First Total Synthesis and Structural Elucidation of Microcystbiopterin C, a Pterin Glycoside From a Microcystis Bloom

The first total synthesis and unambiguous structural elucidation of microcystbiopterin C, a pterin glycoside isolated from a Microcystis bloom, has been achieved. Two candidate biopterin glycosides (5a and 5b) corresponding to the proposed structures of microcystbiopterin C were synthesized by glycosylation of a suitably protected biopterin derivative 10 with 2,4-di-O-benzoyl-6-deoxy-3-O-methyl-α-L-mannopyranosyl bromide (9) and the corresponding α-D-mannopyranosyl bromide (22), respectively, followed by stepwise deprotection. Detailed comparison of the NMR data and the specific rotation of compounds 5a and 5b with those of the natural product established that microcystbiopterin C possesses the structure of 2′-O-(6-deoxy-3-O-methyl-α-D-mannopyranosyl)biopterin (5b).

This is the peer reviewed version of the following article: T. Hanaya and K. Iwasaki, “ First Total Synthesis and Structural Elucidation of Microcystbiopterin C, a Pterin Glycoside From a Microcystis Bloom,” Journal of Heterocyclic Chemistry 63, no. 8 (2026): 1278–1287, https://doi.org/10.1002/jhet.70214., which has been published in final form at https://doi.org/10.1002/jhet.70214. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.

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