Navanax inermis

Chemical studies [31, 32] of the yellow secretion of the Pacific Navanax inermis led to the characterization of three main conjugated methyl ketones navenone-A (1), navenone-B (2), navenone-C (3), together with some minor related metabolites with either an additional methyl at C-3, methyl navenone-A (4) and methylnavenone-B (5), or two cis double bonds, 3,5-di-ds-navenone-A (6) and 3,5-di-d.s-navenone-B (7). 

Spinella, A., Alvarez, L. A., and Cimino, G., Predator-prey relationship between Navanax inermis and Bulla gouldiana a chemical approach, Tetrahedron, 49, 3203, 1993. 

Chemicals released when organisms are attacked can serve to mark a location as dangerous to conspecifics. Many gastropods leave a slime trail behind them as they move, which can allow for easier location by conspecifics in search of mates. However, when sufficiently molested (as by a predator), Navanax inermis secretes a mixture of bright yellow chemicals (navenones A-C Structures 4.9-All) into its slime trail, which causes an avoidance response in trail-following... 

Sleeper, H.L., Paul, V.J., and Fenical, W., Alarm pheromones from the marine opisthobranch Navanax inermis, J. Chem. Ecol., 6, 57, 1980. 

Navenone-A is one of a trio of alarm pheromones produced by the sea slug Navanax inermis. Its structure (37) has been deduced from spectral study in particular, n.m.r. spectroscopy establishes the (E) configuration of all the side-... 

Opisthobranch are marine mollusks that are scarcely protected by a shell, which suggests that they possess defensive substances.1 1 For instance, when the Pacific aglajid Navanax inermis is damaged by enemies, it secretes a bright-yellow water-insoluble mixture into its slime trail. From the extracts, three major compounds have been isolated and identified as polyenic compounds 51-53, navenones A-C.122,123 It has been demonstrated that these secreted constituents induce an avoidance-alarm response in a trail-following Navanax species at a concentration of lOpmoll M24... 

Lignarenone A (152), a possible alarm pheromone of the sea mollusc Navanax inermis, has been synthesized by highly stereoselective... 

The sex attractant of the sea slug Navanax inermis contains pyridine bases, one of which is the 3-pyridyltetraenone (140) (H.L. Sleeper and W. Fenical, J.Amer.chem.Soc., 1977, 99, 2367). Another structure, perhaps of vegetable origin, is pulo upone (153) which has been isolated as a trace constituent of the Hawaiian mollusc Philinopsis speciosa (S.J. Coval et al., Tetrahedron Letters, 1985, 26, 5359). 

Navenone A (25) is an alarm pheromone which was reported isolated from the sea slug Navanax inermis in 1977[124], Recent work has focused on its synthesis, including the report of a recent one-pot synthesis [125]. 

Besides typical cardanol-like structure, Sleeper and Fenical have identified in 1977 navenone, an alkylphenol derivative as a component of trail pheromone of the mollusk Navanax inermis [27]. Another alkylpheno lie derivative, plakinidone, has beed isolated in 1991 from a Caribbean sponge Plakortis angulospiculatus [26]. In 1995 the carboxylic acid derivative of alkylphenol - elenic acid was isolated from the Indonesian sponge Plakinastrella [25]. The structures and formulas of known monohydric phenolic lipids are presented in Fig. (1). 

Monohydric phenols with alkyl chains are rare amongst marine natural products and navenone [27], (Fig. 1-9), is a component of the trail pheromone of the mollusc, Navanax inermis, while plakinidone, (Fig. 1-11), was isolated from the Caribbean sponge, Plakortis angulospiculatus (Plakinidae) [26]. 

Opistobranchia (molluscs) usually live in the tidal regions of the oceans and find prey and partners by chem-oreception of trail hormones (see pheromones) composed of mucopolysaccharides. In case of danger the snails emit an alarm pheromone that induces following animals to seek a different route. The Californian Navanax inermis (Cephalospidea) secretes the brilliant yellow N. (M A., CijHijNO, Mr 225.29, mp. 144-145 °C) the Mediterranean Haminoea navicula emits, among others, haminol (oil, C,7H23NO, Mr 257.37, [alo-rS ). 

Other defense allomones isolated from marine mollusks include panacene (102) from Aplysia brasiliana 391), onchidal (103) from On-chidela binneyi 392), navanones A-C (104-106) from Navanax inermis 393,394), pu lenal (107) from Chromodoris albonotato 398), spiniferin-2... 

Sleeper, H.L., and W. Fenical Navenones A-C Trail-Breaking Alarm Pheromones from the Marine Opisthobranch Navanax inermis. J. Amer. Chem. Soc. 99, 2367-2368 (1977). 

Alarm pheromone of the sea-slug Navanax inermis. Bright yellow cryst. Mp 113-114°. 

MELTING point Oil Acetate 135-137°C SPECTRAL data UV, IR, PMR, Mass Spec organism Navanax inermis (Cooper) (Mollusca) reference 392... 

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