Identification of new limonoids from Swietenia and their biological activity against insects.
BACKGROUND
Natural limonoids are one group of compounds being studied for their insecticidal properties. To discover new limonoids with better activities, analogs were prepared via acylation and hydrolysis, and bioassayed.


RESULTS
Analogs were identified using one- and two-dimensional (COSY, HMQC and HMBC) (1) H and (13) C NMR, IR and MS. 3-O-Isovalerylswietenolide (13) and 3-O-isobutyrylswietenolide (14) showed excellent antifeedant activity, with DC(50) values of 0.19 and 0.009 mg L(-1) respectively, compared with the natural limonoid swietenolide (80.6 mg L(-1) ) against fourth-instar Spodoptera frugiperda (JE Smith) larvae.


CONCLUSIONS
This work shows that limonoid analogs prepared through semi-synthesis can be used as lead compounds for the development of new insecticides.
Fowles
Robert
R
Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada. robert.fowles@ualberta.ca
Mootoo
Baldwin
B
Ramsewak
Russel
R
Khan
Ayub
A
Ramsubhag
Adesh
A
Reynolds
William
W
Nair
Muraleedharan
M
D000818:Animals; D007300:Insect Control; D007306:Insecticides / Q000737:chemistry / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects / Q000254:growth & development; D036701:Limonins / Q000737:chemistry / Q000494:pharmacology*; D029582:Meliaceae / Q000737:chemistry*; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D018411:Spodoptera / Q000187:drug effects* / Q000254:growth & development
D007306:Insecticides; D036701:Limonins; D010936:Plant Extracts