1
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Todorovic M, Rivollier P, Wong AAWL, Wang Z, Pryyma A, Nguyen TT, Newell KC, Froelich J, Perrin DM. Rationally Designed Amanitins Achieve Enhanced Cytotoxicity. J Med Chem 2022; 65:10357-10376. [PMID: 35696491 DOI: 10.1021/acs.jmedchem.1c02226] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
For 70 years, α-amanitin, the most cytotoxic peptide in its class, has been without a synthetic rival; through synthesis, we address the structure-activity relationships to inform the design of new amatoxins and disclose analogues that are more cytotoxic than the natural product when evaluated on CHO, HEK293, and HeLa cells, whereas on liver-derived HepG2 cells, the same toxins show diminished cytotoxicity.
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Affiliation(s)
- Mihajlo Todorovic
- Chemistry Department, 2036 Main Mall, The University of British Columbia, 2036 Main Mall, Vancouver, BC V6T-1Z1, Canada
| | - Paul Rivollier
- Chemistry Department, 2036 Main Mall, The University of British Columbia, 2036 Main Mall, Vancouver, BC V6T-1Z1, Canada
| | - Antonio A W L Wong
- Chemistry Department, 2036 Main Mall, The University of British Columbia, 2036 Main Mall, Vancouver, BC V6T-1Z1, Canada
| | - Zhou Wang
- Chemistry Department, 2036 Main Mall, The University of British Columbia, 2036 Main Mall, Vancouver, BC V6T-1Z1, Canada
| | - Alla Pryyma
- Chemistry Department, 2036 Main Mall, The University of British Columbia, 2036 Main Mall, Vancouver, BC V6T-1Z1, Canada
| | - Tuan Trung Nguyen
- Chemistry Department, 2036 Main Mall, The University of British Columbia, 2036 Main Mall, Vancouver, BC V6T-1Z1, Canada
| | - Kayla C Newell
- Chemistry Department, 2036 Main Mall, The University of British Columbia, 2036 Main Mall, Vancouver, BC V6T-1Z1, Canada
| | - Juliette Froelich
- Chemistry Department, 2036 Main Mall, The University of British Columbia, 2036 Main Mall, Vancouver, BC V6T-1Z1, Canada
| | - David M Perrin
- Chemistry Department, 2036 Main Mall, The University of British Columbia, 2036 Main Mall, Vancouver, BC V6T-1Z1, Canada
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2
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Kobayashi D, Kohmura Y, Sugiki T, Kuraoka E, Denda M, Fujiwara T, Otaka A. Peptide Cyclization Mediated by Metal-Free S-Arylation: S-Protected Cysteine Sulfoxide as an Umpolung of the Cysteine Nucleophile. Chemistry 2021; 27:14092-14099. [PMID: 34302308 DOI: 10.1002/chem.202102420] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Indexed: 11/07/2022]
Abstract
Covalent linking of side chains provides a method to produce cyclic or stapled peptides that are important in developing peptide-based drugs. A variety of crosslinking formats contribute to fixing the active conformer and prolonging its biological activity under physiological conditions. One format uses the cysteine thiol to participate in crosslinking through nucleophilic thiolate anions or thiyl radicals to form thioether and disulfide bonds. Removal of the S-protection from an S-protected Cys derivative generates the thiol, which functions as a nucleophile. S-Oxidation of a protected Cys allows the formation of a sulfoxide that operates as an umpolung electrophile. Herein, the applicability of S-p-methoxybenzyl Cys sulfoxide (Cys(MBzl)(O)) to the formation of a thioether linkage between tryptophan and Cys has been investigated. The reaction of peptides containing Cys(MBzl)(O) and Trp with trifluoromethanesulfonic acid (TFMSA) or methanesulfonic acid (MSA) in TFA in the presence of guanidine hydrochloride (Gn ⋅ HCl) proceeded to give cyclic or stapled peptides possessing the Cys-Trp thioether linkage. In this reaction, strong acids such as TFMSA or MSA are necessary to activate the sulfoxide. Additionally, Gn ⋅ HCl plays a critical role in producing an electrophilic Cys derivative that combines with the indole by aromatic electrophilic substitution. The findings led us to conclude that the less-electrophilic Cys(MBzl)(O) serves as an acid-activated umpolung of a Cys nucleophile and is useful for S-arylation-mediated peptide cyclization.
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Affiliation(s)
- Daishiro Kobayashi
- Institute of Biomedical Sciences and Graduate School of Pharmaceutical Sciences, Tokushima University, Shomachi, Tokushima, 770-8505, Japan
| | - Yutaka Kohmura
- Institute of Biomedical Sciences and Graduate School of Pharmaceutical Sciences, Tokushima University, Shomachi, Tokushima, 770-8505, Japan
| | - Toshihiko Sugiki
- Institute of Protein Research, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Eisuke Kuraoka
- Institute of Biomedical Sciences and Graduate School of Pharmaceutical Sciences, Tokushima University, Shomachi, Tokushima, 770-8505, Japan
| | - Masaya Denda
- Institute of Biomedical Sciences and Graduate School of Pharmaceutical Sciences, Tokushima University, Shomachi, Tokushima, 770-8505, Japan
| | - Toshimichi Fujiwara
- Institute of Protein Research, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Akira Otaka
- Institute of Biomedical Sciences and Graduate School of Pharmaceutical Sciences, Tokushima University, Shomachi, Tokushima, 770-8505, Japan
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3
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Matinkhoo K, Wong AAWL, Hambira CM, Kato B, Wei C, Müller C, Hechler T, Braun A, Gallo F, Pahl A, Perrin DM. Design, Synthesis, and Biochemical Evaluation of Alpha-Amanitin Derivatives Containing Analogs of the trans-Hydroxyproline Residue for Potential Use in Antibody-Drug Conjugates. Chemistry 2021; 27:10282-10292. [PMID: 34058032 DOI: 10.1002/chem.202101373] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Indexed: 01/08/2023]
Abstract
Alpha-amanitin, an extremely toxic bicyclic octapeptide extracted from the death-cap mushroom, Amanita phalloides, is a highly selective allosteric inhibitor of RNA polymerase II. Following on growing interest in using this toxin as a payload in antibody-drug conjugates, herein we report the synthesis and biochemical evaluation of several new derivatives of this toxin to probe the role of the trans-hydroxyproline (Hyp), which is known to be critical for toxicity. This structure activity relationship (SAR) study represents the first of its kind to use various Hyp-analogs to alter the conformational and H-bonding properties of Hyp in amanitin.
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Affiliation(s)
- Kaveh Matinkhoo
- Chemistry Department, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, V6T-1Z1, Canada
| | - Antonio A W L Wong
- Chemistry Department, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, V6T-1Z1, Canada
| | - Chido M Hambira
- Chemistry Department, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, V6T-1Z1, Canada
| | - Brandon Kato
- Chemistry Department, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, V6T-1Z1, Canada
| | - Charlie Wei
- Chemistry Department, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, V6T-1Z1, Canada
| | - Christoph Müller
- Heidelberg Pharma, Gregor-Mendel-Straße 22, 68526, Ladenburg, Germany
| | - Torsten Hechler
- Heidelberg Pharma, Gregor-Mendel-Straße 22, 68526, Ladenburg, Germany
| | - Alexandra Braun
- Heidelberg Pharma, Gregor-Mendel-Straße 22, 68526, Ladenburg, Germany
| | - Francesca Gallo
- Heidelberg Pharma, Gregor-Mendel-Straße 22, 68526, Ladenburg, Germany
| | - Andreas Pahl
- Heidelberg Pharma, Gregor-Mendel-Straße 22, 68526, Ladenburg, Germany
| | - David M Perrin
- Chemistry Department, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, V6T-1Z1, Canada
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4
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Pryyma A, Matinkhoo K, Wong AAWL, Perrin DM. Meeting key synthetic challenges in amanitin synthesis with a new cytotoxic analog: 5'-hydroxy-6'-deoxy-amanitin. Chem Sci 2020; 11:11927-11935. [PMID: 34094418 PMCID: PMC8162882 DOI: 10.1039/d0sc04150e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 10/02/2020] [Indexed: 12/18/2022] Open
Abstract
Appreciating the need to access synthetic analogs of amanitin, here we report the synthesis of 5'-hydroxy-6'-deoxy-amanitin, a novel, rationally-designed bioactive analog and constitutional isomer of α-amanitin, that is anticipated to be used as a payload for antibody drug conjugates. In completing this synthesis, we meet the challenge of diastereoselective sulfoxidation by presenting two high-yielding and diastereoselective sulfoxidation approaches to afford the more toxic (R)-sulfoxide.
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Affiliation(s)
- Alla Pryyma
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver B.C. V6T 1Z1 Canada
| | - Kaveh Matinkhoo
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver B.C. V6T 1Z1 Canada
| | - Antonio A W L Wong
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver B.C. V6T 1Z1 Canada
| | - David M Perrin
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver B.C. V6T 1Z1 Canada
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5
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Pahl A, Lutz C, Hechler T. Amatoxins as RNA Polymerase II Inhibiting Antibody–Drug Conjugate (ADC) Payloads. CYTOTOXIC PAYLOADS FOR ANTIBODY – DRUG CONJUGATES 2019. [DOI: 10.1039/9781788012898-00398] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Amatoxins are a group of natural toxins which occur in the death cap mushroom (Amanita phalloides). They work by inhibiting RNA polymerase II, which results in apoptosis. RNA-polymerase II inhibition is a novel mechanism of action in cancer therapy and offers the possibility of breaking through drug resistance or destroying dormant tumour cells, which could produce major clinical advances. Amanitin, as the most potent member of this toxin family, has been made accessible for cancer therapy by developing it as a payload for antibody–drug conjugates (ADCs). This chapter describes the discovery and chemistry of the amatoxins, and the development of the amanitin-ADC technology.
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Affiliation(s)
- Andreas Pahl
- Heidelberg Pharma Schriesheimer Str. 101 68526 Ladenburg Germany
| | - Christian Lutz
- Heidelberg Pharma Schriesheimer Str. 101 68526 Ladenburg Germany
| | - Torsten Hechler
- Heidelberg Pharma Schriesheimer Str. 101 68526 Ladenburg Germany
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6
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Abstract
This Review is devoted to the chemistry of macrocyclic peptides having heterocyclic fragments in their structure. These motifs are present in many natural products and synthetic macrocycles designed against a particular biochemical target. Thiazole and oxazole are particularly common constituents of naturally occurring macrocyclic peptide molecules. This frequency of occurrence is because the thiazole and oxazole rings originate from cysteine, serine, and threonine residues. Whereas other heteroaryl groups are found less frequently, they offer many insightful lessons that range from conformational control to receptor/ligand interactions. Many options to develop new and improved technologies to prepare natural products have appeared in recent years, and the synthetic community has been pursuing synthetic macrocycles that have no precedent in nature. This Review attempts to summarize progress in this area.
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Affiliation(s)
- Ivan V Smolyar
- Department of Chemistry , Moscow State University , Leninskije Gory , 199991 Moscow , Russia
| | - Andrei K Yudin
- Davenport Research Laboratories, Department of Chemistry , University of Toronto , 80 St. George Street , Toronto , Ontario M5S 3H6 , Canada
| | - Valentine G Nenajdenko
- Department of Chemistry , Moscow State University , Leninskije Gory , 199991 Moscow , Russia
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7
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Pahl A, Lutz C, Hechler T. Amanitins and their development as a payload for antibody-drug conjugates. DRUG DISCOVERY TODAY. TECHNOLOGIES 2018; 30:85-89. [PMID: 30553524 DOI: 10.1016/j.ddtec.2018.08.005] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 08/24/2018] [Accepted: 08/25/2018] [Indexed: 11/30/2022]
Abstract
Amanitin-based ADCs represent a new class of ADCs using a novel mode of action. This payload introduces a novel mode of action into oncology therapy, the inhibition of RNA Polymerase II. The high potency of the toxin leads to highly efficacious ADCs. The development of the technology around this toxin will be described. These developments support the clinical development of amanitin-based ADCs by using a toxin with a new mode of action and with a favorable therapeutic index. HDP-101 is an Amanitin based ADC directed against BCMA and will be advancing to the clinical phase in 2019.
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Affiliation(s)
- Andreas Pahl
- Heidelberg Pharma, Schriesheimer Str. 101, 68526 Ladenburg, Germany.
| | - Christian Lutz
- Heidelberg Pharma, Schriesheimer Str. 101, 68526 Ladenburg, Germany
| | - Torsten Hechler
- Heidelberg Pharma, Schriesheimer Str. 101, 68526 Ladenburg, Germany
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8
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ZANOTTI GIANCARLO, PETERSEN GABRIELE, WIELAND THEODOR. Structure-toxicity relationships in the amatoxin series. ACTA ACUST UNITED AC 2009. [DOI: 10.1111/j.1399-3011.1992.tb00440.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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9
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10
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May JP, Perrin DM. Intraannular Savige-Fontana reaction: one-step conversion of one class of monocyclic peptides into another class of bicyclic peptides. Chemistry 2008; 14:3404-9. [PMID: 18283698 DOI: 10.1002/chem.200701088] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Cyclisation and cross-linking strategies are important for the synthesis of cyclic and bicyclic peptides. These macrolactams are of great interest due to their increased biological activity compared to linear analogues. Herein, we describe the synthesis of a cyclic peptide containing an Hpi toxicophore, reminiscent of phakellistatins and omphalotins. The first intraannular cross-linking of such a peptide is then presented: using neat TFA to catalyse a Savige-Fontana tryptathionylation, the Hpi-containing peptide is converted to a bicyclic amatoxin analogue. As such, this methodology represents an efficient cyclisation method for cross-linking peptides and exposes a heretofore unrealised relationship between two different classes of peptide natural products. This finding increases the degree of potential chemical space for library generation.
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Affiliation(s)
- Jonathan P May
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, Canada
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May J, Fournier P, Patrick B, Perrin D. Synthesis, Characterisation, and In Vitro Evaluation of Pro2-Ile3-S-Deoxo-Amaninamide and Pro2-D-allo-Ile3-S-Deoxo-Amaninamide: Implications for Structure–Activity Relationships in Amanitin Conformation and Toxicity. Chemistry 2008; 14:3410-7. [DOI: 10.1002/chem.200701297] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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12
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Abstract
The tryptathionine linkage is a crosslink formed between tryptophan and cysteine. This feature is characteristic of the bicyclic peptides: the phallotoxins and the amatoxins. These peptides both bind to protein folds of their respective targets (F-actin and RNA pol II, respectively) with extremely high affinities. Studies on these peptides have shown that the tryptathionine crosslink is essential for this binding affinity. Tryptathionines have been investigated for many years and several syntheses exist for their formation. In this review, we report on the various methodologies employed in tryptathionine synthesis, and discuss some of the advantages and disadvantages associated with each of them.
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Affiliation(s)
- Jonathan P May
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, V6T 1Z1, Canada
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13
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Falcigno L, Costantini S, D'Auria G, Bruno BM, Zobeley S, Zanotti G, Paolillo L. Phalloidin synthetic analogues: structural requirements in the interaction with F-actin. Chemistry 2001; 7:4665-73. [PMID: 11757659 DOI: 10.1002/1521-3765(20011105)7:21<4665::aid-chem4665>3.0.co;2-h] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Synthetic derivatives of phalloidin have been investigated in solution by circular dichroism (CD) and NMR spectroscopy. They differ from natural phalloidin (PHD). bicyclo(Ala1-D-Thr2-Cys3-cis-4-hydroxy-Pro4-Ala5-2-mercapto-Trp6-(OH)2Leu7)(S-3 --> 6), in that they are modified at positions 2, 3, and 7. Among these synthetic analogues, structural differences and varying degrees of atropisomerism are found. By comparing the respective molecular models obtained by restrained molecular dynamics (RMD) simulations based on experimental NMR data, structural features that may be responsible for the different biological behavior become apparent. Our results indicate that the structural changes that result from an inversion of chirality of residue 3 lead to a complete loss of toxicity. Conversely, toxicity is less affected by the structural changes that stem from an inversion of chirality of residue 2. Moreover, unlike the other phallotoxins, when the thioether unit bridges to the opposite face of the main peptide ring, in contrast to the situation in other phallotoxins, large structural changes are observed as well as a total loss of activity. Molecular models of the synthetic phalloidin analogues have been used to investigate the necessary structural requirements for the interaction with F-actin. To this end, the F-actin/PHD model of M. Lorenz et al. was employed; docking experiments of our molecular models in the PHD binding site are presented.
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Affiliation(s)
- L Falcigno
- Dipartimento di Chimica, Università di Napoli Federico II, Italy
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14
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Zanotti G, Falcigno L, Saviano M, D'Auria G, Bruno BM, Campanile T, Paolillo L. Solid state and solution conformation of [Ala7]-phalloidin: a synthetic phallotoxin analogue. Chemistry 2001; 7:1479-85. [PMID: 11330902 DOI: 10.1002/1521-3765(20010401)7:7<1479::aid-chem1479>3.0.co;2-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Phallotoxins are toxic compounds produced by poisonous mushroom Amanita phalloides and belong to the class of bicyclic peptides with a transannular thioether bridge. Their intoxication mechanism in the liver involves a specific binding of the toxins to F-actin that, consequently, prevents the depolymerization equilibrium with G-actin. Even though the conformational features of phallotoxins have been worked out in solution, the exact mechanism of interaction with F-actin is still unknown. In this study a toxic phalloidin synthetic derivative, bicyclo(Ala1-D-Thr2-Cys3-cis-4-hydroxy-Pro4-Ala5-2-mercapto-Trp6-Ala7)(S-3-->6) has been synthesized. A substitution at position 7. with an Ala residue replaces the 4,5-dihydroxy-Leu present in the natural phalloidin. This analogue has formed crystals suitable for X-ray analysis, and represents the first case for such a class of compounds. The solid-state structure as well as the solution conformation have been evaluated. NMR techniques have been used to extract interproton distances as restraints in subsequent molecular dynamics calculations. Finally, a direct comparison between structures in solution and in the solid state is presented.
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Affiliation(s)
- G Zanotti
- Dipartimento di Chimcia, Università di Napoli Federico II, Complesso Universitario Monte S. Angelo, Italy.
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Abstract
Pharmacokinetic studies have provided new insights into human Amanita poisoning, but it appears to be impossible to treat this intoxication by immunotherapy. New synthetic analogs have revealed structure-activity relationships that were unknown so far. The main toxin, alpha-amanitin, is in constant use as a tool in molecular biology and in biological research. First experiments have been reported in which amanitin bound to polymers could be internalized into tumor cells via a receptor-mediated endocytosis.
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Affiliation(s)
- T Wieland
- Max-Planck-Institut für Medizinische Forschung, Heidelberg, Germany
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16
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Zanotti G, Wieland T, D'Auria G, Paolillo L, Trivellone E. S-deoxo-Abu1,Ile3-amaninamide, an inactive amatoxin analogue. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1990; 35:263-70. [PMID: 2354877 DOI: 10.1111/j.1399-3011.1990.tb00947.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The title compound 3, an amatoxin analogue containing L-alpha-aminobutyric acid instead of L-asparagine in position 1, as in natural toad stool peptides, has been synthesized. It does not inhibit the eukaryotic DNA-dependent RNA polymerase form II (or B) in concentrations up to 10(-4)M, whereas 50% inhibition is exerted in 10(-6)M solution by the corresponding Asn-analogue S-deoxo-Ile3-amaninamide 2. The striking difference seems to be due to a relatively small variation of the conformation recognized by sensitive NMR spectroscopic methods.
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Affiliation(s)
- G Zanotti
- CNR, Department of Pharmaceutical Sciences, University La Sapienza, Rome, Italy
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17
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Zanotti G, Wieland T, Benedetti E, Di Blasio B, Pavone V, Pedone C. Structure-toxicity relationships in the amatoxin series. Synthesis of S-deoxy[gamma(R)-hydroxy-Ile3]-amaninamide, its crystal and molecular structure and inhibitory efficiency. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1989; 34:222-8. [PMID: 2599760 DOI: 10.1111/j.1399-3011.1989.tb00234.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The amatoxins, highly toxic components of Amanita mushrooms, strongly inhibit the DNA-dependent RNA polymerase II (or B) in eukaryotic cell nuclei. For optimal binding to the enzyme a gamma-hydroxyisoleucine side chain in the 3-position is important as in gamma-amanitin (compound 1), where the OH-group is bound in the [S]-configuration. Amanullin, a non-toxic component, having an oxygen-free isoleucine side chain no. 3, exhibits an inhibitory effect on RNA polymerase II about two orders of magnitude smaller than that of gamma-amanitin. An equal, relatively weak, inhibitory effect has previously been found with the synthetically obtained Ile3-analog 7. In the present paper the synthesis of an analog (2) bearing a gamma-hydroxyl group in the isoleucine side chain is described. The compound was found to have about the same inhibitory effect on RNA polymerase II from Drosophila embryos as amanullin and the Ile3-analog 7. Structure analysis by X-ray diffraction revealed that the hydroxyl group at the -carbon atom of side chain-3 has the [R]-configuration, the new analog thus being -deoxo[( )-hydroxy-[Ile3]-amaninamide. It follows that the [S]-configuration of this chiral center is a prerequisite to maximal toxicity. Crystallographic data demonstrating great similarity between the peptide backbones of the new analog and those of natural amatoxins are given.
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Affiliation(s)
- G Zanotti
- Department of Pharmaceutical Studies, University La Sapienza, Rome, Italy
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18
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Hino T, Nakagawa M. Chapter 1 Chemistry and Reactions of Cyclic Tautomers of Tryptamines and Tryptophans. THE ALKALOIDS: CHEMISTRY AND PHARMACOLOGY 1989. [DOI: 10.1016/s0099-9598(08)60226-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Zanotti G, Möhringer C, Wieland T. Synthesis of analogues of amaninamide, an amatoxin from the white Amanita virosa mushroom. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1987; 30:450-9. [PMID: 3429128 DOI: 10.1111/j.1399-3011.1987.tb03353.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Analogs of amaninamide, due to the absence of a 6-hydroxy group in the tryptophan moiety, are more easily accessible by synthesis than derivatives of alpha-amanitin. Syntheses of bicyclic octapeptide thioethers 1f-1m have been carried out starting from linear Hpi-S-trityl-octapeptides (3), cyclization by intramolecular 2'-indolylthioether formation yielding monocyclic peptides (2) and final cyclization by DCCI. One of the bicyclic thioethers was oxidized to yield the corresponding chromatographically separated (R)- and (S)-sulfoxides, respectively. The products were characterized by RF-values, u.v. and CD spectra as well as by mass (FAB) spectroscopy. The widely differing inhibitory activities on RNA polymerase II (or B) from calf thymus are listed.
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Affiliation(s)
- G Zanotti
- C.N.R. Institute of Pharmaceutical Chemistry, University La Sapienza, Rome, Italy
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20
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Zanotti G, D'Auria G, Paolillo L, Trivellone E. Synthetic amatoxin analogue. A two-dimensional proton NMR study of S-deoxy-(Ile3)-(D-Ala7)-amaninamide. BIOCHIMICA ET BIOPHYSICA ACTA 1986; 870:454-62. [PMID: 3697361 DOI: 10.1016/0167-4838(86)90253-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The effect of substitution of L and D amino acids in amatoxin analogues is discussed in this paper. The structure of the analog where D-alanine substitutes for glycine in position 7 has been worked out in solution by two-dimensional NMR methods using a 500 MHz instrument. The combined use of COSY and NOESY two-dimensional spectra allows a clear assignment of the resonances. The use of the coupling constants permits the calculation of the phi angles of the backbone. The NOE effects reveal the through-space contacts between protons of different peptide units, thus determining the rigidity of the amatoxin structure. On these grounds it has been possible to elucidate the conformation of the amatoxin analogue that resembles very closely that of beta-amanitin, thus explaining the high inhibitory activity toward RNA polymerase B.
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21
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Wieland T. The toxic peptides from Amanita mushrooms. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1983; 22:257-76. [PMID: 6354951 DOI: 10.1111/j.1399-3011.1983.tb02093.x] [Citation(s) in RCA: 107] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The results of 50 years of effort in the chemistry of Amanita toxins are reviewed. The phallotoxins, fast acting components, but not responsible for fatal intoxications after ingestion, are bicyclic heptapeptides. They combine with F-actin, stabilizing this protein against several destabilizing influences. The virotoxins likewise fast acting are monocyclic heptapeptides. The amatoxins which are the real toxins lead to death within several days by inhibiting the enzymatic synthesis of m-RNA. They are bicyclic octapeptides. The structures of all of these compounds are described, as well as conformations, chemical reactions and modification, syntheses and correlations between structures and biological activities.
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