Synthesis of (S,E)-1-Methyl-9-dodecenyl Acetate,the Sex Pheromone of the Hessian Fly,Mayetiola destructor

(S,E)-1-Methyl-9-dodecenyl acetate (1), the sex pheromone of the Hessian fly, was synthesized by starting from ethyl (S)-3-hydroxybutanoate (2).     

Inhibitory Activity of (9R,10S,12Z)-9,10-Dihydroxy-8-oxo-octadecenoic Acid,Its C-9 Epimer and Their Derivatives toward the Growth of Tea Pollen Tubes

The inhibitory activity of (9R,10S,12Z)-9,10-dihydroxy-8-oxooctadecenoic acid and its diacetate, acetonide and methyl ester toward tea pollen tube growth were different, the inhibition by the diacetate being the strongest. Each compound of the fatty acid and its derivatives exhibited more inhibition than its C-9 epimer. The fatty acid and its C-9 epimer showed the same toxicity against HeLa cells.     

Stereoselective Synthesis of erythro-Serricornin, (4R, 6R, 7S)-, and (4S, 6R, 7S)-4,6-Dimethyl-7-hydroxynonan-3-one,Stereoisomers of the Sex Pheromone of Cigarette Beetle

A stereoselective synthesis of erythro-serricornin [(4RS,6R,7S)-4,6-dimethyl-7-hydroxynonan-3-one] was completed starting from l-(+)-tartaric acid. The relative configuration of C(6)-methyl and C(7)-hydroxyl groups in naturally occurring serricornin was threo.     

Synthesis of (S,E)-1-Methyl-9-dodecenyl Acetate,the Sex Pheromone of the Hessian Fly,Mayetiola destructor,by Lipase-catalyzed Enantioselective Hydrolysis

(S,E)-1-Methyl-9-dodecenyl acetate [(S)-8], the sex pheromone of the hessian fly, Mayetiola destructor, was synthesized in a highly enantiomerically pure form by Pseudomonas cepacia lipase-catalyzed hydrolysis.     

Synthesis of (E)-9-(1-pyrenyl)-4-hydroxynon-2-enal, a fluorescent probe of the (E)-4-hydroxynon-2-enal with retained biological properties

(E)-9-(1-pyrenyl)-4-hydroxynon-2-enal (FHNE), a fluorescent probe of (E)-4-hydroxynon-2-enal (HNE) is synthesised in seven steps and in 35% overall yield, starting from commercially available 1-pyrencarboxyaldehyde. When incubated with cultured HeLa cells this fluorescent probe penetrates cells and particularly concentrates in the region surrounding the nucleus. As the parent compound, HNE it is able to induce the activation of heat shock factor (HSF) and it is able to induce the binding of HSF to heat shock element (HSE).     

Synthesis of (3E, 5Z)-3,5-Dodecadienylacetate,the Sex Pheromone of Phtheochroa cranaodes (Lepidoptera: Tortricidae)

(3E, 5Z)-3,5-Dodecadienyl acetate, the female sex pheromone of Phtheochroa cranaodes, was regio and stereo-selectively synthesized from 1-octyne and (E)-4-bromo-3-buten-1-ol by using Pd(PPh₃)₄, CuI and piperidine to afford the enyne (5). Further elaboration afforded the target pheromone. The synthetic pheromone was identified with the natural product by its MS and IR, data GLC retention time and biological activity.     

Stereoselective Synthesis of a Promising Flower-Inducing KODA Analog, (9R,12S,13R,15Z)-9-Hydroxy-12,13-methylene-10-oxooctadec-15-enoic Acid

Stereoselective synthesis of a promising flower-inducing 9,10-ketol octadecadienoic acid (KODA) analog, (9R,12S,13R,15Z)-9-hydroxy-12,13-methylene-10-oxooctadec-15-enoic acid, was designed to obtain the desired stereoisomer via coupling between chiral sulfone and aldehyde segments. A known chiral cyclopropane derivative was converted to the sulfone segment via carbon-chain elongation and sulfonylation. Dec-9-en-1-ol was converted to the aldehyde segment, whose C-9 configuration was introduced by Sharpless asymmetric dihydroxylation. Coupling of the both segments and subsequent assembly gave the desired (9R,12S,13R,15Z)-analog. The (9S,12S,13R,15Z)-analog was also synthesized by using the enatiomeric aldehyde segment. This strategy made it possible to synthesize the remaining stereoisomeric analogs.     

Stereoselective synthesis of chirally deuterated (S)-D-(6-(2)H(1))glucose

Chirally deuterated (S)-D-(6-(2)H(1))glucose has been prepared in good overall yield from d-(6,6'-(2)H(2))glucose by a short, five-step synthesis from D-(6,6-(2)H(2))glucose utilizing (R)-(+)-Alpine-Borane [(R)-9-[(6,6-dimethylbicyclo[3.1.1]hept-2-yl)methyl]-9-borabicyclo[3.3.1]nonane]. Suitably protected methyl 2,3,4-tri-O-benzyl-D-(6,6-(2)H(2))glucopyranoside was prepared and the deuterated O-6 primary alcohol was oxidized to an aldehyde by Swern oxidation. Stereoselective reduction with nondeuterated (R)-(+)-Alpine-Borane gave methyl 2,3,4-tri-O-benzyl-(6S)-D-(6-(2)H(1))glucopyranoside, which was deprotected under standard conditions to afford the title compound. The key stereoselective reduction step was achieved in 90% yield. The preparation uses economical, commercially available starting materials and will be useful for elucidating biosynthetic mechanisms.     

Synthesis of a Glandular Secretion of the Civet Cat, (2S,6S)-(6-Methyltetrahydropyran-2-yl)acetic Acid and Its Enantiomer,by Using the Yeast-Reduction Product and Recovered Substrate from Yeast Reduction

A glandular secretion of the civet cat, (2S,6S)-(6-methyltetrahydropyran-2-yl)acetic acid 1 and its enantiomer, were synthesized from the yeast-reduction product and recovered substrate from yeast reduction.     

Synthesis of (4R,6S,7R)-7-hydroxy-4,6-dimethyl-3-nonanone and (3R,5S,6R)- 6-hydroxy-3,5-dimethyl-2-octanone,the pheromone components of the bostrychid beetle,Dinoderus bifoveolatus

(4R,6S,7R)-7-Hydroxy-4,6-dimethyl-3-nonanone and (3R,5S,6R)-6-hydroxy-3,5-dimethyl-2-octanone, the pheromone components of the bostrychid beetle, Dinoderus bifoveolatus, as well as their (4R,6S,7S)- and (3R,5S,6S)-isomers were synthesized from (2R,4S,5R)- and (2R,4S,5S)-2,4-dimethyl-5-heptanolide, respectively.     

Enantioselective Synthesis of the (1S,5R)-Enantiomer of Litseaverticillols A and B

An enantioselective synthesis of the (1S,5R)-enantiomer of litseaverticillols A and B was accomplished in line with our previously reported synthetic pathway for their (1R,5S)-enantiomer. The use of “EtSCeCl₂” prepared from EtSLi and CeCl₃, instead of previously employed EtSLi itself, for the formation of thiol ester intermediates prevented any undesirable epimerization occurring in the process.     

Syntheses of 2-Deoxy-2-[(2R,3S)-2-fluoro-3-hydroxytetradecanamido]-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phosphono-D-glucopyranose and Its (2S,3R)-Isomer

2-Deoxy-2-[(2R,3S)-2-fluoro-3-hydroxytetradecanamido]-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phosphono-D-glucopyranose and its (2S,3R)-isomer were respectively synthesized from allyl 2-[(2R,3S)-3-(benzyloxycarbonyloxy)-2-fluorotetradecanamido]-2-deoxy-4,6-O-isopropylidene-β-D-glucopyranoside and its corresponding (2S,3R)-isomer. Both target compounds did not activate macrophage, but the (2S,3R)-analogue strongly inhibited the binding of LPS to macrophage.     

Stereoselective Synthesis of (Z,Z)-3, 13-Octadecadienyl Acetate,the Attractant for Smaller Clear Wing Moth

(Z)-3-Hexene-1, 6-diol, a new synthon for the synthesis of (Z)-olefinic pheromones, was prepared from 1, 4-cyclohexadiene. This synthon was used in the synthesis of (Z, Z)-3, 13-octadecadienyl acetate, whose high stereochemical purity at C–3 was essential in attracting male Synanthedon tenuis Butler.     

Synthesis and biochemical evaluation of highly enantiomerically pure (R,R)- and (S,S)-alexidine

Alexidine is in everyday human use as oral disinfectant and contact lens disinfectant. It is used as a mixture of stereoisomers. Since all of alexidine’s known biological targets are chiral, the biological activity of any of its chiral stereoisomers could be significantly higher than that of the mixture of stereoisomers. This makes a synthetic methodology for obtaining the individual enantiomers of the chiral diastereoisomer highly desirable. Here, we describe the first synthesis of both enantiomers of alexidine in high enantiomeric purity, and demonstrate their activity against the protein–protein interaction between the anti-apoptotic protein Bcl-x_L and the pro-apoptotic protein Bak.     

A New Synthesis of (E,E)-8, 10-Dodecadien-1-ol,Sex Pheromone of Codling Moth

A methanol-utilizing bacterium, which produced red to pink pigments and assimilated methanol via icl^- serine pathway, was isolated from soil and tentatively designated as Pseudomonas MS 31. This bacterium produced L-serine when glycine was added to the growth medium at the late exponential phase of growth. The cells showed high L-serine degradation activity. Chelating agents and some metal ions, which inhibited L-serine degradation, stimulated the L-serine accumulation. In the presence of 0.1 ? 1 mM EDTA, o-phenanthroline, 8-hydroxyquinoline, α,α'-dipyridyl, cobalt sulfate or nickel sulfate, this bacterium produced 0.7?2.1mg L-serine from 4mg glycine per ml culture.     

Synthesis of (S)-13-Hydroxy (2E,4E,8E)- and (2E,4E,8Z)-Tetradecatrienoic Acids

The syntheses of (S)-13-hydroxy-(2E,4E,8E)-tetradecatrienoic acid (1) and (2E,4E,8Z)-tetradecatrienoic acid (2) were carried out by using the Wittig reaction as the key step. The asymmetric center at C-13 and the double bond between C-8 and C-9 for natural compound 1 were reconfirmed as being of (S) configuration and E, respectively.

The relationship between the structure of the unsaturated hydroxy fatty acids and their inhibitory effect on the growth of lettuce was investigated.     

The morphology and ecology of Nemastoma and Predaea species (Nemastomataceae,Rhodophyta) from Ghana

Two members of the family Nemastomataceae (Gigartinales, Rhodophyta) are described from subtidal habitats in Ghana. Nemastoma confusum sp. nov. is a plant of irregularly lobed, thick gelatinous blades with subacute marginal projections and surface proliferations. It is composed of a lax medulla and submoniliform cortical filaments with prominent intercalary gland cells. Carposporophytes are one to three spherical lobes of carposporangia borne on gonimoblast initials arising directly from auxiliary cells contacted by connecting filaments. A rudimentary involucre is formed around the gonimoblast by elongating vegetative cortical cells borne on the auxiliary cell. The genus Predaea is recorded for the first time from Africa, and P. feldmannii Boerg. is described in morphological detail together with some observations on its ecology in Ghana. Distinctive features of connecting filament formation, nutritive cell production and gonimoblast initiation and development are illustrated and compared to other species of the genus. A second species, P. masonii (Setch. & Gardn.) De Toni fil., is represented by a single specimen in the collections and appears to be distinct from P. feldmannii on cortical and gland cell features.     

Synthesis of methyl (5S,6R,7E,9E,11Z,13E,15S)-16-(4-fluorophenoxy)-5,6,15-trihydroxy-7,9,11,13-hexadecatetraenoate,an analogue of 15R-lipoxin A4

We describe a method for the synthesis of methyl (5S,6R,7E,9E,11Z,13E,15S)-16-(4-fluorophenoxy)-5,6,15-trihydroxy-7,9,11,13-hexadecatetraenoate, a compound that has been described as a metabolically stable analogue of 15R-lipoxin A(4).