Synthesis of (+)-(S)-isorobinal together with its antipod, a cyclic monoterpene functioning as the sex pheromone of Rhizoglyphus setosus and its distribution among Astigmata

Abstract

A total of 88 compounds, classified into 27 compounds with monoterpenoid carbon skeletons, two sesquiterpenes, eight aromatics, and 24 aliphatic compounds (a ketone, aldehydes, fatty acid esters and alkyl formates) together with 27 aliphatic hydrocarbons have been demonstrated as components of the opisthonotal gland secretions from 61 species of mites belonging to ten families of Astigmata in Acari.1) Parts of the compounds are known to function either as an alarm pheromone, an aggregation pheromone or a sex pheromone in each corresponding species. Among 27 monoterpenoids, ten compounds were first isolated and identified from Astigmata, with the structures unequivocally confirmed by synthesis. 1)Isorobinal [4-isopropenyl-3-oxo-1-cyclohexene-1-carbaldehyde, 1], one of such novel cyclic monoterpenes, has been identified from the secretion of the astigmatid mite Rhizoglyphus sp. "oki"2) [its ITS-II (internal transcriptive spacer-II) region consists of 460 bps (code name RH 6, GenBank Accession Number: AB104931)].3) (S)-Isomer of 1 has been demonstrated as the female sex pheromone of the related mite, Rhizoglyphus setosus (Acari: Acaridae), 4) using both enantiomers of 1 prepared by a group from Tohoku University 5) and also by us. Herein we report the syntheses of both enantiomers to determine the stereochemistry and the natural distribution of 1 among Astigmata. Methods and Materials Analytical methodsGC/MS was carried out using a Hewlett Packard HP-5989B gas chromatograph/mass spectrometer operated at 70 eV in the split-less mode, with an HP-5 MS capillary column (0.25 mm in diameter ϫ30 m in length, 0.25 mm in film thickness). Helium was used as the carrier gas at 1.23 ml/min, at temperatures programmed from 60°C to 290°C at 10°C/min, with an initial 2-min hold at 60°C and then at 290°C for 5 min.1 Hand 13 C-NMR spectra were obtained with a Bruker AC300 instrument ( 1 H at 300 MHz, 13 C at 75 MHz) in CDCl 3 solution with TMS as an internal standard. UV spectra were measured with a Beckman DU-64 spectrophotometer. Optical rotation values were measured with a Jasco DIP-370 spectropolarimeter.J. Pestic. Sci., 31(3), 311-315 (2006) Synthesis of (؉)-(S)-isorobinal together with its antipod

Cell physiology rather than enzyme kinetics can determine the efficiency of cytochrome P450-catalyzed C–H-oxyfunctionalization

“…It is currently being tested in clinical trials for the prevention (e.g., as a dietary supplement) and for treatment of various kinds of cancer [19,26]. Perillyl alcohol is also applied in cosmetics [32] and as synthetic precursor [28,29,43]. Because of its low natural abundance, extraction of perillyl alcohol from plant tissues only yields small amounts of the desired terpenoid [27].…”

Sex Pheromone of the Invasive Mealybug Citrus Pest, Delottococcus aberiae (Hemiptera: Pseudococcidae). A New Monoterpenoid with a Necrodane Skeleton

“…Unfortunately, the direct separation of enantiomers of racemic 1 by employing preparative chiral LC was not possible under any of the assayed conditions. However, the separation of the corresponding racemic alcohol of 1 , after deacetylation with potassium carbonate in methanol, by chiral LC afforded a small amount of pure enantiomers. The specific optical rotation of each enantiomer of (4,5,5-trimethyl-3-methylenecyclopent-1-en-1-yl)­methyl acetate ( 1 ) was then measured after reacetylation under standard conditions by using triethylamine as a base and acetic anhydride in DCM .…”

“…13 C NMR (75 MHz, CDCl 3 ): δ 206.7, 181.2, 170.5, 127.6, 60.3, 52.2, 41.9, 27.4 (2C), 20.8. MS (70 eV): m/z 43 (100), 67 (23), 79 (42), 95 (12), 110 (18), 125 (63), 140 (52), 167 (10), 182 (12, M + ).…”