Gluco-indole Alkaloids from Nauclea cadamba in Thailand and Transformation of 3.ALPHA.-Dihydrocadambine into the Indolopyridine Alkaloid, 16-Carbomethoxynaufoline.
摘要:
Three monoterpenoid gluco-indole alkaloids, 3β-isodihydrocadambine, cadambine, and 3α-dihydrocadambine, were isolated from Nauclea cadamba ROXB. growing in Thailand. The stereochemistry at C19 in 3β-isodihydrocadambine was elucidated to be R by spectroscopic analysis. Treatment of 3α-dihydrocadambine with β-glucosidase in aqueous ammonium acetate solution gave an indolopyridine alkaloid, 16-carbomethoxynaufoline, and an unusually rearranged compound.
A collective synthesis of glycosylated monoterpenoid indole alkaloids is reported. A highly diastereoselective Pictet–Spenglerreaction with α‐cyanotryptamine and secologanin tetraacetate as substrates, followed by a reductive decyanation reaction, was developed for the synthesis of (−)‐strictosidine, which is an important intermediate in biosynthesis. This two‐step chemical method was established
Gluco-indole Alkaloids from Nauclea cadamba in Thailand and Transformation of 3.ALPHA.-Dihydrocadambine into the Indolopyridine Alkaloid, 16-Carbomethoxynaufoline.
Three monoterpenoid gluco-indole alkaloids, 3β-isodihydrocadambine, cadambine, and 3α-dihydrocadambine, were isolated from Nauclea cadamba ROXB. growing in Thailand. The stereochemistry at C19 in 3β-isodihydrocadambine was elucidated to be R by spectroscopic analysis. Treatment of 3α-dihydrocadambine with β-glucosidase in aqueous ammonium acetate solution gave an indolopyridine alkaloid, 16-carbomethoxynaufoline, and an unusually rearranged compound.