Journal of Chemical Ecology, Vol. 10, No. 10, 1984
ANTIFEEDANT ACTIVITY OF QUASSINOIDS
VIOLA LESKINEN, j JUDITH POLONSKY, 2 and S U B O D H B H A T N A G A R 2 IDepartment of Chemistry, Columbia University New York, New York 2Institut de Chimie des Substances Naturelles C.N.R.S., 91190 Gif-sur- Yvette, France
(Received December 2, 1983; revised March 5, 1984) Abstract--The antifeedant activity of 13 quassinoids of different structural types has been studied against the Mexican bean beetle (Epilachna varivestis Mulsant) 4th instar larvae and the southern armyworm (Spodoptera eridania Crawer) 5th instar larvae. All quassinoids tested displayed significant activity against the Mexican bean beetle and, thus, do not reveal a simple structure-activity relationship. Five quassinoids were active against the southern armyworm. Interestingly, four of these-bruceantin (I), glaucarubinone (VI), isobruceine A (VIII), and simalikalactone D (XI)--possess the required structural features for antineoplastic activity. The noncytotoxic quassin (X) is an exception; it is active against both pests. Key Words--Antifeedant, Mexican bean beetle, Epilachna varivestis, Coleoptera, Coccinetlidae, southern armyworm, Spodoptera eridania, Lipidoptera, Noctuidae, quassinoids, Simaroubaceae.
INTRODUCTION Q u a s s i n o i d s are the c h a r a c t e r i s t i c b i t t e r principles o f the p l a n t f a m i l y S i m a r o u b a c e a e ( P o l o n s k y , 1973) which is o f m o s t l y p a n t r o p i c a l d i s t r i b u tion. T h e y are d e g r a d e d t r i t e r p e n e s , and m a n y o f t h e m possess diverse and p o t e n t i a l l y useful b i o l o g i c a l p r o p e r t i e s . Thus, m u c h a t t e n t i o n c o n t i n u e s to be focused on q u a s s i n o i d s b e c a u s e o f their p o t e n t in vivo a n t i n e o p l a s t i c activity ( C a s s a d y et al., 1980), their a b i l i t y to i n h i b i t cell t r a n s f o r m a t i o n i n d u c e d b y the R o u s s a r c o m a virus ( P i e r r 6 et al., 1980), a n d the a n t i a m e b i c (Gillin a n d R e i n e r , 1982; Gillin et al., 1982) a n d the recently o b s e r v e d a n t i m a l a r i a l p r o p e r t i e s (Trager et al., 1981). T h e q u a s s i n o i d c o n s t i t u e n t s 1497 0098-0331/ 84/i000-1497503.50/09 1984PlenumPublishingCorporation
LESKINEN ET AL.
such as bruceantin (I), now undergoing clinical trial by the U.S. National Cancer Institute (Kupchan et al., 1975), have been of special interest. Since it is highly desirable to develop new methods of pest control (Meinwald, 1978), it seemed interesting to investigate the possible antifeedant effects of the quassinoids. Preliminary antifeedant test (Odjo et al., 1981) were carried out on third stage larvae of Locusta migratoria migratorioides R and F (Orthoptera, Acrididae). The quassinoids bruceine A (II), bruceine B (III), chaparrinone (V), glaucarubinone (VI), and simalikalactone D (XI) were found to be insect antifeedants, whereas soulameanone (XIII) (Polonsky et al., 1980), soulameolide (Polonsky et al., 1979), and simarolide (XII) were inactive. We now report on the antifeedant activity of 13 quassinoids against two pests, Epilachna varivestis Mulsant (Mexican bean beetle) and Spodoptera eridania Crawer (southern armyworm). The former is monophagous and highly selective, whereas the latter is polyphagous and is a voracious eater.
METHODS AND MATERIALS The quassinoids tested were isolated in the pure state from natural sources. Only those which did not appear in the review (Polonsky, 1973) have been referenced. Quassin is commercially available, and its total synthesis has been accomplished recently (Grieco et al., 1980). Each compound was dissolved in acetone at the concentrations (in ppm) indicated in Tables 1 and 2. The feeding bioassays were carried out as follows: A mature bush bean plant, with two leaves approximately the same size, was chosen for each replicate (Figure 1). One leaf top was coated with compound, and one leaf top with solvent alone as a control. These were allowed to dry. In the initial southern armyworm tests, and in all Mexican bean beetle tests, the cut stem was placed in a vial with water and a tissue plug to support the stem. The base of the stem was coated with vaseline to prevent the insects from crawling off. If any compound merited further testing against the southern armyworms, the plant was left rooted in its pot, the leaves coated as before, and the stem covered with vaseline as before. This change in procedure was initiated because the cut stems did not survive the 24-hr test period too well; they tended to wilt and also suffered from the heavier weight of the worms. All plants were then placed inside a cage for the test period to prevent the insects from escaping. Care was taken that no plants or leaves touched, so that the original test subjects stayed on their original plants. Five replicates were run for each test. For the Mexican bean beetles, two fourth instar larvae were placed on each leaf. For the southern
TABLE 1. ANTIFEEDANT ACTIVITY OF QUASSlNOIDS AGAINST MEXICAN BEAN BEETLE
Perforalactone A (1), a new 20S quassinoid with a unique cagelike 2,4-dioxaadamantane ring system and a migrated side chain, was isolated from the plant Harrisonia perforata together with two biosynthetically related new quassinoids. The structures o
Xanthohumol, a prenylated flavonoid from hops, and a supercritical carbon dioxide extract of spent hops were studied for their antifeedant activity against stored product insect pests: Sitophilus granarius L., Tribolium confusum Duv. and Trogoderma g
For the first time, a set of 56 compounds representing structural derivatives of naturally occurring alpha-asarone as an antifeedants against stored product pests Sitophilus granarius L., Trogoderma granarium Ev., and Tribolium confusum Duv., were su
Ginkgo biloba is a typical relic plant that rarely suffers from pest hazards. This study analyzed the pattern of G. biloba pest hazards in Beijing; tested the antifeedant activity of G. biloba extracts, including ginkgo flavonoids, ginkgolide, and bi
Two racemic and two enantiomeric pairs of new δ-hydroxy-γ-lactones based on the p-menthane system were prepared from racemic and optically active cis- and trans-piperitols. The Johnson-Claisen rearrangement of the piperitols, epoxidation of the γδ-un
Four new limonoids, azadiraindins A-D (1-4, resp.), together with seven known analogs, were isolated from the MeOH extract of Azadirachta indica. The structures of 1-4 were elucidated by NMR and MS spectroscopic analyses, and the relative configurati
Seven compounds were isolated from the roots of Eurycoma longifolia, and characterized by comprehensive analysis of 1D and 2D NMR experiments along with single crystal X-ray diffraction. Among them, four new quassinoids were identified and three of t
The acetylenic acid,Z-dihydromatricaria acid (DHMA), previously isolated from the defensive secretion ofChauliognathus lecontei, and now shown to occur also inC. pennsylvanicus, is a potent feeding deterrent to jumping spiders (Phidippus spp.). A sim
A new bioassay employing a natural fungivore, the opossumDidelphis virginiana, is described. Using this bioasssay, eighteen species of fungi were tested for palatability. Five species of mushrooms, all of which taste pungent to humans, were found to
The first asymmetric total synthesis of the antifeedant terpenoids (+)-norleucosceptroid A, (-)-norleucosceptroid B, and (-)-leucosceptroid K has been accomplished. This highly concise synthetic route was guided by our efforts to develop a platform f