Geographic variation in the field response of male European pine sawflies, Neodiprion sertifer, to different pheromone stereoisomers and esters

The European pine sawfly, Neodiprion sertifer (Geoffroy) (Hymenoptera: Diprionidae), is a widespread and economically important forest insect. The sex pheromone communication system of this species has been previously investigated in North America, Japan and Europe, with the acetate or propionate of the alcohol (2S,3S,7S)-3,7-dimethyl-2-pentadecanol (diprionol) shown to be the main pheromone component. In some locations, male attraction either increased or decreased by the addition of the (2S,3R,7R)-diprionyl acetate isomer. However, these studies were made with different batches of synthetic pheromones, with different types of traps and according to different procedures, so the observed differences might not reflect true geographic variation. Here we investigate the geographic pattern of male sawfly response by using identical chemicals, traps and experimental procedures at eight field sites ranging from Japan in the east to Canada in the west. We found an increased inhibitory effect of the (2S,3R,7R)-isomer from Japan and Siberia to Europe. At the eastern sites, increasing amounts of the (2S,3R,7R)-isomer up to and equal to the amount of the (2S,3S,7S )-isomer, did not influence the trap catch, whereas at sites in Europe, as little as 1% of the (2S,3R,7R)-isomer almost completely inhibited the attraction. The response of the North American population was intermediate. The only site in which the (2S,3R,7R)-isomer was essential for the attraction of males was in Siberia. A similar pattern was found for the (2S,3R,7S)-isomer. Both the acetate and the propionate form of the (2S,3S,7S)-isomer were attractive by themselves in Japan, Europe and North America, and neither the (2S,3R,7S)-isomer nor the (2S,3R,7R)-isomer alone were attractive, in the acetate or propionate form. We discuss the significance of our findings for the development of more efficient monitoring schemes and for the causes of population divergence and speciation in the European pine sawfly.     

Substrate specificity and stereospecificity of limonene-1,2-epoxide hydrolase from Rhodococcus erythropolis DCL14; an enzyme showing sequential and enantioconvergent substrate conversion

Limonene-1,2-epoxide hydrolase (LEH) from Rhodococcus erythropolis DCL14, an enzyme involved in the limonene degradation pathway of this microlorganism, has a narrow substrate specificity. Of the compounds tested, the natural substrate, limonene-1,2-epoxide, and several alicyclic and 2-methyl-1,2-epoxides (e.g. 1-methylcyclohexene oxide and indene oxide), were substrates for the enzyme. When LEH was incubated with a diastereomeric mixture of limonene-1,2-epoxide, the sequential hydrolysis of first the (1R,2S)- and then the (1S,2R)-isomer was observed. The hydrolysis of (4R)- and (4S)-limonene-1,2-epoxide resulted in, respectively, (1S,2S,4R)- and (1R,2R,4S)-limonene-1,2-diol as the sole product with a diastereomeric excess of over 98%. With all other substrates, LEH showed moderate to low enantioselectivities (E ratios between 34 and 3).     

Asymmetric Hydrolysis of (±)-α-Substituted Garboxylic Acid Esters with Microorganisms

Microorganisms that hydrolyze methyl 2-phenylpropionate (1) or reduce 4-phenyl-2-butanone (3) were screened from 250 type cultures. Several Aspergilli and two bacteria hydrolyzed ester 1, and Asp. sojae IAM 2703 preferentially hydrolyzed (R)-isomer of (±)-1, whereas Bacillus subtilis var. niger IFO 3108 and Mycobacterium smegmatis ATCC 10143 preferentially hydrolyzed (S)-isomer. The hydrolysis of the related esters of 1 with these organisms was also examined.     

Docking based design of diastereoisomeric MTCA as GPIIb/IIIa receptor inhibitor

In GPIIb/IIIa mediated arterial thrombosis platelet activation plays a central role. To discover platelet activation inhibitor the pharmacophores of GPIIb/IIIa receptor inhibitors and anti-thrombotic agents were analyzed. This led to the design of (1R,3S)- and (1S,3S)-1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acids as GPIIb/IIIa inhibitors. Comparing to (1S,3S)-isomer (1R,3S)-isomer had lower cdocker interaction energy. AFM image showed that the minimal effective concentration of (1S,3S)-isomer and (1R,3S)-isomer inhibiting platelet activation were 10^?5?M and 10^?6?M, respectively. In vivo 1?μmol/kg of oral (1S,3S)-isomer effectively inhibited the rats to form arterial thrombus and down regulated GPIIb/IIIa expression, but the activities were significantly lower than those of 1?μmol/kg of oral (1R,3S)-isomer. Both (1S,3S)-isomer and (1R,3S)-isomer can be safely used for structural modifications, but (1R,3S)-isomer should be superior to (1S,3S)-isomer.     

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.     

Screening of yeasts for cell-free production of (R)-phenylacetylcarbinol

105 yeast strains from 10 genera and 40 species were evaluated for cell-free production of (R)-phenylacetylcarbinol (PAC), the chiral precursor in the manufacture of the pharmaceuticals ephedrine and pseudoephedrine. Carboligase activity of pyruvate decarboxylase (PDC), forming PAC from benzaldehyde and pyruvate, was found in extracts of 98 strains. PAC was not formed from benzaldehyde and acetaldehyde, an activity of bacterial PDCs from Zymomonas mobilis and Zymobacter palmae. Two interesting groups of candidates were identified in the yeast screening: carboligase activities of Schizosaccharomyces pombe PDCs were very low but showed best resistance to pre-incubation with acetaldehyde and benzaldehyde; and highest carboligase activities combined with medium resistance were found in strains of Candida utilis, C. tropicalis and C. albicans.     

Pyruvate Decarboxylase Catalysed Formation of Terpenoid α-hydroxy Ketones

Enzyme extracts of the wild type yeast Zygosaccharomyces bisporus were applied for the pyruvate decarboxylase catalysed condensation of pyruvate and (R)-(+)-and (S)-(?)-perillyl aldehyde, (±)-citronellal, neral, geranial or (R)-(?)-myrtenal to form novel α-hydroxy ketones. Best yields were obtained when the transformation medium contained 25% (v/v) of the cosolvent N,N-dimethylformamide. Conversion of (R)-(+)-perillyl aldehyde to (1R)-1-hydroxy-1-[(4’R)-4’-isopropenyl-1-cyclohexen-1-yl]-2-propanone proceeded highly stereospecifically (>99% de), whereas the stereoselectivity was somewhat less in the transformation of (S)-(?)-perillyl aldehyde (58% de) and (R)-(?)-myrtenal (92% de). All of the new compounds imparted characteristic odour impressions as determined by means of GC-olfactometry.     

L-Cystathionine as a Component of Ezomycins A1 and B1 from a Streptomyces

(1R,2S)-1-(3′-Chloro-4′-methoxyphenyl)-1,2- propanediol (Trametol, 3), a metabolite of the fungus Trametes sp. IVP-F640 and Bjerkandera sp. BOS55, was synthesized by employing Sharpless asymmetric dihydroxylation as the key step. Similarly, the (1R,2S)-isomer of 1-(3′,5′-dichloro-4′-methoxyphenyl)-1,2-propanediol (4), another metabolite of Bjerkandera sp. BOS55, was synthesized by asymmetric dihydroxylation.     

Rhodococcus erythropolis DCL14 Contains a Novel Degradation Pathway for Limonene

Strain DCL14, which is able to grow on limonene as a sole source of carbon and energy, was isolated from a freshwater sediment sample. This organism was identified as a strain of Rhodococcus erythropolis by chemotaxonomic and genetic studies. R. erythropolis DCL14 also assimilated the terpenes limonene-1,2-epoxide, limonene-1,2-diol, carveol, carvone, and (−)-menthol, while perillyl alcohol was not utilized as a carbon and energy source. Induction tests with cells grown on limonene revealed that the oxygen consumption rates with limonene-1,2-epoxide, limonene-1,2-diol, 1-hydroxy-2-oxolimonene, and carveol were high. Limonene-induced cells of R. erythropolis DCL14 contained the following four novel enzymatic activities involved in the limonene degradation pathway of this microorganism: a flavin adenine dinucleotide- and NADH-dependent limonene 1,2-monooxygenase activity, a cofactor-independent limonene-1,2-epoxide hydrolase activity, a dichlorophenolindophenol-dependent limonene-1,2-diol dehydrogenase activity, and an NADPH-dependent 1-hydroxy-2-oxolimonene 1,2-monooxygenase activity. Product accumulation studies showed that (1S,2S,4R)-limonene-1,2-diol, (1S,4R)-1-hydroxy-2-oxolimonene, and (3R)-3-isopropenyl-6-oxoheptanoate were intermediates in the (4R)-limonene degradation pathway. The opposite enantiomers [(1R,2R,4S)-limonene-1,2-diol, (1R,4S)-1-hydroxy-2-oxolimonene, and (3S)-3-isopropenyl-6-oxoheptanoate] were found in the (4S)-limonene degradation pathway, while accumulation of (1R,2S,4S)-limonene-1,2-diol from (4S)-limonene was also observed. These results show that R. erythropolis DCL14 metabolizes both enantiomers of limonene via a novel degradation pathway that starts with epoxidation at the 1,2 double bond forming limonene-1,2-epoxide. This epoxide is subsequently converted to limonene-1,2-diol, 1-hydroxy-2-oxolimonene, and 7-hydroxy-4-isopropenyl-7-methyl-2-oxo-oxepanone. This lactone spontaneously rearranges to form 3-isopropenyl-6-oxoheptanoate. In the presence of coenzyme A and ATP this acid is converted further, and this finding, together with the high levels of isocitrate lyase activity in extracts of limonene-grown cells, suggests that further degradation takes place via the β-oxidation pathway.     

Steroid sapogenins from Tristagma uniflorum

From bulbs of Tristagma uniflorum the known sapogenins tigogenin, neotigogenin and (20S,22R,25S)-5α-spirostan-3β,25-diol, as well as the new (20S,22R,25R)-5α-spirostan-3β,25-diol, (20S,22S,25S)-5α-furostan-22,25-epoxy-3β,26-diol and (20S,22S,25R) -5α-furostan-22,25-epoxy-3β,26-diol, were isolated and characterized by spectroscopic (IR, ¹H NMR, ¹³C NMR, MS) methods.     

Anthranilic Acid,as a Fruiting Body Inducing Substance in Favolus arcularius,from a Strain TA 7 of Actinomycetes

The stereochemical inversion of (R)-5-hydroxymethyl-3-tert-butyl-2-oxazolidinone (la) or (R)-5-hydroxymethyl-3-isopropyl-2-oxazolidinone (lb) to the corresponding (S)-isomer was accomplished via a key intermediate, (R)-3-N-ethoxycarbonyl-N-tert-butylamino-l,2-epoxypropane (5a) or (R)-3-N-ethoxycarbonyl-N-isopropylamino-l,2-epoxypropane (5b), in a high enantiomeric excess. (S)-la (99%e.e.) or (S)-lb (91%e.e.) was thus obtained from the respective (R)-isomer (la; 99%e.e., lb; 95%e.e.).     

Configurational studies on red algae carotenoids

The configurations of (6′R)-β,ε-carotene, (3′R,6′R)-β,ε-caroten-3′-ol (α-cryptoxanthin), (3R,3′R,6′R)-β,ε-carotene-3,3′-diol (lutein), (3R)-β,β-caroten-3-ol (β-cryptoxanthin), (3R,3′R)-β,β-carotene-3,3′-diol (zeaxanthin) and all-trans (3S,5R,6S,3′R)-5,6-epoxy-5,6-dihydro-β,β-carotene-3,3′-diol (antheraxanthin) were established by CD and ¹H NMR studies. The red algal carotenoids consequently possessed chiralities at each chiral center (C-3, C-5, C-6, C-3′, C-6′), corresponding to the chiralities established for the same carotenoids in higher plants. Two post mortem artifacts from Erythrotrichia carnea were assigned the chiral structures (3S,5R,8R,3′R)-5,8-epoxy-5,8-dihydro-β,β-carotene-3,3′-diol [(8R)-mutatoxanthin] and (3S,5R,8S,3′R)-5,8-epoxy-5,8-dihydro-β,β-carotene-3,3′-diol [(8S)-mutatoxanthin]. This is the first well documented report of a naturally occurring β,ε-caroten-3′-ol (¹H NMR, CD, chemical derivatization).     

Benzaldehyde is a precursor of phenylpropylamino alkaloids as revealed by targeted metabolic profiling and comparative biochemical analyses in Ephedra spp.

Ephedrine and pseudoephedrine are phenylpropylamino alkaloids widely used in modern medicine. Some Ephedra species such as E. sinica Stapf (Ephedraceae), a widely used Chinese medicinal plant (Chinese name: Ma Huang), accumulate ephedrine alkaloids as active constituents. Other Ephedra species, such as E. foeminea Forssk. (syn. E. campylopoda C.A. Mey) lack ephedrine alkaloids and their postulated metabolic precursors 1-phenylpropane-1,2-dione and (S)-cathinone. Solid-phase microextraction analysis of freshly picked young E. sinica and E. foeminea stems revealed the presence of increased benzaldehyde levels in E. foeminea, whereas 1-phenylpropane-1,2-dione was detected only in E. sinica. Soluble protein preparations from E. sinica and E. foeminea stems catalyzed the conversion of benzaldehyde and pyruvate to (R)-phenylacetylcarbinol, (S)-phenylacetylcarbinol, (R)-2-hydroxypropiophenone (S)-2-hydroxypropiophenone and 1-phenylpropane-1,2-dione. The activity, termed benzaldehyde carboxyligase (BCL) required the presence of magnesium and thiamine pyrophosphate and was 40 times higher in E. sinica as compared to E. foeminea. The distribution patterns of BCL activity in E. sinica tissues correlates well with the distribution pattern of the ephedrine alkaloids. (S)-Cathinone reductase enzymatic activities generating (1R,2S)-norephedrine and (1S,1R)-norephedrine were significantly higher in E. sinica relative to the levels displayed by E. foeminea. Surprisingly, (1R,2S)-norephedrine N-methyltransferase activity which is a downstream enzyme in ephedrine biosynthesis was significantly higher in E. foeminea than in E. sinica. Our studies further support that benzaldehyde is the metabolic precursor to phenylpropylamino alkaloids in E. sinica.     

Biotransformation of electron-poor alkenes by yeasts: Asymmetric reduction of (4S)-(+)-carvone by yeast enoate reductases

Within the framework of a large-scale screening carried out on 146 yeasts of environmental origin, 16 strains (11% of the total) exhibited the ability to biotransform (4S)-(+)-carvone. Such positive yeasts, belonging to 14 species of 6 genera (Candida, Cryptococcus, Hanseniaspora, Kluyveromyces, Pichia and Saccharomyces), were thus used under different physiological state (growing, resting and lyophilised cells). Yields (expressed as% of biotransformation) varied from 0.14 to 30.04%, in dependence of both the strain and the physiological state of the cells. Products obtained from reduction of (4S)-(+)-carvone were 1S,4S- and 1R,4S-dihydrocarvone, (1S,2S,4S)-, (1S,2R,4S)- and (1R,2S,4S)-dihydrocarveol. Only traces of (1R,2R,4S)-dihydrocarveol were observed in a few strains. As far as the stereoselectivity of the biocatalysis, with the sole exception of a few strains, the use of yeasts determined the prevalent accumulation of 1S,4S-isomers [(1S,4S)-dihydrocarvone + (1S,2S,4S)-dihydrocarveol + (1S,2R,4S)-dihydrocarveol].The addition of glucose (acting as auxiliary substrate for cofactor-recycling system) to lyophilised yeast cells determined a considerable increase of biocatalytic activity: in particular, two strains showed a surprising increase of the% of biotransformation of (4S)-(+)-carvone (to values >98%).     

Kinetics of Pyruvate Decarboxylase Deactivation by Benzaldehyde

Based on experimental data, a kinetic model for the deactivation of partially purified pyruvate decarboxylase (PDC) by benzaldehyde (0–200 mM) in MOPS buffer (2.5 M) has been developed. An initial lag period prior to deactivation was found to occur. With first order dependencies of PDC deactivation on exposure time and on benzaldehyde concentration, a reaction time deactivation constant of 2.64×10^?3 h^?1 and a benzaldehyde deactivation coefficient of 1.98×10^?4 mM^?1 h^?1 were determined for benzaldehyde concentrations up to 200 mM. The PDC deactivation kinetic equations established in this study are an essential component in an overall model being developed to describe the enzymatic biotransformation of benzaldehyde and pyruvate to produce the pharmaceutical intermediate (R)-phenylacetylcarbinol (R-PAC).     

The absolute configuration of the acetylenic compound falcarindiol

The absolute configuration of the acetylenic compound falcarindiol is established as (3R,8S) and falcarindiol is thus (+)-(3R,8S)-(Z)-heptadeca-1,9-dien-4,6-diyn-3,8-diol. (R)-Heptadecan-8-ol and (S)-heptadecan-8- ol are synthesized and (3R,8S)-heptadecan-3,8-diol is characterized.     

Constitutional Studies on the Mucilage of “Yamanoimo,” Dioscorea batatas Decne,forma Tsukune

All four stereoisomers of 10,14-dimethyloctadec-1-ene, a sex pheromone component of the apple leafminer (Lyonetia prunifoliella: Lepidoptera), were synthesized starting from (R)- and (S)-propylene oxide by applying stereospecific inversion of chiral secondary tosylates as a key step. Field evaluation showed that male moths of the Japanese population were selectively attracted by the (10S,14S)-isomer and that the activity was not inhibited by the enantiomer.     

Dolabellane diterpenoids from Aglaia odorata

Dolabellane diterpenoids, (1R,3E,7E,10S,11S,12R)-dolabella-3,7-dien-10,18-diol (1), (1R,3S,7E,11S,12R)-dolabella-4(16),7-dien-3,18-diol (2), (1R,7E,11S,12R)-18-hydroxydolabella-4(16),7-dien-3-one (3), (1R,3S,4S,7E,11S,12R)-3,4-epoxydolabella-7-en-18-ol (4), and (1R,3R,7E,11S,12R)-dolabella-4(16),7,18-trien-3-ol (5), were obtained from the ornamental plant Aglaia odorata. Their structures were characterized on the basis of spectroscopic analyses and further confirmed by X-ray diffraction. Compounds 1 and 5 showed weak cytotoxicity against the human myeloid leukemia HL-60, hepatocellular carcinoma SMMC-7721, and lung cancer A-549 cells.     

Production of Cephalosporin Antibiotics by Strains Belonging to the Genera Arachnomyces,Anixiopsis and Spiroidium

The absolute configuration of a phytoalexin “Safynol” (3E, 11E)-3, 11-tridecadiene-5, 7, 9-triyne-l, 2-diol (I), separated from Phytophthora drechsleri-infected safflower (Carthamus tinctorius L.) was confirmed. (R) and (S)-safynol were synthesized from 2, 3-O-isopropyli- dene-(S)- and (R)-glyceraldehyde respectively, and the (R) configuration was assigned to the natural product. The inhibitory effects of (R)- and (S)-safynol on mycelial growth of five fungi were almost the same and their ED₅₀ values ranged from 6 to 70 ppm.     

4-Hydroxyisoleucine from seed of Trigonella foenum-graecum

The principal free amino acid present in seed of Trigonella foenum-graecum has been isolated and identified as (2S, 3R, 4R)-4-hydroxyisoleucine. This compound has not been reported previously as a constituent of higher plants, but it is a component of the toxic peptide, γ-amanitin, produced by Amanita phalloides. The (2S, 3R, 4R)-isomer lactonizes readily under acidic conditions, whilst strong acid causes partial epimerization. The (2R, 3R, 4R)-isomer forms a minor component of Trigonella seed. The 4-hydroxyisoleucine content of fenugreek increases during the growth of seedlings and plants, and ¹⁴C-isoIeucine was used effectively as a biosynthetic precursor.