Photooxidation of cedrelone, a tetranortriterpenoid from Toona ciliata.
Cedrelone, a tetranortriterpenoid on photolysis by UV light yields a true photooxidation product 3 [14 beta,15beta,22beta,23beta-diepoxy-6-hydroxy-1,5, 20(22)-meliatriene-2,7,21-trione] whose structure is well established by NMR studies and confirmed by X-ray crystallography, along with product 4 [14 beta,15beta-epoxy-6,23-dihydroxy-1,5,20(22)-meliatriene-2,7, 21-trione]. Addition of rose bengal increases the rate of photooxidation whereas DABCO decreases rate of photolysis proving the involvement of singlet oxygen in the photooxygenation. Both the photoproducts exhibited antifeedant activity.
Gopalakrishnan
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Centre for Natural products, SPIC Science Foundation, Guindy, Chennai, India. geethagopal@hotmail.com
Pradeep Singh
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ND
Kasinath
V
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Malathi
R
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Rajan
S S
SS
D018360:Crystallography, X-Ray; D036701:Limonins; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010777:Photochemistry; D010936:Plant Extracts / Q000737:chemistry; D014197:Trees / Q000737:chemistry; D014315:Triterpenes / Q000737:chemistry*
D036701:Limonins; D010936:Plant Extracts; D014315:Triterpenes; C414666:cedrelone