DOI: 10.1002/cbic.201200708 Bicyclic Derivatives of l-Idonojirimycin as Pharmacological Chaperones for Neuronopathic Forms of Gaucher Disease Pilar Alfonso, [a, b, c] Vanesa Andreu, [b, c] Almudena Pino-Angeles,* [a, d] Aurelio A. Moya- García, [a, d] M. Isabel García-Moreno, [e] JosØ C. Rodríguez-Rey, [f] Francisca Sµnchez-JimØnez, [a, d] Miguel Pocoví, [a, c, g] Carmen Ortiz Mellet,* [e] Jose M. García Fernµndez, [h] and Pilar Giraldo* [a, b, c, i] Gaucher disease (GD), the most prevalent lysosomal storage disorder (LSD), [1] is caused by mutations in the GBA1 gene, which encodes lysosomal acid b-glucosidase (b-glucocerebrosi- dase, GCase; EC 3.2.1.45). The mutant enzymes exhibit im- paired cellular trafficking as a consequence of aberrant folding, and ultimately undergo degradation by the endoplasmic retic- ulum (ER) quality control system. [2] Defective GCase activity in phagocytic cells results in lysosomal accumulation of glucosyl- ceramide (GlcCer), which often leads to hepatosplenomegaly, anemia, bone lesions, respiratory failure, and, sometimes, cen- tral nervous system (CNS) involvement. Three distinct major forms of GD are recognized: non-neuronopathic type 1 (OMIM# 230800), neuronopathic type 2 (OMIM# 230900), and type 3 GD (OMIM# 231000). [3] Of the approximately 300 mis- sense mutations that have been described in GBA1, N370S and L444P are the most prevalent in the general population. [4] Tra- ditionally, the N370S allele is associated with type 1 GD. How- ever, several recent reports have described some neurological manifestations in heterozygous individuals with this muta- tion. [5] In contrast, homozygosity for L444P indicates a high risk of neurological manifestations. [6] Enzyme replacement therapy (ERT) [7] and substrate reduction therapy (SRT), [8] the current therapeutic strategies for GD, are effective against visceral, hematologic, and skeletal abnormalities in type 1 GD. Both ERT and SRT address accumulation of the substrate, but ignore the contribution of defective protein folding to the disease. Types 2 and 3 GD remain refractory to these treatments. [9] Pharmacological chaperone therapy (PCT) [10] has emerged in the past decade as a promising new treatment for diseases caused by protein misfolding and mistrafficking, and several compounds are currently being evaluated for the treatment of GD. [11] PCT relies on the ability of pharmacological chaperones (PCs) to promote the correctly folded conformation of the target mutant protein, thereby enabling it to meet the quality control standards in the ER and restore trafficking. Recent evi- dence has shown that accumulation of substrate in GD cells re- sults from low levels of functional GCase, not from low intrinsic catalytic GCase activity, thus supporting the feasibility of PCT in GD treatment. [12] Although somewhat counterintuitive, enzyme competitive inhibitors can increase steady-state lyso- somal levels of active enzymes through this rescuing mecha- nism and act as PCs. At high lysosomal substrate concentra- tion, the inhibitor is eventually displaced from the active site of the enzyme and metabolic activity recovers. With few exceptions, PCs in GD research mimic the glycone portion of the putative substrate, that is, the d-glucopyranose moiety of GlcCer, which is shared across the target for a series of isoenzymes and enzymes that act on anomeric substrates. This is the case for the iminosugar 1-deoxynojirimycin (DNJ), the 1-azasugar isofagomine (IFG), and their N-alkyl derivatives. Not surprisingly, they frequently lead to insufficient selectivity for clinical application. [13] C-substituted iminosugars (e.g., a-C 9 - DIX) [14] and aminocyclitol glycomimetics (e.g., myo-(C 9 ) 2 ; Scheme 1) [15] have shown considerable promise, but their syn- theses often involve costly reaction sequences. Recently we demonstrated that bicyclic glycomimetics with an endocyclic pseudoamide-type nitrogen atom (sp 2 -iminosugars), [16] such as 6S-NOI-NJ [17] (Scheme 1), provide excellent opportunities to [a] Dr. P. Alfonso, Dr. A. Pino-Angeles, Dr. A. A. Moya-García, Prof. F. Sµnchez-JimØnez, Prof. M. Pocoví, Prof. P. Giraldo Biomedical Network Research Center on Rare Diseases (CIBERER), ISCIII Alvaro de Bazµn 10 bajo, 46010 Valencia (Spain) [b] Dr. P. Alfonso, Dr. V. Andreu, Prof. P. Giraldo Translational Research Unit, Miguel Servet University Hospital Paseo Isabel la Católica 1–3, 50009 Zaragoza (Spain) [c] Dr. P. Alfonso, Dr. V. Andreu, Prof. M. Pocoví, Prof. P. Giraldo Aragon Health Sciences Institute (IACS) Avda. San Juan Bosco 13, planta 1, 50009 Zaragoza (Spain) [d] Dr. A. Pino-Angeles, Dr. A. A. Moya-García, Prof. F. Sµnchez-JimØnez Department of Molecular Biology and Biochemistry, University of Mµlaga Campus de Teatinos, s/n, 29071 Mµlaga (Spain) E-mail : almupino@gmail.com [e] Dr. M. I. García-Moreno, Prof. C. Ortiz Mellet Departamento de Química Orgµnica Facultad de Química, Universidad de Sevilla Profesor García Gonzµlez 1, 41012 Sevilla (Spain) E-mail : mellet@us.es [f] Prof. J. C. Rodríguez-Rey Department of Molecular Biology, University of Cantabria and Instituto de Formación e Investigación MarquØs de Valdecilla (IFIMAV) Avda. Valdecilla s/n, 39008 Santander (Spain) [g] Prof. M. Pocoví Department of Biochemistry and Cellular and Molecular Biology University of Zaragoza Pedro Cerbuna 1, 50009 Zaragoza (Spain) [h] Prof. J. M. García Fernµndez Instituto de Investigaciones Químicas (IIQ), CSIC—Universidad de Sevilla AmØrico Vespucio 49, Isla de la Cartuja, 41092 Sevilla (Spain) [i] Prof. P. Giraldo Hematology Department, Miguel Servet University Hospital Paseo Isabel la Catolica 1-3, 50009 Zaragoza (Spain) E-mail : giraldocastellano@gmail.com Supporting information for this article is available on the WWW under http ://dx.doi.org/10.1002/cbic.201200708. # 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim ChemBioChem 0000, 00,1–7 &1& These are not the final page numbers! ÞÞ CHEMBIOCHEM COMMUNICATIONS