In:
Angewandte Chemie International Edition, Wiley, Vol. 56, No. 19 ( 2017-05-02), p. 5327-5331
Kurzfassung:
Saxitoxin (STX) and its analogues are potent voltage‐gated sodium channel blockers biosynthesized by freshwater cyanobacteria and marine dinoflagellates. We previously identified genetically predicted biosynthetic intermediates of STX at early stages, Int‐A′ and Int‐C′2, in these microorganisms. However, the mechanism to form the tricyclic skeleton of STX was unknown. To solve this problem, we screened for unidentified intermediates by analyzing the results from previous incorporation experiments with 15 N‐labeled Int‐C′2. The presence of monohydroxy‐Int‐C′2 and possibly Int‐E′ was suggested, and 11‐hydroxy‐Int‐C′2 and Int‐E′ were identified from synthesized standards and LC‐MS. Furthermore, we observed that the hydroxy group at C11 of 11‐hydroxy‐Int‐C′2 was slowly replaced by CD 3 O in CD 3 OD. Based on this characteristic reactivity, we propose a possible mechanism to form the tricyclic skeleton of STX via a bicyclic intermediate from 11‐hydroxy‐Int‐C′2.
Materialart:
Online-Ressource
ISSN:
1433-7851
,
1521-3773
DOI:
10.1002/anie.201612461
Sprache:
Englisch
Verlag:
Wiley
Publikationsdatum:
2017
ZDB Id:
2011836-3
ZDB Id:
123227-7
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