- The Formation of Cyclic Peroxide from Guaia-6,9-diene as a Model for Hanalpinol Biosynthesis
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Autooxidation and photosensitized oxidation converted guaia-6,9-diene into hanalpinol, both compounds are contained in the rhizomes of Alpinia japonica.This process may be considered to be a biomimetic conversion.Guaia-6,9-diene may be regarded as an immediate precursor of hanalpinol, and a biogenetic pathway has been proposed.The results of molecular orbital calculation (modified neglect of differential overlap (MNDO) method) supported this proposal and provided a basis for conformational analysis. Keywords---Alpinia japonica; guaia-6,9-diene; hanalpinol; biosynthesis; molecular orbital calculation; MNDO; autooxidation; photosensitized oxidation; conformational analysis
- Morita, Hiroshi,Tomioka, Nobuo,Iitaka, Yoichi,Itokawa, Hideji
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p. 2984 - 2989
(2007/10/02)
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- Novel Guaiane- and Secoguaiane- Type Sesquiterpenes from Alpinia japonica (THUNB.) MIQ.
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Three novel guaiane-type sesquiterpenes, hanalpinone (I), isohanalpinone (II), and alpinenone (III), and two novel secoguaiane-type sesquiterpenes, alpinolide peroxide (IV) and 6-hydroxyalpinolide (V) have been isolated from the rhizomes of Alpinia japonica.Their structures were determined by spectroscopic methods, chemical conversions, and X-ray analysis.Their biosynthetic relationships with previously identified sesquiterpenes from Alpinia japonica are discussed.Keywords-Alpinia japonica; Zingiberaceae; sesquiterpene; guaiane; secoguaiane; peroxide; X-ray analysis; 13C-NMR; biosynthesis
- Itokawa, Hideji,Morita, Hiroshi,Osawa, Kenji,Watanabe, Kinzo,Iitaka, Yoichi
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p. 2849 - 2859
(2007/10/02)
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- Novel Sesquiterpenes from Alpinia intermedia GAGNEP.
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Three novel sesquiterpene peroxides, hanalpinol peroxide (I), isohanalpinol (II), and aokumanol (III), a new secoguaiane-type sesquiterpene, epialpinolide (IV), and a new elemophilane-type sesquiterpene, Δ11(12)-eremophilen-10β-ol (V), have been isolated from the rhizomes of Alpinia intermedia together with eight known sesquiterpenes, hanalpinol (VI), hanalpinone (VII), isohanalpinone (VIII), alpinenone (IX), furopelargone B (X), furopelargone A (XI), intermedeol (XII) and β-selinene (XIII).The structures of I-V were determined by spectroscopic methods, chemical conversion, and X-ray analysis.Their biosynthetic relationships are discussed.From the point of view of chemotaxonomy, it is suggested that Alpinia intermedia and Alpinia japonica are closely related plants.Keywords-Alpinia intermedia; Zingiberaceae; sesquiterpene; guaiane; cyclic peroxide; X-ray analysis; eremophilane; secoguaiane; chemotaxonomy; biosynthesis
- Itokawa, Hideji,Morita, Hiroshi,Kobayashi, Takeshi,Watanabe, Kinzo,Iitaka, Yoichi
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p. 2860 - 2868
(2007/10/02)
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