- Oligosaccharides derived from ribose-ribitol-phosphate, and vaccines containing them
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The present invention relates to the field of the Medicine, in particular with the chemical synthesis of oligosaccharide mixtures derived of ribose-ribitol-phosphate, which are used as active principle in vaccines for the prevention of infections caused byHaemophilus influenzaetype b (Hib), as well as with the vaccines containing said oligosaccharide mixtures. The oligasaccharide mixtures obtained by chemical synthesis of the present invention, comprise repeating units of formulae (phosphate-ribosa-ribitol)n or (ribose-ribitol-phosphate)n of at least 5 compounds of structure A or B, which represent the repeating unit of the capsular polysaccharide ofHaemophilus influenzaetype b and differ only by n, being n a value contained between 4 and 25 (n≧4 y≦25), and wherein R1or R2is a spacer for conjugation to a carrier, with the condition of R1=spacer if R2=H, or R2=spacer if R1=H. The invention also is related with the immunogens containing such oligosaccharide mixtures, with the vaccines containing said immunogens and with the methods to prepare these oligosaccharides as mixtures. Furthermore, the invention includes the use of the vaccines, alone or combined with other vaccines, for the prevention of the infections caused byHaemophilus influenzaetype b.
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Page column 19
(2010/02/07)
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- Synthesis of fragments of the capsular polysaccharide of Haemophilus influenzae type b. Part I. Preparation of suitably protected 1-O-β-d-ribofuranosyl-d-ribitol building blocks
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The synthesis of the protected ribosylribitol derivatives 15 and 17, which are building blocks for the preparation of fragments of the H. influenzae type b polysaccharide, is presented. Starting from d-ribonolactone (1), 5-O-allyl-2,3,4-tri-O-benzyl-d-ribitol (8) was prepared in seven steps (Scheme 1). Coupling of 8 with 1-O-acetyl-2,3,5-tri-O-benzoyl-β-d-ribofuranose (9) in the presence of trimethylsilyl trifluoromethanesulfonate gave the ribosylribitol derivative 10 (Scheme 2), which was debenzoylated to afford compound 11. The C-3′- and C-5′-hydroxyl functions of the ribose moiety of 11 were protected with the 1,1,3,3-tetraisopropyldisiloxane-1,3-diyl group and the C-2′ position with the benzyloxymethyl group. Compound 13 thus obtained was converted into its 5-O-trans-1-propenyl isomer 14. Cleavage of the propenyl group from 14 gave compound 15, which can be phosphorylated at O-5 of the ribitol. On the other hand, removal of the 3′,5′-protection from 14 and subsequent blocking of the primary hydroxyl function yielded ribosylribitol derivative 17 having a 3′-hydroxyl function available for phosphorylation.
- Hermans,Poot,Kloosterman,van der Marel,van Boeckel,Evenberg,Poolman,Hoogerhout,van Boom
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p. 498 - 504
(2007/10/02)
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- SYNTHESIS OF FRAGMENTS OF THE CAPSULAR POLYSACCHARIDE OF HAEMOPHILUS INFLUENZAE TYPE B, COMPRISING TWO OR THREE REPEATING UNITS
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The synthesis of the ribosyl-ribitol derivatives 15 and 17 (Scheme 2) is presented.The compounds served as building blocks for the preparation of protected fragments (24, n=1 or 2; Fig. 2) of the title polysaccharide.The bifunctional reagent bis-2-chlorophenylphosphate (18, Fig. 2) was used for all phosphorylation reactions.Attachment to a spacer and complete deprotection of the products, to afford 25 (n=2 or 3), is described.
- Hoogerhout, P.,Evenberg, D.,Boeckel, C. A. A. van,Poolman, J. T.,Beuvery, E. C.,et al.
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p. 1553 - 1556
(2007/10/02)
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