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Anderson AM, Manet I, Malanga M, Clemens DM, Sadrerafi K, Piñeiro Á, García-Fandiño R, O'Connor MS. Addressing the complexities in measuring cyclodextrin-sterol binding constants: A multidimensional study. Carbohydr Polym 2024; 323:121360. [PMID: 37940263 DOI: 10.1016/j.carbpol.2023.121360] [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: 07/24/2023] [Revised: 08/22/2023] [Accepted: 08/30/2023] [Indexed: 11/10/2023]
Abstract
A class of cyclodextrin (CD) dimers has emerged as a potential new treatment for atherosclerosis; they work by forming strong, soluble inclusion complexes with oxysterols, allowing the body to reduce and heal arterial plaques. However, characterizing the interactions between CD dimers and oxysterols presents formidable challenges due to low sterol solubility, the synthesis of modified CDs resulting in varying number and position of molecular substitutions, and the diversity of interaction mechanisms. To address these challenges and illuminate the nuances of CD-sterol interactions, we have used multiple orthogonal approaches for a comprehensive characterization. Results obtained from three independent techniques - metadynamics simulations, competitive isothermal titration calorimetry, and circular dichroism - to quantify CD-sterol binding are presented. The objective of this study is to obtain the binding constants and gain insights into the intricate nature of the system, while accounting for the advantages and limitations of each method. Notably, our findings demonstrate ∼1000× stronger affinity of the CD dimer for 7-ketocholesterol in comparison to cholesterol for the 1:1 complex in direct binding assays. These methodologies and findings not only enhance our understanding of CD dimer-sterol interactions, but could also be generally applicable to prediction and quantification of other challenging host-guest complex systems.
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Affiliation(s)
- Amelia M Anderson
- Cyclarity Therapeutics, 8001 Redwood Blvd Novato, CA 94945, USA; Departamento de Física Aplicada, Facultade de Física, Universidade de Santiago de Compostela, E-15782 Santiago de Compostela, Spain; Departamento de Química Orgánica, Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS), Universidade de Santiago de Compostela, Campus Vida s/n, E-15782 Santiago de Compostela, Spain
| | - Ilse Manet
- Istituto per la Sintesi Organica e la Fotoreattività (ISOF), Consiglio Nazionale delle Ricerche (CNR), via P. Gobetti 101, Bologna 40129, Italy
| | - Milo Malanga
- CarboHyde, Budapest, Berlini u. 47-49, 1045, Hungary; Cyclolab Cyclodextrin Research and Development Ltd., Budapest, Illatos út 7 1097, Hungary
| | | | | | - Ángel Piñeiro
- Departamento de Física Aplicada, Facultade de Física, Universidade de Santiago de Compostela, E-15782 Santiago de Compostela, Spain; MD.USE Innovative Solutions S.L., Edificio Emprendia, Campus Vida, Santiago de Compostela, Spain
| | - Rebeca García-Fandiño
- Departamento de Química Orgánica, Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS), Universidade de Santiago de Compostela, Campus Vida s/n, E-15782 Santiago de Compostela, Spain; MD.USE Innovative Solutions S.L., Edificio Emprendia, Campus Vida, Santiago de Compostela, Spain
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Lebedinskiy K, Jindřich J. Preparation of 6-Monohalo-β-cyclodextrin Derivatives with Selectively Methylated Rims via Diazonium Salts. ACS OMEGA 2023; 8:28268-28276. [PMID: 37576619 PMCID: PMC10413458 DOI: 10.1021/acsomega.3c01950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 07/14/2023] [Indexed: 08/15/2023]
Abstract
A series of 6-monohalo (Cl, Br, and I) β-cyclodextrin derivatives with various types of methylations were synthesized via a diazotization/nucleophilic displacement reaction from the corresponding methylated cyclodextrin amines. All four starting compounds (6A-amino-6A-deoxy derivatives of native β-CD, per-6-O-methyl-, per-2,3-O-methyl-, and per-2,3,6-O-methyl-β-CD) were found to have different reactivities under the same reaction conditions. Unsubstituted and fully per-O-methylated cyclodextrin amines undergo fast transformation, giving lower yields of the monohalogenated product. The selectively methylated cyclodextrin amines react remarkably slower and provide almost complete conversion into the desired monohalogenated compound. A pure product was, in several cases, successfully isolated with simple purification techniques (extraction and precipitation), allowing large-scale preparations. This new method opens the way for preparing poorly investigated monofunctionalized selectively methylated cyclodextrins.
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Affiliation(s)
- Konstantin Lebedinskiy
- Department of Organic Chemistry,
Faculty of Science, Charles University, Hlavova 8, CZ-128 43 Prague, Czech Republic
| | - Jindřich Jindřich
- Department of Organic Chemistry,
Faculty of Science, Charles University, Hlavova 8, CZ-128 43 Prague, Czech Republic
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