Organoselenides from Nicotiana tabacum genetically modified to accumulate selenium

Nicotiana tabacum L. (tobacco) plants were transformed to overexpress a selenocysteine methyltransferase gene from the selenium hyperaccumulator Astragalus bisulcatus (Hook.) A. Gray (two-grooved milkvetch), and an ATP-sulfurylase gene from Brassica oleracea L. var. italica (broccoli). Solvent extraction of leaves harvested from plants treated with selenate revealed five selenium-containing compounds, of which four were identified by chemical synthesis as 2-(methylseleno)acetaldehyde, 2,2-bis(methylseleno)acetaldehyde, 4-(methylseleno)-(2E)-nonenal, and 4-(methylseleno)-(2E,6Z)-nonadienal. These four compounds have not previously been reported in nature.     

The Influences of Jasmonic Acid Methyl Ester on Microtubules in Potato Cells and Formation of Potato Tubers

Amides in a CH₂Cl₂ extract from the fruits of Piper retrofractum were detected by HPLC/APCI-MS. Seven new unsaturated amides, together with six known ones, were isolated, and their structures were determined to be N-isobutyl-2E,4E,12Z-octadecatrienamide (1), N-isobutyl-2E,4E,14Z-eicosatrienamide (2), 1-(octadeca-2E,4E,12Z-trienoyl)piperidine (3), 1-(eicosa-2E,4E,14Z-trienoyl)piperidine (4), 1-(octadeca-2E,4E-dienoyl)piperidine (5), 1-(eicosa-2E,4E-dienoyl)piperidine (6), and 1-(eicosa-2E,14Z-dienoyl)piperidine (7) on the basis of chemical and spectroscopic evidence.     

Ionylideneacetic Acids and Abscisic Acid Biosynthesis by Cercospora rosicola

Several compounds having the basic α-ionylideneacetic acid structure were tested in Cercospora rosicola resuspensions. At 100 μm, all the compounds inhibited abscisic acid (ABA) biosynthesis. Time studies with unlabelled and deuterated (2Z,4E)- and (2E,4E)-α-ionylideneacetic acids showed rapid conversions into both (2Z,4E)- and (2E,4E)-4′-keto-α-ionylideneacetic acids as major products. Incorporation of the label into ABA was specific for the 2Z,4E-isomer. Minor products, identified by GC-MS, were (2Z,4E)- and (2E,4E)-4′-hydroxy-α-ionylideneacetic acids and (2Z,4E)-1′-hydroxy-α-ionylideneacetic acid. The conversion to (2Z,4E)-l′-hydroxy-α-ionylideneacetic acid has not been previously reported and was specific for the 2Z,4E-isomer. A time study for the conversion of methyl esters of [²H₃]-(2Z,4E)- and [²H₃]-(2E,4E)-4′-keto-α-ionylideneacetates showed a slow introduction of the l′-hydroxyl group and specificity for 2Z,4E-isomer. Conversion of the ethyl esters of (2Z,4E)- and (2E,4E)-l′-hydroxy-α-ionylideneacetates into the ethyl esters of both ABA and (2E,4E)-ABA demonstrated that ABA can be formed by oxidation of the 4′-position after the insertion of the 1′-hydroxy group. The ethyl 1′-hydroxy acids were also isomerized to the corresponding ethyl (2Z,4E)- and ethyl (2E,4E)-3′-hydroxy-β-ionylideneacetates. Ethyl (2Z,4E)-1′-hydroxy acid also gave small amounts of ethyl l′,4′-trans-diol of ABA. These results suggest that ABA may be formed through a (2Z,4E)-1′-hydroxy-α-ionylidene-type intermediate in addition to the previously proposed route through (2Z,4E)-4′-keto-α-ionylideneacetic acid.     

Minor alkamides from Heliopsis longipes S.F. Blake (Asteraceae) fresh roots

From the fresh roots of Heliopsis longipes three new minor alkamides: longipinamide A (N-isobutyl-8,10-diynoic-3Z-undecenamide), longipenamide A (N-isobutyl-syn-8,9-dihydroxy-2E,6Z-decadienamide) and longipenamide B (N-isobutyl-syn-6,9-dihydroxy-2E,7E-decadienamide); three known alkamides: affinin (spilanthol, N-isobutyl-2E,6Z,8E-decatrienamide), N-isobutyl-2E,6Z-decadienamide and N-isobutyl-2E-decenamide; and 11 other known compounds were isolated. The structures of the three new minor alkamides were established by 1D and 2D NMR spectroscopy including ¹H, ¹³C, DEPT, COSY, HSQC, and HMBC experiments, as well as by EI and FAB⁺ mass spectrometry. To our knowledge, this is the first report of the isolation of linear dihydroxyalkamides as natural products.     

Isolation and structural elucidation of the geometrical isomers of lutein and zeaxanthin in extracts from human plasma

All-E-(3R,3′R,6′R)-lutein, all-E-(3R,3′R)-zeaxanthin, all-E-(3R,3′S,6′R)-3′-epilutein and some geometrical isomers of the former two dihydroxycarotenoids have been separated from an extract of human plasma by semipreparative high-performance liquid chromatography on a silica-based nitrile-bonded column. In the order of chromatographic elution, the isolated fractions were identified as all-E-lutein, all-E-zeaxanthin, all-E-3′-epilutein, 9Z-lutein, 9′Z-lutein, a mixture of 13Z-lutein and 13′Z-lutein, 9Z-zeaxanthin, 13Z-zeaxanthin and 15Z-zeaxanthin. The structures of all compounds, including the relative configuration at C(3′) and C(6′) of the luteins and the position of the stereomutated double bonds in the geometrical isomers, were unambiguously established by ¹H nuclear magnetic resonance spectroscopy. The absolute configuration of the three all-E compounds was derived by circular dichroism and is also assumed to be valid for the geometrical isomers. The ultraviolet—visible absorption and mass spectra of each of the individually isolated compounds were also in agreement with the proposed structures.     

Synthesis and Biological Activity of Methyl 3-Demethyl-Abscisate and Its Related Analogs

To elucidate the role of the methyl substituent on the side chain of abscisic acid (ABA), we synthesized (2Z,4E)-3-demethyl-α-ionylideneacetic acid (4) and its related analogs, methyl (2Z)-3-demethyl-β-ionylideneacetate 1′,2′-epoxide (9) and methyl (2Z) and (2E)-3-demethyl-abscisate (12) and (13). The biological assay of these compounds suggested that the 3-methyl group on the side chain of ABA was indispensable to biological activity.     

Acaricidal effects of natural six-carbon and nine-carbon aldehydes on stored-product mites

The toxicities of three plant volatiles, (2E)-hexenal, (2E, 6Z)-nonadienal and (2E)-nonenal, intermediate products of the oxylipin biosynthesis pathway, were tested on three mites of importance for medical purposes and as pests. The aldehydes were diluted in hexane separately and incorporated into diets in ranges of 4–143 mg g⁻¹. The final density of mites in control and aldehyde-enriched diets was compared after 21 days. The aldehydes were toxic to the mites, whose final density showed an inverse correlation with aldehyde concentration. In addition to the effects of aldehyde concentration, the final density of mites was also influenced by the different aldehydes tested and the interaction among aldehyde concentration and chemical structure. In a functional combination of aldehydes and species, the doses calculated for growth inhibition and eradication of mites ranged from 4 to 35 mg g⁻¹ and from 36 to 314 mg g⁻¹, respectively. Due to the protective role displayed by natural six-carbon and nine-carbon aldehydes, these compounds are potential candidates for controlling stored-product mites in stored food and feed products.     

Synthesis of “Reversed” Methylenecyclopropane Analogues of Antiviral Phosphonates

Synthesis of “reversed” methylenecyclopropane analogues of nucleoside phosphonates 6a,7a, 6b, and 7b is described. 1-Bromo-1-bromomethylcyclopropane 8 was converted to the bromocyclopropyl phosphonate 9 by Michaelis-Arbuzov reaction with triisopropyl phosphite. Base-catalyzed β-elimination and deacetylation gave the key Z- and E-hydroxymethylcyclopropyl phosphonates 10 and 11 separated by chromatography. The Mitsunobu type of alkylation of 10 or 11 with adenine or 2-amino-6-chloropurine afforded phosphonates 12a, 12b, 13a, and 13b. Acid hydrolysis furnished the adenine and guanine analogues 6a, 7a, 6b, and 7b. The E and Z configuration was assigned on the basis of NOE experiments with phosphonates 6b and 7b. All Z- and E-isomers were also distinguished by different chemical shifts of CH₂O or CH₂N (H₄ or H_4′). Significant differences of the chemical shifts of the cyclopropane C_3(3’) carbons and coupling constants ³J_P,C2(2’) or ³J_P,C3(3’) selective for the Z- or E-isomers were also noted. Phosphonates 6a, 7a, 6b, and 7b are devoid of significant antiviral activity.     

Cynasibirolide A,One New Humulanolide Sesquiterpene from Cynanchum acutum subsp. sibiricum

Cynasibirolide A ( 1 ), one new humulanolide sesquiterpene, together with four known analogs, asteriscanolide ( 2 ), (1S,8S)-8-hydroxyhumula-2Z,6E,9E-trien-1,12-olide ( 3 ), (1S,7R)-8-oxohumula-2Z,9E-dien-1,12-olide ( 4 ), and (+)-6,7,9,10-tetrahydroasteriscunolide ( 5 ) were isolated from the roots and rhizomes of Cynanchum acutum subsp. sibiricum. Their structures and configurations were elucidated by spectroscopic methods, including 2D-NMR techniques, and the structure of 1 was confirmed by single-crystal X-ray diffraction. All compounds were evaluated for their anti-complementary activity in vitro, and compound 3 exhibited anti-complement effect with CH₅₀ value of 0.45 mM.     

Isobutyl Amides from Pepper (Piper nigrum L.)

Four isobutyl amides were isolated from the fruits of white pepper (Piper nigrum L.) and identified to be N-isobutyl-13-(3,4-methylenedioxyphenyl)-2E,4E,12E-tridecatrienamide (3, guineensine), N-isobutyl-2E,4E,8Z-eicosatrienamide (5), N-isobutyl-2E,4E-octadecadienamide (6) and N-isobutyl-2E,4E-decadienamide (7, pellitorine).     

Conversion of (2Z,4E)-5-(1′,2′-epoxy-2′,6′,6′-trimethylcyclohexyl)-3-methyl-2,4-pentadienoic acid to xanthoxin acid by Cercospora cruenta, a fungus producing (+)-abscisic acid

(±)-(2Z,4E)-5-(1′,2′-epoxy-2′,6′,6′-trimethylcyclohexyl)-3-methyl-2,4-pentadienoic acid was metabolized by Cercospora cruenta, which has the ability to produce (+)-abscisic acid (ABA), to give (±)-(2Z,4E)-xanthoxin acid, (±)-(2Z,4E)-5′-hydroxy-1′,2′-epoxy-1′,2′-dihydro-β-ionylideneacetic acid, (±)-1′,2′-epoxy-1′,2′-dihydro-β-ionone and trace amounts of ABA.     

Isomer-specific effects of conjugated linoleic acid on gene expression in RAW 264.7

Conjugated linoleic acid (CLA) is a mixture of dietary fatty acids that has various beneficial effects including decreasing cancer, atherosclerosis, diabetes and inflammation in animal models. Some controversy exists on the specific isomers of CLA that are responsible for the benefits observed. This study was conducted to examine how different CLA isomers regulate gene expression in RAW 264.7. A mouse macrophage cell line, RAW 264.7, was treated with five different CLA isomers (9E,11E-, 9Z,11E-, 9Z,11Z-, 10E,12Z- and 11Z,13E-CLA). Gene expression microarrays were performed, and several significantly regulated genes of interest were verified by a real-time polymerase chain reaction (PCR). Examination of the biological functions of various significantly regulated genes by the five CLA isomers showed distinct properties. Isomers 9E,11E-, 9Z,11Z-, 10E,12Z- and 11Z,13E-CLA decreased production of proinflammatory cytokines such as interleukin (IL)-1α, IL-1β and IL-6. Many of CLA's effects are believed to be mediated by the fatty acid receptors such as the peroxisome proliferator-activated receptors (PPAR) and retinoid-X-receptors (RXR). Using PPAR and RXR specific antagonists and coactivator recruitment assays, it was evident that multiple mechanisms were responsible for gene regulation by CLA isomers. Coactivator recruitment by CLA isomers showed their distinct properties as selective receptor modulators for PPARγ and RXRα. These studies demonstrate distinct isomer differences in gene expression by CLA and will have important ramifications for determining the potential therapeutic benefit of these dietary fatty acids in prevention of inflammation-related diseases.     

Antennal and behavioural response of codling moth Cydia pomonella to plant volatiles

Identification of host volatile compounds attractive to codling moth Cydia pomonella, a most important insect of apple, will contribute to the development of safe control techniques. Synthetic apple volatiles in two doses were tested for antennal and behavioural activity in codling moth. Female antennae strongly responded to (Z)3‐hexenol, (Z)3‐hexenyl benzoate, (Z)3‐hexenyl hexanoate, (±)‐linalool and E,E‐α‐farnesene. Two other compounds eliciting a strong antennal response were the pear ester, ethyl (E,Z)‐2,4‐decadienoate, and its corresponding aldehyde, E,E‐2,4‐decadienal, which is a component of the larval defence secretion of the European apple sawfly. Attraction of codling moth to compounds eliciting a strong antennal response was tested in a wind tunnel. Male moths were best attracted to a blend of (E,E)‐α‐farnesene, (E)‐beta‐farnesene and ethyl (E,Z)‐2,4‐decadienoate. The aldehyde E,E‐2,4‐decadienal had an antagonistic effect when added to the above mixture.     

Metabolism of (2Z,4E)-γ-Ionylideneethanol and (2Z,4E)-γ-Ionylideneacetic Acid in Cercospora cruenta

[2–¹⁴C]-(2Z,4E)-γ-Ionylideneethanol and [2–¹⁴C]-(2Z,4E)-γ-ionylideneacetic acid were converted by Cercospora cruenta to [2–¹⁴C]-(2Z,4E)-1′,4′-dihydroxy-γ-ionylideneacetic acid and [2-¹⁴C]-(2Z,4E)-4′-hydroxy-γ-ionylideneacetic acid, which are intermediates of ABA biosynthesis in C. cruenta.     

Sexual communication in the termite Prorhinotermes simplex (Isoptera, Rhinotermitidae) mediated by a pheromone from female tergal glands

We studied the post-flight behavior and sex attraction in imagoes of the termite Prorhinotermes simplex (Rhinotermitidae, Prorhinotermitinae). Pairing is mediated by the secretion from tergal glands, exposed by females in a calling posture and highly attractive to males. Analysis of extracts of these glands by means of gas chromatography with electroantennographic detection indicated a chromatographic area corresponding to an intense physiological response of males. The retention characteristics of this area proved to be identical with those of (3Z,6Z,8E)-dodeca-3,6,8-trien-1-ol. Electroantennographic and behavioral assays revealed that units of picograms of the compound represent a stimulus qualitatively and quantitatively equivalent to one female tergal gland. Thus, we hypothesize that (3Z,6Z,8E)-dodeca-3,6,8-trien-1-ol is a major component of the female sex pheromone in P. simplex.     

Syntheses,Characterizations, and Biological Activities of Tetradeca‐4,8‐dien‐1‐yl Acetates as Sex Attractants of Leaf‐Mining Moth of the Genus Phyllonorycter (Lepidoptera: Gracillariidae)

The four possible isomers of tetradeca‐4,8‐dien‐1‐yl acetate and corresponding alcohols were synthesized stereoselectively by synthetic routes employing Wittig coupling reaction for the preparation of (Z,E)‐ and (Z,Z)‐isomers, and alkylation of terminal alkynes for the preparation of (E,E)‐ and (E,Z)‐isomers as the key steps. Synthetic products were characterized by ¹³C‐ and ¹H‐NMR spectroscopy as well as mass‐spectrometric methods. All four isomers gave distinctive mass spectra where m/z 81 fragments clearly dominated. Elution order, followed by retention index presented in parenthesis, of tetradeca‐4,8‐dien‐1‐ols was determined as (Z,Z) (2082.1), (Z,E) (2082.8), (E,E) (2083.1), and (E,Z) (2083.2) from unpolar SPB‐1 column, and as (E,E) (2210.2), (Z,E) (2222.1), (E,Z) (2223.4), and (Z,Z) (2224.7) from polar DB‐WAX column. The isomers of tetradeca‐4,8‐dien‐1‐yl acetates eluted in the order of (Z,Z) (2176.1), (Z,E) (2178.4), (E,Z) (2185.9), and (E,E) (2186.4) from SPB‐1, and (Z,E) (2124.3), (E,E) (2157.7), (Z,Z) (2128.9), and (E,Z) (2135.9) from DB‐WAX columns. Field‐screening tests for attractiveness of tetradeca‐4,8‐dien‐1‐yl acetates revealed that (4Z,8E)‐tetradeca‐4,8‐dien‐1‐yl acetate significantly attracted Phyllonorycter coryli and Chrysoesthia drurella males. (4E,8E)‐Tetradeca‐4,8‐dien‐1‐yl acetate was the most efficient attractant for Ph. esperella and Ph. saportella males, and (4E,8Z)‐tetradeca‐4,8‐dien‐1‐yl acetate was attractive to Ph. cerasicolella males.     

Three Antinematodal Diterpenes from Euphorbia kansui

Three compounds, 20-O-acetyl-[3-O-(2′E,4′Z)-decadienoyl]-ingenol (1), 20-O-acetyl-[5-O-(2′E,4′Z)-decadienoyl]-ingenol (2) and 3-O-(2′E,4′Z)-decadienoylingenol (3), were isolated from Euphorbia kansui under the bioassay-guided method. Each compound showed the same antinematodal activity against the nematode, Bursaphelenchus xylophilus, at a minimum effective dose (MED) of 5 μg/cotton ball.     

Antennal response of codling moth males, Cydia pomonella L. (Lepidoptera: Tortricidae), to the geometric isomers of codlemone and codlemone acetate

Single sensillum recordings from Cydia pomonella male antennae showed three different types of receptor neurons. The most abundant type was most sensitive to the main pheromone compound (E,E)-8,10-dodecadienol, while its response to the geometric isomers E,Z, Z,E and Z,Z was comparable to a tenfold lower dose of (E,E)-8,10-dodecadienol. This neuron type also responded to the four behaviorally antagonistic isomers of (Δ,Δ)-8,10-dodecadienyl acetate, among which it was most sensitive to the E,E isomer. Cross-adaptation studies showed that these compounds were all detected by the same receptor neuron type. Receptor neurons specifically tuned to (E,Z) or (Z,Z)-8,10-dodecadienol were not found, although these two compounds are behaviorally active. A second type of receptor neuron responded to all isomers of (Δ,Δ)-8,10-dodecadienyl acetate and was most sensitive to the E,E isomer. This neuron type did not respond to any of the isomers of (Δ,Δ)-8,10-dodecadienol. A third receptor neuron type was highly sensitive to the plant compound α-farnesene. The finding that the receptor neuron type tuned to the main pheromone compound responded even to strong behavioral antagonists aids the interpretation of ongoing behavioral studies for the development of the mating disruption technique in codling moth. Accepted: 3 March 2000     

The conformational properties of α,β‐dehydroamino acids with a C‐terminal ester group

α,β‐Dehydroamino acid esters occur in nature. To investigate their conformational properties, a systematic theoretical analysis was performed on the model molecules Ac‐ΔXaa‐OMe [ΔXaa = ΔAla, (E)‐ΔAbu, (Z)‐ΔAbu, ΔVal] at the B3LYP/6‐311+ + G(d,p) level in the gas phase as well as in chloroform and water solutions with the self‐consistent reaction field‐polarisable continuum model method. The Fourier transform IR spectra in CCl₄ and CHCl₃ have been analysed as well as the analogous solid state conformations drawn from The Cambridge Structural Database. The ΔAla residue has a considerable tendency to adopt planar conformations C5 (?, ψ ≈ ? 180°, 180°) and β2 (?, ψ ≈ ? 180°, 0°), regardless of the environment. The ΔVal residue prefers the conformation β2 (?, ψ ≈ ? 120°, 0°) in a low polar environment, but the conformations α (?, ψ ≈ ? 55°, 35°) and β (?, ψ ≈ ? 55°, 145°) when the polarity increases. The ΔAbu residues reveal intermediate properties, but their conformational dispositions depend on configuration of the side chain of residue: (E)‐ΔAbu is similar to ΔAla, whereas (Z)‐ΔAbu to ΔVal. Results indicate that the low‐energy conformation β2 is the characteristic feature of dehydroamino acid esters. The studied molecules constitute conformational patterns for dehydroamino acid esters with various side chain substituents in either or both Z and E positions. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.     

(10E,12Z,15Z)-9-Hydroxy-10,12,15-octadecatrienoic Acid Methyl Ester as an Anti-inflammatory Compound from Ehretia dicksonii

The methanol extract of Ehretia dicksonii provided (10E,12Z,15Z)-9-hydroxy-10,12,15-octadecatrienoic acid methyl ester (1) which was isolated as an anti-inflammatory compound. Compound 1 suppressed 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-induced inflammation on mouse ears at a dose of 500 μg (the inhibitory effect (IE) was 43%). Linolenic acid methyl ester did not inhibit this inflammation at the same dose. However, the related compounds of 1, (9Z,11E)-13-hydroxy-9,11-octadecadienoic acid (5) and (9Z,11E)- 13-oxo-9,11-octadecadienoic acid (6), showed potent activity (IE_{500 μg} of 63% and 79%, respectively). Compounds 1, 4 ((9Z,12Z,14E)-16-hydroxy-9,12,14-octadecatrienoic acid), 5 and 6 also showed inhibitory activity toward soybean lipoxygenase at a concentration of 10 μg/ml.