Genetic structure of the Mongols as derived from the ABO, MN, Rh, EsD, GLO1, PGM1, AcP, 6-PGD, Hp, Gc, Tf, C'3 and ChE2 loci

According to integral characterization of gene frequencies of the investigated loci AB0, MN, Rh, GLO1, PGM1, EsD, AcP, 6-PGD, Hp, Tf, Gc, C'3 and ChE2, Mongolian population has high level of polymorphism, with the exception of haplotypes R" (cdE) and Ry(CdE) at the Rh locus and TfB0-1 at the Tf locus. The data on biochemical and immunological polymorphic gene markers analysed in the population of Mongolia show that the Mongolians have some distinctive features, in comparison with the mean-in-the-world characteristics: high frequencies of the B genes at the AB0 locus; D, E, R1 and R2 at the Rh locus; GLO11, PGDc, TfDChi, E2(C5+), PGM1(1+); low frequencies of the genes A(AB0), R0(Rh), AcPc, Hp1, Gc2, C'3F, PGM 1(2-); the rest of the genes at the above-mentioned loci and the genes of the locus MN have the mean-in-the-world frequencies.     

Genetic structure of the populations of native inhabitants of the northeastern USSR. IV. The Koryaks of Kamchatka

Genetic structure of four Kamchatka subpopulations (675 individuals) was estimated for 25 erytrocyte and serum systems, some blood groups and for taste sensitivity to PTC. 23 of 38 loci examined are completely monomorphic. These are: AK, Ca-1, Cat, Dia, Est1-4, GOT, G-6-PD, LDH A and B, MDH, PGM2, SoD, Hb alpha and beta, ChE1, Lap, Alb, Cp, Tf, Rh. Following allele frequencies were found for polymorphic loci: AcPA = = 0.616; AcPB = 0.383; AcPC = 0.0015; EsD1 = 0.882; GLO - I1 = 0.156; GPT1 = 0.611; PGDA = = 0.959; PGM1(1) = 0.953; ChE2+ = 0.039; Gc1 = 0.888; Hp1 = 0.173; r(0) = 0.620; P(A) = 0.201; q(B) = 0.179; le = 0.192; M = 0.397; P1+ = 0.585; t = 0.371. According to monomorphic and polymorphic loci set, Kamchatka Koryaks are rather similar to other ethnic North-East Asiatic groups, being the most approximate to Reindeer Chuckchies and the most remote from Alaskan and Asiatic Eskimos. In other words, the extent of genetic differences between Kamchatka Koryaks and North-East populations corresponds to the geographic distribution and the degree of ecological differences in these populations. Analysis of interpopulation heterogeneity permitted to reveal the extent of contribution of individual loci to "differentiation" of North-East ethnic groups. The possible influence of ecological factors on interpopulation and intersubpopulation heterogeneity of the loci analysed is discussed.     

10,20-Methanorhodopsins: (7E,9E,13E)-10,20-methanorhodopsin and (7E,9Z,13Z)-10,20-methanorhodopsin. 11-cis-locked rhodopsin analog pigments with unusual thermal and photo-stability

Synthesis of the retinal analog, 10,20-methanoretinal (R6), where the 11Z conformation is locked in a six-membered ring, yielded four stereoisomers (7E,9E,13E, 7E,9E,13Z, 7E,9Z,13E and 7E,9Z,13Z). These four isomers were separated by straight-phase isocratic HPLC and identified by 1H-NMR and NOE analysis. All isomers smoothly recombined with bovine opsin at a relatively high rate (5-10% of that of the natural chromophore 11Z-retinal). The corresponding 13E and 13Z isomers yielded identical analog pigments, probably due to rapid thermal isomerization around the C13 = C14 double bond. The (7E,9E)-isomers produced a pigment with maximal absorbance at 510 nm, while the pigment produced from the (7E,9Z)-isomers had maximal absorbance at 494 nm. Based upon kinetic considerations, the chromophore structure in the 510-nm-absorbing pigment should be (7E,9E,13E), i.e. equivalent to 11Z-retinal and rhodopsin, while the chromophore structure in the 494-nm-absorbing pigment should be (7E,9Z,13Z), i.e. equivalent to (9Z,11Z,13Z)-rhodopsin, an isorhodopsin analog. In analogy to the 11-cis-locked rhodopsin analogs Rh5 and Rh7, the 510-nm-absorbing pigment, (7E,9E,13E)-10,20-methanorhodopsin, was dubbed Rh6 and the 494-nm-absorbing pigment. (7E,9Z,13Z)-10,20-methanorhodopsin, was dubbed Iso6. The opsin shift of Rh6 (2660 cm-1) is practically identical to that of rhodopsin itself (2650 cm-1). Rh6 and Iso6 are nearly as stable as rhodopsin towards hydroxylamine and solubilization in detergent solution and could be easily purified and reconstituted into proteoliposomes by established procedures. Due to the 11-cis-lock, Rh6 is much less photolabile (bleaching rate less than 1%) than rhodopsin, but it is not completely photostable, probably since photoisomerization around the C7 = C8, C9 = C10 and C13 = C14 bonds is allowed. Illumination of either Rh6 or Iso6 does not generate the common photointermediates but instead produces a complex pattern of photochemical transitions, which during continuous illumination leads to the same final steady state, absorbing at 498 nm. This process is accompanied by a slow but steady loss of pigment, probably due to hydrolytic release of chromophore, which is markedly accelerated in the presence of hydroxylamine. In a physiological assay (light-dependent activation of rod cGMP phosphodiesterase) Rh6 is only marginally active and this probably reflects conformational changes accompanying the above-mentioned photochemical transitions. This supports the concept that normal rhodopsin-based phototransduction requires 11Z to all-E isomerization.(ABSTRACT TRUNCATED AT 400 WORDS)     

11(R),12(S),15(S)-trihydroxyeicosa-5(Z),8(Z),13(E)-trienoic acid: an endothelium-derived 15-lipoxygenase metabolite that relaxes rabbit aorta

Previous studies indicate that 11,12,15-trihydroxyeicosatrienoic acid (11,12,15-THETA), an endothelium-derived hyperpolarizing factor in the rabbit aorta, mediates a portion of the relaxation response to acetylcholine by sequential metabolism of arachidonic acid by 15-lipoxygenase, hydroperoxide isomerase, and epoxide hydrolase. To determine the stereochemical configuration of the endothelial 11,12,15-THETA, its activity and chromatographic migration were compared with activity and migration of eight chemically synthesized stereoisomers of 11,12,15(S)-THETA. Of the eight isomers, only 11(R),12(S),15(S)-trihydroxyeicosa-5(Z),8(Z),13(E)-trienoic acid comigrated with the biological 11,12,15-THETA on reverse- and normal-phase HPLC and gas chromatography. The same THETA isomer (10(-7)-10(-4) M) relaxed the rabbit aorta in a concentration-related manner (maximum relaxation = 69 +/- 5%). These relaxations were blocked by apamin (10(-7) M), an inhibitor of small-conductance Ca2+-activated K+ channels. In comparison, 11(S),12(R),15(S),5(Z),8(Z),13(E)-THETA (10(-4) M) relaxed the aorta by 22%. The other six stereoisomers were inactive in this assay. With use of the whole cell patch-clamp technique, it was shown that 10(-4) M 11(R),12(S),15(S),5(Z),8(Z),13(E)-THETA increased outward K+ current in isolated aortic smooth muscle cells by 119 +/- 36% at +60 mV, whereas 10(-4) M 11(R),12(R),15(S),5(Z),8(Z),13(E)-THETA increased outward K+ current by only 20 +/- 2%. The 11(R),12(S),15(S),5(Z),8(Z),13(E)-THETA-stimulated increase in K+ current was blocked by pretreatment with apamin. These studies suggest that 11(R),12(S),15(S)-trihydroxyeicosa-5(Z),8(Z),13(E)-trienoic acid is the active stereoisomer produced by the rabbit aorta. It relaxes smooth muscle by activating K+ channels. The specific structural and stereochemical requirements for K+ channel activation suggest that a specific binding site or receptor of 11,12,15-THETA is involved in these actions.     

Polymorphic biochemical systems in a population of newly arrived inhabitants of the northeastern USSR. IV. The characteristics of the genetic structure of persons with chronic pathological processes

Analysis of properties of the genetic structure in 2847 individuals with different chronic diseases (1261 men and 1586 women) for 14 polymorphic loci (AcP, PGM1, PGD, GPT, GLO-I, EsD, AK, Pp, E2, Hp, Gc, Tf, AB0 and Rh) is presented. Discrepancy between the observed and expected phenotype frequencies for PGM1, GLO-I, EsD and AB0 loci is observed in a sample of patients Deviation from the expected frequencies is unequal for the representatives of different sex. Male and female portions of the sample differ significantly from each other for AcP, GPT, GLO-I, AK, EsD, Tf and AB0 loci, i. e. for 7 from 14 systems analysed. Highly significant differences between healthy and sick individuals have been detected: in general samples for 8 loci (AcP, PGM1, GPT, GLO-I, AK, Pp, Hp, AB0); in men for 8 loci (AcP, GPT, AK, PGD, Pp, Tf, AB0); in women for 5 loci (PGD, Pp, Gc, Tf, AB0). The difference between sick and healthy individuals of different sex is not only of qualitative but also of quantitative expression. The difference between sick and healthy men is much stronger, as compared to that between women. A decline in the average heterozygosity is noted in sick individuals. From the results obtained it is possible to conclude that the group of different pathologic conditions for the complex of genetic parameters differs significantly from that of healthy individuals. This may be a reflection of adaptation and disadaptation processes under the extreme environmental conditions.     

Genetic structure of the populations of native inhabitants in the northeastern USSR. V. The Chukot Evens

The genetic structure of two Chukot Evens subpopulations (314 individuals) for electrophoretic protein systems and taste sensitivity to PTC was studied. 17 of the 39 loci were polymorphic (43.59%). The following systems were completely monomorphic: diaphorase NAD H (Dia); glucose-6-phosphate dehydrogenase (G-6-PD); glutamatoxalate transaminase (GOT); carbonic anhydrase (Ca-1); catalase (Ct), lactate dehydrogenase (loci LDH-A and LDH-B); leucine aminopeptidase (Lap); malate dehydrogenase (MDH); purine nucleoside phosphorylase (PNP); superoxide phosphorylase (PNP); superoxide dismutase (SOD); phosphoglucomutase-2 (PGM2); cholinesterase (locus E1); red cell esterase (4 loci); albumin (Alb); hemoglobin (Hb A and B); ceruloplasmin (Cp); and blood, gren, using the standard method. The following systems were polymorphic: red cell acid phosphatase (AcP); phosphoglucomutase-1 (PGM1); 6-phosphogluconate dehydrogenase (PGD); glutamatepyruvate transaminase (GPT); glyoxalase-1 (GLO-1); esterase (EsD); adenilatkinase (AK); alkaline phosphatase (Pp); cholinesterase (locus E2); haptoglobin (Hp); transferrin (Tf); group-specific component (Gc) and ABO, MN, Lewis, P blood groups and taste sensitivity to PTC. The following allele frequencies for polymorphic loci have been detected: AKI = 0.994; GLO = 1I = 0.082; GPT1 = 0.653; AcPA = 0.400; AcPB = 0.599; AcPC = 0.001; PGDA = 0.944; PGM1(1) = 0.906; EsD1 = 0.897; E2+ = 0.048; HpI = 0.394; GcI = 0,919; Tfc = 0.987; r(O) = 0.669; p(A) = 0.184; q(B) = 0.146; M = 0.711; Le = 0.411; P1+ = 0.521; t = 0.295. The genetic structure of Chukot Evens population is significantly nearer to that of the other ethnic groups of the North-East, in comparison with the genetic structure of Evenks of the Middle Siberia.     

Occurrence of multiple sexual chromosomes (XX/XY1Y2 and Z1Z1Z2Z2/Z1Z2W1W2) in catfishes of the genus Ancistrus (Siluriformes: Loricariidae) from the Amazon basin

Loricariid catfishes show a predominance of homomorphism in sex chromosomes, but cases of simple and multiple systems were also found. Here we describe two cases of multiple sex chromosome systems in loricariids from Brazilian Amazonia. Males of Ancistrus sp.1 "Balbina" have a modal number of 2n = 39 chromosomes, fundamental number (FN) of 78, and karyotypic formula of 27 m + 10 sm + 2 st; females have 2n = 38 chromosomes, FN = 76, and 26 m + 10 sm + 2 st. Ancistrus sp.2 "Barcelos" has 2n = 52 chromosomes for both sexes, FN = 80 for males and FN = 79 for females. Karyotypic formula is 12 m + 12 sm + 4 st + 24a for males and 11 m + 12 sm + 4st + 25a for females. The two species show different arrangements of constitutive heterochromatin blocks, which are coincident with NORs and absent in sex chromosomes. We suggest a XX/XY(1)Y(2) mechanism for Ancistrus sp.1 "Balbina", and a Z(1)Z(1)Z(2)Z(2)/Z(1)Z(2)W(1)W(2) mechanism for Ancistrus sp.2 "Barcelos". The XX/XY(1)Y(2) mechanism here reported is the second known occurrence of this type of multiple sex chromosomes for Loricariidae and the third for Neotropical fishes; the mechanism Z(1)Z(1)Z(2)Z(2)/Z(1)Z(2)W(1)W(2) represents the first record among fishes. The presence of different sex chromosome systems in Ancistrus indicates a probable independent origin and suggests that the differentiation of sex chromosomes is evolutionarily recent among species in this genus.     

Localization of Rh1(D), 2(C), 3(E), 4(c), 5(e) and 25(LW) antigens of human Rh blood groups in fetal erythrocyte membranes

The fetal erythrocyte membranes were partially solubilized with Triton X-100 at the low concentration (0.5%). The localizations of Rh1(D), 2(C), 3(E), 4(c), 5(e) and 25(LW) were investigated. Using hemagglutination inhibition assay, Rh1(D) antigen activity was observed in the Triton-treated membrane (Triton shell) containing mainly band 1, 2 (spectrin), band 5 (actin), band 4.1 and a part of band 3, while Rh2(C), 3(E), 4(c), 5(e) and 25(LW) antigens were detected in the supernatant containing band 3, 6, 2.2, 2.3 and 4.2. It is suggested that: Rh1(D) antigen would associate with cytoskeleton matrix of fetal erythrocyte membranes; Rh1(D) and Rh25(LW) antigens might be integral membrane proteins, while Rh2(C), 3(E), 4(c) and 5(e) antigens would be surface membrane proteins which are easily released from membranes by EDTA, mercaptoethanol and alkaline treatments.     

Chemistry of tris(2,4,6-trimethoxyphenyl)phosphine with rhodium(I) and iridium(I) olefin complexes

Rh(I) and Ir(I) complexes of the type [Rh(cod)(η²-TMPP)]¹⁺ (1) and M(cod)(η²-TMPP-O) (M = Rh (2), Ir (3); cod = cyclooctadiene; TMPP = tris(2,4,6-trimethoxyphenyl)phosphine; TMPP-O = mono-demethylated form of TMPP) have been isolated from reactions of [M(cod)Cl]₂ with M′BF₄ (M′ = Ag⁺, K⁺, Na⁺) followed by addition of the tertiary phosphine ligand. This chemistry is dependent on the identity of the metal, as both the cationic phosphine complex and the neutral phosphino-phenoxide compound are stable for Rh(I), whereas only the latter is stable for Ir(I). The three complexes have been characterized by IR and NMR (¹H and ³¹P) spectroscopies as well as by cyclic voltammetry. The ¹H NMR spectrum of [Rh(cod)(η²-TMPP)]¹⁺ (1) is in accord with the formula and reveals that the TMPP phenyl rings are undergoing rapid exchange between coordinated and non-coordinated modes; the corresponding spectra of 2 and 3 support free rotation about the P---C bonds of the unbound phenyl rings with no fluxionality of the bound demethylated ring. The ³¹P{¹H} NMR spectrum of the neutral species 2 exhibits a significant upfield shift with respect to the analogous cationic compound 1. This shielding is the result of improved electron donation to the metal from a phenoxide group as compared to an ether substituent. In situ addition of CO to the reaction between TMPP and [Rh(cod)Cl]₂ or [Ir(cod)Cl]₂ in the presence of M′BF₄ results in the isolation of the monocarbonyl species [Rh(TMPP)(η²-TMPP)(CO)][BF₄] (5) and the stable dicarbonyl compound [Ir(TMPP)₂(CO)₂][BF₄] (4), respectively. Single crystal X-ray data for

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. The geometry of 4 is square planar, with essentially ideal angles for the mutually trans disposed phosphine and carbonyl ligands, as found in earlier studies for the analogous Rh dicarbonyl compound. The ¹H NMR spectrum of 4 supports the assignment of magnetically equivalent phosphorus nuclei in solution. The results of this study indicate that cyclooctadiene is a particularly strong ligand for monovalent late transition metals ligated by TMPP, to the extent that it is inert with respect to substitution in the absence of π-acceptor ligands such as carbon monoxide.     

Protein subtype polymorphisms (Gc and Tf) in a Catalan population from Gerona (northeastern Spain)

The Tf and Gc polymorphic subtype variants have been examined by means of isoelectric focusing in a population sample from two subpyrenean regions in the province of Gerona (Northeast Spain). The estimated allele frequencies were Tf*C1 = 0.774, Tf*C2 = 0.167, TF*C3 = 0.055, TF*B = 0.004; Gc*1F = 0.129, Gc*1S = 0.555 and Gc*2 = 0.316. These values are in general similar to those so far reported in other Spanish populations. The comparisons between our data and those published in Spain, indicate that the present sample is closer to Barcelona than to the other groups compared.     

Structural and conformational properties of (Z)-beta-(1-naphthyl)- dehydroalanine residue

To understand how chemical structure of beta-substituted alpha, beta-dehydroalanine (particularly size and pi conjugation of beta substituent) affects conformational property, x-ray crystallographic analysis was performed on Boc-Ala-Delta(Z) Nap-Val-OMe [Boc: t-butoxycarbonyl; Delta(Z) Nap: (Z)-beta-(1-naphthyl)dehydroalanine; OMe: methoxy] having the naphthyl group as a bulky beta substituent. Single crystals were grown by slow evaporation from an ethanol solution in the triclinic space group P1 with a = 9.528 (3) A, b = 12.410(4) A, c = 5.975(2) A, alpha = 96.77(3) degrees, beta = 102. 81(2) degrees, gamma = 88.74(3) degrees, V = 684.1(4) A3, and Z = 1. Phase determination was carried out by a direct method (SHELEXS), and the final structure was refined to R = 8.1% and R(w) = 9.0% for 1964 observed reflections. The bond lengths and bond angles of the Delta(Z)Nap residue, characterized by a sp(2) hybridized C(alpha) atom, did not differ from those of other dehydroresidues such as Delta(Z) Phe, Delta(Z) Leu, and DeltaVal essentially. The peptide backbone took a type II beta-turn conformation involving an intramolecular hydrogen bond between CO(Boc) and NH(Val), similar to di- or tripeptides containing a Delta(Z) Phe or Delta(Z) Leu residue in the second positions. Here the naphthyl group was found to be nonplanar [chi(2) = 55(1) degrees ] relative to the C(alpha)==C(beta)==C(gamma) plane. The nonplanarity was supported by conformational energy calculation. The molecular packing was stabilized by two kinds of intermolecular hydrogen bonds and van der Waals interactions. Naphthyl groups were arranged in a partially overlapped face-to-face orientation with a center-to-center distance of 5.97 A. For additional information, peptide Boc-(Ala-Delta(Z) Nap-Leu)(2)-OMe was synthesized and its solution conformation was investigated by (1)H-NMR spectroscopy. The hexapeptide showed the tendency to form a 3(10)-helical conformation in solution essentially. Conformational properties of Delta(Z) Nap residue, characterized by a type II beta-turn and 3(10)-helix, were supported by a conformational energy contour map of the Delta(Z)Nap residue.     

The structure of 1,3-diphenyl-1,3-propandionatobis(triphenylantimony)diphenylrhodium(III)dibenzene

1,3-Diphenyl-1,3-propandionatobis(triphenylantimony)diphenylrhodium(III)dibenzene, [Rh(DPD)(SbPh₃)₂Ph₂]·2(C₆H₆) has been isolated as the product of the reaction between the Rh(I) complex 1,3-diphenyl-1,3-propandionatodicarbonylrhodium(I), [Rh(DPD)(CO)₂], and triphenylantimony in acetone and in n-hexane medium. The crystal and molecular structure was determined from single crystal X-ray diffractometer data. The unit cell is triclinic with a = 19.083, b = 13.167, c = 13.536 Å, α = 81.81°, β = 111.59°, γ = 100.49°, Z = 2 and space group P_$\text{1}$. The structure was refined to a R-value of 0.079 for 6637 contributing reflections. The coordination polyhedron can be described as a slightly distorted octahedron in which the Rh-atom is coordinated by two phenyl groups, two oxygen atoms of a chelate ring, which are in cis position to one another, and two antimony-atoms of the two SbPh₃ ligands, which are in trans positions.     

The structure of 2-carboxyquinolinatobis(triphenylphosphite)rhodium(I)

2-Carboxyquinolinatobis(triphenylphosphite)rhodium (I) was prepared by means of the following reaction: [Rh(Qin)(CO)₂] + 2P(OPh)₃→ [Rh(Qin)(P(OPh)₃)₂] + 2CO It crystallizes in the triclinic space groupP] witha = 12.406,b = 18.702,c = 9.547 Å, α = 76.36, β = 111.35, γ = 97.88^o and Z = 2. The structure was determined from 4520 observed reflections. the final R value was 0.051. The RhP bond distances may indicate (although the difference is only about 3σ) that the nitrogen atom the chelate ring has the largest trans influence. The chelate ring is significantly folded along the N---O axis.     

Preliminary crystallographic data for plastocyanins from an alga (Enteromorpha prolifera) and from cucumber (Cucumis sativus)

The plastocyanins from a green alga (Enteromorpha prolifera) and cucumber (Cucumis sativus) have been crystallized. Crystal data are as follows: E. prolifera plastocyanin, space group I4, a = b = 53.9 A, c = 59.4 A, Z = 8; C. sativus plastocyanin, space group P4(1) (or P4(3) ), a = b = 66.7 A, c = 46.0 A, Z = 8. Accordingly, the asymmetric units of the crystals contain one and two molecules, respectively.     

Distribution of ABO, MN, Rh blood groups and Hp, Tr, Gc and C3 serum factors in the Buryat population

Polymorphism of blood groups ABO, MN, Rh and serum proteins Hp, Tf, Gc, C3 was studied in Buryat populations of Zabaikalie, Pribaikalie, Olkhon island. No indication of significant heterogeneity was observed. Gene frequencies varied in different systems within the ranges: ABO (p-0.142-0.183; q-0.205-0.324; r-0.567-0.630); MN (m-0.531-0.624), Rh(d) (0-0.214), Hp (Hp 1-0.268-0.339), C3 (C3F-0.023-0.090), Tf (TfC-0.971-1.0), Gc (Gc1-0.728-0.840). Genetic distances between main Buryat groups were estimated.     

Linkage relationships among 20 genetic markers in cattle. Evidence for linkage between two pairs of blood group systems: B-Z and S-F/V respectively

Five bovine paternal half-sib pedigrees for a total of 527 individuals were typed for six blood group systems: A, B, F/V, L, S, Z; for nine biochemical polymorphisms: ADA, MPI, PGM-3(slow), NP, Gc, Pi2, Tf, Ptf1 and Ptf2; and for restriction fragment length polymorphisms at five autosomal loci: Tg, GH, LDLr, BoLA-DQ and BoLA-DY. Two of the pedigrees were informative for segregation at the 'muscular hypertrophy' locus, and one was informative at the coat colour determining 'roan' locus. Linkage analysis was performed between all markers. Linkage was demonstrated between the S and F/V blood group systems (z = 3.11), adding one locus to the previously identified linkage group VII (LGVII) [Pi-2 and S], the most likely order being Pi2-S-F/V with maximum likelihood recombination rates of 0.208 and 0.211. Also shown to be linked were the blood group systems B and Z (z = 5.7, theta = 0.245). We confirmed the observation previously made by Andersson et al. (1988) of a high recombination rate between class II genes DQ and DY, suggesting either a larger physical distance between those genes than expected from comparative data, or the presence of a 'recombinational hotspot' in the bovine major histocompatibility complex. No linkage was found either with the 'muscular hypertrophy' locus, or with the 'roan' locus. However, these two loci could be excluded from respectively 1.7 and 2.5 Morgans of the bovine genome.     

Simple sequence repeat (SSR) markers linked to E1, E3, E4, and E7 maturity genes in soybean.

Soybean near isogenic lines (NILs), contrasting for maturity and photoperiod sensitivity loci, were genotyped with approximately 430 mapped simple sequence repeats (SSRs), also known as microsatellite markers. By analysis of allele distributions across the NILs, it was possible to confirm the map location of the Dt1 indeterminate growth locus, to refine the SSR mapping of the T tawny pubescence locus, to map E1 and E3 maturity loci with molecular markers, and to map the E4 and E7 maturity loci for the first time. Molecular markers flanking these loci are now available for marker-assisted breeding for these traits. Analysis of map locations identified a putative homologous relationship among four chromosomal regions; one in the middle of linkage group (LG) C2 carrying E1 and E7, one on LG I carrying E4, one at the top of LG C2, at which there is a reproductive period quantitative trait locus (QTL), and the fourth on LG B1. Other evidence suggests that homology also exists between the E1 + E7 region on LG C2 and a region on LG L linked to a pod maturity QTL. Homology relationships predict possible locations in the soybean genome of additional maturity loci, as well as which maturity loci may share a common evolutionary origin and similar mechanism(s) of action.     

Sequential substitution of 1,2-dichloro-ethene: a convenient stereoselective route to (9Z,11E)-, (10E,12Z)- and (10Z,12Z)-

Conjugated linoleic acid (CLA) isomers are present in human foods derived from milk or ruminant meat. To study their metabolism, (9Z,11E)-, (10E,12Z)- and (10Z,12Z)-[1-(14)C]-octadecadienoic acids with high radiochemical and isomeric purities (>98%) were prepared by stereoselective multi-step syntheses involving sequential substitution of 1,2-dichloro-ethene. In the case of the (9Z,11E) isomer, a first metal-catalyzed cross-coupling reaction between (E)-1,2-dichloro-ethene and 2-non-8-ynyloxy-tetrahydro-pyran, obtained from 7-bromo-heptan-1-ol, gave a conjugated chloroenyne. A second coupling reaction with hexylmagnesium bromide provided a heptadecenynyl derivative. Stereoselective reduction of the triple bond and bromination afforded (7E,9Z)-17-bromo-heptadeca-7,9-diene. Formation of the Grignard reagent and carbonation with 14CO(2) gave (9Z,11E)-[1-(14)C]-octadeca-9,11-dienoic acid (overall yield from 7-bromo-heptan-1-ol, 14.4%). (10E,12Z)- and (10Z,12Z)-[1-(14)C]-octadeca-10,12-dienoic acids were synthesized by the same methodology using 1-heptyne, 8-bromo-octan-1-ol and, respectively, (E)-1,2-dichloro-ethene and its (Z) isomer (overall yield from 8-bromo-octan-1-ol, 13.1% (10E,12Z); 17.2% (10Z,12Z)). Impurities (<2% if present) were identified as being (E,E) CLA isomers and were removed by RP-HPLC. Metabolism studies in animal are in progress.     

(E)-3-Cyanophosphoenolpyruvate, a new inhibitor of phosphoenolpyruvate-dependent enzymes

(E)-3-Cyanophosphoenolpyruvate has been synthesized by reacting dimethyl chlorophosphate with the potassium enolate of ethyl cyanopyruvate. The resulting trialkyl ester was deesterified with bromotrimethylsilane followed by potassium hydroxide. Subsequent treatment with Dowex-50-H+ resin and cyclohexylamine afforded the tricyclohexylammonium salt; only the E geometric isomer was obtained. This compound can be photoisomerized to a 70:30 E:Z mixture. (E)-3-Cyanophosphoenolpyruvate is an excellent competitive inhibitor of phosphoenolpyruvate carboxylase [KI(Mn2+) = 16 microM, KI(Mg2+) = 1360 microM], pyruvate kinase [KI(Mn2+) = 0.085 microM, KI(Mg2+) = 0.76 microM], and enolase [KI(Mn2+) = 360 microM, KI(Mg2+) = 280 microM]. The compound is a substrate for pyruvate kinase (Vmax approximately 1% of phosphoenolpyruvate rate), but not for the other two enzymes. No irreversible inactivation is observed with phosphoenolpyruvate carboxylase of pyruvate kinase.     

Stereoselective synthesis of (6Z,10E,12Z)-octadeca-6,10,12-trienoic acid, (8Z,12E,14Z)-eicosa-8,12,14-trienoic acid,and their [1-14C]-radiolabeled analogs

To study the metabolic fate of conjugated linoleic acid isomers, we synthesized, in seven steps, from 1-heptyne, (6Z,10E,12Z)-octadeca-6,10,12-trienoic acid, (8Z,12E,14Z)-eicosa-8,12,14-trienoic acid, and their [1-(14)C]-analogs. In the case of (6Z,10E,12Z)-octadecatrienoic acid, a series of palladium-catalyzed cross-coupling reactions between 1-heptyne and (E)-1,2-dichloro-ethene, a coupling reaction with a Grignard reagent and cleavage of the dioxolane gave (E)-dodec-4-en-6-ynal 3. Stereoselective Wittig reaction between aldehyde 3 and triphenyl-[5-(tetrahydro-pyran-2-yloxy)-pentyl]-phosphonium provided a dienyne. Stereocontrolled reduction of the triple bond and replacement of the tetrahydropyranyl group by a bromine gave (5Z,9E,11Z)-1-bromo-heptadeca-5,9,11-triene 10. Formation of the alkenyl lithium derivative and carbonation with CO(2) furnished (6Z,10E,12Z)-octadecatrienoic acid. (8Z,12E,14Z)-eicosa-8,12,14-trienoic acid was obtained by the same route but using triphenyl-[5-(tetrahydro-pyran-2-yloxy)-heptyl]-phosphonium iodide for the Wittig reaction. [1-(14)C]-analogs were obtained from the bromides by carbonation with (14)CO2. In all cases, chemical or radiochemical purities were found to be better than 95% after purification by flash chromatography on silica gel (>99% after additional purification by RP-HPLC). Metabolism studies in animals are in progress.