1
|
Fairbanks AJ. Synthetic and semi-synthetic approaches to unprotected N-glycan oxazolines. Beilstein J Org Chem 2018; 14:416-429. [PMID: 29520306 PMCID: PMC5827820 DOI: 10.3762/bjoc.14.30] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 01/31/2018] [Indexed: 12/15/2022] Open
Abstract
N-Glycan oxazolines have found widespread use as activated donor substrates for endo-β-N-acetylglucosaminidase (ENGase) enzymes, an important application that has correspondingly stimulated interest in their production, both by total synthesis and by semi-synthesis using oligosaccharides isolated from natural sources. Amongst the many synthetic approaches reported, the majority rely on the fabrication (either by total synthesis, or semi-synthesis from locust bean gum) of a key Manβ(1-4)GlcNAc disaccharide, which can then be elaborated at the 3- and 6-positions of the mannose unit using standard glycosylation chemistry. Early approaches subsequently relied on the Lewis acid catalysed conversion of peracetylated N-glycan oligosaccharides produced in this manner into their corresponding oxazolines, followed by global deprotection. However, a key breakthrough in the field has been the development by Shoda of 2-chloro-1,3-dimethylimidazolinium chloride (DMC), and related reagents, which can direct convert an oligosaccharide with a 2-acetamido sugar at the reducing terminus directly into the corresponding oxazoline in water. Therefore, oxazoline formation can now be achieved in water as the final step of any synthetic sequence, obviating the need for any further protecting group manipulations, and simplifying synthetic strategies. As an alternative to total synthesis, significant quantities of several structurally complicated N-glycans can be isolated from natural sources, such as egg yolks and soy bean flour. Enzymatic transformations of these materials, in concert with DMC-mediated oxazoline formation as a final step, allow access to a selection of N-glycan oxazoline structures both in larger quantities and in a more expedient fashion than is achievable by total synthesis.
Collapse
Affiliation(s)
- Antony J Fairbanks
- Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
- Biomolecular Interaction Centre, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
| |
Collapse
|
2
|
Di Bussolo V, Calvaresi EC, Granchi C, Del Bino L, Frau I, Lang MCD, Tuccinardi T, Macchia M, Martinelli A, Hergenrother PJ, Minutolo F. Synthesis and biological evaluation of non-glucose glycoconjugated N-hydroyxindole class LDH inhibitors as anticancer agents. RSC Adv 2015; 5:19944-19954. [PMID: 26167277 PMCID: PMC4497792 DOI: 10.1039/c5ra00946d] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Inhibitors of human lactate dehydrogenase A (LDH-A) are promising therapeutic agents against cancer. The development of LDH-A inhibitors that possess cellular activities has so far proved to be particularly challenging, since the enzyme's active site is narrow and highly polar. In the recent past, we were able to develop a glucose-conjugated N-hydroxyindole-based LDH-A inhibitor designed to exploit the sugar avidity expressed by cancer cells (the Warburg effect). Herein we describe a structural modulation of the sugar moiety of this class of inhibitors, with the insertion of α-D-mannose, β-D-gulose, or β-N-acetyl-D-glucosamine portions in their structures. Their stereospecific chemical synthesis, which involves a substrate-dependent stereospecific glycosylation step, and their biological activity in reducing lactate production and proliferation in cancer cells are reported. Interestingly, the α-D-mannose conjugate displayed the best properties in the cellular assays, demonstrating an efficient antiglycolytic and antiproliferative activity in cancer cells.
Collapse
Affiliation(s)
- Valeria Di Bussolo
- Dipartimento di Farmacia, Università di Pisa, Via Bonanno 33, 56126 Pisa, Italy
| | - Emilia C. Calvaresi
- Department of Chemistry, University of Illinois, 600 S. Mathews Avenue, Urbana, IL 61801, USA
| | - Carlotta Granchi
- Dipartimento di Farmacia, Università di Pisa, Via Bonanno 33, 56126 Pisa, Italy
| | - Linda Del Bino
- Dipartimento di Farmacia, Università di Pisa, Via Bonanno 33, 56126 Pisa, Italy
| | - Ileana Frau
- Dipartimento di Farmacia, Università di Pisa, Via Bonanno 33, 56126 Pisa, Italy
| | | | - Tiziano Tuccinardi
- Dipartimento di Farmacia, Università di Pisa, Via Bonanno 33, 56126 Pisa, Italy
| | - Marco Macchia
- Dipartimento di Farmacia, Università di Pisa, Via Bonanno 33, 56126 Pisa, Italy
| | - Adriano Martinelli
- Dipartimento di Farmacia, Università di Pisa, Via Bonanno 33, 56126 Pisa, Italy
| | - Paul J. Hergenrother
- Department of Chemistry, University of Illinois, 600 S. Mathews Avenue, Urbana, IL 61801, USA
| | - Filippo Minutolo
- Dipartimento di Farmacia, Università di Pisa, Via Bonanno 33, 56126 Pisa, Italy
| |
Collapse
|
3
|
Lindhorst TK. Multivalent glycosystems for nanoscience. Beilstein J Org Chem 2014; 10:2345-7. [PMID: 25383104 PMCID: PMC4222442 DOI: 10.3762/bjoc.10.244] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 09/24/2014] [Indexed: 12/15/2022] Open
Affiliation(s)
- Thisbe K Lindhorst
- Otto Diels Institute of Organic Chemistry, Christiana Albertina University of Kiel, Otto-Hahn-Platz 3/4, 24098 Kiel, Germany
| |
Collapse
|