• Bulletin of the Korean Chemical Society
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• v.15 no.11
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• pp.924-926
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• 1994

• Korean Journal of Pharmacognosy
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• v.37 no.1 s.144
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• pp.60-66
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• 2006

Norditerpene alkaloids are the main toxic principles of traditional oriental herb 'chuawu(bu-shi),' which have been used in Chinese materia medica mainly for the treatment of musculoskeletal disorders. They are biosynthesized via cyclization of geranylgeranyl pyrophosphate, incoration of 2-aminoethanol and decarboxylation not via amino acid pathway, and the structural characteristics have tempted several oxidative reactions. In this study various norditerpene alkaloids were subjected to react active manganese dioxide and oxoammonium salt as oxidants. The oxidation was proceeded as dealkylation with aconitine type and dehydrogenations with lycoctonin and heteratisine type.

• Korean Journal of Pharmacognosy
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• v.39 no.2
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• pp.127-134
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• 2008

From the under ground part of Aconitum volubile Pall. (Ranunculaceae),seven nor- or di-terpenoid alkaloids were isolated and identified by NMR spectra and mass spectrum. The alkaloids were three $C_{19}$-norditerpenoid alkaloids such as isotalatizidine, altaconitine and vilmorrianine A, and four $C_{20}$-diterpenoid alkaloids such as 12-epidehydronapelline, 12-epinapelline, songoramine and songorine. Some of the isolated diterpenoid alkaloids were subjected to oxidation reaction with active $MnO_2$ and oxoammonium salt. The results were C-12 oxidation(ketone formation) and N-dealkylation in veatchin-type and decomposition to non-alkaloidal compounds in atisine-type ajaconine.

• Journal of the Korean Chemical Society
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• v.39 no.8
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• pp.657-665
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• 1995

The oxidation of various benzyl ethers and benzyl alkyl ethers to benzoates has been studied in two-phase system of $CH_3CO_2Et$ and aqueous NaOCl (6.6 mol eq.). The oxidant N-oxo-4-methoxy-2,2,6,6-tetramethylpiperidium bromide (N-oxoammonium salt) was prepared in situ and recycled by addition of 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl (0.03 mol eq., 4-methoxy-TEMPO), co-catalyst KBr (0.03mol eq.) and second oxidant NaOCl. Thus the catalytic amount of 4-methoxy-TEMPO was used. An adjustment of the pH value of below 8.0 was also required for this reaction with 2.5 hr of reaction time at 0∼5$^{\circ}C$. Under these conditions benzyl ethers were oxidized to benzoates. The selectivity of oxidation of benzyl alkyl ethers is dependent on the acidity of hydrogen and steric effect of alkyl group.