Ladybirds

Hyperaspine alkaloid (1) was isolated from ladybird beetle Hyperaspis campestris. 

Hyperaspine (1), a perhydropyrido[l,2-c][l,3]oxazine alkaloid was isolated from the ladybird beetle H. campestris (01TL4621). 9-Epi-6-epipinidinol (90), a piperidine alkaloid, was prepared from a perhydropyrido[l,2-c][l,3]oxazin-l-one derivative (98T13505). Perhydropyrido[l,2-c][l,3]oxa-zin-l-ones were used to prepare 2,6-disubstituted piperidines (96CJC2434). 

Marien-bad, n. water bath, -distel, /. milk thistle (Silybum marianum). -glas, n. selenite (ruasisches) mica. -kSfer, m. ladybird. -kSmer, n.pl. milk-thistle seed. 

Or an improving tract, says Anne Stewart, stacking Series Three Communion booklets briskly on a shelf, next to worn but gaudily illustrated Ladybird Stories from the Holy Land and The Good Samaritan. Like all those awful Victorian moral tales. Do sit down, by the way. ... 

We have recently characterized the heptacyclic alkaloid chilocorine from the ladybird (coccinellid) beetle Chilocorus cacti (23). In spite of its superficial complexity, this structure is easily dissected into two tricyclic moieties, A and B, each of which can be regarded as an acetogenin which has been elaborated from a straight chain of 13 carbon atoms stitched together at three points by a trivalent nitrogen atom. 

Attractive Compounds. While the defence chemistry of ladybird beetles has been extensively investigated, little is known about intraspecific communication. The role of chemical and behavioural cues has been described in mate recognition in Adalia bipunctata. Cuticular hydrocarbons, especially 7- and 9-methyltri-cosane seem to play an important role [301]. In Coccinella septempunctata, 2-isopropyl-3-methoxypyrazine 158 (see Scheme 17) accounting for the dis-... 

Defensive Compounds. The defensive chemistry of ladybird beetles was treated in the chapter by Laurent et al. in this volume. 

When disturbed or molested, these insects release small droplets of hemo-lymph from the tibio-femoral joints of their legs, and it is now well established that the deterrency exhibited by many species of coccinellids towards potential predators results from the presence of repellent and bitter alkaloids in that fluid [ 12,13]. In ladybirds, this unpalatability is associated with a bright aposematic coloration and a characteristic smell due to 3-alkyl-2-methoxypyrazines [14, 15]. The beetles use these molecules not only to reinforce the visual alerting signal on an olfactory level, but also as aggregation pheromones [16]. 

This ladybird is protected by hyperaspine (23) (Fig. 4), the structure of which was deduced from its ID and 2D NMR data. These spectra disclosed the presence in the molecule of a 3-oxaquinolizidine skeleton substituted by a 2-pyrro-lecarboxylate moiety, by a secondary methyl group, and by a n-pentyl side chain. The ds-fused ring conformation and the relative configuration of 23 were based on IR and 2D NMR methods [37]. 

Hyperaspine (23) is the first 3-oxaquinolizidine alkaloid reported so far from ladybird beetles. Its skeleton, however, which is based on a chain of 13 carbon atoms, is biosynthetically related to those of the homotropane and perhydroazaphenalene alkaloid already isolated from ladybirds [38]. 

On the other hand, adults of E. varivestis turned out to be the most versatile alkaloid producer of all ladybird species so far examined. Indeed, not less than 12 alkaloids have been isolated from this beetle, including euphococcinine (32), a complex mixture of simple piperidines (33-36), 2-phenylethylamine (37) and long chain pyrrolidines (38-41) (Fig. 7) [43-45]. The syntheses of optically pure (2S,12 R)-2-(12 -aminotridecyl)-pyrrolidine (38) and (2S,12 R)-l-(2"-hydroxy-... 

Monocyclic Carotenoids. Eighteen carotenoid hydrocarbons have been isolated from the ladybird beetle Coccinella septempunctata. Amongst the minor components were detected small amounts of the new y-ring derivatives 3, 4 -didehydro-y.i/f-carotene (6), 7, 8 -dihydro-y,i/f-carotene (7), and 7, 8, 1T,12 -tetrahydro-y,i -carotene (8). 

So when Stevens3 wanted the amino-diacetal 33 for his synthesis of coccinelline 32, the defence compound ladybirds exude from their knees, he changed the amine into a ketone 34 with reductive amination in mind so that there would be two concealed 1,5-diCO relationships, more obvious when the acetals are removed 35. 

The compound Aphox, that kills greenfly without harming ladybirds, is a pyrimidine 70. Disconnection of the ester side chain reveals a pyrimidine 71 that we should rather draw as a pyrimidone 72. Disconnection of two C-N bonds gives simple starting materials available dimethyl guanidine 73 and the acetoacetate derivative 74. 

Holloway, G. J., de Jong, P. W. and Oltenheim, M. 1993. The genetics and cost of chemical defense in the two-spot ladybird (Adalia bipunctata). Evolution 47, 1229-1239... 

WITTE, L., EHMKE, A., HARTMANN, T., Interspecific flow of pyrrolizidine alkaloids from plants via aphids to ladybirds. Naturwissenschqfien, 1990, 77, 540-543. 

Next, pirimicarb, a selective insecticide that kills sap-sucking aphid pests but does not affect the useful predators such as ladybirds (ladybugs) that eat them. It contains a pyrimidine ring—a benzene ring with two nitrogen atoms. 

This is a synthesis for the ladybird defence compound coc-cinelline. 

A wasp, parasite of glasshouse whitefly—most widely used Ladybird consumer of aphids and other pests A wasp, parasite of mealybugs used in horticultural and fruit crops... 

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