C h a p t e r 48
Diterpenoids as Insect Antifeedants and Growth Inhibitors: Role in Solidago Species G. A. Cooper-Driver and P. W. Le Quesne 1
2
Department of Biological Sciences, Boston University, Boston, M A 02215 Department of Chemistry, Northeastern University, Boston, M A 02115
1
Downloaded by UNIV OF SYDNEY on October 7, 2015 | http://pubs.acs.org Publication Date: January 8, 1987 | doi: 10.1021/bk-1987-0330.ch048
2
Diterpenoids have a wide range of biological activities. Their role in plant-insect interactions, both as antifeedants and growth inhibitors, is reviewed. Four ent-kauranes, kaur-16-en-19-oic acid, (-)-kauran-16αol, 15α-hydroxy-(-)-kaur-16-en-19-oic acid, and 17hydroxy-(-)-kaur-15-en-19-oic acid, have recently been isolated from the leaves of Solidago nemoralis.These compounds were found to have antifeedant activity against Trirhabda canadensis. Plant chemists show several different approaches to the way they view chemicals in plants. Some are interested in the isolation of the molecule per se, its structure and synthesis (1). Others are searching for interesting and hopefully patentable biologically active plant products or molecules as new drugs (2), as antibiotics (3), or as pesticides (40. A third group seeks to understand the role such compounds (allelochemicals) play in the environment, that is the way in which they may influence or control many of the complex interactions that occur between living organisms in natural plant communities Ç5, 6). As has been shown in this Symposium these three approaches are not necessarily mutually exclusive. A study of the latter type is made more difficult since plants, even a single plant, usually contain a large number of different classes of chemical compounds and at the same time may be interacting with a wide variety of different organisms as well as with each other C7, 8). Nevertheless over recent years great progress has been made towards understanding the role of allelochemicals in natural systems particularly with regard to insect-plant interactions (9-12). Terpenoids are one of the many classes of allelochemicals known to play an important role in such interactions (13). Of particular interest are the diterpenoids. These are widely distributed in plants, and are also present in fungi and marine organisms, and as such provide a ready source for the isolation of new compounds (13-15). They also show a wide range of biological activities (13-15). These include antitumor properties (16), antimicrobial activity (17), 0097-6156/87/0330-0534$06.00/0 © 1987 American Chemical Society
In Allelochemicals: Role in Agriculture and Forestry; Waller, G.; ACS Symposium Series; American Chemical Society: Washington, DC, 1987.
48.
COOPER-DRIVER AND LE QUESNE
Diterpenoids
as Insect Antifeedants
535
f e r t i l i t y regulation (18), plant growth regulation Q9, 20), and a l l e l o p a t h i c action (21). Several groups of diterpenoids are also known to be active as l a r v a l growth i n h i b i t o r s or feeding deterrents against a number of a g r i c u l t u r a l and forest pests (22-24) (Table I ) .
Downloaded by UNIV OF SYDNEY on October 7, 2015 | http://pubs.acs.org Publication Date: January 8, 1987 | doi: 10.1021/bk-1987-0330.ch048
B i o l o g i c a l A c t i v i t y of Diterpenes Against
Insects
B i c y c l i c diterpenes-clerodanes. An important group of insect antifeedants are the clerodane diterpenoids, which have been i s o l a t e d from several d i f f e r e n t plant families (13)(Figure 1). P a r t i c u l a r l y well studied are the antifeedant a c t i v i t i e s of caryoptin and clerodin, and t h e i r d e r i v a t i v e s , from Clerodendron and Caryopteris, Verbenaceae, against the tobacco cutworm Spodoptera l i t u r a L . (25-27). Examining the b i t t e r - t a s t i n g leaves of Ajuga remota, an East African medicinal plant, known l o c a l l y to be r e s i s t a n t to insects, led to the i s o l a t i o n of another group of clerodanes, the ajugarins, active against both the monophagous African armyworm, Spodoptera exempta, and the polyphagous S_. l i t t o r a l i s (22, 28) . When added to a r t i f i c i a l diets ajugarins are also i n s e c t i c i d a l to the silkworm, Bombyx mori, but merely i n h i b i t the growth of the pink bollworm, Pectinophora gossypiella (28)» Ajugareptansones A and Β from A. reptans (29, 30), and ivains I-IV from Ajuga i v a also exhibit high antifeedant a c t i v i t y against the African armyworm and other lepidopterous species (31). Two chlorine-containing clerodanes, t a f r i c a n i n s A and B, with similar antifeedant properties, have been i s o l a t e d from a South African bush, Teucrium africanum (32). Teucjaponin B, from Teucrium japonicum, i s also i n h i b i t o r y to the feeding of Spodoptera l i t u r a (33). Belles et a^l. have recently discussed the s t r u c t u r e - a c t i v i t y relationships of several natural clerodane diterpenoids and their derivatives, and have compared their a c t i v i t y with that of some synthetic butenolide derivatives (34). Grindelane diterpenoids. Grindelanes, labdane-type diterpenoids (Figure 2) from Chrysothamnus and Grindelia species, show s i g n i f i c a n t antifeedant a c t i v i t y (35). Two grindelane diterpenes, 18-hydroxyg r i n d e l i c acid and 18-succinyloxygrindelic acid, present i n the bicarbonate-soluble f r a c t i o n of Chrysothamnus nauseosus ( P a l l . ) B r i t t , the rabbit bush, were found by Rose (36) to i n h i b i t feeding of t h i r d instar Colorado potato beetles. Additional grindelane diterpenes, o^hydroxy and £4hydroxygrindelic acids, also i n h i b i t e d feeding by the aphid Schizaphis graminum (37). Cuticular diterpenes-duvanes and labdanes. Cutler et_ a l . have found that the c u t i c u l a r diterpenes of green tobacco have both a l l e l o p a t h i c and insect-deterrent e f f e c t s (38). Present i n the c u t i c l e are duvane and/or labdane diterpenes (Figure 3) The l e v e l s of these s p e c i f i c c u t i c u l a r components are believed to be responsible for the observed resistance of some types of tobacco to green peach aphids Myzus persicae (Sulzer), tobacco budworm H e l i o t h i s virescens (F.), and tobacco hornworm Manduca sexta (L.) (39). T r i c y c l i c diterpenes-resin acids. Wood r e s i n constituents, e.g. abietane derivatives, have also been -implicated i n pest resistance (Figure 4). Among the conifer-associated sawflies many prefer to feed
In Allelochemicals: Role in Agriculture and Forestry; Waller, G.; ACS Symposium Series; American Chemical Society: Washington, DC, 1987.
In Allelochemicals: Role in Agriculture and Forestry; Waller, G.; ACS Symposium Series; American Chemical Society: Washington, DC, 1987. 18-Hydroxygrindelic and 18-succinyloxygrindelic acids 6PMlydroxygrindelic and 6^-hydroxygrindelic acids
Asteraceae
Labiatae
Pinaceae
Duvanes and labdanes Nicotiana spp.
Abietanes Pinus banksiana
13-oxo-8(14)-podocarpen18-oic, dehydroabietic,
Labda-12,14-dien-8d(-ol, labda-13-en-8*, 15-diol, ctfi^-4,8,13-duvatrien-l, 3-diols, (Αδ^-4,8,13duvatrien-l-ols
Ajugareptansones A & Β Ivains I-IV Tafricanins A & Β Teucjaponin Β
Labiatae
Ajuga remota
Labiatae Labiatae Labiatae Labiatae
Verbenaceae Verbenaceae
cryptophyllum Caryopteris d i v a r i c a t a
A. reptans A. i v a Teucrium africanum T_. japonicum Grindelane diterpenoids Chrysothamnus nauseosus
Diterpene(s)
Clerodendrins A & B, 3-epicaryoptin Clerodendrin A Caryoptin, clerodin, and derivatives Ajugarins I-IV
tricotomum
Family
Verbenaceae
Clerodanes Clerodendron
Source
(25-27) (25-27)
Spodoptera l i t u r a Spodoptera l i t u r a
Keodiprion swainei, N. rugifrons, N.
H e l i o t h i s virescens, Manduca sexta, Myzus persicae
Schizaphis graminum
(40-42)
(39)
(37)
Leptinotarsa decemlineata(36)
Spodoptera l i t t o r a l i s , (22, 28) Spodoptera exempta, Schistocerca gregaria, Bombyx mori, Pectinophora g o s s y p i e l l a Spodoptera l i t t o r a l i s (29, 30) Spodoptera l i t t o r a l i s (31) Locusta migratoria (32) Spodoptera l i t u r a (33)
(25-27)
Reference
Spodoptera l i t u r a
Insect affected
Table I. Diterpenes with Known B i o l o g i c a l A c t i v i t y against Insects
Downloaded by UNIV OF SYDNEY on October 7, 2015 | http://pubs.acs.org Publication Date: January 8, 1987 | doi: 10.1021/bk-1987-0330.ch048
73
Η
m
Ο 73
m > ζ α
> Ο 73 η c r Η c 73
73 Ο
00
π > r
χ m
Ο Ο
In Allelochemicals: Role in Agriculture and Forestry; Waller, G.; ACS Symposium Series; American Chemical Society: Washington, DC, 1987.
Asteraceae
H. o c c i d e n t a l i s
Isodon diterpenes Rhabdosia spp.
Isodons and derivatives
C i l i a r i c and angelylg r a n d i f l o r i c acids (-)-cis and (-)-trans ozic acids
Asteraceae
Helianthus spp.
Labiatae
Trachyloban-19-oic and kaur-16-en-19-oic acids
Asteraceae
annuus
Kauranes Helianthus
C, D, F,
Kalmitoxin-I, kalmitoxin-IV, grayanotoxin-III
Nagilactone podolide
Ericaceae
Podocarpaceae
Pinaceae
Grayanoid diterpenes Kalmia l a t i f o l i a
Norditerpenedilactones Podocarpus n i v a l i s , P. h a l l i i , P. g r a c i l i o r
Larix l a r i c i n a
p a l u s t r i c , levopimaric, neoabiètic acids A b i e t i c , neoabietic, dehydroabietic, iso^> pimaric, sandaracopimaric acids (43, 44) (37)
( 5 5 , 56)
(54) Lepidopterous larvae
Spodoptera exempta, S. l i t t o r a l i s
(52)
(50, 51)
(48)
Homoesoma electellum, H e l i o t h i s virescens, H. zea, Pefctinophora gossypiella Homoesoma electellum
Lymantria dispar
Pectinophora gossypiella,(45-47) H e l i o t h i s zea, Spodoptera frugiperda, Musca domestica, Laspeyresia pomonella, Epiphyas postvittana
Pristiphora erichsonii Schizaphis graminum
dubiosus, N. l e c o n t e i
Downloaded by UNIV OF SYDNEY on October 7, 2015 | http://pubs.acs.org Publication Date: January 8, 1987 | doi: 10.1021/bk-1987-0330.ch048
538
Downloaded by UNIV OF SYDNEY on October 7, 2015 | http://pubs.acs.org Publication Date: January 8, 1987 | doi: 10.1021/bk-1987-0330.ch048
ALLELOCHEMICALS: ROLE IN AGRICULTURE AND FORESTRY
OAc
ajuganptonsin
Figure 1.
Clerodanes with insect antifeedant a c t i v i t y .
In Allelochemicals: Role in Agriculture and Forestry; Waller, G.; ACS Symposium Series; American Chemical Society: Washington, DC, 1987.
Downloaded by UNIV OF SYDNEY on October 7, 2015 | http://pubs.acs.org Publication Date: January 8, 1987 | doi: 10.1021/bk-1987-0330.ch048
48.
COOPER-DRIVER AND LE QUESNE
R = OH:
18-hydroxygrindelic
acid
Z
R *fl-OH, 1
2
18-succinoyloxygrindelic
Figure 2.
539
as Insect Antifeedants
R W - O H , R =H-
R = 0C0CH CH C00H: 2
Diterpenoids
6a-hydroxygrindelic
R * H : 6/3-hydroxygrindelic z
acid acid
acid
Grindelanes with insect antifeedant a c t i v i t y .
aa/3-4,8,13-duvatrien-1,3-diols
Labda-12,14-dien-8