A new cucurbitacin profile forCucurbita andreana: A candidate for cucurbitacin tissue culture

In addition to previously reported cucurbitacins B,1, and D,2, cucurbitacin E,3, and I,4, aglycones and their glucosides 2-O--glucopyranosyl-cucurbitacin E,5, and 2-O--glucopyranosyl-cucurbitacin I,6, were isolated and identified as constituents ofCucurbita andreana on the basis of MS, FD-MS, 1 H NMR and¹³C NMR spectroscopy. Also, 2-O--glucopy-ranosyl-cucurbitacin B, 7, cucurbitacin B glucoside was isolated and identified.     

(Z,E)-α-farnesene: Major component of secretion from metathoracic scent gland of cotton seed bug,Oxycarenus hyalinipennis (Costa) (Heteroptera; Lygaeidae)

The isolation and identification of (Z,E)--farnesene[(3Z, 6E)-3,7,11-trimethyldodeca-1,3,6,10-tetraene] (III) as the major component of the secretion from the metathoracic scent gland of the cotton seed bug,Oxycarenus hyalinipennis, is reported. The compound was identified by a combination of [1H] NMR, [¹³C] NMR, UV, and mass spectral data and by comparison with a synthetic sample, prepared by dehydration of (E)-nerolidol. (Z,E)--Farnesene (III) has been recorded previously in insects (ants and termites), but this is the first report of its occurrence in a member of the Heteroptera. (E)2-Octenyl acetate (XIII) and 2-octenal (XIV) were identified as minor components of the secretion. In addition, three minor monoterpenoid and two other sesquiterpenoid components were detected and tentatively identified.     

Cardenolides fromErysimum cheiranthoides: Feeding deterrents toPieris rapae larvae

Larvae of the cabbage butterfly,Pieris rapae, refuse to feed on the wild mustard,Erysimum cheiranthoides, due to the presence of alcoholextractable deterrents. The active components were extracted inton-BuOH, and this extract was separated into four fractions (I–IV) by reverse-phase HPLC. Fractions III and IV retained the feeding deterrent activity. The activity of fraction III was found to be due to the cardenolide diglycosides 1 and 2, which were previously reported as oviposition deterrents for gravidP. rapae butterflies. Three active compounds were isolated from fraction IV by column chromatography on silica gel followed by reverse-phase HPLC. These compounds were identified as a monoglycoside, digitoxigenin 3-O--D-glucoside (4), and two diglycosides, glucodigigulomethyloside (5) and glucodigifucoside (6). An additional cardenolide isolated from fraction II was identified as cheirotoxin (7). All compounds were identified by UV, NMR (¹H and¹³C), and mass spectrometry, as well as hydrolysis experiments. The feeding deterrent activity of these compounds was compared with that of related commercially available chemicals and other compounds isolated fromE. cheiranthoides.     

Geographic variation of natural products of tropical nudibranch Asteronotus cespitosus

Extracts of the dorid nudibranch Asteronotus cespitosus from two geographically separate regions of Australia and from the Philippines were compared using thin-layer, high-performance liquid and gas chromatography and ¹H NMR analysis. Halogenated metabolites were detected in all mollusk specimens. The major component detected in digestive tissue of specimens from the Great Barrier Reef in northeastern Australia was 4,6-dibromo-2-(2,4-dibromophenoxy)phenol (1), with minor amounts of 3,5-dibromo-2-(3,5-dibromo-2-methoxyphenoxy)phenol (2). In a specimen collected from northwestern Australia, only 3,5-dibromo-2-(3,5-dibromo-2-methoxyphenoxy)phenol was found. The specimen from the Philippines contained 2,3,4,5-tetrabromo-6-(2-bromophenoxy)phenol (3) together with a novel chlorinated pyrrolidone (4). In addition, the sesquiterpenes dehydroherbadysidolide (5) and spirodysin (6) were detected in the digestive organs and mantle tissue of the nudibranchs from the Great Barrier Reef and from the Philippines, whereas these chemicals were not found in the specimen from northwestern Australia. All of the chemicals (1-3,5, and 6) have previously been isolated from the sponge Dysidea herbacea, as have chlorinated metabolites related to 4. This is the first time the characteristic halogenated metabolites that typify Dysidea herbacea have been reported from a carnivorous mollusk, which implies a dietary origin as opposed to de novo synthesis.     

Studies on sex pheromone of American cockroach,with emphasis on structure elucidation of periplanone-A

Two independently biologically active compounds, periplanone A and periplanone B can be isolated from fecal material of the American cockroach,Periplaneta americana. In fecal material these occur in a ratio of 1 10 while, in intestinal tracts only periplanone B has been found. The latter has been identified as (1Z,5E)-1,10(14)-diepoxy-4(15),5-germacradien-9-one; the identification was confirmed by synthesis. Only the CD (–) enantiomer (1R,2R,5E,7S,10R) exhibited activity. The lower threshold of activity of both natural and synthetic CD (–) pheromone, is 10^–6–10^–7 g. Periplanone A has been identified (apart from its stereochemical configuration) as 7-methylene-4-isopropyl-12-oxa-tricyclo[4.4.2.0^1,5]-9-dodecen-2-one). The structure of this rather unstable compound could be deduced by comparing its NMR, UV, IR, and mass spectra with the NMR and mass spectra of its rearrangement product. Both structures still require confirmation by synthesis, but their spectral data are in complete agreement with the proposed structures. The presence of only periplanone B in the gut and the presence of both periplanone A and periplanone B in the feces suggests that periplanone B is a genuine sex pheromone, whereas peri-planone A might be a biologically active transformation product, which in turn can isomerize into a more stable, but inactive compound.     

Two New Monogalactosyl Diacylglycerols from Brown Alga <Emphasis Type="Italic">Sargassum thunbergii</Emphasis>

Two new monogalactosyl diacylglycerols (MGDGs) along with two known glycolipids were isolated from the moderate polar fraction of the methanolic extract of the brown alga Sargassum thunbergii by using reversed silica flash chromatography. Two new MGDGs were identified as (2S)-1-O-(5Z,8Z,11Z,14Z,17Z-eicosapentaenoyl)-2-O-(9Z,12Z,15Z-octadecatrienoyl)-3-O-β-d-galactopyranosyl-sn-glycerol (1) and (2S)-1-O-(9Z,12Z,15Z-octadecatrienoyl)-2-O-(6Z,9Z,12Z,15Z-octadecatetraenoyl)-3-O-β-d-galactopyranosyl-sn-glycerol (2) by FAB tandem mass spectrometry, NMR techniques, and specific enzyme-catalyzed hydrolysis of the sn-1 fatty acyl linkage. The regiochemical attachment of the acyl chains in the glycerol moiety was established by 2D NMR correlations and confirmed by enzymatic hydrolysis.     

Acid-Alkali Extraction of Triterpene Acids from Poria and Preparative Separation by High-Speed Counter-Current Chromatography

A method for the acid-alkali extraction and preparative separation of triterpene acids from poria was established. The triterpene acids were enriched and separated into two fractions after extraction at the optimized pH value. The two fractions were subjected to high-speed counter-current chromatography for the preparative separation of triterpene acids, separately. As a result, dehydropachymic acid, pachymic acid, 3-epi-dehydropachymic acid, poricoic acid B, dehydrotumulosic acid, and 3-epi-dehydrotumulosic acid were obtained with purities of 94.1%, 96.2%, 93.5%, 85.9%, 80.1%, and 93.1%, respectively. The structures were identified by ESI-MS, ¹H NMR, and ¹³C NMR.     

Isolation of the diterpenoids, ent-kauran-16alpha-ol and ent-atisan-16alpha-ol, from sunflowers, as oviposition stimulants for the banded sunflower moth, Cochylis hospes

Two diterpenoid alcohols, ent-kauran-16-ol (1) and ent-atisan-16-ol (2), were isolated from pre bloom (R3-R4 stage) sunflower heads as oviposition stimulants for the banded sunflower moth, Cochylis hospes. Fractionation of a sunflower head extract, by normal-phase flash column chromatography, resulted in an early eluting fraction exhibiting significant activity in an egg-laying bioassay. Compounds 1 and 2, along with ent-trachyloban- 19-oic acid (3) and ent-kaur-16-en-19-oic acid (4), were isolated as the major components of this fraction and identified by their NMR and mass spectra. The purified compounds were individually tested for ovipositional activity in dose-response bioassays. In these bioassays, compounds 1 and 2 gave linear dose responses, with increasing numbers of eggs laid as the dosage of either increased. Compounds 3 and 4 failed to stimulate significant egg-laying at any of the dosages tested. A factorial design bioassay, using compounds 1 and 2, showed that 1 was relatively more stimulatory than 2, and that there was no synergistic effect on oviposition when the two compounds were combined.     

Volatile components in dorsal gland secretions of the collared peccary,Tayassu tajacu (Tayassuidae,mammalia)

Secretions of the dorsal gland of free-ranging adult male and female collared peccaries (Tayassu tajacu) were analyzed by gas chromatography-mass spectrometry. Both sexes contain (2E,6E,10E)-geranylgeraniol; squalene (allE isomer); and the following isomers of springene, a diterpene homolog of -farnesene: (3E,6E,10E)--springene, (3Z,6E,10E)--springene, and (6E,10E)--springene. A diterpene alcohol and an additional isomer each of squalene and springene also were observed. Straight- and branched-chain esters abound in the secretions of females, but they were not detected in males.     

3Z,6Z,9Z-Trienes and unsaturated epoxides as sex attractants for geometrid moths

Sex attractants for three species of geometrid moths were discovered during field screening of 3Z,6Z,9Z-trienes, and the racemic monoepoxydienes derived therefrom. MaleProbole amicaria moths were attracted to lure blends containing 6Z,9Z-cis-3,4-epoxy-nonadecadiene (6Z,9Z-cis-3,4-epoxy-19H) with 3Z,9Z-cis-6,7-epoxy-19H. 3Z,6Z,9Z-19H was positively identified and 6Z,9Z-cis-3,4-epoxy-19H was tentatively identified in extracts of female pheromone glands by coupled gas chromatography-electroantennogram detection (GC-EAD) and gas chromatography-mass spectrometry (GC-MS).Sicya macularia male moths were attracted by blends of 3Z,6Z,9Z-19H and 6Z,9Z-cis-3,4-epoxy-19H. The attractive response was strongly antagonized by small amounts of 3Z,9Z-cis-6,7-epoxy-19H, or by larger amounts of 3Z,6Z-cis-9,10-epoxy-19H.Lomographa semiclarata male moths were attracted by a variety of lures containing 3Z,6Z,9Z-17H as a major component. 3Z,6Z,9Z-17H was tentatively identified in a female pheromone gland extract by GC-EAD.Issued as NRCC No. 30258.     

Chiral specificity in responses by the bark beetleDendroctonus valens to host kairomones

The attraction of the red turpentine beetle,Dendroctonus valens, to the resin volatiles of its host,Pinus ponderosa, is elicited by three chiral monoterpenes. In field assays response was greatest to (S)-(–)--pinene; 92% (S)-(–)--pinene found inP ponderosa resin was not attractive. However, 75% (R)-(+)--pinene, which occurs inPinus lambertiana, a sympatric host ofD. valens, was attractive. (S)-(–)--Pinene interrupted response to (R)-(+)--pinene. (S)-(+)-3-Carene from both hosts was attractive at the (R)-(+)--pinene level. Three sympatric coniferous nonhosts each have the same attractive monoterpenes but produce less resin. These studies demonstrate the importance of chirality of host compounds in the host finding behavior of this bark beetle.     

Syntheses and Characterization of Diorganotin Derivatives of 2-Mercapto-5-methyl-1,3,4-thiadiazole: X-ray Crystal Structure of Polymeric (C3H3S2N2) [(n-C4H9)6Sn3O(OH)2](C3H3S2N2)

Diorganotin derivatives of 2-mercapto-5-methyl-1,3,4 -thiadiazole, (R = Me 1, n-Bu 2, Ph 3, PhCH₂ 4), have been synthesized and characterized by IR, ¹H, ¹³C and ¹¹⁹Sn NMR spectroscopy. Among them, polymer 2 was also characterized by X-ray crystallography diffraction analysis. This revealed that 2 showed a unique tricyclic structure consisting of a fused five-membered Sn₂ON₂ ring and a four-membered Sn₂O₂ ring. These formed a planar N₂Sn₃O₂ skeleton, with distorted trigonal bipyramidal coordination at the two tin centers and a distorted octahedral coordination at the other tin center. The supramolecular structure of polymer 2 was a 1D zig-zag polymeric chain stabilized by intermolecular O–H...S hydrogen bonds. An erratum to this article can be found at     

Substantially enhancing enzymatic regioselective acylation of 1-β-d-arabinofuranosylcytosine with vinyl caprylate by using a co-solvent mixture of hexane and pyridine

Novozym 435-catalyzed regioselective acylation of 1-β-d-arabinofuranosylcytosine (ara-C) with vinyl caprylate for the preparation of its 5′-O-acyl derivative has been performed in six co-solvent mixtures and three pure polar solvents for the first time. Novozym 435 displayed low activity towards 1-β-d-arabinofuranosylcytosine in pure polar solvents, although those solvents can dissolve the nucleosides well. When a hexane–pyridine co-solvent system was adopted, both the initial rate and the substrate conversion were enhanced markedly. The most suitable co-solvent, initial water activity, reaction temperature and the molar ratio of vinyl caprylate to ara-C were hexane/pyridine (28/72, v/v), 0.03, 40 °C and 15, respectively. Under these conditions, the initial rate, the substrate conversion and the regioselectivity were as high as 99.0 mmol h⁻¹, 98% and >99%, respectively. The product of the Novozym 435-catalyzed reaction was characterized by ¹³C NMR and confirmed to be 5′-O-octanoyl 1-β-d-arabinofuranosylcytosine.     

Response of The Lacewing Chrysopa cognata to Pheromones of its Aphid Prey

The lacewing Chrysopa cognata, one of the principal predators of aphids in Korea, was tested for responses to the aphid sex pheromone components (4aS,7S,7aR)-nepetalactone and (1R,4aS,7S,7aR)-nepetalactol and the aphid alarm pheromone (E)--farnesene. Electroantennogram responses were obtained to the sex pheromone components but not to (E)--farnesene. The sex pheromone components were attractive in a Y-tube olfactometer assay and in field trials with water traps, but no attraction was observed to (E)--farnesene.     

Sex phermone components of mulberry looper,Hemerophila atrilineata butler (lepidoptera: Geometridae)

(6Z-9S, 10R)-Epoxy-octadecene (SR-1) and (3Z, 6Z-9S, 10R)-epoxy-octadecadiene (SR-2) are sex pheromone components of the mulberry looper (MBL),Hemerophila atrilineata Butler. Compounds extracted from female MBL pheromone glands were identified by coupled gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometry. In field experiments in China,SR-2,RS-2, or both combined were hardly attractive, butSR-2 in combination withSR-1 attracted significant numbers of MBL males. Synergistic behavioral activity ofSR-1 plusSR-2, but not of corresponding antipode mixtures, indicates enantiospecificity of MBL pheromone communication. Because blends of racemic and enantiospecific (SR)1 plus2 were similarly attractive, racemic1 plus2 may have potential for mass trapping or confusion of MBL males in commercial mulberry plantations.     

Synthesis of Ethyl 5 Z ,9 Z ,12 Z -octadecatrienoate (ethyl pinolenate) and Methyl 12 Z ,15 Z -octadecadienoate

Pinolenic acid (5Z,9Z,12Z-octadecatrienoic acid, 1a), one of the most abundant trienoic fatty acids in nature, is very difficult to obtain in quantity in a pure state from the highly complex mixture of unsaturated tall oil fatty acids. For this reason its chemistry has been little studied when compared to linolenic or linoleic acids. A simple synthesis of esters of 1a and of 12Z,15Z-octadecadienoic acid 3 using the one pot double Wittig procedure is described here. The products of double Wittig reactions were purified by argentation chromatography, and their structural purity was established by ¹H-, ¹³C-NMR and 2D-NMR spectroscopies.

Exocrine secretions of the andromeda lace bugStephanitis takeyai (Hemiptera: Tingidae)

The four major components of the setal exudate of nymphs of the andromeda lace bug,Stephanitis takeyai, were identified. They are 7-hydroxy-3-nonylchromanone1, the novel 3,5-dihydroxy-2-dodecanoylcyclohex-2-en-1-one2,2,6-dihydroxydodecanophenone3, and its 3-hydroxy derivative4. Only three species ofStephanitis commonly occur in the United States; withS. takeyai we have now identified the major compounds secreted by each of these species. The individual species of the genus are chemotaxonomically distinct and are characterized by the oxidation states of the secreted compounds.     

Comparison of polymerization catalyzed by thesyn andanti diastereomers of [ethylidene(1-η 5-tetramethylcyclopentadienyl)(1-η 5-indenyl)]titanium dichloride and methylaluminoxane

Summary Both the pure anti (1) and an equimolar mixture of1 and the syn (2) diastereomers ofrac-[ethylidene(1- ⁵-tetramethylcyclopentadienyl)(1- ⁵-indenyl)titanium dichloride have been synthesized. The polymerization behaviors of the two systems, activated by methylaluminoxane (MAO), have been compared from -20°C to +25°C. The2/MAO catalyst has about 30% more active species, which polymerizes propylene 20 to 50% faster depending on T _p , undergoes chain transfers less frequently, and produces PP of higher molecular weight than the1/MAO system.See reference 1     

Aggregation arrestant pheromone of the German cockroach,Blattella germanica (L.) (Dictyoptera: Blattellidae): Isolation and structure elucidation of blattellastanoside-A and -B

The aggregation pheromone of the German cockroach,Blattella germanica, consists of attractant and arrestant, which can be detected by olfactometer and choice-chamber assay, respectively. Both were extracted from the frass-contaminated filter paper being used as a shelter. They were separated by solvent partition withn-butanol and water. The arrestant from then-butanol phase was purified by open column chromatography and then successive HPLC isolated two major arrestant components. Spectral evidence from SI-MS, HR-EI-MS, and NMR experiments with pulse techniques provided possible structures as 1-(6-chloro-4,5-epoxy-5-stigmast-3-yl)--d-glucopyranoside and 1-(6-chloro-5-hydroxy-5-stigmast-3-yl)--d-glu-copyranoside, denoted as blattellastanoside-A and blattellastanoside-B, respectively. They represented arrestant activity as median effective doses (ED₅₀) at 0.044 (A) and 3.2 (B) nmol on 1.0 cm² of Whatman No. 1 filter paper.     

Identification and Distribution of Oviposition Stimulants for Monarch Butterflies in Hosts and Nonhosts

Flavonol glycosides that act as oviposition stimulants for monarch butterflies were surveyed from a range of asclepiad hosts and some nonhosts. Major stimulants also were identified as quercetin-3-O-(2-O--xylosyl)--D-galactoside and quercetin-3-O--D-galactoside from Asclepias syriaca and A. incarnata, respectively. The flavonol glycosides in A. curassavica, A. tuberosa, A. incarnata, A. syriaca, A. humistrata, A. albicans, A. eriocarpa, Calotropis procera, Cynanchum acutum, Vincetoxicum (Cynanchum) nigrum and in nonhosts Hoya australis and Nerium oleander were compared and characterized by HPLC and spectral studies. There was great variation in quercetin glycoside content. On the basis of the sugar moieties attached to quercetin, the asclepiad glycosides were classified broadly as those containing: (1) galactose, glucose, and rhamnose; (2) galactose, glucose, and xylose; and (3) galactose, glucose, xylose, and rhamnose. In most cases, galactose was attached to the 3-O-position (1) of quercetin and other sugars were attached either to the 2 or 6 position of galactose. The sugars of triglycosides were attached at both 2 and 6 positions. A geographical pattern of flavonol distribution that may have affected the evolution of host recognition by the butterflies is suggested.