9, CXCL12, ID2, PRS6KA3, AREG, and DUSP6) have been reported as the target biomarkers and even the diagnostic tools in cancer therapy. In addition, weighted correlation network analysis (WGCNA) was used to identify 18 modules. Among them, blue and thistle2 were the most relevant modules. A total of 26 hub genes in blue and thistle2 modules were identified as the hub genes. In conclusion, we screened out three new TCM (R. communis L., E. cochinchinensis Lour., and B. fruticosa) that have the potential to develop natural drugs for breast cancer therapy, and obtained the therapeutic targets.

High-Throughput Screen of Natural Compounds and Biomarkers for NSCLC Treatment by Differential Expression and Weighted Gene Coexpression Network Analysis (WGCNA).

Lung cancer is known as the leading cause which presents the highest fatality rate worldwide; non-small-cell lung cancer (NSCLC) is the most prevalent type of lung carcinoma with high severity and affects 80% of patients with lung malignancies. Up to now, the general treatment for NSCLC includes surgery, chemotherapy, and radiotherapy; however, some therapeutic drugs and approaches could cause side effects and weaken the immune system. The combination of conventional therapies and traditional Chinese medicine (TCM) significantly improves treatment efficacy in lung cancer. Therefore, it is necessary to investigate the chemical composition and underlying antitumor mechanisms of TCM, so as to get a better understanding of the potential natural ingredient for lung cancer treatment. In this study, we selected 78 TCM to treat NSCLC cell line (A549) and obtained 92 transcriptome data; differential expression and WGCNA were applied to screen the potential natural ingredient and target genes. The sample which was treated with A. pierreana generated the most significant DEG set, including 6130 DEGs, 2479 upregulated, and 3651 downregulated. KEGG pathway analyses found that four pathways (MAPK, NF-kappa B, p53, and TGF-beta signaling pathway) were significantly enriched; 16 genes were significantly regulated in these four pathways. Interestingly, some of them such as EGFR, DUSP4, IL1R1, IL1B, MDM2, CDKNIA, and IDs have been used as the target biomarkers for cancer diagnosis and therapy. In addition, classified samples into 14 groups based on their pharmaceutical effects, WGCNA was used to identify 27 modules. Among them, green and darkgrey were the most relevant modules. Eight genes in the green module and four in darkgrey were identified as hub genes. In conclusion, we screened out three new TCM (B. fruticose, A. pierreana, and S. scandens) that have the potential to develop natural anticancer drugs and obtained the therapeutic targets for NSCLC therapy. Our study provides unique insights to screen the natural components for NSCLC therapy using high-throughput transcriptome analysis.

Xenopus RCOR2 (REST corepressor 2) interacts with ZMYND8, which is involved in neural differentiation.

Regulation of neuronal gene expression is critical to nervous system development. REST (RE1-silencing transcription factor) regulates neuronal gene expression through interacting with a group of corepressor proteins including REST corepressors (RCOR). Here we show that Xenopus RCOR2 is predominantly expressed in the developing nervous system. Through a yeast two-hybrid screen, we isolated Xenopus ZMYND8 (Zinc finger and MYND domain containing 8) as an XRCOR2 interacting factor. XRCOR2 and XZMYND8 bind each other in co-immunoprecipitation assays and both of them can function as transcriptional repressors. XZMYND8 is co-expressed with XRCOR2 in the nervous system and overexpression of XZMYND8 inhibits neural differentiation in Xenopus embryos. These data reveal a RCOR2/ZMYND8 complex which might be involved in the regulation of neural differentiation.

RNF220, an E3 ubiquitin ligase that targets Sin3B for ubiquitination.

Modification of proteins by ubiquitination plays important roles in various cellular processes. During this process, the target specificity is determined by ubiquitin ligases. Here we identify RNF220 (RING finger protein 220) as a novel ubiquitin ligase for Sin3B. As a conserved RING protein, RNF220 can bind E2 and mediate auto-ubiquitination of itself. Through a yeast two-hybrid screen, we isolated Sin3B as one of its targets, which is a scaffold protein of the Sin3/HDAC (histone deacetylase) corepressor complex. RNF220 specifically interacts with Sin3B both in vitro and in vivo. Sin3B can be regulated by the ubiquitin-proteasome system. Co-expression of RNF220 promotes the ubiquitination and proteasomal degradation of Sin3B. Taken together, these results reveal a new mechanism for regulating the Sin3/HDAC complex.

Tuning nanocavities of Au@Cu2O yolk-shell nanoparticles for highly selective electroreduction of CO2 to ethanol at low potential.

The electrosynthesis of high-value ethanol from carbon dioxide and carbon monoxide addresses the need for the large-scale storage of renewable electricity and reduction of carbon emissions. However, the electrosynthesis of ethanol by the CO2 reduction reaction (CO2RR) has suffered from low selectivity and energy efficiency. Here, we report a catalyst composed of Au nanoparticles in Cu2O nanocavities (Au@Cu2O) that is very active for CO2 reduction to ethanol through the confinement of the CO intermediate. The architecture shows tandem catalysis mechanisms in which CO2 reduction on Au yolks produces CO filling Cu nanocavities, where a sufficiently high CO concentration due to the confinement effect promotes ethanol formation and then results in an ethanol faradaic efficiency of 52.3% at -0.30 V versus the reversible hydrogen electrode (vs. RHE) via regulating the hollow size of the Cu2O nanocavities. Such a strategy provides a new way of fabricating various tandem catalysts with high selectivity and efficiency for the CO2RR.

Synthesis and antitumor activity of camptothecin- 4ß-triazolopodophyllotoxin conjugates.

Two new compounds (9 and 10) having a camptothecin (CPT) analog conjugated to the 4ß-azido-4-deoxypodophyllotixin analog by untilizing the copper-catalyzed azide-alkyne cycloadditon (CuAAC) reaction, and were evaluated for their cytotoxicity against a panel of five human cancer cell lines (HL-60, SMMC-7721, A-549, MCF-7 and SW480) using the MTT (3-(4,5-dimethyl-thiahiazo-2-yl)-2,5-diphenyltetrazolium bromide) assay. Two novel conjugates shown weak cytotoxicity, compound 10 showed highly potent against HL-60 cell line tested, with IC50 value 17.69 ± 0.19 µM. This compound suggested its potential as anticancer agents for further development. [Formula: see text].