On-Line Coupling of High-Performance Liquid Chromatography to Atmospheric Pressure Chemical Ionization Mass Spectrometry (HPLC/APCI-MS and MS/MS). The Pollen Analysis of Hippeastrum x hortorum (Amaryllidaceae)

A H₂O/MeOH extract of the pollen of Hippeastrum x hortorum (Amaryllidaceae) was analyzed. A mixture of different compounds (at the most 84) was found, namely the geometrically ((E,E), (E,Z), (Z,E), and (Z,Z) and structurally isomeric N,N′-dicoumaroyl (=N,N′-bis[3-(4-hydroxyphenyl)prop-2-enoyl]), N,N′-diferuloyl (=N,N′-bis[3-(4-hydroxy-3-methoxyphenyl)prop-2-enoyl]), N,N′-disinapoyl (=N,N′-bis[3-(4-hydroxy-3,5-dimethoxyphenyl)prop-2-enoyl]), N-coumaroyl-N′-feruloyl, and N-feruloyl-N′-sinapoyl derivatives of spermidine (=4-azaoctane-1,8-diamine=N-(3-aminopropyl)butane-1,4-diamine). Their structures were proven by using on-line-coupled high-performance liquid chromatography and atmospheric-pressure chemical-ionization mass spectrometry (HPLC-UV(DAD)/APCI-MS and MS/MS), UV-induced (E)⇌(Z) photoisomerization, and catalytic hydrogenation, as well by comparing their spectra and chromatographic behavior with those of synthetic standards. According to the physicochemical properties of these natural compounds, a proposed biological function is discussed.     

Biosynthesis of δ-Jasmin Lactone ( = (Z)-Dec-7-eno-5-lactone) and (Z,Z)-Dodeca-6,9-dieno-4-lactone in the Yeast Sporobolomyces odorus

(all-Z)-(9,10,12,13,15,16-²H₆)Octadeca-9,12,15-trienoic acid ( = α-linolenic acid; D₆- 4 ) was synthesized to investigate the biochemical formation of linolenic-acid-derived aroma compounds in cultures of the yeast Sporobolomyces odorus, using an established gas chromatographic/mass spectrometric (GC/MS) method. Three compounds were identified as labeled: (Z)-dec-7-eno-5-lactone (δ-jasmin lactone), (Z,Z)-dodeca-6,9-dieno-4-lactone, and (2E,4Z)-hepta-2,4-dienoic acid. Both lactones were biosynthesized mostly under conservation of the initial configuration from their corresponding oxygenated linolenic-acid intermediates. The application of (13S,9Z,11E,15Z)-13-hydroxy(9,10,12,13,15, 16-²H₆)octadeca-9,11,15-trienoic acid (D₆- 7 ) as a OH-functionalized precursor of δ-jasmin lactone allowed to gain insight into the stereochemical course of the biosynthesis to both enantiomers of this lactone. In this experiment, 88.3% of the metabolized labeled precursor was transformed under retention of the original configuration of the (R)-enantiomer. This investigation is also a contribution to a better understanding of the C?C bond isomerization steps which took place during the β-oxidative degradation of the substrate.     

Hydrocarbon components of the trail pheromone of the red imported fire ant, Solenopsis Invicta

Terpenoid trail pheromone components were isolated from whole worker extracts of the red imported fire ant, and identified as Z,E and E,E-α-farnesene, and the previously unreported homofarnesenes Z,Z and Z,E-3,4,7,11-tetramethy1-1,3,6,10-dodecatetraene.     

Novel 10-Hydroxydocosapolyenoic Acids from Deep-Water Scleractinian Corals

The new 10-hydroxydocosapolyenoic acids (10R,7Z,11E,13E,16Z,19Z)-10-hydroxydocosa-7,11,13,16,19-pentaenoic acid ( 1a ) and (10R*,4Z,7Z,11E,13Z,16Z,19Z)-10-hydroxydocosa-4,7,11,13,16,19-hexaenoic acid ( 2a ) were isolated as methyl esters 1b and 2b , respectively, following CH₂N₂ treatment of the EtOH extract of the scleractinian coral Madrepora oculata from deep-water of the southern Indian Ocean. From the same species from the Norwegian Sea, 1b and the methyl ester 3b of the new (10R,7Z,11E,13Z,16Z)-10-hydroxydocosa-7,11,13,16-tetraenoic acid ( 3a ) were analogously isolated, while from the untreated extract, the free acid 3a itself could be isolated. The absolute configuration of 1a and 3a was established by the chiral exciton coupling of the C(10) benzoate esters 1c and 3c . Other known 10-hydroxydocosapolyenoic acids and 8-hydroxyeicosapolyenoic acid were also isolated from M. oculata from both locations. These results imply the intervention of a rare lipooxygenase with high ω13 specificity. In an examination of several other deep-water scleractinians, hydroxypolyenoic acids were found only in Lophelia pertusa from the northeastern Atlantic Ocean.     

Novel Aplysinopsin-Type Alkaloids from Scleractinian Corals of the Family Dendrophylliidae of the Mediterranean and the Philippines. Configurational-assignment criteria,stereospecific synthesis,and photoisomerization

From the scleractinian coral Tubastraea sp. (Dendrophylliidae) collected at Palawan, Philippines, 3′-deimino-3′-oxoaplysinopsin ( 4 ) and 6-bromo-3′-deimino-3′-oxoaplysinopsin ( 6 ) are now isolated as 5:2 mixtures of (E/Z) stereoisomers. The 3′-deimino-2′,4′-bis(demethyl)-3′-oxoaplysinopsin ( 7 ) and 6-bromo-3′-demino-2′,4-bis(demethyl)-3′-oxoaplysinopsin ( 5 ) are isolated as 2:3 and 1:1 (E/Z) mixtures, respectively, from another dendrophylliid, Leptopsammia pruvoti, collected near Marseille, Mediterranean coast of France. Larger amounts of these and related compounds, needed for a full structural determination, are obtained by synthesis. Thus, condensations of indol-3-carboxaldehyde (9) or of its 6-bromo derivative 14 with hydantoin (15) , 3-methylhydantoin (11) , or 1,3dimethylhydantoin (10) give the prevalent natural aplysinopsins with high stereospecificity. The minor stereoisomers (Z)- 4 , (Z)- 6 , (E)- 7 , and (E)- 5 are obtained by (E/Z) photoisomerization under UV light of the condensation mixtures. The configuration is assigned from larger H? C(8)/C(5′) ¹H, ¹³C couplings in the (E) than in the (Z) isomer, and, in the case of 4 and 6 , from NOE enhancement at Me? N(2′) on irradiation at H? C(8). The stereospecificity of the condensations is attributed to steric inhibition to planarity in the rate-limiting transition states, due to N(2′)/H? C(2) repulsion with (Z)- 4 and (Z)- 6 , or to C(5′)?O/H? C(2) repulsion with (E)–7 or (E)- 5 . As the aplysinopsins undergo (E/Z ) phostoisomerization also under the daylight conditions of the laboratory, their isomeric composition in nature can not be presently assessed.     

Chiral [2H]-Labelled Methylene Groups in Trienoic- and Dienoic Fatty Acids: A Facile Approach via Asymmetric Epoxidation of [2H] Allyl Alcohols

Chiral [²H] -labelled methylene groups flanked by two double bonds within (poly)unsaturated fatty acids are readily available from trans-2,3-epoxy[2,3-²H₂] alk-4-yn-l-ols, obtained in their turn by asymmetric epoxidation of the corresponding (E)-[2,3-²H₂] alk-2-en-4-yn-l-ols (see Scheme 3). The procedure is exemplified for (8S,3Z,6Z,9Z)-[7,8-²H₂] trideca-3,6,9-trienoic acid ((8S)- 11 ) and (8R)- 11 (Scheme 4) as well as for (5S,3Z,6Z)-[4,5^?2H₂]deca-3,6-dienoic acid ((5S)- 13 ) and (5R)- 13 (Scheme 5).     

Photoelectron-Spectroscopic Characterization of 3,4-Dimethyl-2,4-hexadienes

The He(Ia) photoelectron (PE) spectra of the (E,E)-, (E,Z)- and (Z,Z)-isomers of the title compound have been recorded to obtain information about their conformation in the gas phase. For a valid correlation with the PE data of other dienes it is necessary to take the potentials V(φ) for internal rotation and the corresponding conformer population densities P (φ) into account, as well as the rather complicated way wy in which the π^?1 ionization energy gap ΔI(φ) depends on the direct π-orbital interaction and the long-range ‘through-space’ interaction between the semi-localized methyl-group orbitals and the π-orbitals. These factors being taken into account, the mean twist angles, φ , compatible with the PE-spectroscopic results are φ (E,E) ≈? O° ± 30°, φ (E,Z) ≈? 80° or 110° within ± 15°, and φ (Z,Z) ≈? 85° to 105°. These results are in rough agreement with electron diffraction data by Traetteberg [15], other spectroscopic results and, for the (E, E)- and (Z,Z)-isomers, internal rotation potentials V(φ) previously calculated by Roth [17]. On the other hand the potential V (φ) proposed for the (E,Z)-isomer does not seem to be compatible with our findings.     

Glycosylidene Carbenes. Part 24 Reactivity modulation by protecting groups of the addition of glycosylidene carbenes to electron-rich alkenes

The reactivity of glycosylidene carbenes derived from pivaloylated vs. benzylated diazirines 1 and 2 towards enol ethers have been examined. The pivaloylated 1 led to higher yields of spirocyclopropanes than the benzylated 2. Among the enol ethers tested, dihydrofuran 6 proved most reactive, yielding 71–72% of the spiro-linked tetrahydrofuran 7 , while the benzylated diazirine 2 afforded only 33% of the analogue 8 (Scheme 1 ). Other enol ethers proved much less reactive. The addition of 1 and 2 to the dihydropyran 10 and the 2, 3-dihydro-5-methyl-furan 15 gave low yields of single cyclopropanes (→ 12 , 14 , and 16 ), and the glycals 17 and 18 , and (E)-1-methoxy-oct-1-ene ( 23 ) did not react. The main products of these reactions were the azines (Z, Z)- 11 and (Z, Z)/( E, E)- 13. Similarly, 1 and 2 reacted poorly with (Z)-1-methoxyoct-1-ene ( 24 ), leading to cyclopropanes 25 / 26 / 27 and 28 / 29 / 30 / 31 (Scheme 2). Main products were again the azines (Z, Z)- 11 and (Z, Z)/(E, E)- 13 . The structure of 70 and 25 was established by X-ray analysis (Figs. 1 and 2). The mechanism of addition of glycosylidene carbenes to enol ethers is discussed, AMI Calculations indicate that the LUMO_carbene/HOMO_alkoxyalkene interaction is dominant at the beginning of the reaction, while the transition states are characterized by a dominant interaction of the doubly occupied, sp²-hybridized orbital of the carbene with the LUMO of the enol ether. The relative reactivity of the carbenes towards either the enol ethers or the diazirines determine type and yields of the products.     

On the synthesis of geometric isomers of 2-methyl (or phenyl)-4-[α-arylethylidene]-5(4H)-oxazolones

Several Z-2-methyl(or phenyl)-4-[α-arylethylidene]-5(4H)-oxazolones 3Z, 4Z were prepared. The results obtained were compared by diazomethane insertion and condensation procedure. In order to synthesize E-2-phenyl-4-[α-arylethylidene]-5(4H)-oxazolones 4E hydrogen bromide isomerization in dry benzene was used.     

Photochemical reactions. 133rd Communication. Photochemistry of epoxydienes of the ionone series: Influence of a methyl group at the diene side chain on the oxirane cleavage

On triplet excitation (λ > 280 nm, acetone), the epoxydiene (E)- 2 undergoes (E)/(Z)-isomerization exclusively, leading to the conformers (Z)- 2A and (Z)- 2B . On singlet excitation (λ = 254 nm), apart from (Z)- 2A + B , the cyclobutenes 3A + B are formed. However, the epoxydiene (E)- 2 does not undergo reactions leading to carbene and C,O-bond cleavage products, which are normally observed on singlet and triplet excitation, respectively, of the epoxydienes of the ionone series.     

Identification of a potential sex pheromone of the processionary moth, Thaumetopea pityocampa (lepidoptera,notodontidae)

The major component of the active fraction from the Thaumetopoea pityocampa (Denis and Schiff.) virgin female extract has been identified as (Z)-13-hexadecen-11-ynyl acetate on the basis of spectroscopic and microchemical reactions data. This is the first report of an acetylenic structure found in the insect pheromone field.     

Valenzisomerisierung von cis-dienonen IV. Die vier stereoisomeren Formen von 4-Methyl-6-phenyl-3, 5-hexadien-2-on

(Z,Z)-4-Methyl-6-phenyl-3,5-hexadien-2-one ( 5 ) is converted to its (Z,E)-isomer 6 at 35° in the dark. This ready, uncatalysed cis,trans-isomerization is shown to proceed through 2H-pyran 9 . Irradiation of either stereoisomeric dienone 6, 7 or 8 at 0° produces a photostationary mixture of 5, 6, 7 and 8 in which the (Z,Z)-isomer 5 predominates.     

Isolation and antiproliferative activity of triterpenoids and fatty acids from the leaves and stem of Turraea vogelii Hook. f. ex benth

Chloroform extract from the leaves of Turraea vogelii Hook f. ex Benth demonstrated cytotoxic activity against a chronic myelogenous leukemia cell, K-562 with IC₅₀ of 14.27 μg/mL, while chloroform, ethyl acetate and methanol extracts from the stem of the plant inhibited K-562 cells growth with IC₅₀ of 19.50, 24.10 and 85.40 μg/mL respectively. Bioactive chloroform extract of Turraea vogelii leaves affords two triterpenoids: oleana-12,15,20-trien-3β-ol (1), and oleana-11,13-dien-3β,16α,28-triol (2), with six fatty esters, ethyl hexaeicos-5-enoate (3), 3-hydroxy-1,2,3-propanetriyltris(tetadecanoate) (4), 1,2,3-propanetriyl(7Z,7′Z,7′′Z)tris(-7-hexadecenoate) (5), 1,2,3-propanetriyl(5Z,5′Z,5′′Z)tris(-5-hexadecenoate) (6), 1,2,3-propanetriyltris(octadecanoate) (7), and 2β-hydroxymethyl tetraeicosanoate (8). Tetradecane (9), four fatty acids: hexadecanoic acid (10), tetradecanoic acid (11), (Z)-9-eicosenoic acid (12), and ethyl tetradec-7-enoate (13) were isolated from chloroform extract of Turraea vogelii stem. 1,2,3-propanetriyltris(heptadecanoate) (14), (Z)-9-octadecenoic acid (15) and (Z)-7-tetradecenoic acid (16) were isolated from ethyl acetate extract while (Z)-5-pentadecenoic acid (17) was obtained from methanol extract of the plant stem. Compounds 1, 2, 5, 6, 11, 12, 15, 16 and 17 exhibited pronounced antiproliferative activity against K-562 cell lines.     

Beiträge zur Chemie der Pyrrolpigmente,LVIII Phytochrommodellstudien: Konformationsanalytische Untersuchungen an 2,3-Dihydrobilatrien-abc-Derivaten

Two 3,4-dihydropyrromethenones and two 2,3-dihydrobilatrienes-abc O-methylated at rings A and D resp. have been prepared. Their configurations were established as (Z), (E), (Z, Z, Z) and (Z, Z, Z), respectively, using¹H-NMR-techniques (NOE); they are also shown to exist predominantly in the lactam form. Within the pyrromethene fragment of the bilatrienes the pyrrolic and pyrroleninic ring type depends on the position of O-methylation. A helical all-synperiplanar conformation in solution could be established for all cases by applying the lanthanide induced shift (LIS) technique.

     

溶剂对钯催化的叔丁基乙炔低聚反应化学选择性的调控作用

报道了溶剂对钯催化的叔丁基乙炔低聚反应化学选择性的调控作用. 反应可在苯-正丁醇双组分溶剂体系中顺利进行, 当双组分溶剂体系中苯占优势比例时, 反应发生递次的三分子炔烃顺式插入, 经由顺式s-烯钯中间体生成环三聚产物1,3,5-三叔丁基苯; 而当双组分溶剂中正丁醇组分上升至一定比例, 反应选择性生成(3Z,5Z)-2,2,7,7-四甲基- 3,6-二氯-3,5-辛二烯或(3Z,5Z)-2,2,7,7-四甲基-3,6-二溴-3,5-辛二烯, 这是由于正丁醇可显著加快C—Pd σ键的断裂, 并与叔丁基乙炔、σ-烯钯中间体形成弱氢键作用力, 同时也与Pd(II)和Cu(II)等离子存在配位效应. 在强极性质子溶剂H₂O中, 反应生成偶联双炔: 2,2,7,7-四甲基-3,5-辛二炔. 文中就反应溶剂体系、钯铜催化剂及反应可能机理等分别进行了探讨.     

Synthesis,Isolation, and NMR-Spectroscopic Characterization of Fourteen (Z)-Isomers of Lycopene and of Some Acetylenic Didehydro- and Tetradehydrolycopenes

Eight (Z)-isomers of lycopene were prepared by stereocontrolled syntheses and fully characterized by ¹H-NMR, ¹³C-NMR, mass, and UV/VIS spectroscopy: (5Z)-, (7Z)-, (15Z)-, (5Z,5′Z)-, (7Z,7′Z)-, (7Z,9Z)-, (9Z,9′Z)-, and (7Z,9Z,7′Z,9′Z)-lycopene. Six additional (Z)-isomers, namely (9Z)-, (13Z)-, (5Z,9′Z)-, (9Z,13′Z)-, (5Z,9Z,5′Z)-, and (5Z,13Z,5′Z)-lycopene, were isolated in small quantities from isomer mixtures by semiprep. HPLC and were identified by ¹H-NMR spectroscopy.     

Ligand-Controlled Diastereoselective Cobalt-Catalysed Hydroalkynylation of Terminal Alkynes to E- or Z-1,3-Enynes

A diastereoselective hydroalkynylation of terminal alkynes to form the head-to-head dimerization products by two different cobalt-phosphine catalyst system is reported. The use of the bidentate ligand dppp and additional triphenylphosphine led to the selective formation of the (E)-1,3-enynes (E:Z>99:1) in good to excellent yields, while the tridentate ligand TriPhos led to the corresponding (Z)-1,3-enynes in moderate to good yields with excellent stereoselectivities (up to E:Z=1:99). Both pre-catalysts are easy to handle, because of their stability under atmospheric conditions. The optimized reaction conditions were identified by the Design of Experiments (DoE) approach, which has not been used before in cobalt-catalysed reaction optimisation. DoE decreased the number of required reactions to a minimum.     

GC-MS analyses of flower ether extracts of <Emphasis Type="Italic">Prunus domestica</Emphasis> L. and <Emphasis Type="Italic">Prunus padus</Emphasis> L. (Rosaceae)

Volatiles of fresh flowers of Prunus domestica L. and Prunus padus L. (their diethyl ether extracts) were analyzed by GC and GC-MS. 110 and 33 constituents were identified in P. domestica and P. padus extracts, respectively. 32 of the identified constituents were previously unreported as metabolites of taxa belonging to the genus Prunus. Six of them (4-methoxybenzyl palmitate, isoamyl stearate, isoamyl eicosanoate, isoamyl docosanoate and penta-O-acetyl-α- and β-D-glucopyranoses) are compounds reported for the first time from a natural source and one (isoamyl tetracosanoate) is a new compound in general. The major component of P. domestica extract was kaempferol (35.0 %), while P. padus extract was found to be rich in (Z)-8-hydroxylinalool (30.4 %), benzaldehyde (19.8 %) and 2-phenylethanol (15.1 %). Both extracts (P. domestica and P. padus) contained rather large amounts of shikimate metabolites (51.7 % and 39.1 %, respectively) and anther related odd-carbon numbered alkanes (23.2 % and 27.0 %, respectively). The observed differences between P. domestica and P. padus extracts corroborate the placement of P. domestica and P. padus in separate subgenera (Prunus and Cerasus, respectively) of the genus Prunus.     

GC-MS and GC-FID analyses of the volatile constituents of Brachychiton rupestris and Brachychiton discolor,their biological activities and their differentiation using multivariate data analysis

Abstract

The volatile constituents of the leaves and flowers of Brachychiton rupestris and Brachychiton discolor (Malvaceae) were characterized by GC-FID and GC-MS. A total of 92 compounds were identified. The major component of B. rupestris leaves was α-farnesene (34.57%) while in the flowers it was n-heptacosane (29.5%). (8Z, 11Z, 14Z)-heptadecatrienal (21.2%) in the leaves and palmitic acid (83.49%) in the flowers represent the abundant ingredients of B. discolor. Unsupervised pattern recognition techniques of multivariate data analysis exemplified by hierarchical cluster analysis (HCA) and principle component analysis (PCA) relying upon chromatographic results effectively discriminate the two related species. Also, both investigated species were assessed for their cytotoxic and antimicrobial efficacy. Results revealed that B. discolor flowers showed the highest cytotoxicity against human lung carcinoma (A-549) cell lines with IC₅₀ equals 7.98?μg/mL, whereas B. discolor leaves exhibited the highest antimicrobial potency against all tested microorganisms namely Streptococcus pneumonia, Bacillus subtilis, Escherichia coli as well as Aspergillus fumigatus and Geotrichum candidum (MICs between 0.98 and 15.63?µg/mL) except for Salmonella typhi.     

Diepoxy[18]annulene(10.0) : (Z,E,Z,E,Z)‐Diepoxy[18]annulen(10.0) – ein hochdynamisches Annulen

Diepoxy[18]annulenes(10.0): ( Z , E , Z , E , Z )‐Diepoxy[18]annulene(10.0) – a Highly Dynamic Annulene The McMurry reaction of (all‐E)‐5,5′‐([2,2′‐bifuran]‐5,5′‐diyl)bis[penta‐2,4‐dienal] ( 13 ) only occurs intramolecularly to give a mixture of the diepoxy[18]annulenes(10.0) 6 and 7 . Tetraepoxy[36]annulene(10.0.10.0) resulting from an intermolecular McMurry reaction is not formed. According to spectroscopic data, 6 is (Z,E,Z,E,Z)‐ and 7 (Z,E,E,Z,E)‐configured. The ¹H‐NMR data confirm that in 6 the (E)‐ethene‐1,2‐diyl bonds (C(11)=C(12) and C(15)=C(16)) rotate around the adjacent σ‐bonds. Beginning at −70°, this rotation freezes, and 6 is becoming a diatropic aromatic ring system. Beside [18]annulene itself, (Z,E,Z,E,Z)‐diepoxy[18]annulene(10.0) 6 is the only hitherto known [18]annulene derivative with dynamic properties.