Female sex pheromone of a lichen moth Eilema japonica (Arctiidae, Lithosiinae): Components and control of production

Seven candidates for components of the female sex pheromone of Eilema japonica (Arctiidae, Lithosiinae) were detected in an extract of pheromone glands with a gas chromatograph-electroantennographic detector. The compounds were identified as (Z,Z)-6,9-icosadiene (D20), (Z,Z)-6,9-henicosadiene (D21), (Z,Z,Z)-3,6,9-henicosatriene (T21), (Z,Z)-6,9-docosadiene (D22), (Z,Z,Z)-3,6,9-docosatriene (T22), (Z,Z)-6,9-tricosadiene (D23), and (Z,Z,Z)-3,6,9-tricosatriene (T23). Assays using synthetic lures in a wind tunnel showed that D21 (proportion, 0.39), T21 (0.08), D22 (0.27), and T22 (0.26) are important for evoking full behavioral responses from the males. Titers of the pheromone components did not show clear temporal fluctuations. Moreover, decapitation of the female moth had no effect on the titers of pheromone components in the pheromone gland, suggesting that cephalic endocrine factors such as pheromone biosynthesis activating neuropeptide (PBAN) are not involved in the control of pheromone biosynthesis in this species.     

Acetogenins from the aquatic plant Elodea canadensis

13-(2-furyl)-Tridec-12E-en-1-yne and (7S)-hydroxyhexadeca-8E,10Z,13Z-trienoic acid have been isolated from Elodea canadensis in addition to the already known 13-(2-furyl)-tridec-1-yne, hexadec-11Z-enoic, hexadeca-7Z,10Z,13Z-trienoic and (10R)-hydroxyhexadeca-7Z,11E,13Z-trienoic acids.     

Conformation and dynamics in a Z-DNA tetramer

Two kinds of conformational variability have been reported for left-handed Z-DNA: the Z to Z′ transition, which involves a change in guanine sugar pucker from C-3′-endo to C-1′-exo, and the Z_Ito Z_II transition, which corresponds to a simple three-atom phosphate-group rotation. Neither of these motions substantially affects base stacking or helical twist, and this is because the degree of independent motion of phosphate groups, sugar molecules and base-pairs is greater in the left-handed Z helix than in right-handed B-DNA. Detailed considerations of Z helix geometry suggest that Z_I, Z_IIand Z′ are not separate species, but only samplings of the full range of conformation open to Z-DNA.     

Sex pheromone composition of Ascotis selenaria (Lepidoptera: Geometridae) and its regional variation in Korea

This study was conducted to investigate sex pheromone composition of Ascotis selenaria (Lepidoptera: Geometridae) in Korea. Two sex pheromone compounds such as (Z,Z)-6,9-cis-3,4-epoxynonadecadiene (6Z,9Z-cis-3,4-epoxy-19:H) and (Z,Z,Z)-3,6,9-nonadecatriene (3Z,6Z,9Z-19:H) were identified in the glands of A. selenaria females by gas chromatography–mass spectrometry analysis. However, the component 3Z,6Z,9Z-19:H neither elicited an electroantennogram response nor increased the attractiveness for A. selenaria males in the field. The role of 3Z,6Z,9Z-19:H seems to be as an antagonistic signal for mating behavior of A. selenaria males.The blend ratios of two 6Z,9Z-cis-3,4-epoxy-19:H isomers such as, 6Z,9Z-cis-3R,4S-epoxy-19:H and 6Z,9Z-cis-3S,4R-epoxy-19:H, were critical to attract A. selenaria males. The blend ratios of the two isomers showing peak catch of A. selenaria males had large variations among the locations investigated. A. selenaria populations in Gunwi showed peak activity at ratios of 0.9:0.1 and 0.8:0.2, whereas the populations in Goheung, Yeongam, and Jeju (Aewol and Harye) showed peak activity at a 0.5:0.5 ratio. In Changnyeong, the peak activity occurred in a bimodal form at ratios of 0.7:0.3 and 0.4:0.6. Such variation was partially explained by geographical isolation due to mountain ranges. Consequently, the results of our study should be useful for designing a region-specific pheromone lure for successful A. selenaria monitoring.     

Polyacetylenes from the rabbitbrush,Chrysothamnus nauseosus

Four new polyacetylenes, methyl Z,Z-10-acetoxymatricariate, methyl Z,Z-10-hydroxymatricariate, methyl 2(Z)-10-acetoxy-8,9-epoxydecen- 4,6-diynoate and methyl 2(Z)-10-hydroxy-8,9-epoxydecen-4,6-diynoate, were isolated from the composite Chrysothamnus nauseosus. These compounds are naturally-occurring antifeedants of the Colorado potato beetle. The assigned structures rest on their spectroscopic properties as well as chemical interconversions.     

Isolation of Fucoxanthin and Highly Unsaturated Monogalactosyldiacylglycerol from Brown Alga Fucus evanescens C Agardh and In Vitro Investigation of Their Antitumor Activity

Fucoxanthin (FX) and highly unsaturated monogalactosyldiacylglycerol (MGDG) were isolated from the ethanol extract of brown alga Fucus evanescens. Their structures were identified by nuclear magnetic resonance, complemented by electrospray ionization mass spectrometry (ESIMS). MGDG was identified as 1-O-(5Z,8Z,11Z,14Z,17Z-eicosapentanoyl)-2-O-(6Z,9Z,12Z,15Z-octadecatetraenoyl)-3-O-β-d-galactopiranosyl-sn-glycerol. Antitumor activity of these compounds was tested on human melanoma (SK-MEL-28) cells. MGDG and FX inhibited the growth of human melanoma cells in a dose-dependent manner. IC₅₀ values for growth inhibition were 104 and 114 μM, correspondently.     

Structure and biosynthesis of malloprenols from Mallotus japonicus

The mallo prenol isolated from the leaves of Mallotus japonicus was elucidated to be a mixture of (2Z,6Z, 10Z, 14Z, 18Z, 22Z, 26E, 30E, 34E)-3,7,11,15,19,23,27,31,35,39-decamethyl-2,6,10,14,18,22,26,30,34,38-tetracontadecaen-1-ol and its C₄₅- and C₅₅-homologues and not the previously reported structure. The malloprenols were demonstrated to be biosynthesized by successive cis condensation of isoprene residues with (2E, 6E, 10E)-geranylgeranyl pyrophosphate.     

Sterically hindered carotenoids with 3Z, 5Z configuration from the seeds of oriental bitter sweet, Celastrus orbiculatus

Sterically hindered cis-carotenoids 1 and 2 were isolated from seeds of the oriental bitter sweet, Celastrus orbiculatus. Their structures were determined to be (3′Z, 5′Z)-celaxanthin and (3′Z, 5′Z)-torulene, respectively, on the basis of spectroscopic data and iodine-catalyzed stereomutation. This is the first report on carotenoids with a 3Z, 5Z configuration.     

Substrate specificity of the epoxidation reaction in sex pheromone biosynthesis of the Japanese giant looper (Lepidoptera: Geometridae)

Female moths of the Japanese giant looper (Ascotis selenaria cretacea, Lepidoptera: Geometridae) secrete (Z,Z)-6,9-cis-3,4-epoxynonadecadiene as a sex pheromone component. To the pheromone glands of the decapitated females, [19,19,19-D₃](Z,Z,Z)-3,6,9-nonadecatriene was applied after an injection of pheromone biosynthesis activating neuropeptide. GC-MS analysis of the gland extract showed its specific conversion into the pheromonal cis-3,4-epoxide indicating that the C₁₉ triene which had been identified in the gland was a precursor of the pheromone. In order to examine the substrate specificity of the enzyme catalyzing this epoxidation step, several unsaturated hydrocarbons not occurring in the gland were applied to it. Not only (Z,Z,Z)-3,6,9-trienes with varying chain lengths (C₁₇, C₁₈ and C₂₀ to C₂₂) but (Z,Z)-3,6-dienes (C₁₇, C₁₉ and C₂₀) were converted into the corresponding cis-3,4-epoxides in a rather good yield, while no 6,7- and 9,10-epoxides could be detected. (Z)-3-Nonadecene was also changed to the cis-epoxide, but (E)-3-, (Z)-2- and (Z)-4-double bonds in the C₁₉ chain were not oxidized. These in vivo experiments revealed that the monooxygenase regiospecifically attacked the (Z)-3-double bond of straight chain hydrocarbons regardless of their length and degree of unsaturation.     

Sex pheromone precursors in Spodoptera littoralis (Lepidoptera: Noctuidae)

Female pheromone gland extracts of Spodoptera littoralis were analyzed for pheromone precursors. Large amounts of fatty methyl esters were found and a positive relationship between the methyl esters and the pheromonal components was observed. The esters were identified on the basis of capillary gas chromatography, coupled gas chromatography with mass spectroscopy and dimethyl disulfide derivatization, and subsequent gas chromatography with mass spectrometry. The characteristic fatty esters of S. littoralis are methyl (Z)-9-tetradecenoate, (E)- and (Z)-11-tetradecenoate, (Z,E)-9,12-tetradecadienoate, (Z,E)-9,11-tetradecadienoate, and (Z)-11-hexadecenoate. The biosynthesis of the monosaturated acids involves probably the common E11 and Z11 desaturases and chain shortening. For the biosynthesis of the novel diene acids, we propose a second, specific desaturation of (Z)-9-tetradecenoate by an E11 desaturase to produce (Z,E)-9,11-tetradecadienoate or by an E12 desaturase to produce (Z,E)-9,12-tetradecadienoate.     

Studies on the biological activities of actinomycins Z1 and Z5

The biological activities of actinomycins Z₁, Z₅, and IV (D) were compared. No consistent pattern was observed between the in vitro and in vivo results. Inhibition of E. coli DNA-dependent RNA polymerase in vitro followed the sequence IV > Z₁ > Z₅; however, for inhibition of RNA synthesis in B. subtilis and in HeLa cells the sequence was IV > Z₅ > Z₁ and the latter relationship was seen in the antimicrobial activity also. Physicochemical data did not agree with any of these findings. Difference spectra obtained with B. subtilis and M. lysodeikticus DNA followed the sequence Z₁ > IV > Z₅, while the relative thermal denaturation profiles were the exact opposite, Z₅ > IV > Z₁. These physicochemical criteria appear to be less reliable quantitative guides to biological activity. The relative ineffectiveness of actinomycin Z₁in vivo is probably the result of permeability differences associated with the presence of an hydroxylated proline residue (3-hydroxy-4-oxo-5-methylproline).     

Lipoxygenase inhibitors derived from marine macroalgae

The solvent extracts from the algae Sargassum thunbergii (Sargassaceae) and Odonthalia corymbifera (Rhodomelaceae) were subjected to soybean lipoxygenase inhibitory screening. Two hydrophobic inhibitors were obtained from the extracts of S. thunbergii through inhibitory assay-guided fractionation. The inhibitors were identified as known exo-methylenic alkapolyenes (6Z,9Z,12Z,15Z)-1,6,9,12,15-henicosapentaene (1) and (6Z,9Z,12Z,15Z,18Z)-1,6,9,12,15,18-henicosahexaene (2). The alkapolyenes 1 and 2 showed higher inhibitory activity than the known inhibitor nordihydroguaiaretic acid (NDGA). Pheophytin a (3) was obtained from the extract of O. corymbifera. The inhibitor 3 also showed higher inhibitory activity than NDGA. This is the first report on lipoxygenase inhibition of exo-methylenic alkapolyenes and a chlorophyll a-related substance.     

Prostaglandin synthases: Molecular characterization and involvement in prostaglandin biosynthesis

Prostaglandins (PGs) belong to a subclass of eicosanoids and are classified based on the structures of the cyclopentane ring and their number of double bonds in their hydrocarbon structures. PGs are important lipid mediators that are involved in inflammatory response. The biosynthesis of diverse PGs from unsaturated C20 fatty acids containing at least three double bonds such as dihomo-γ-linoleic acid (20:3^Δ8Z,11Z,14Z), arachidonic acid (20:4^{Δ5Z,8Z,11Z,14Z}), and eicosapentaenoic acid (20:5^{Δ5Z,8Z,11Z,14Z,17Z}) is enables by various PG synthases, including prostaglandin H synthase (PGHS), 15-hydroxyprostaglandin dehydrogenase (15-HPGD), PGES, PGDS, PGFS, PGIS, and thromboxane A synthase (TXAS). This review summarizes the biochemical properties, reaction mechanism, and active site details of PG synthases. Because PGs are involved in the immune system, an understanding of PG synthases is important in the design of new anti-inflammatory drugs. The biosynthesis of PGs in various organisms, such as mammals, corals, florideae (a class of red algae), yeast, and fungi, is also introduced. The expression of PG synthases in the microbial systems for the synthesis of PGs is discussed. Now, the biosynthesis of PGs from glucose or glycerol is possible using metabolically engineered cells expressing both unsaturated fatty acid-producing enzymes and PG synthases.     

Glyceroglycolipids,a novel class of platelet-activating factor antagonists from Kalimeris indica

The bioassay-guided purification of chloroform extracts of Kalimeris indica (Linn) Schultz-Bip led to the isolation of three diacylglycerols: 1-O-(9Z,12Z,15Z-octadecatrienoyl)-2-O-hexadecanoylglycerol (1), 1-O-(9Z,12Z,15Z-octadecatrienoyl)-2-O-hexadecanoyl-3-O-α-(6-sulfoquinovopyranosyl)glycerol (2), 1-O-(9Z,12Z,15Z-octadecatrienoyl)-2-O-hexadecanoyl-3-O-[α-d-galactopyranosyl(1 → 6)-O-β-d-galactopyranosyl]glycerol (3). Their structures were established on the basis of spectral and chemical methods. The glyceroglycolipids 2 and 3 exhibited significant PAF receptor binding inhibitory activities. Our studies have identified diacylglycolipids as a novel class of potent PAF antagonist.     

A novel acylphloroglucinol from the brown alga Zonaria tournefortii

A novel acylphloroglucinol, (5Z,8Z11Z,13E,17Z)-2′-eicosa-15(S)-hydroxy-5,8,11,13,17-pentaenoylphloroglucinol, has been isolated from the brown alga Zonaria tournefortii and its structure proved by spectroscopic and chemical methods.     

The E/Z isomerization step in the biosynthesis of Z-coniferyl alcohol in Fagus grandifolia

Beech bark contains significant amounts of Z-coniferyl and Z-sinapyl alcohols but not the corresponding E-isomers. There are a number of steps along the cinnamate pathway where E/Z isomerism of the cinnamyl double bond could occur. Studies of the conversion, in beech bark, of ¹⁴C-labelled E- and Z-ferulic acids, E-coniferylaldehyde and E- and Z-coniferyl alcohols indicate that this isomerism occurs at the level of the hydroxycinnamyl alcohols. This system differs, therefore, from that described for the isomerism of geraniol to nerol which proceeds via the corresponding aldehyde.     

Identification and behavioral evaluation of sex pheromone components of the Chinese pine caterpillar moth, Dendrolimus tabulaeformis

Background

The Chinese pine caterpillar moth, Dendrolimus tabulaeformis Tsai and Liu (Lepidoptera: Lasiocampidae) is the most important defoliator of coniferous trees in northern China. Outbreaks occur over enormous areas and often lead to the death of forests during 2–3 successive years of defoliation. The sex pheromone of D. tabulaeformis was investigated to define its chemistry and behavioral activity.

Methodology/Principal Findings

Sex pheromone was collected from calling female D. tabulaeformis by headspace solid phase microextraction (SPME) and by solvent extraction of pheromone glands. Extracts were analyzed by coupled gas chromatography/mass spectrometry (GC-MS) and coupled GC-electroantennographic detection (GC-EAD), using antennae from male moths. Five components from the extracts elicited antennal responses. These compounds were identified by a combination of retention indices, electron impact mass spectral matches, and derivatization as (Z)-5-dodecenyl acetate (Z5-12:OAc), (Z)-5-dodecenyl alcohol (Z5-12:OH), (5Z,7E)-5,7-dodecadien-1-yl acetate (Z5,E7-12:OAc), (5Z,7E)-5,7-dodecadien-1-yl propionate (Z5,E7-12:OPr), and (5Z,7E)-5,7-dodecadien-1-ol (Z5,E7-12:OH). Behavioral assays showed that male D. tabulaeformis strongly discriminated against incomplete and aberrant blend ratios. The correct ratio of Z5,E7-12:OAc, Z5,E7-12:OH, and Z5,E7-12:OPr was essential for optimal upwind flight and source contact. The two monoenes, Z5-12:OAc and Z5-12:OH, alone or binary mixtures, had no effect on behavioral responses when added to the optimal three-component blend.

Conclusions/Significance

The fact that deviations from the optimal ratio of 100∶100∶4.5 of Z5,E7-12:OAc, Z5,EZ7-12:OH, and Z5,E7-12:OPr resulted in marked decreases in male responses suggests that biosynthesis of the pheromone components is precisely controlled. The optimal blend of the sex pheromone components of D. tabulaeformis worked out in this study should find immediate use in monitoring this pest in Chinese forests.     

An amide from salmea scandens

Costunolide and the isobutylamides of 2E,4E,8Z,10Z- and 2E,4E,8Z,10E-dodeca-2,4,8,10-tetraenoic acid were isolated from the roots of Salmea scandens.     

LTA4-derived 5-oxo-eicosatetraenoic acid: pH-dependent formation and interaction with the LTB4 receptor of human polymorphonuclear leukocytes

5-Oxo-(7E,9E,11Z,14Z)-eicosatetraenoic acid (5-oxo-ETE) has been identified as a non-enzymatic hydrolysis product of leukotriene A₄ (LTA₄) in addition to 5,12-dihydroxy-(6E,8E,10E,14Z)-eicosatetraenoic acids (5,12-diHETEs) and 5,6-dihydroxy-(7E,9E,11Z,14Z)-eicosatetraenoic acids (5,6-diHETEs). The amount of 5-oxo-ETE detected in the mixture of the hydrolysis products of LTA₄ was found to be pH-dependent. After incubation of LTA₄ in aqueous medium, the ratio of 5-oxo-ETE to 5,12-diHETE was 1:6 at pH 7.5, and 1:1 at pH 9.5. 5-Oxo-ETE was isolated from the alkaline hydrolysis products of LTA₄ in order to evaluate its effects on human polymorphonuclear (PMN) leukocytes. 5-Oxo-ETE induced a rapid and dose-dependent mobilization of calcium in PMN leukocytes with an EC₅₀ of 250 nM, as compared to values of 3.5 nM for leukotriene B₄ (LTB₄) and >500 nM for 5(S)-hydroxy-(6E,8Z,11Z,14Z)-eicosatetraenoic acid (5-HETE). Pretreatment of the cells with LTB₄ totally abolished the calcium response induced by 5-oxo-ETE. In contrast, the preincubation with 5-oxo-ETE did not affect the calcium mobilization induced by LTB₄. The calcium response induced by 5-oxo-ETE was totally inhibited by the specific LTB₄ receptor antagonist LY223982. These data demonstrate that 5-oxo-ETE can induce calcium mobilization in PMN leukocyte via the LTB₄ receptor in contrast to the closely related analog 5-oxo-(6E,8Z,11Z,14Z)-eicosatetraenoic acid which is known to activate human neutrophils by a mechanism independent of the receptor for LTB₄.     

Factors affecting electrical impedance of internodal stem sections

A sample holder was designed and built to facilitate measuring the magnitude and phase angle of the electrical impedance of internodal stem sections from Cornus stolonifera Michx. A nonpolarizing, electrically conducting manganese dioxidecarbon paste used between the stem sample and the electrodes of the sample holder allowed measurement of impedance at frequencies from 50 hertz to 500 kilohertz without electrode polarization or electrical interference. The impedance magnitude was linearly dependent on the sample length, but this dependence was minimized by computing a normalized impedance magnitude. The normalized impedance magnitude (Z_nf) was calculated using the impedance magnitude (Z) at any specified frequency (f) and the impedance magnitude at 500 kilohertz (Z_{500 khz}) in the following formula: Z_nf = (Z - Z_{500 khz})/Z_{500 khz}. The normalized impedance magnitude was sensitive to injury produced by boiling and peeling the sample. Electrical impedance measurements on the bark and wood separately demonstrated that they have different electrical properties.