1
|
Wang KD, Zhu ML, Qin CJ, Dong RF, Xiao CM, Lin Q, Wei RY, He XY, Zang X, Kong LY, Xia YZ. Sanguinarine induces apoptosis in osteosarcoma by attenuating the binding of STAT3 to the single-stranded DNA-binding protein 1 (SSBP1) promoter region. Br J Pharmacol 2023; 180:3175-3193. [PMID: 37501645 DOI: 10.1111/bph.16202] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 06/19/2023] [Accepted: 07/20/2023] [Indexed: 07/29/2023] Open
Abstract
BACKGROUND AND PURPOSE Osteosarcoma, a primary malignant bone tumour prevalent among adolescents and young adults, remains a considerable challenge despite protracted progress made in enhancing patient survival rates over the last 40 years. Consequently, the development of novel therapeutic approaches for osteosarcoma is imperative. Sanguinarine (SNG), a compound with demonstrated potent anticancer properties against various malignancies, presents a promising avenue for exploration. Nevertheless, the intricate molecular mechanisms underpinning SNG's actions in osteosarcoma remain elusive, necessitating further elucidation. EXPERIMENTAL APPROACH Single-stranded DNA-binding protein 1 (SSBP1) was screened out by differential proteomic analysis. Apoptosis, cell cycle, reactive oxygen species (ROS) and mitochondrial changes were assessed via flow cytometry. Western blotting and quantitative real-time reverse transcription PCR (qRT-PCR) were used to determine protein and gene levels. The antitumour mechanism of SNG was explored at a molecular level using chromatin immunoprecipitation (ChIP) and dual luciferase reporter plasmids. KEY RESULTS Our investigation revealed that SNG exerted an up-regulated effect on SSBP1, disrupting mitochondrial function and inducing apoptosis. In-depth analysis uncovered a mechanism whereby SNG hindered the JAK/signal transducer and activator of transcription 3 (STAT3) signalling pathway, relieved the inhibitory effect of STAT3 on SSBP1 transcription, and inhibited the downstream PI3K/Akt/mTOR signalling axis, ultimately activating apoptosis. CONCLUSIONS AND IMPLICATIONS The study delved further into elucidating the anticancer mechanism of SNG in osteosarcoma. Notably, we unravelled the previously undisclosed apoptotic potential of SSBP1 in osteosarcoma cells. This finding holds substantial promise in advancing the development of novel anticancer drugs and identification of therapeutic targets.
Collapse
Affiliation(s)
- Kai-Di Wang
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Miao-Lin Zhu
- Department of Oncology, The Affiliated Cancer Hospital of Nanjing Medical University and Jiangsu Cancer Hospital and Jiangsu Institute of Cancer Research, Nanjing, China
| | - Cheng-Jiao Qin
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Rui-Fang Dong
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Cheng-Mei Xiao
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Qing Lin
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Rong-Yuan Wei
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Xiao-Yu He
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Xin Zang
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Ling-Yi Kong
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Yuan-Zheng Xia
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| |
Collapse
|
2
|
Yan S, Tu CY, Du CY, Luo J, Liu JF, Liu TQ, Liu Q, Liu J, Li XH, Wang LC, Fang ZP, Yi WM, Chen YJ, Li QL, Ni Y, Wu JC, Qin CJ, Gu YL, Lu Z, Lun ZJ, Du LX, Chen G, Zheng QC, Sun KJ, Han WQ, Yu J. [Effect of recombinant human thrombin for hemostasis in liver resection: a randomized controlled phase Ⅲ clinical trial]. Zhonghua Yi Xue Za Zhi 2023; 103:3416-3423. [PMID: 37963740 DOI: 10.3760/cma.j.cn112137-20230911-00438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/16/2023]
Abstract
Objective: To evaluate the hemostatic efficacy, safety and immunogenicity of recombinant human thrombin in the treatment of liver wounds that still ooze after conventional surgical hemostasis. Methods: A multicenter, stratified randomized, double-blind, placebo-controlled phase Ⅲ trial with a planned enrollment of 510 subjects at 33 centers, with a 2∶1 randomization to the thrombin group versus the placebo group. An interim analysis will be conducted after approximately 70% of the subjects have completed the observation period. The primary efficacy endpoint was the rate of hemostasis within 6 minutes at the point of bleeding that could be evaluated. Safety analysis was performed one month after surgery, and the positive rates of anti-drug antibody (ADA) and neutralizing antibody were evaluated. Results: At the interim analysis, a total of 348 subjects had been randomized and received the study drug (215 were male and 133 were female). They were aged 19-69 (52.9±10.9)years. Among them, 232 were in the thrombin group and 116 were in the placebo group, with balanced and comparable demographics and baseline characteristics between the two groups. The hemostasis rate at 6 minutes was 71.6% (95%CI:65.75%-77.36%) in the thrombin group and 44.0% (95%CI: 34.93%-53.00%) in the placebo group, respectively (P<0.001). No grade≥3 drug-related adverse events and no drug-related deaths were reported from the study.No recombinant human thrombin-induced immunologically-enhanced ADA or immunologically-induced ADA was detected after topical use in subjects. Conclusion: Recombinant human thrombin has shown significant hemostatic efficacy and good safety in controlling bleeding during liver resection surgery, while also demonstrating low immunogenicity characteristics.
Collapse
Affiliation(s)
- S Yan
- Department of Hepatobiliary and Pancreatic Surgery, the Second Hospital of Zhejiang University School of Medicine, Hangzhou 310003, China
| | - C Y Tu
- Department of General Surgery, Lishui Central Hospital, Lishui 323020, China
| | - C Y Du
- Department of Hepatobiliary Surgery, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400042, China
| | - J Luo
- Department of Hepatobiliary and Intestinal Surgery, Hunan Cancer Hospital, Changsha 410031, China
| | - J F Liu
- Department of Hepatobiliary and Pancreatic Surgery, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou 350025, China
| | - T Q Liu
- Department of General Surgery, Jiangbin Hospital of Guangxi Zhuang Autonomous Region, Nanning 530021, China
| | - Q Liu
- Department of Hepatobiliary Surgery, Liuzhou People's Hospital, Liuzhou 545006, China
| | - J Liu
- Department of Hepatobiliary Surgery, Guizhou Provicial People's Hospital, Guiyang 550002, China
| | - X H Li
- Department of Hepatobiliary Surgery, Liaocheng People's Hospital, Liaocheng 252000, China
| | - L C Wang
- Department of General Surgery, the Third People's Hospital of Hainan Province, Sanya 572000, China
| | - Z P Fang
- Department of Hepatobiliary Surgery, Taizhou Hospital of Zhejiang Province, Linhai 317099, China
| | - W M Yi
- Department of Hepatobiliary Surgery, Hunan Provincial People's Hospital, Changsha 410005, China
| | - Y J Chen
- Department of Hepatobiliary Surgery, Sun Yat-sen Memorial Hospital of Sun Yat-sen University, Guangzhou 510120, China
| | - Q L Li
- Department of Hepatobiliary and Pancreatic Surgery, the Second Xiangya Hospital of Central South University, Changsha 410011, China
| | - Y Ni
- Department of Hepatobiliary and Pancreatic Surgery, Shenzhen Second People's Hospital, Shenzhen 518035, China
| | - J C Wu
- Department of Hepatobiliary Surgery, Hainan Provincial People's Hospital, Haikou 570311, China
| | - C J Qin
- Department of General Surgery, Huaihe Hospital of Henan University, Kaifeng 475000, China
| | - Y L Gu
- Department of Hepatobiliary Surgery, Affiliated Hospital of Jiangnan Univeisity, Wuxi 214122, China
| | - Z Lu
- Department of Hepatobiliary Surgery, the First Affiliated Hospital of Bengbu Medical College, Bengbu 233004, China
| | - Z J Lun
- Department of Hepatobiliary Vascular Surgery, Zaozhuang Municipal Hospital, Zaozhuang 277101, China
| | - L X Du
- Department of Hepatobiliary Surgery, Shanxi Provincial People's Hospital, Xi'an 710068, China
| | - G Chen
- Department of Hepatobiliary and Pancreatic Surgery, the First People's Hospital of Kunming, Kunming 650034, China
| | - Q C Zheng
- Department of Hepatobiliary Surgery, Union Hospital Affiliated to Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430022, China
| | - K J Sun
- Department of Hepatobiliary Surgery, Zibo Central Hospital, Zibo 255036, China
| | - W Q Han
- Department of Urinary Surgery, Hunan Cancer Hospital, Changsha 410031, China
| | - J Yu
- Department of Hepatobiliary and Pancreatic Surgery, the First Hospital of Zhejiang University School of Medicine, Hangzhou 310003, China
| |
Collapse
|
3
|
Dong RF, Qin CJ, Yin Y, Han LL, Xiao CM, Wang KD, Wei RY, Xia YZ, Kong LY. Discovery of a potent inhibitor of chaperone-mediated autophagy that targets the HSC70-LAMP2A interaction in non-small cell lung cancer therapy. Br J Pharmacol 2023. [PMID: 37311689 DOI: 10.1111/bph.16165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 05/26/2023] [Accepted: 05/27/2023] [Indexed: 06/15/2023] Open
Abstract
BACKGROUND AND PURPOSE Chaperone-mediated autophagy (CMA) is a selective type of autophagy for targeting proteins degradation and maintains high activity in multiple malignancies. Inhibition of the combination of HSC70 and LAMP2A can potently block CMA. At present, knockdown of LAMP2A remains the most specific method for inhibiting CMA and chemical inhibitors against CMA have not yet been discovered. EXPERIMENTAL APPROACH The levels of CMA in NSCLC tissue samples were confirmed by tyramide signal amplification (TSA) dual immunofluorescence assay. High-content screening was performed based on CMA activity, to identify the potential CMA inhibitors. The target of the inhibitor was determined by drug affinity responsive target stability-mass spectrum (DARTS-MS) and verified by protein mass spectrometry. Inhibition and activation of CMA were performed to elucidate the molecular mechanism of the CMA inhibitor. KEY RESULTS We revealed that suppression of the interaction between HSC70 and LAMP2A blocked CMA in NSCLC and restrained tumor growth. Polyphyllin D (PPD) was firstly identified as a targeted CMA small-molecule inhibitor through disturbing HSC70-LAMP2A interaction. The binding sites for PPD were E129 and T278 at the nucleotide binding domain of HSC70 and C-terminal of LAMP2A respectively. PPD accelerated unfold protein generation to induce ROS accumulation by inhibiting HSC70-LAMP2A-eIF2α signaling axis. Besides, PPD prevented the regulatory compensation of macroautophagy induced by CMA inhibition via blocking STX17-SNAP29-VAMP8 signaling axis. CONCLUSION AND IMPLICATIONS PPD is a targeted CMA inhibitor that can block both HSC70-LAMP2A interaction and LAMP2A homomultimerization. CMA suppression without increasing the regulatory compensation from macroautophagy is a good strategy for NSCLC therapy.
Collapse
Affiliation(s)
- Rui-Fang Dong
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, 24 Tong Jia Xiang, 210009, Nanjing, China
| | - Cheng-Jiao Qin
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, 24 Tong Jia Xiang, 210009, Nanjing, China
| | - Yong Yin
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, 24 Tong Jia Xiang, 210009, Nanjing, China
| | - Liang-Liang Han
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, 24 Tong Jia Xiang, 210009, Nanjing, China
| | - Cheng-Mei Xiao
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, 24 Tong Jia Xiang, 210009, Nanjing, China
| | - Kai-Di Wang
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, 24 Tong Jia Xiang, 210009, Nanjing, China
| | - Rong-Yuan Wei
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, 24 Tong Jia Xiang, 210009, Nanjing, China
| | - Yuan-Zheng Xia
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, 24 Tong Jia Xiang, 210009, Nanjing, China
| | - Ling-Yi Kong
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, 24 Tong Jia Xiang, 210009, Nanjing, China
| |
Collapse
|
4
|
Yuan LL, Chen Z, Qin J, Qin CJ, Bian J, Dong RF, Yuan TB, Xu YT, Kong LY, Xia YZ. Single-cell sequencing reveals the landscape of the tumor microenvironment in a skeletal undifferentiated pleomorphic sarcoma patient. Front Immunol 2022; 13:1019870. [DOI: 10.3389/fimmu.2022.1019870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 10/25/2022] [Indexed: 11/17/2022] Open
Abstract
Skeletal undifferentiated pleomorphic sarcoma (SUPS) is an invasive pleomorphic soft tissue sarcoma with a high degree of malignancy and poor prognosis. It is prone to recur and metastasize. The tumor microenvironment (TME) and the pathophysiology of SUPS are barely described. Single-cell RNA sequencing (scRNA-seq) provides an opportunity to dissect the landscape of human diseases at an unprecedented resolution, particularly in diseases lacking animal models, such as SUPS. We performed scRNA-seq to analyze tumor tissues and paracancer tissues from a SUPS patient. We identified the cell types and the corresponding marker genes in this SUPS case. We further showed that CD8+ exhausted T cells and Tregs highly expressed PDCD1, CTLA4 and TIGIT. Thus, PDCD1, CTLA4 and TIGIT were identified as potential targets in this case. We applied copy number karyotyping of aneuploid tumors (CopyKAT) to distinguish malignant cells from normal cells in fibroblasts. Our study identified eight malignant fibroblast subsets in SUPS with distinct gene expression profiles. C1-malignant Fibroblast and C6-malignant Fibroblast in the TME play crucial roles in tumor growth, angiogenesis, metastasis and immune response. Hence, targeting malignant fibroblasts could represent a potential strategy for this SUPS therapy. Intervention via tirelizumab enabled disease control, and immune checkpoint inhibitors (ICIs) of PD-1 may be considered as the first-line option in patients with SUPS. Taken together, scRNA-seq analyses provided a powerful basis for this SUPS treatment, improved our understanding of complex human diseases, and may afforded an alternative approach for personalized medicine in the future.
Collapse
|
5
|
Zhao DX, Chen LQ, Qin JG, Qin CJ, Zhang H, Wu P, Li EC. Molecular characterization of a cytosolic manganese superoxide dismutase from the Chinese mitten crab, Eriocheir sinensis. Genet Mol Res 2014; 13:9429-42. [PMID: 25501153 DOI: 10.4238/2014.november.11.8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
A cytosolic manganese superoxide dismutase gene (Es-cMnSOD) was cloned from the Chinese mitten crab Eriocheir sinensis, using reverse transcription-polymerase chain reaction and the rapid amplification of cDNA ends. The open reading frame of Es-cMnSOD is 867 bp in length and encodes a 288-amino acid protein without a signal peptide. The calculated molecular mass of the translated protein of Es-cMnSOD is 31.43 kDa, with an estimated isoelectric point of 6.30. The deduced amino acid sequence of Es-cMnSOD has similarities of 90, 89, 84, 87, and 81% to those of white shrimp Litopenaeus vannamei MnSOD, black tiger shrimp Penaeus monodon MnSOD, giant freshwater prawn Macrobrachium rosenbergii MnSOD, blue crab Callinectes sapidus MnSOD, and red swamp crayfish Procambarus clarkii MnSOD, respectively. Es-cMnSOD contains a manganese superoxide dismutase domain (DVWEHAYY) and 4 conserved amino acids responsible for binding manganese. Es-cMnSOD was expressed in the hemocytes, eyestalk, muscle, intestine, gill, and hepatopancreas. Es-cMnSOD transcripts in hemocytes of E. sinensis increased at 1.5 and 48 h after injection of Aeromonas hydrophila, indicating that the induction of the SOD system response occurred within a short period of time. This study suggests that MnSOD may play a critical role in crab immunity, allowing efficient activation of an early innate immune response in the crab.
Collapse
Affiliation(s)
- D X Zhao
- Department of Biology, East China Normal University, Shanghai, China
| | - L Q Chen
- Department of Biology, East China Normal University, Shanghai, China
| | - J G Qin
- School of Biological Sciences, Flinders University, Adelaide, Australia
| | - C J Qin
- Department of Biology, East China Normal University, Shanghai, China
| | - H Zhang
- Department of Biology, East China Normal University, Shanghai, China
| | - P Wu
- Department of Biology, East China Normal University, Shanghai, China
| | - E C Li
- Department of Biology, East China Normal University, Shanghai, China
| |
Collapse
|
6
|
Sheng ZJ, Qin CJ, Wei CW, Miao LC, Hua ZG, Rui C, Lin L, Cai WM. The effect of aerobic exercise and Macrothele raven venom on tumor-bearing mice. Int J Sports Med 2014; 36:93-100. [PMID: 25254897 DOI: 10.1055/s-0034-1385877] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Liver cancer is one of the most common cancers in the world. Macrothele raven venom, a complicated mixture of neurotoxic peptides, proteins and low molecular weight material, has antitumor properties, but its mechanism of action is unknown. Moderate exercise has been shown to shrink tumors and cause a remarkable reduction in the tumor growth rate. In this study, we examined the antitumor effect of Macrothele raven venom in combination with exercise on tumor-bearing mice. Our results demonstrate that aerobic exercise in combination with venom administered at different doses was much more effective in a mouse H22 hepatoma model compared to separate administration of the 2 treatments. The underlying mechanism of this effect may be related to the expression of various tumor suppressor factors.
Collapse
Affiliation(s)
- Z J Sheng
- College of Physical Education, Hunan Normal University, Changsha, China
| | - C J Qin
- College of Physical Education, Hunan Normal University, Changsha, China
| | - C W Wei
- College of Physical Education, Hunan Normal University, Changsha, China
| | - L C Miao
- Central Hospital of Shaoyang, Shaoyang, China
| | - Z G Hua
- Central Hospital of Shaoyang, Shaoyang, China
| | - C Rui
- Central Hospital of Shaoyang, Shaoyang, China
| | - L Lin
- College of Physical Education, Hunan Normal University, Changsha, China
| | - W M Cai
- Central Hospital of Shaoyang, Shaoyang, China
| |
Collapse
|
7
|
Lin L, Cai WM, Qin CJ, Miao LC, Yun LT, Hua Y, Weilin L. Intervention of TLR4 signal pathway cytokines in severe liver injury with obstructive jaundice in rats. Int J Sports Med 2012; 33:572-9. [PMID: 22562737 DOI: 10.1055/s-0031-1301318] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Obstructive jaundice is a common surgical disease and a variety of end-stage severe liver injuries still lack effective treatments. Compared to traditional liver transplantation therapy, herbal treatment is noninvasive and has fewer side effects. Research results have shown that a modified major decoction of bupleurum can reduce the toxic reaction of obstructive jaundice, even though the mechanism is unclear. A period of chronic exercise training can significantly reduce TLR4 expression in mononuclear cells and the secretion of inflammatory cell factors. Our study administered a modified major decoction of bupleurum in combination with exercise in rats with obstructive jaundice and the results indicated that applying a major bupleurum decoction in combination with moderately intense aerobic exercise showed a beneficial effect on adjusting the expression of liver inflammatory cytokines, which thus improved immunity and finally reduced the liver injury of rats with obstructive jaundice.
Collapse
Affiliation(s)
- L Lin
- Hunan Normal University, College of Physical Education, Changsha, China
| | | | | | | | | | | | | |
Collapse
|
8
|
Incarvito C, Rheingold AL, Gavrilova AL, Qin CJ, Bosnich B. Bimetallic reactivity. One-site addition two-metal oxidation reactions using a di-Co(II) complex of a binucleating ligand with 5- and 6-coordinate sites. Inorg Chem 2001; 40:4101-8. [PMID: 11487311 DOI: 10.1021/ic010235r] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The preparation of an unsymmetrical binucleating ligand bearing a bridging oxadiazole ring flanked on one side by three ligands and on the other by four ligands is described. When bound to two metals, the ligand forms complexes where the metals are in 5- and 6-coordinate sites after the incorporation of an exogenous bridging ligand. A di-Co(2+) complex of this ligand has been prepared containing a hydroxide bridge. The complex is readily oxidized to the di-Co(3+) state by outer sphere electron transfer with ferrocenium ions. Addition of Br(2) or NO(2)(+) to the di-Co(2+) complex leads to the rapid formation of the di-Co(3+) bromo or nitro complexes, respectively. The ligand characteristics which allow for double oxidation with ferrocenium ions and for the one-site addition two-metal oxidations with Br(2) and NO(2)(+) are discussed in terms of mechanical coupling between the two metal sites.
Collapse
Affiliation(s)
- C Incarvito
- Department of Chemistry, The University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637, USA
| | | | | | | | | |
Collapse
|
9
|
Liable-Sands LM, Incarvito C, Rheingold AL, Qin CJ, Gavrilova AL, Bosnich B. Bimetallic reactivity. Preparation and properties of bimetallic complexes formed by binucleating ligands bearing 4- and 6-coordinate sites. Inorg Chem 2001; 40:2147-55. [PMID: 11304160 DOI: 10.1021/ic0012625] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Four binucleating ligands bearing 4- and 6-coordinate sites employing phenolate bridges have been prepared. Bimetallic copper(II) and nickel(II) complexes of some of these ligands have been isolated and characterized. Crystal structures of two of the copper(II) complexes have been determined. A monometallic manganese(II) complex of one of these ligands was isolated. Upon exposure to dioxygen, acetonitrile solutions of the complex in the presence of chloride ions lead to the formation of a manganese(IV) complex. The crystal structure of this complex is reported, and it is shown that the metal is in the 4-coordinate ligand site and is bound to two chloride ions.
Collapse
Affiliation(s)
- L M Liable-Sands
- Department of Chemistry, The University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637, USA
| | | | | | | | | | | |
Collapse
|
10
|
Abstract
Two (1,3,4)-oxadiazole ligands have been prepared. In one case the oxadiazole ring is flanked by two o-aniline groups, and in the other case it is an extension of the first where the amines are condensed with 2-picolyl groups. A monometallic copper(II) complex of the former has been prepared, and its crystal structure was determined. A number of bimetallic copper(II), cobalt(II), and nickel(II) complexes of the di-deprotonated latter ligand were prepared and isolated. The crystal structure of the cobalt(II) complex bearing two acetate bridges is reported. The work demonstrates that the seldom-employed oxadiazole ring can be used effectively for generating bimetallic complexes.
Collapse
Affiliation(s)
- C Incarvito
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, USA
| | | | | | | | | |
Collapse
|