Optimum neighborhood seed orchard design

Original seed orchard algorithm “Optimum Neighborhood Seed Orchard Design” was developed as local heuristics to facilitate the establishment of advanced-generation seed orchards with complex configurations. The scheme leads to uniform spatial distribution among adjacent genetic entries, promoting panmixia. The resulting scheme is thus suitable to establishing both productive seed orchards as well as clonal archives of threatened species, etc. Further, it can accommodate variable clonal sizes, uneven grids, relatedness, assortative mating. It may supplement existing layouts (clonal rows, etc.). Layouts outperformed existing advanced-generation alternative schemes in most parameters and thus could be recommended to operational forestry and gene conservation management.     

Synthesis of (R)-2-trimethylsilyl-2-hydroxyl-propionitrile catalyzed by (R)-hydroxynitrile lyase from Prunus japonica seed meal

Synthesis of (R)-2-trimethylsilyl-2-hydroxyl-propionitrile via asymmetric transcyanation of acetyltrimethylsilane with acetone cyanohydrin in an aqueous/organic biphasic system catalyzed by (R)-hydroxynitrile lyase from Prunus japonica seed meal was successfully carried out for the first time. The optimal volume ratio of aqueous to organic phase, buffer pH value and reaction temperature were 15% (v/v), 5.0 and 30°C, respectively, under which both substrate conversion and product enantiomeric excess (ee) were 99%. Silicon atom in the substrate showed great effect on the reaction. Acetyltrimethylsilane was a much better substrate for (R)-hydroxynitrile lyase from Prunus japonica than its carbon analogue.     

Synthesis of (R)-2-trimethylsilyl-2-hydroxyl-propionitrile catalyzed by (R)-hydroxynitrile lyase from Prunus japonica seed meal

Synthesis of (R)-2-trimethylsilyl-2-hydroxyl-propionitrile via asymmetric transcyanation of acetyltrimethylsilane with acetone cyanohydrin in an aqueous/organic biphasic system catalyzed by (R)-hydroxynitrile lyase from Prunus japonica seed meal was successfully carried out for the first time. The optimal volume ratio of aqueous to organic phase, buffer pH value and reaction temperature were 15% (v/v), 5.0 and 30°C, respectively, under which both substrate conversion and product enantiomeric excess (ee) were 99%. Silicon atom in the substrate showed great effect on the reaction. Acetyltrimethylsilane was a much better substrate for (R)-hydroxynitrile lyase from Prunus japonica than its carbon analogue.     

Analogues of 2-crotonyloxymethyl-(4R,5R,6R)-4,5,6-trihydroxycyclohex-2-enone (COTC) with anti-tumor properties

The syntheses of three novel analogues of the naturally occurring cytotoxic agent COTC are described and the results of bioassays of the target compounds against two lung cancer cell lines are presented.     

Short and efficient synthesis of (2S,3R,4R,5R) and (2S,3R,4R,5S)-tetrahydroxyazepanes via the Henry reaction

The Henry reaction with the easily available alpha-d-xylo-pentodialdose afforded a diastereomeric mixture of nitroaldoses with the alpha-d-gluco- and beta-l-ido-configuration, respectively, in good yield. When n-BuLi was used as the base, the reaction afforded the alpha-d-gluco-nitroaldose as the only product. The reduction of the nitro group in the alpha-d-gluco- and beta-l-ido-nitroaldoses, removal of the protecting groups and intramolecular reductive cyclo-amination afforded the corresponding (2S,3R,4R,5R) and (2S,3R,4R,5S) tetrahydroxyazepanes.     

Synthesis of (2R,5S)-dihydroxymethyl-(3R,4R)-dihydroxypyrrolidine (DGDP) via stereoselective amination using chlorosulfonyl isocyanate

A stereoselective approach for synthesizing (2R,5S)-dihydroxymethyl-(3R,4R)-dihydroxypyrrolidine 1 (2,5-dideoxy-2,5-imino-d-glucitol, DGDP) was achieved using a seven-step approach starting from 2,3,4,6-tetra-O-benzyl-d-mannose (7). Key steps for the preparation of the title compound 1 involved the regioselective and diastereoselective amination of the cinnamyl anti-1,2-polybenzyl ethers 5 and 6 using chlorosulfonyl isocyanate (CSI) and ring cyclization to form the pyrrolidine ring. The reaction between anti-1,2-polybenzyl ether 5 and CSI in toluene at 0 degrees C afforded the corresponding anti-1,2-amino alcohol 4 as a major product with a diastereoselectivity of 16:1 in 76% yield. The mechanism underlying these reactions may be explained by the neighboring-group effect leading to the retention of stereochemistry.     

Practical access to the proline analogs (S,S,S)- and (R,R,R)-2-methyloctahydroindole-2-carboxylic acids by HPLC enantioseparation

An efficient methodology for the preparation of the α‐tetrasubstituted proline analog (S,S,S)‐2‐methyloctahydroindole‐2‐carboxylic acid, (S,S,S)‐(αMe)Oic, and its enantiomer, (R,R,R)‐(αMe)Oic, has been developed. Starting from easily available substrates and through simple transformations, a racemic precursor has been synthesized in excellent yield and further subjected to HPLC resolution using a cellulose‐derived chiral stationary phase. Specifically, a semipreparative (250 mm × 20 mm ID) Chiralpak® IC column has allowed the efficient resolution of more than 4 g of racemate using a mixture of n‐hexane/tert‐butyl methyl ether/2‐propanol as the eluent. Multigram quantities of the target amino acids have been isolated in enantiomerically pure form and suitably protected for incorporation into peptides. Chirality, 2011. © 2011 Wiley‐Liss, Inc.     

Synthesis of enantiomerically pure trans-(1R,2R)- and cis-(1S,2R)-1-amino-2-indanol by lipase and omega-transaminase

Syntheses of trans-(1R,2R) and cis-(1S,2R)-1-amino-2-indanol (AI) were accomplished by a series of enantioselective enzymatic reactions using lipase and transaminase (TA). Lipase catalysed enantioselective hydrolysis of 2-acetoxyindanone was employed to prepare (R)-2-hydroxy indanone (HI). trans-AI (5 mM) (de > 98%) was produced from 20 mM (R)-2- HI using omega-TA and 50 mM (S)-1-aminoindan as an amino donor in water-saturated ethyl acetate. For the production of cis-AI, the diastereomeric (2R)-AI was synthesized from (R)-2-HI using reductive amination, and the kinetic resolution was performed with omega-TA. The enantioselectivity of omega-TA for (2R)-AI was increased to 22.1 in the presence of 5% gamma-cyclodextrin. cis-AI (15.4 mM) (96% de) was obtained from 40 mM (2R)-AI using 30 mM pyruvate and omega-TA (25 mg) in 10 mL of 100 mM phosphate buffer (pH 7.0).     

Synthesis and antiproliferative activity of (2R,3R)-disubstituted tetrahydropyrans

In this study, we synthesized a series of enantiomerically pure (2R,3R)-disubstituted tetrahydropyrans with diverse functional groups. The in vitro antiproliferative activities were examined in the human solid tumor cell lines A2780 (ovarian cancer), SW1573 (non-small cell lung cancer), and WiDr (colon cancer). Overall, the results show the relevance for antiproliferative activity of the alpha,beta-unsaturated ester side chain at position 2 of the THP ring.     

Facile synthesis of (R)N-2-hydroxyacyl-L-cysteine derivatives: (R)N-2-hydroxyacyl transfer from enzymatically-synthesized (R)S-2-hydroxyacylglutathione derivatives to L-cysteine

Summary N-(R)-2-Hydroxyacyl-L-cysteine derivatives were conveniently synthesized by the reaction of the corresponding S-(R)-2-hydroxyacyl-glutathione with cysteine. The (R)2-hydroxyacyl group was transferred from the S-glutathionyl moiety to S-cysteinyl, forming the corresponding (R)S-2-hydroxyacylcysteine; this rearranged to the (R)N-hydroxyacylcysteine. These compounds have anti-proliferative activity associated with the inhibition ofde novo pyrimidine synthesis.Abbreviations TRIS tris(hydroxymethyl) aminomethane - DTNB 5,5-dithiobis(2-nitrobenzoic acid)     

(1′R,2′S,5′R)-Menthyl-(5R)-acetoxy-1,3-oxathiolan-(2R)-carboxylate: Synthesis and isomeric purity determination by HPLC

Chemoselective reduction of one isomer of the 1-menthylester of 1,3-oxathiolan-5-one-2-carboxylic acid produces a mixture of four lactol diastereomers from which the title compound was isolated after acylation. The isomeric purity and absolute stereochemistry were determined by spectroscopic methods, chiral HPLC techniques, and conversion to (?)-2′-deoxy-3′-thiacytidine (Lamivudine, 3TC^TM). © 1994 Wiley-Liss, Inc.     

(2R,3S)-(+)- and (2S,3R)-(-)-Halofuginone lactate: synthesis, absolute configuration, and activity against Cryptosporidium parvum

The trans-enantiomers of the commercially important anti-protozoal compound Halofuginone have been prepared and characterized, and the absolute configuration was assigned by X-ray crystallography. The activity of both enantiomers against Cryptosporidium parvum was determined in vitro and related to acute toxicity in vivo. It was shown that both the activity and the toxicity are properties of the (2R,3S)-enantiomer. We conclude that with respect to broadening the therapeutic window there is no advantage in application of one enantiomer over the application of the racemic mixture in the treatment of C. parvum infections.     

Rare carotenoids, (3R)-saproxanthin and (3R,2'S)-myxol, isolated from novel marine bacteria (Flavobacteriaceae) and their antioxidative activities

We isolated three orange or yellow pigment-producing marine bacteria, strains 04OKA-13-27 (MBIC08261), 04OKA-17-12 (MBIC08260), and YM6-073 (MBIC06409), off the coast of Okinawa Prefecture in Japan. These strains were classified as novel species of the family Flavobacteriaceae based on their 16S rRNA gene sequence. They were cultured, and the major carotenoids produced were purified by chromatographic methods. Their structures were determined by spectral data to be (3R)-saproxanthin (strain 04OKA-13-27), (3R,2'S)-myxol (strain YM6-073), and (3R,3'R)-zeaxanthin (strains YM6-073 and 04OKA-17-12). Saproxanthin and myxol, which are monocyclic carotenoids rarely found in nature, demonstrated significant antioxidative activities against lipid peroxidation in the rat brain homogenate model and a neuro-protective effect from L-glutamate toxicity.     

Effects of male fecundity, interindividual distance and anisotropic pollen dispersal on mating success in a Scots pine (Pinus sylvestris) seed orchard

Quantifying the effect of pollen dispersal and flowering traits on mating success is essential for understanding evolutionary responses to changing environments and establishing strategies for forest tree breeding. This study examined, quantitatively, the effects of male fecundity, interindividual distance and anisotropic pollen dispersal on the mating success of Scots pine (Pinus sylvestris), utilizing a well-mapped Scots pine seed orchard. Paternity analysis of 1021 seeds sampled from 87 trees representing 28 clones showed that 53% of the seeds had at least one potential pollen parent within the orchard. Pronounced variation in paternal contribution was observed among clones. Variations in pollen production explained up to 78% of the variation in mating success, which was 11.2 times greater for clones producing the largest amount of pollen than for clones producing the least pollen. Mating success also varied with intertree distance and direction, which explained up to 28% of the variance. Fertilization between neighboring trees 2.3 m apart was 2.4 times more frequent than between trees 4.6 m apart, and up to 12.4 times higher for trees downwind of the presumed prevailing wind direction than for upwind trees. The effective number of pollen donors recorded in the seed orchard (12.2) was smaller than the theoretical expectation (19.7). Based on the empirical observations, a mating model that best describes the gene dispersal pattern in clonal seed orchards was constructed.     

Synthesis of 2(R),3-dihydroxypropyl and 2(R),3(R)-dihydroxybutyl beta-D-fructopyranosides and some derivatives

The synthesis of 2(R),3-dihydroxypropyl and 2(R),3(R)-dihydroxybutyl β-d-fructopyranosides, and some derivatives, employing Sharpless-type catalytic asymmetric dihydroxylation procedures is described. Some aspects of the reactions, including stereoselectivities and chemical evidence for the assigned stereochemistry of the main products are reported.     

Arene cis-dihydrodiols: useful precursors for the preparation of analogues of the anti-tumour agent, 2-crotonyloxymethyl-(4R,5R,6R)-4,5,6-trihydroxycyclohex-2-enone (COTC)

The synthesis of 6-epi-COTC, a diastereoisomer of Streptomyces metabolite 2-crotonyloxymethyl-(4R,5R,6R)-4,5,6-trihydroxycyclohex-2-enone (COTC), is described. The anti-cancer activities of the novel analogue, in racemic and enantiomerically pure forms, are presented.     

Mating patterns and pollen dispersal in a Japanese larch(Larix kaempferi) clonal seed orchard: a case study

Pollination dynamics highly determines the genetic quality of seed orchard crops. However, there is less research about the effect of mating patterns on seed productivity of orchard crops. So far, clonal seed orchards have been producing genetically improved seedlings used for most Japanese larch(Larix kaempferi(Lamb.) Carr.) plantations in China. In the present study, a total of 17 highly variable simple sequence repeat(SSR) markers were used for genotyping a progeny trial population consisting of 647 open-pollinated progenies germinated from seeds which were collected from 63 maternal clones with 140 potential paternal clones in a Japanese larch clonal seed orchard in China. Paternity analysis was used in the present case study in order to evaluate the level of paternal gametic contribution, estimate pollen contamination and selfing rates, and investigate pollination patterns,pollen dispersal patterns and the impact of mating patterns on seed productivity of orchard crops. We observed 93.7% of the success rate of the parental assignment, unequal paternal gametic contribution(0–12.4%) with 6.3% of the progenies derived from pollen contamination or unsampled pollen donors, and absence of evidence for selfing. We also found that pollination rate highly depended on the distance between pollen donors and maternal parents, the majority of the identified crossing(65.7%)occurred between clones within a 150-m radius, and large variations in growth performance existed among the paternal halfsiblings. Progeny growth performance(diameter at breast(DBH) and height(HGT)) was measured at Age-20 in order to investigate the impact of mating patterns on timber production of orchard crops. As either the paternal or maternal, two clones(i.e., clones Z38 and Z62) were identified to have produced progenies with higher average stem volume breeding values than that of all of the progenies. Specifically, the genetic gains for volume were 3.53% for the two clones as paternal parents, and 8.26% as the maternal parents at Age-20. Thus, both elite clones were ideal candidates for the construction of next-generation clonal seed orchards due to their synchronous reproductive phenology with greater crossing rate and higher genetic gain. These results improved the pedigree information to provide solid evidence of mating patterns for future design and effective management of seed orchards and for the development of viable long-term breeding strategies for other coniferous species.