Nepetalactones

Aerial parts of N. sintenisii yielded 0.3% of a clear yellowish oil. Forty constituents (96.5% of the total oil) were identified. The main components were 4aP,7a,7aP-nepetalactone (23.4%), elemol (16.1%), E- -farnesene (9.5%), 1,8-cineole (8.2%), cw-sabinene hydrate (6.5%), P-bisabolene (4.2%), germacrene-D (3.5%), P-sesquiphellandrene (2.8%), P-bourbonene (1.5%) and a-epi-cadinol (1.3%). According to available data, Nepeta species can be divided into two groups of nepetalactone-containing and nepetalactone-free species. The results of this study indicate that the compositions of volatile oil of N. sintenisii are similar to the other Nepeta genus and this plant could be classified in the group which 4aP,7a,7aP-nepetalactone is the major component of their oils. 

Content and composition of essential oils from Nepeta L. species, most of them containing diastereomeric nepetalactones, unsaturated 8-lactones with annelated cyclopentane ring 98KPS84. 

Solid extracts of (1) alfalfa and (2) red clover (used in food flavorings) were examined by GC/MS. 389 of 450 detected components were identified in (1), vs. 210 of 309 components detected in (2). In both extracts, predominant compounds identified were esters (1) 105, (2) 55 acids (1) 42, (2) 31 alcohols (1) 34, (2) 31 and hydrocarbons (1) 28, (2) 14. Many other compounds were also found, including cannabinol, caffeine, scopolamine, isocoumarin, phenylpentadienal, phenylhexadiene, and nepetalactone.25... 

Defensive substances are often general irritants that can be used in a variety of contexts. For example, the alloxystine wasps (Cynipoidea), all hyperpara-sitoids of other hymenopteran parasitoids, produce a large number of compounds in their cephalic (mainly mandibular) glands. These compounds include m/p-xylol, 6-methylhept-5-en-2-one 16, various iridoids 21 and frans-dihydro-nepetalactone 22 [46,73]. 

Aphidius ervi Aphid sp. (Aphidinae) Host sex pheromone [attraction, increased parasitization] (4aS,7S,7aR)-Nepetalactone 26 (lR,4aS,7S,7aR)-nepetalactol 27 [77,78]... 

Smoking the leaves of catnip (Nepeta cataria) produces only mild effects in man. However, the pure active agent, cis, trans-nepetalactone, seems not to have been tested on man. Seeds are available from several companies and the freshly picked leaves are probably more potent. Catnip is not orally active in cats, For synthesis see Corsi Semin, chim. 11,93(1968) et seq. BCSJ 22,1737(1960) Proc. Chem. Soc. 166(1963). JOC 37,3376 (1972) gives a synthesis of dihydronepetalactone (more attractive to cats than nepetalactone). 

Neostigmine bromide, 4 360t Neotame, 12 42 24 231-232, 247 NEP1 gene, 13 351 Nepetalactone, 2 101 24 473 Nepheline, 2 345t... 

The active agent for this effect is uncertain, but catnip has in it several terpenes, including nepetalactone. One terpene, c/s-trans-nepetalactone was hypothesized to be responsib e for the sedative effect based on its structural similarity to valepotriates, the depressant principles from valerian. 

Paradoxically, catnip fed to mice had stimulant effects, with increased rearing, locomotion, and stereotypical behavior, increased susceptibility to chemically induced (picrotoxin and strychnine) seizures, and decreased sleeping time after barbiturate administration (Massoco et al. 1995). The LD50 for nepetalactone in mice was reported to be quite high at 1300 mg/kg (Harney et al. 1978). In chicks, an a cohol extract of catnip had biphasic effects, where low to moderate doses (25-1800 mg/kg) produced sedative effects, while higher doses (>2 g/kg) had less sedative and perhaps stimulant effects (Sherry and Hunter 1979). Humans have reported sedative effects of catnip, and one accidental ingestion by a young child reportedly produced sedative effects (Osterhoudt et al. 1997). 

Nepetalactone (Fig. 11.5c), a monoterpene lactone (or iridoid) from the volatile oil of catmint, Nepeta cataria, excites domestic cats and other felids (Todd, 1962 Palen and Goddard, 1966 Hill etal, 1976). 

FIGURE 11.5 Terpenoids, (a) The basic five-carbon units isopentane and isoprene. (b) The monoterpenes borneol and a-pinene. (c) A monoterpene lactone, nepetalactone. (d) A sesquiterpene, germacrone. (e) A triterpene, papyriferic acid, from paper birch. 

Fig. 8. Insect repellent compounds from catnip (elemol and nepetalactone) and osage orange (citronellal).

Schultz G, Simbro E, Belden J, ZhuJ, Coats J, Catmp, Nepeta catariaiharoiaAes Lamiaceae) — a closer look Seasonal occurrence of nepetalactone isomers and comparative repellency of three terpenoids to insects. Environ Entomol AA 5(>2— 1569,2004. 

Analyses of the volatiles released by females of the peach aphid Tube-rocephalus momonis showed two sex pheromone components that were identified as (4a5,75,7ai )-nepetalactone and (4a5,75, 7ai )-nepetalactol, in a ratio of 4 1. The most effective blend for trapping males was found to be 85 15 nepetalactone to nepetalactol respectively. In addition to T. momonis, over 20 other species of aphids were also caught. 

Females of the potato aphid Macrosiphum euphorbiae produced (17 , aS, IS, 7 7 )-nepetalactol and (4a5, 75, 7a7 )-nepetalactone in ratios that varied with age from 4 1 to 2 1. Males did not respond to either of the components when presented alone. However, the 5 1 ratio, which proved quite attractive in lab tests, was not as effective during three years of field trials. ... 

Some volatile iridoid monoterpenes with biological activity are also found in essential oils and in insect pheromonal and defensive substances. Eisner ( ) found that 17 species of insects were repelled by the iridoid monoterpene nepetalactone. Lacewings (Chrysopa septempunctata) are attracted by the leaves and fruits of Actinidia polyqama (Actinidiaceae) which contain a series of volatile iridoid monoterpenes (67). 

Coumarin 162 (Structure 4.49) is a naturally occurring lactone in crystal form found in hay and tonka beans. It is one of the most used fragrance materials and is responsible for spicy green notes. Dihydrocoumarine 163 is also present in various essential oils with a characteristic sweet herbal odour. Umbellif-erone 164, scopoletin 165, bergaptene 166 and coumarin are found in Rutaceae, Apiaceae, Lamiaceae and Asteraceae oils. Nepetalactones 167 are confined to the oils of Nepeta species [1,3, 21-23, 63]. 

Actinidia arguta (Sieb. et Zucc.) Planch ex Miq. A. chinensis Planch. A. japonica Nakai A. kolomikta (Maxim, ex Rupr.) Maxim. A. polygama (Sieb. et Zucc.) Planch, ex Maxim. Mi Hou Tao (Kiwi) (whole plant) Matatabic acid, iridomyrmecin, actinidine, allomatatabiol, iridomyrmecin, neo-nepetalactone, dihydronepetalactol, matatabiether, isoneomatatabiol, matatabistic acid, neomatabiol, vitamin C, vitamin B.48>50>52 For esophageal and liver cancers, rheumatoid arthritis, arthralgia, urinary stones, fever. 

Neo-nepetalactone Actinidia arguta, A. chinensis, A. japonica, A. kolomikta, A. polygama... 

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