1
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Blanco C, Ramos Castellanos R, Fogg DE. Anionic Olefin Metathesis Catalysts Enable Modification of Unprotected Biomolecules in Water. ACS Catal 2024; 14:11147-11152. [PMID: 39114091 PMCID: PMC11301623 DOI: 10.1021/acscatal.4c02811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2024] [Revised: 06/24/2024] [Accepted: 07/01/2024] [Indexed: 08/10/2024]
Abstract
Stability problems have limited the uptake of cationic olefin metathesis catalysts in chemical biology. Described herein are anionic catalysts that improve water-solubility, robustness, and compatibility with biomolecules such as DNA. A sulfonate tag is installed on the cyclic (alkyl)(amino) carbene (CAAC) ligand platform, chosen for resistance to degradation by nucleophiles, base, water, and β-elimination. Hoveyda-Grubbs catalysts bearing the sulfonated CAAC ligands deliver record productivity in metathesis of unprotected carbohydrates and nucleosides at neutral pH. Decomposed catalyst has negligible impact on metathesis selectivity, whereas N-heterocyclic carbene (NHC) catalysts degrade rapidly in water and cause extensive C=C migration.
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Affiliation(s)
- Christian
O. Blanco
- Center
for Catalysis Research & Innovation, and Department of Chemistry
and Biomolecular Sciences, University of
Ottawa, Ottawa, Ontario, K1N 6N5, Canada
| | - Richard Ramos Castellanos
- Center
for Catalysis Research & Innovation, and Department of Chemistry
and Biomolecular Sciences, University of
Ottawa, Ottawa, Ontario, K1N 6N5, Canada
| | - Deryn E. Fogg
- Center
for Catalysis Research & Innovation, and Department of Chemistry
and Biomolecular Sciences, University of
Ottawa, Ottawa, Ontario, K1N 6N5, Canada
- Department
of Chemistry, University of Bergen, Allégaten 41, N-5007 Bergen, Norway
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2
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Alves PM, Barrias CC, Gomes P, Martins MCL. How can biomaterial-conjugated antimicrobial peptides fight bacteria and be protected from degradation? Acta Biomater 2024; 181:98-116. [PMID: 38697382 DOI: 10.1016/j.actbio.2024.04.043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 03/19/2024] [Accepted: 04/25/2024] [Indexed: 05/05/2024]
Abstract
The emergence of antibiotic-resistant bacteria is a serious threat to public health. Antimicrobial peptides (AMP) are a powerful alternative to antibiotics due to their low propensity to induce bacterial resistance. However, cytotoxicity and short half-lives have limited their clinical translation. To overcome these problems, AMP conjugation has gained relevance in the biomaterials field. Nevertheless, few studies describe the influence of conjugation on enzymatic protection, mechanism of action and antimicrobial efficacy. This review addresses this gap by providing a detailed comparison between conjugated and soluble AMP. Additionally, commonly employed chemical reactions and factors to consider when promoting AMP conjugation are reviewed. The overall results suggested that AMP conjugated onto biomaterials are specifically protected from degradation by trypsin and/or pepsin. However, sometimes, their antimicrobial efficacy was reduced. Due to limited conformational freedom in conjugated AMP, compared to their soluble forms, they appear to act initially by creating small protuberances on bacterial membranes that may lead to the alteration of membrane potential and/or formation of holes, triggering cell death. Overall, AMP conjugation onto biomaterials is a promising strategy to fight infection, particularly associated to the use of medical devices. Nonetheless, some details need to be addressed before conjugated AMP reach clinical practice. STATEMENT OF SIGNIFICANCE: Covalent conjugation of antimicrobial peptides (AMP) has been one of the most widely used strategies by bioengineers, in an attempt to not only protect AMP from proteolytic degradation, but also to prolong their residence time at the target tissue. However, an explanation for the mode of action of conjugated AMP is still lacking. This review extensively gathers works on AMP conjugation and puts forward a mechanism of action for AMP when conjugated onto biomaterials. The implications of AMP conjugation on antimicrobial activity, cytotoxicity and resistance to proteases are all discussed. A thorough review of commonly employed chemical reactions for this conjugation is also provided. Finally, details that need to be addressed for conjugated AMP to reach clinical practice are discussed.
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Affiliation(s)
- Pedro M Alves
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; LAQV-REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal
| | - Cristina C Barrias
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal
| | - Paula Gomes
- LAQV-REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal
| | - M Cristina L Martins
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira, 4050-313 Porto, Portugal.
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3
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He J, Ghosh P, Nitsche C. Biocompatible strategies for peptide macrocyclisation. Chem Sci 2024; 15:2300-2322. [PMID: 38362412 PMCID: PMC10866349 DOI: 10.1039/d3sc05738k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 01/04/2024] [Indexed: 02/17/2024] Open
Abstract
Peptides are increasingly important drug candidates, offering numerous advantages over conventional small molecules. However, they face significant challenges related to stability, cellular uptake and overall bioavailability. While individual modifications may not address all these challenges, macrocyclisation stands out as a single modification capable of enhancing affinity, selectivity, proteolytic stability and membrane permeability. The recent successes of in situ peptide modifications during screening in combination with genetically encoded peptide libraries have increased the demand for peptide macrocyclisation reactions that can occur under biocompatible conditions. In this perspective, we aim to distinguish biocompatible conditions from those well-known examples that are fully bioorthogonal. We introduce key strategies for biocompatible peptide macrocyclisation and contextualise them within contemporary screening methods, providing an overview of available transformations.
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Affiliation(s)
- Junming He
- Research School of Chemistry, Australian National University Canberra ACT Australia
| | - Pritha Ghosh
- Research School of Chemistry, Australian National University Canberra ACT Australia
| | - Christoph Nitsche
- Research School of Chemistry, Australian National University Canberra ACT Australia
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4
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Zheng WF, Chen J, Qi X, Huang Z. Modular and diverse synthesis of amino acids via asymmetric decarboxylative protonation of aminomalonic acids. Nat Chem 2023; 15:1672-1682. [PMID: 37973941 DOI: 10.1038/s41557-023-01362-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 10/06/2023] [Indexed: 11/19/2023]
Abstract
Stereoselective protonation is a challenge in asymmetric catalysis. The small size and high rate of transfer of protons mean that face-selective delivery to planar intermediates is hard to control, but it can unlock previously obscure asymmetric transformations. Particularly, when coupled with a preceding decarboxylation, enantioselective protonation can convert the abundant acid feedstocks into structurally diverse chiral molecules. Here an anchoring group strategy is demonstrated as a potential alternative and supplement to the conventional structural modification of catalysts by creating additional catalyst-substrate interactions. We show that a tailored benzamide group in aminomalonic acids can help build a coordinated network of non-covalent interactions, including hydrogen bonds, π-π interactions and dispersion forces, with a chiral acid catalyst. This allows enantioselective decarboxylative protonation to give α-amino acids. The malonate-based synthesis introduces side chains via a facile substitution of aminomalonic esters and thus can access structurally and functionally diverse amino acids.
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Affiliation(s)
- Wei-Feng Zheng
- State Key Laboratory of Synthetic Chemistry, Department of Chemistry, The University of Hong Kong, Hong Kong, China
| | - Jingdan Chen
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, China
| | - Xiaotian Qi
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, China.
| | - Zhongxing Huang
- State Key Laboratory of Synthetic Chemistry, Department of Chemistry, The University of Hong Kong, Hong Kong, China.
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5
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James CC, de Bruin B, Reek JNH. Transition Metal Catalysis in Living Cells: Progress, Challenges, and Novel Supramolecular Solutions. Angew Chem Int Ed Engl 2023; 62:e202306645. [PMID: 37339103 DOI: 10.1002/anie.202306645] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 06/20/2023] [Accepted: 06/20/2023] [Indexed: 06/22/2023]
Abstract
The importance of transition metal catalysis is exemplified by its wide range of applications, for example in the synthesis of chemicals, natural products, and pharmaceuticals. However, one relatively new application is for carrying out new-to-nature reactions inside living cells. The complex environment of a living cell is not welcoming to transition metal catalysts, as a diverse range of biological components have the potential to inhibit or deactivate the catalyst. Here we review the current progress in the field of transition metal catalysis, and evaluation of catalysis efficiency in living cells and under biological (relevant) conditions. Catalyst poisoning is a ubiquitous problem in this field, and we propose that future research into the development of physical and kinetic protection strategies may provide a route to improve the reactivity of catalysts in cells.
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Affiliation(s)
- Catriona C James
- van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Bas de Bruin
- van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Joost N H Reek
- van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
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6
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Fan M, Huang Y, Zhu X, Zheng J, Du M. Octreotide and Octreotide-derived delivery systems. J Drug Target 2023; 31:569-584. [PMID: 37211679 DOI: 10.1080/1061186x.2023.2216895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 04/01/2023] [Accepted: 04/29/2023] [Indexed: 05/23/2023]
Abstract
Pharmaceutical peptide Octreotide is a somatostatin analog with targeting and therapeutic abilities. Over the last decades, Octreotide has been developed and approved to treat acromegaly and neuroendocrine tumours, and Octreotide-based radioactive conjugates have been leveraged clinically to detect small neuroendocrine tumour sites. Meanwhile, variety of Octreotide-derived delivery strategies have been proposed and explored for tumour targeted therapeutics or diagnostics in preclinical or clinical settings. In this review, we especially focus on the preclinical development and applications of Octreotide-derived drug delivery systems, diagnostic nanosystems, therapeutic nanosystems and multifunctional nanosystems, we also briefly discuss challenges and prospects of these Octreotide-derived delivery systems.
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Affiliation(s)
- Mingliang Fan
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai, China
| | - Yue Huang
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai, China
| | - Xinlin Zhu
- Department of Dermatology, Shanghai Key Laboratory of Medical Mycology, Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Jiayu Zheng
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai, China
| | - Mingwei Du
- Department of Dermatology, Shanghai Key Laboratory of Medical Mycology, Changzheng Hospital, Naval Medical University, Shanghai, China
- Department of Cardiology, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai Key Laboratory of Traditional Chinese Clinical Medicine, Shanghai, China
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7
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Vasilyev KA, Antonova AS, Volchkov NS, Logvinenko NA, Nikitina EV, Grigoriev MS, Novikov AP, Kouznetsov VV, Polyanskii KB, Zubkov FI. Influence of Substituents in a Six-Membered Chelate Ring of HG-Type Complexes Containing an N→Ru Bond on Their Stability and Catalytic Activity. Molecules 2023; 28:molecules28031188. [PMID: 36770854 PMCID: PMC9921640 DOI: 10.3390/molecules28031188] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 01/18/2023] [Accepted: 01/21/2023] [Indexed: 01/27/2023] Open
Abstract
An efficient approach to the synthesis of olefin metathesis HG-type catalysts containing an N→Ru bond in a six-membered chelate ring was proposed. For the most part, these ruthenium chelates can be prepared easily and in high yields based on the interaction between 2-vinylbenzylamines and Ind II (the common precursor for Ru-complex synthesis). It was demonstrated that the increase of the steric volume of substituents attached to the nitrogen atom and in the α-position of the benzylidene fragment leads to a dramatic decrease in the stability of the target ruthenium complexes. The bulkiest iPr substituent bonded to the nitrogen atom or to the α-position does not allow the closing of the chelate cycle. N,N-Diethyl-1-(2-vinylphenyl)propan-1-amine is a limiting case; its interaction with Ind II makes it possible to isolate the corresponding ruthenium chelate in a low yield (5%). Catalytic activity of the synthesized complexes was tested in RCM reactions and compared with α-unsubstituted catalysts obtained previously. The structural peculiarities of the final ruthenium complexes were thoroughly investigated using XRD and NMR analysis, which allowed making a reliable correlation between the structure of the complexes and their catalytic properties.
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Affiliation(s)
- Kirill A. Vasilyev
- Organic Chemistry Department, Faculty of Science, Peoples’ Friendship University of Russia (RUDN University), Miklukho-Maklaya St., 6, Moscow 117198, Russia
| | - Alexandra S. Antonova
- Organic Chemistry Department, Faculty of Science, Peoples’ Friendship University of Russia (RUDN University), Miklukho-Maklaya St., 6, Moscow 117198, Russia
| | - Nikita S. Volchkov
- Organic Chemistry Department, Faculty of Science, Peoples’ Friendship University of Russia (RUDN University), Miklukho-Maklaya St., 6, Moscow 117198, Russia
| | - Nikita A. Logvinenko
- Organic Chemistry Department, Faculty of Science, Peoples’ Friendship University of Russia (RUDN University), Miklukho-Maklaya St., 6, Moscow 117198, Russia
| | - Eugeniya V. Nikitina
- Organic Chemistry Department, Faculty of Science, Peoples’ Friendship University of Russia (RUDN University), Miklukho-Maklaya St., 6, Moscow 117198, Russia
| | - Mikhail S. Grigoriev
- Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Leninsky pr. 31, bld. 4, Moscow 119071, Russia
| | - Anton P. Novikov
- Organic Chemistry Department, Faculty of Science, Peoples’ Friendship University of Russia (RUDN University), Miklukho-Maklaya St., 6, Moscow 117198, Russia
- Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Leninsky pr. 31, bld. 4, Moscow 119071, Russia
| | - Vladimir V. Kouznetsov
- Laboratorio de Química Orgánica y Biomolecular, Escuela de Química, Universidad Industrial de Santander, Cl. 9 # Cra 27, Bucaramanga 680006, Colombia
| | - Kirill B. Polyanskii
- Organic Chemistry Department, Faculty of Science, Peoples’ Friendship University of Russia (RUDN University), Miklukho-Maklaya St., 6, Moscow 117198, Russia
- Correspondence: (K.B.P.); (F.I.Z.)
| | - Fedor I. Zubkov
- Organic Chemistry Department, Faculty of Science, Peoples’ Friendship University of Russia (RUDN University), Miklukho-Maklaya St., 6, Moscow 117198, Russia
- Correspondence: (K.B.P.); (F.I.Z.)
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8
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Blanco C, Fogg DE. Water-Accelerated Decomposition of Olefin Metathesis Catalysts. ACS Catal 2023; 13:1097-1102. [PMID: 36714054 PMCID: PMC9872090 DOI: 10.1021/acscatal.2c05573] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 12/22/2022] [Indexed: 01/04/2023]
Abstract
Water is ubiquitous in olefin metathesis, at levels ranging from contaminant to cosolvent. It is also non-benign. Water-promoted catalyst decomposition competes with metathesis, even for "robust" ruthenium catalysts. Metathesis is hence typically noncatalytic for demanding reactions in water-rich environments (e.g., chemical biology), a challenge as the Ru decomposition products promote unwanted reactions such as DNA degradation. To date, only the first step of the decomposition cascade is understood: catalyst aquation. Here we demonstrate that the aqua species dramatically accelerate both β-elimination of the metallacyclobutane intermediate and bimolecular decomposition of four-coordinate [RuCl(H2O)n(L)(=CHR)]Cl. Decomposition can be inhibited by blocking aquation and β-elimination.
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Affiliation(s)
- Christian
O. Blanco
- Center
for Catalysis Research & Innovation and Department of Chemistry
and Biomolecular Sciences, University of
Ottawa, Ottawa, Ontario, Canada K1N 6N5
| | - Deryn E. Fogg
- Center
for Catalysis Research & Innovation and Department of Chemistry
and Biomolecular Sciences, University of
Ottawa, Ottawa, Ontario, Canada K1N 6N5,Department
of Chemistry, University of Bergen, Allégaten 41, N-5007 Bergen, Norway,,
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9
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Gutiérrez S, Tomás-Gamasa M, Mascareñas JL. Organometallic catalysis in aqueous and biological environments: harnessing the power of metal carbenes. Chem Sci 2022; 13:6478-6495. [PMID: 35756533 PMCID: PMC9172117 DOI: 10.1039/d2sc00721e] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 05/15/2022] [Indexed: 11/24/2022] Open
Abstract
Translating the power of transition metal catalysis to the native habitats of enzymes can significantly expand the possibilities of interrogating or manipulating natural biological systems, including living cells and organisms. This is especially relevant for organometallic reactions that have shown great potential in the field of organic synthesis, like the metal-catalyzed transfer of carbenes. While, at first sight, performing metal carbene chemistry in aqueous solvents, and especially in biologically relevant mixtures, does not seem obvious, in recent years there has been a growing number of reports demonstrating the feasibility of the task. Either using small molecule metal catalysts or artificial metalloenzymes, a number of carbene transfer reactions that tolerate aqueous and biorelevant media are being developed. This review intends to summarize the most relevant contributions, and establish the state of the art in this emerging research field.
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Affiliation(s)
- Sara Gutiérrez
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS), Departamento de Química Orgánica, Universidade de Santiago de Compostela 15705 Santiago de Compostela Spain
| | - María Tomás-Gamasa
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS), Departamento de Química Orgánica, Universidade de Santiago de Compostela 15705 Santiago de Compostela Spain
| | - José Luis Mascareñas
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS), Departamento de Química Orgánica, Universidade de Santiago de Compostela 15705 Santiago de Compostela Spain
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10
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Occhipinti G, Nascimento DL, Foscato M, Fogg DE, Jensen VR. The Janus face of high trans-effect carbenes in olefin metathesis: gateway to both productivity and decomposition. Chem Sci 2022; 13:5107-5117. [PMID: 35655574 PMCID: PMC9093171 DOI: 10.1039/d2sc00855f] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 03/19/2022] [Indexed: 11/25/2022] Open
Abstract
Ruthenium–cyclic(alkyl)(amino)carbene (CAAC) catalysts, used at ppm levels, can enable dramatically higher productivities in olefin metathesis than their N-heterocyclic carbene (NHC) predecessors. A key reason is the reduced susceptibility of the metallacyclobutane (MCB) intermediate to decomposition via β-H elimination. The factors responsible for promoting or inhibiting β-H elimination are explored via density functional theory (DFT) calculations, in metathesis of ethylene or styrene (a representative 1-olefin) by Ru–CAAC and Ru–NHC catalysts. Natural bond orbital analysis of the frontier orbitals confirms the greater strength of the orbital interactions for the CAAC species, and the consequent increase in the carbene trans influence and trans effect. The higher trans effect of the CAAC ligands inhibits β-H elimination by destabilizing the transition state (TS) for decomposition, in which an agostic MCB Cβ–H bond is positioned trans to the carbene. Unproductive cycling with ethylene is also curbed, because ethylene is trans to the carbene ligand in the square pyramidal TS for ethylene metathesis. In contrast, metathesis of styrene proceeds via a ‘late’ TS with approximately trigonal bipyramidal geometry, in which carbene trans effects are reduced. Importantly, however, the positive impact of a strong trans-effect ligand in limiting β-H elimination is offset by its potent accelerating effect on bimolecular coupling, a major competing means of catalyst decomposition. These two decomposition pathways, known for decades to limit productivity in olefin metathesis, are revealed as distinct, antinomic, responses to a single underlying phenomenon. Reconciling these opposing effects emerges as a clear priority for design of robust, high-performing catalysts. In ruthenium catalysts for olefin metathesis, carbene ligands of high trans influence/effect suppress decomposition via β-H elimination, but increase susceptibility to bimolecular decomposition.![]()
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Affiliation(s)
- Giovanni Occhipinti
- Department of Chemistry, University of Bergen Allégaten 41 N-5007 Bergen Norway
| | - Daniel L Nascimento
- Center for Catalysis Research & Innovation, Department of Chemistry and Biomolecular Sciences, University of Ottawa Ottawa Canada K1N 6N5
| | - Marco Foscato
- Department of Chemistry, University of Bergen Allégaten 41 N-5007 Bergen Norway
| | - Deryn E Fogg
- Department of Chemistry, University of Bergen Allégaten 41 N-5007 Bergen Norway .,Center for Catalysis Research & Innovation, Department of Chemistry and Biomolecular Sciences, University of Ottawa Ottawa Canada K1N 6N5
| | - Vidar R Jensen
- Department of Chemistry, University of Bergen Allégaten 41 N-5007 Bergen Norway
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11
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Patrzałek M, Zieliński A, Pasparakis G, Vamvakaki M, Ruszczyńska A, Bulska E, Kajetanowicz A, Grela K. Testing Diverse Strategies for Ruthenium Catalyst Removal After Aqueous Homogeneous Olefin Metathesis. J Organomet Chem 2022. [DOI: 10.1016/j.jorganchem.2022.122320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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12
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Sornay C, Vaur V, Wagner A, Chaubet G. An overview of chemo- and site-selectivity aspects in the chemical conjugation of proteins. ROYAL SOCIETY OPEN SCIENCE 2022; 9:211563. [PMID: 35116160 PMCID: PMC8790347 DOI: 10.1098/rsos.211563] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 12/20/2021] [Indexed: 05/03/2023]
Abstract
The bioconjugation of proteins-that is, the creation of a covalent link between a protein and any other molecule-has been studied for decades, partly because of the numerous applications of protein conjugates, but also due to the technical challenge it represents. Indeed, proteins possess inner physico-chemical properties-they are sensitive and polynucleophilic macromolecules-that make them complex substrates in conjugation reactions. This complexity arises from the mild conditions imposed by their sensitivity but also from selectivity issues, viz the precise control of the conjugation site on the protein. After decades of research, strategies and reagents have been developed to address two aspects of this selectivity: chemoselectivity-harnessing the reacting chemical functionality-and site-selectivity-controlling the reacting amino acid residue-most notably thanks to the participation of synthetic chemistry in this effort. This review offers an overview of these chemical bioconjugation strategies, insisting on those employing native proteins as substrates, and shows that the field is active and exciting, especially for synthetic chemists seeking new challenges.
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Affiliation(s)
- Charlotte Sornay
- Bio-Functional Chemistry (UMR 7199), LabEx Medalis, University of Strasbourg, 74 Route du Rhin, Illkirch-Graffenstaden 67400, France
| | - Valentine Vaur
- Bio-Functional Chemistry (UMR 7199), LabEx Medalis, University of Strasbourg, 74 Route du Rhin, Illkirch-Graffenstaden 67400, France
| | - Alain Wagner
- Bio-Functional Chemistry (UMR 7199), LabEx Medalis, University of Strasbourg, 74 Route du Rhin, Illkirch-Graffenstaden 67400, France
| | - Guilhem Chaubet
- Bio-Functional Chemistry (UMR 7199), LabEx Medalis, University of Strasbourg, 74 Route du Rhin, Illkirch-Graffenstaden 67400, France
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13
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Czarnocki S, Monsigny L, Sienkiewicz M, Kajetanowicz A, Grela K. Ruthenium Olefin Metathesis Catalysts Featuring N-Heterocyclic Carbene Ligands Tagged with Isonicotinic and 4-(Dimethylamino)benzoic Acid Rests: Evaluation of a Modular Synthetic Strategy. Molecules 2021; 26:molecules26175220. [PMID: 34500654 PMCID: PMC8433898 DOI: 10.3390/molecules26175220] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/11/2021] [Accepted: 08/20/2021] [Indexed: 11/26/2022] Open
Abstract
A modular and flexible strategy towards the synthesis of N-heterocyclic carbene (NHC) ligands bearing Brønsted base tags has been proposed and then adopted in the preparation of two tagged NHC ligands bearing rests of isonicotinic and 4-(dimethylamino)benzoic acids. Such tagged NHC ligands represent an attractive starting point for the synthesis of olefin metathesis ruthenium catalysts tagged in non-dissociating ligands. The influence of the Brønsted basic tags on the activity of such obtained olefin metathesis catalysts has been studied.
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14
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Toward E-selective Olefin Metathesis: Computational Design and Experimental Realization of Ruthenium Thio-Indolate Catalysts. Top Catal 2021. [DOI: 10.1007/s11244-021-01468-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
AbstractThe selective transformation of 1-alkenes into E-olefins is a long-standing challenge in olefin metathesis. Density functional theory (DFT) calculations predict high E-selectivity for catalysts incorporating a bidentate, dianionic thio-indolate ligand within a RuXX’(NHC)(py)(= CHR) platform (NHC = N-heterocyclic carbene; py = pyridine). Such complexes are predicted to yield E-olefins by favoring anti-disposed substituents in the transition state expected to be rate-determining: specifically, that for cycloreversion of the metallacyclobutane intermediate. Three pyridine-stabilized catalysts Ru21a-c were synthesized, in which the thio-indolate ligand bears a H, Me, or Ph substituent at the C2 position, and the NHC ligand is the unsaturated imidazoline-2-ylidene Me2IMes (which bears N-mesityl groups and methyl groups on the C4,5 backbone). Single-crystal X-ray diffraction analysis of Ru21c confirms the ligand orientation required for E-selective metathesis, with the thio-indolate sulfur atom binding cis to the NHC, and the indolate nitrogen atom trans to the NHC. However, whereas the new complexes mediated metathetic exchange of their 2-thienylmethylidene ligand in the presence of the common metathesis substrates styrene and allylbenzene, no corresponding self-metathesis products were obtained. Only small amounts of 2-butene (73% (Z)-2-butene) were obtained in self-metathesis of propene using Ru21a. Detailed DFT analysis of this process revealed that product release is surprisingly slow, limiting the reaction rate and explaining the low metathesis activity. With the barrier to dissociation of (Z)-2-butene being lower than that of (E)-2-butene, the calculations also account for the observed Z-selectivity of Ru21a. These findings provide guidelines for catalyst redesign in pursuit of the ambitious goal of E-selective 1-alkene metathesis.
Graphic abstract
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15
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Li M, Blum NT, Wu J, Lin J, Huang P. Weaving Enzymes with Polymeric Shells for Biomedical Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2008438. [PMID: 34197008 DOI: 10.1002/adma.202008438] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/13/2021] [Indexed: 06/13/2023]
Abstract
Enzyme therapeutics have received increasing attention due to their high biological specificity, outstanding catalytic efficiency, and impressive therapeutic outcomes. Protecting and delivering enzymes into target cells while retaining enzyme catalytic efficiency is a big challenge. Wrapping of enzymes with rational designed polymer shells, rather than trapping them into large nanoparticles such as liposomes, have been widely explored because they can protect the folded state of the enzyme and make post-functionalization easier. In this review, the methods for wrapping up enzymes with protective polymer shells are mainly focused on. It is aimed to provide a toolbox for the rational design of polymeric enzymes by introducing methods for the preparation of polymeric enzymes including physical adsorption and chemical conjugation with specific examples of these conjugates/hybrid applications. Finally, a conclusion is drawn and key points are emphasized.
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Affiliation(s)
- Meng Li
- Marshall Laboratory of Biomedical Engineering, International Cancer Center, Laboratory of Evolutionary Theranostics (LET), School of Biomedical Engineering, Health Science Center, Shenzhen University, Shenzhen, 518060, China
| | - Nicholas Thomas Blum
- Marshall Laboratory of Biomedical Engineering, International Cancer Center, Laboratory of Evolutionary Theranostics (LET), School of Biomedical Engineering, Health Science Center, Shenzhen University, Shenzhen, 518060, China
| | - Jiayingzi Wu
- Marshall Laboratory of Biomedical Engineering, International Cancer Center, Laboratory of Evolutionary Theranostics (LET), School of Biomedical Engineering, Health Science Center, Shenzhen University, Shenzhen, 518060, China
| | - Jing Lin
- Marshall Laboratory of Biomedical Engineering, International Cancer Center, Laboratory of Evolutionary Theranostics (LET), School of Biomedical Engineering, Health Science Center, Shenzhen University, Shenzhen, 518060, China
| | - Peng Huang
- Marshall Laboratory of Biomedical Engineering, International Cancer Center, Laboratory of Evolutionary Theranostics (LET), School of Biomedical Engineering, Health Science Center, Shenzhen University, Shenzhen, 518060, China
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Nascimento D, Foscato M, Occhipinti G, Jensen VR, Fogg DE. Bimolecular Coupling in Olefin Metathesis: Correlating Structure and Decomposition for Leading and Emerging Ruthenium-Carbene Catalysts. J Am Chem Soc 2021; 143:11072-11079. [PMID: 34270895 PMCID: PMC8397316 DOI: 10.1021/jacs.1c04424] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Indexed: 12/19/2022]
Abstract
Bimolecular catalyst decomposition is a fundamental, long-standing challenge in olefin metathesis. Emerging ruthenium-cyclic(alkyl)(amino)carbene (CAAC) catalysts, which enable breakthrough advances in productivity and general robustness, are now known to be extraordinarily susceptible to this pathway. The details of the process, however, have hitherto been obscure. The present study provides the first detailed mechanistic insights into the steric and electronic factors that govern bimolecular decomposition. Described is a combined experimental and theoretical study that probes decomposition of the key active species, RuCl2(L)(py)(═CH2) 1 (in which L is the N-heterocyclic carbene (NHC) H2IMes, or a CAAC ligand: the latter vary in the NAr group (NMes, N-2,6-Et2C6H3, or N-2-Me,6-iPrC6H3) and the substituents on the quaternary site flanking the carbene carbon (i.e., CMe2 or CMePh)). The transiently stabilized pyridine adducts 1 were isolated by cryogenic synthesis of the metallacyclobutanes, addition of pyridine, and precipitation. All are shown to decompose via second-order kinetics at -10 °C. The most vulnerable CAAC species, however, decompose more than 1000-fold faster than the H2IMes analogue. Computational studies reveal that the key factor underlying accelerated decomposition of the CAAC derivatives is their stronger trans influence, which weakens the Ru-py bond and increases the transient concentration of the 14-electron methylidene species, RuCl2(L)(═CH2) 2. Fast catalyst initiation, a major design goal in olefin metathesis, thus has the negative consequence of accelerating decomposition. Inhibiting bimolecular decomposition offers major opportunities to transform catalyst productivity and utility, and to realize the outstanding promise of olefin metathesis.
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Affiliation(s)
- Daniel
L. Nascimento
- Center
for Catalysis Research & Innovation, and Department of Chemistry
and Biomolecular Sciences, University of
Ottawa, Ottawa, Canada K1N 6N5
| | - Marco Foscato
- Department
of Chemistry, University of Bergen, Allégaten 41, N-5007 Bergen, Norway
| | - Giovanni Occhipinti
- Department
of Chemistry, University of Bergen, Allégaten 41, N-5007 Bergen, Norway
| | - Vidar R. Jensen
- Department
of Chemistry, University of Bergen, Allégaten 41, N-5007 Bergen, Norway
| | - Deryn E. Fogg
- Center
for Catalysis Research & Innovation, and Department of Chemistry
and Biomolecular Sciences, University of
Ottawa, Ottawa, Canada K1N 6N5
- Department
of Chemistry, University of Bergen, Allégaten 41, N-5007 Bergen, Norway
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Blanco C, Nascimento DL, Fogg DE. Routes to High-Performing Ruthenium-Iodide Catalysts for Olefin Metathesis: Ligand Lability Is Key to Efficient Halide Exchange. Organometallics 2021; 40:1811-1816. [PMID: 34295013 PMCID: PMC8289337 DOI: 10.1021/acs.organomet.1c00253] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Indexed: 12/14/2022]
Abstract
Clean, high-yielding routes are described to ruthenium-diiodide catalysts that were recently shown to enable high productivity in olefin metathesis. For the second-generation Grubbs and Hoveyda catalysts (GII: RuCl2(H2IMes)(PCy3)(=CHPh); HII: RuCl2(H2IMes)(=CHAr), Ar = C6H4-2-O i Pr), slow salt metathesis is shown to arise from the low lability of the ancillary PCy3 or ether ligands, which retards access to the four-coordinate intermediate required for efficient halide exchange. To exploit the lability of the first-generation catalysts, the diiodide complex RuI2(PCy3)(=CHAr) HI-I 2 was prepared by treating "Grubbs I" (RuCl2(PCy3)2(=CHPh), GI) with NaI, H2C=CHAr (1a), and a phosphine-scavenging Merrifield iodide (MF-I) resin. Subsequent installation of H2IMes or cyclic (alkyl)(amino)carbene (CAAC) ligands afforded the second-generation iodide catalysts in good to excellent yields. Given the incompatibility of the nitro group with a free carbene, the iodo-Grela catalyst RuI2(H2IMes)(=CHAr') (nG-I 2 : Ar' = C6H3-2-O i Pr-4-NO2) was instead accessed by sequential salt metathesis of GI with NaI, installation of H2IMes, and finally cross-metathesis with the nitrostyrenyl ether H2C=CHAr' (1b), with MF-I as the phosphine scavenger. The bulky iodide ligands improve the selectivity for macrocyclization in ring-closing metathesis.
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Affiliation(s)
- Christian
O. Blanco
- Center
for Catalysis Research & Innovation and Department of Chemistry
and Biomolecular Sciences, University of
Ottawa, Ottawa, ON, Canada K1N 6N5
| | - Daniel L. Nascimento
- Center
for Catalysis Research & Innovation and Department of Chemistry
and Biomolecular Sciences, University of
Ottawa, Ottawa, ON, Canada K1N 6N5
| | - Deryn E. Fogg
- Center
for Catalysis Research & Innovation and Department of Chemistry
and Biomolecular Sciences, University of
Ottawa, Ottawa, ON, Canada K1N 6N5
- Department
of Chemistry, University of Bergen, Allégaten 41, N-5007 Bergen, Norway
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Rodriguez J, Dhanjee HH, Buchwald SL. Amphiphilic Biaryl Monophosphine Ligands by Regioselective Sulfonation. Org Lett 2021; 23:777-780. [PMID: 33475382 PMCID: PMC8057820 DOI: 10.1021/acs.orglett.0c04001] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Amphiphilic ligands are valued for their ability to facilitate organometallic reactions in the presence of water. The regioselective sulfonation of a series of commercially available biaryl monophosphines to generate amphiphilic ligands is presented. In this one-step protocol, the temperature and addition of fuming sulfuric acid were carefully controlled to arrive at sulfonated biaryl monophosphine ligands in high yields with >95% regioselectivity without the need for chromatographic purification.
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Affiliation(s)
| | | | - Stephen L. Buchwald
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139, United States
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Blanco CO, Sims J, Nascimento DL, Goudreault AY, Steinmann SN, Michel C, Fogg DE. The Impact of Water on Ru-Catalyzed Olefin Metathesis: Potent Deactivating Effects Even at Low Water Concentrations. ACS Catal 2021; 11:893-899. [PMID: 33614193 PMCID: PMC7886052 DOI: 10.1021/acscatal.0c04279] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 12/29/2020] [Indexed: 12/14/2022]
Abstract
Ruthenium catalysts for olefin metathesis are widely viewed as water-tolerant. Evidence is presented, however, that even low concentrations of water cause catalyst decomposition, severely degrading yields. Of 11 catalysts studied, fast-initiating examples (e.g., the Grela catalyst RuCl2(H2IMes)(=CHC6H4-2-O i Pr-5-NO2) were most affected. Maximum water tolerance was exhibited by slowly initiating iodide and cyclic (alkyl)(amino)carbene (CAAC) derivatives. Computational investigations indicated that hydrogen bonding of water to substrate can also play a role, by retarding cyclization relative to decomposition. These results have important implications for olefin metathesis in organic media, where water is a ubiquitous contaminant, and for aqueous metathesis, which currently requires superstoichiometric "catalyst" for demanding reactions.
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Affiliation(s)
- Christian O. Blanco
- Center for Catalysis Research & Innovation, and
Department of Chemistry and Biomolecular Sciences, University of
Ottawa, Ottawa, Ontario K1N 6N57, Canada
| | - Joshua Sims
- Univ. Lyon, ENS de Lyon,
CNRS UMR 5182, Université Claude Bernard Lyon 1, Laboratorie de Chimie, F-69342
Lyon, France
| | - Daniel L. Nascimento
- Center for Catalysis Research & Innovation, and
Department of Chemistry and Biomolecular Sciences, University of
Ottawa, Ottawa, Ontario K1N 6N57, Canada
| | - Alexandre Y. Goudreault
- Center for Catalysis Research & Innovation, and
Department of Chemistry and Biomolecular Sciences, University of
Ottawa, Ottawa, Ontario K1N 6N57, Canada
| | - Stephan N. Steinmann
- Univ. Lyon, ENS de Lyon,
CNRS UMR 5182, Université Claude Bernard Lyon 1, Laboratorie de Chimie, F-69342
Lyon, France
| | - Carine Michel
- Univ. Lyon, ENS de Lyon,
CNRS UMR 5182, Université Claude Bernard Lyon 1, Laboratorie de Chimie, F-69342
Lyon, France
| | - Deryn E. Fogg
- Center for Catalysis Research & Innovation, and
Department of Chemistry and Biomolecular Sciences, University of
Ottawa, Ottawa, Ontario K1N 6N57, Canada
- Department of Chemistry, University of
Bergen, Allégaten 41, N-5007 Bergen,
Norway
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Hernández D, Carro C, Boto A. "Doubly Customizable" Unit for the Generation of Structural Diversity: From Pure Enantiomeric Amines to Peptide Derivatives. J Org Chem 2021; 86:2796-2809. [PMID: 33433228 DOI: 10.1021/acs.joc.0c02751] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Readily available, low-cost 4R-hydroxy-l-proline (Hyp) is introduced as a "doubly customizable" unit for the generation of libraries of structurally diverse compounds. Hyp can be cleaved at two points, followed by the introduction of new functionalities. In the first cycle, the removal and replacement of the carboxylic group are carried out, followed (second cycle) by the scission of the 4,5-position and manipulation of the resulting chains. In this way, three new chains are generated and can be transformed independently to afford a diversity of products with tailored substituents, such as β-amino aldehydes, diamines, β-amino acid derivatives, including N-alkylated ones, or modified peptides. Many of these products are high-profit compounds but, in spite of their commercial value, are still scarce. Moreover, the process takes place with stereochemical control, and either pure R or S isomers can be obtained with small variations of the synthetic route.
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Affiliation(s)
- Dacil Hernández
- Instituto de Productos Naturales y Agrobiología del CSIC, Avda. Astrofísico Fco. Sánchez, 3, 38206 La Laguna, Tenerife, Spain
| | - Carmen Carro
- Instituto de Productos Naturales y Agrobiología del CSIC, Avda. Astrofísico Fco. Sánchez, 3, 38206 La Laguna, Tenerife, Spain.,BIOSIGMA, Antonio Domínguez Alfonso 16, 38003 Santa Cruz de Tenerife, Tenerife, Spain
| | - Alicia Boto
- Instituto de Productos Naturales y Agrobiología del CSIC, Avda. Astrofísico Fco. Sánchez, 3, 38206 La Laguna, Tenerife, Spain
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Boto A, González CC, Hernández D, Romero-Estudillo I, Saavedra CJ. Site-selective modification of peptide backbones. Org Chem Front 2021. [DOI: 10.1039/d1qo00892g] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Exciting developments in the site-selective modification of peptide backbones are allowing an outstanding fine-tuning of peptide conformation, folding ability, and physico-chemical and biological properties.
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Affiliation(s)
- Alicia Boto
- Instituto de Productos Naturales y Agrobiología del CSIC, Avda. Astrofísico Francisco Sánchez 3, 38206-La Laguna, Tenerife, Spain
| | - Concepción C. González
- Instituto de Productos Naturales y Agrobiología del CSIC, Avda. Astrofísico Francisco Sánchez 3, 38206-La Laguna, Tenerife, Spain
| | - Dácil Hernández
- Instituto de Productos Naturales y Agrobiología del CSIC, Avda. Astrofísico Francisco Sánchez 3, 38206-La Laguna, Tenerife, Spain
| | - Iván Romero-Estudillo
- Centro de Investigaciones Químicas-IICBA, Universidad Autónoma del Estado de Morelos. Av. Universidad 1001, Cuernavaca, Morelos 62209, Mexico
- Catedrático CONACYT-CIQ-UAEM, Mexico
| | - Carlos J. Saavedra
- Instituto de Productos Naturales y Agrobiología del CSIC, Avda. Astrofísico Francisco Sánchez 3, 38206-La Laguna, Tenerife, Spain
- Programa Agustín de Betancourt, Universidad de la Laguna, 38200 Tenerife, Spain
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Church DC, Takiguchi L, Pokorski JK. Optimization of Ring-Opening Metathesis Polymerization (ROMP) under Physiologically Relevant Conditions. Polym Chem 2020; 11:4492-4499. [PMID: 33796158 PMCID: PMC8009303 DOI: 10.1039/d0py00716a] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Ring opening metathesis polymerization (ROMP) is widely considered an excellent living polymerization technique that proceeds rapidly under ambient conditions and is highly functional group tolerant when performed in organic solvents. However, achieving the same level of success in aqueous media has proved to be challenging, often requiring an organic co-solvent or a very low pH to obtain fast initiation and high monomer conversion. The ability to efficiently conduct ROMP under neutral pH aqueous conditions would mark an important step towards utilizing aqueous ROMP with acid-sensitive functional groups or within a biological setting. Herein we describe our efforts to optimize ROMP in an aqueous environment under neutral pH conditions. Specifically, we found that the presence of excess chloride in solution as well as relatively small changes in pH near physiological conditions have a profound effect on molecular weight control, polymerization rate and overall monomer conversion. Additionally, we have applied our optimized conditions to polymerize a broad scope of water-soluble monomers and used this methodology to produce nanostructures via ring opening metathesis polymerization induced self-assembly (ROMPISA) under neutral pH aqueous conditions.
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Affiliation(s)
- Derek C. Church
- Department of NanoEngineering, Jacobs School of Engineering, University of California San Diego, La Jolla, CA 92093, USA
| | - Lauren Takiguchi
- Department of NanoEngineering, Jacobs School of Engineering, University of California San Diego, La Jolla, CA 92093, USA
| | - Jonathan K. Pokorski
- Department of NanoEngineering, Jacobs School of Engineering, University of California San Diego, La Jolla, CA 92093, USA
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