Ryania species

Flubendiamide is an example of a new chemical class of insecticides that have been termed phthalic acid diamides (Nauen 2006, Copping and Duke 2007). They are related to the alkaloid ryanodine, which is extracted from Ryania species. Ryanodine affects muscles by binding to calcium channels of the sarcoplasmic reticulum. Ca + ions act as intracellular messengers, and their flux is modulated by calcium channels of this type. The toxic action of ryanodine and synthetic insecticides related to it is due to the disturbance of calcium flux. 

Ryania speciosa (Flacourtiaceae) and several related species are unique in that their insecticidal activity was discovered as a part of a search for new insecticides (89). The toxic principle is a diterpene esterified to pyrrole-2-carboxylic acid. This insecticide proved to be somewhat selective in its activity (89). 

Two other important natural products are rotenone and ryanodine. Rotenone (101) (B-71MI10700) is the main insecticidal constituent of certain Derris and Lonchocarpus species, and derris dust is still available as an insecticide. It has been the subject of extensive structural and synthetic studies (B-72MI10704). Ryanodine (102) (B-7lMH070i) is extracted from the wood of Ryania speciosa and has been used in crude extract form as ryania. Despite its extreme complexity it has been totally synthesized (77PAC1329). 

Ryania. A genus of tropical American shrubs and trees belonging to the Flacourtiaceae family. The wood of various species is insecticidal. Oround stem wood of Ryanie speciosa Vahl., Flacourtiaceae is employed in the commercial insecticide formulations Ryanex, Ryanicide (formerly). See Polkers et al., U.S. pat. 2,400,295 (1946 to Merck Co.) Pepper, Carruth, J. Econ, Entomol 38, 59 (1945) Heal, Agr. Chem. 4, 37 (May. 1949). Insecticidal components such as ryanodine, g.v., are extractable by water, chloroform, or methanol. Toxicity data Kuna, Heal, J. Pharmacol Exp. Then 93, 407 (1948). 

Quinolizidine alkaloids are found in many species of the Fabaceae, Ber-beridaceae, Leguminosae, and Solanaceae and are derived from lysine (67, 68). Some quinolizidine alkaloids are very toxic insecticides that have the potential of commercial use for the control of insects. For example, the alkaloid ryanodine, which is found in the stems and roots of Ryania speciosa, is effective as both an insect contact and stomach insecticide and is particularly effective against Lepidoptera. It has been used to control the codling moth without affecting parasites and predators of the moth (69). 

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