Microchemical Reactions Research Articles

Identification of a sex pheromone component of the geometrid moth Milionia basalis pryeri

A single component in extracts of virgin female Milionia basalis pryeri moths elicited responses from male moth antennae. This compound (ca. 7 ng/female) was identified as (Z,Z)-(3S,4R)-3,4-epoxynonadeca-6,9-diene by GC-MS and NMR analyses, microchemical reactions, and comparative chiral HPLC. In a field test, synthetic (Z,Z)-(3S,4R)-3,4-epoxynonadeca-6,9-diene attracted male moths. The opposite enantiomer, the racemic mixture, and virgin female moths held in small cages attracted no more moths than the solvent controls.

Androgen and Estrogen Metabolism during Sex Differentiation in Mono-Sex Populations of the Nile Tilapia, Oreochromis niloticus

Androgen and estrogen metabolism were examined in the period of steroid sensitivity during sex differentiation in mono-sex populations of Oreochromis niloticus. Fry (XX, XY, and YY genotypes) were maintained at 28° and were sampled at 8, 10, 11, and 13 days postfertilization. Subsamples (n = 2–4) of pooled fry from each maternally distinct family were homogenized and incubated with either [3H]androstenedione or [3H]estradiol. Metabolites present in organic extracts were identified by thin-layer chromatography, microchemical reactions, and recrystallization to constant specific activity. Androstenedione was metabolized into at least seven readily identifiable compounds by all genotypes. In the XY genotype, 5β-androstane-3α,17β-diol synthesis decreased rapidly from 8 to 13 days postfertilization, with a concomitant increase in testosterone synthesis. Testosterone synthesis did not increase in the XX genotype. Testosterone synthesis in the YY genotype was intermediate to that of the XY and XX genotypes. Estrogens were not synthesized by any genotype. We hypothesize that 5β-reduction (or further hydroxylation) is a mechanism important in regulating testosterone production and subsequent sex differentiation. Results of incubations with estradiol show an age-dependent increase in metabolism which did not vary among genotypes. Metabolites synthesized included estrone and up to five unidentified compounds.

Identification of a female-specific, antennally active volatile compound of the currant stem girdler.

We identified (Z)-9-octadecen-4-olide as a female-specific, antennally active compound from the currant stem girdler Janus integer Norton. Female specificity was demonstrated by gas chromatographic comparison of liquid chromatography fractions of male and female volatile emissions and whole body extracts. The gamma-lactone was identified by coupled gas chromatographic-electroantennographic detection (GC-EAD), coupled gas chromatographic-mass spectrometric (GC-MS) analysis, microchemical reactions, and GC and MS comparison with authentic standards. GC-EAD analysis of female volatile emissions and cuticular extracts showed a single peak of activity on male antennae, which was not present in male-derived materials. Female antennae did not respond to any of the tested materials. The hydrogenation product of the natural EAD-active material was a known saturated gamma-lactone. The mass spectrum of the dimethyl disulfide derivative of the natural y -lactone was consistent with a double bond present in the 9 position. Comparison of the natural gamma-lactone and a synthesized racemic mixture of (Z)-9-octadecen-4-olide on a chiral GC column showed the presence of a single enantiomer in the natural material.

Identification of maturation-inducing steroid in a freshwater perchAnabas testudineus and differential responses of intact follicles and denuded oocytes to cyclic AMP in oocyte maturation

Postvitellogenic follicles of freshwater perch Anabas testudineus incubated with [(3)H]pregnenolone as exogenous precursor produced several metabolites, including 17 alpha, 20 beta-dihydroxy-4-pregnen-3-one (DHP) and 5 beta-pregnane-3 alpha, 17 alpha,20 beta-triol (5 beta-3 alpha,17 alpha,20 beta-P). These were identified by chromatography, microchemical reactions, and crystallization to constant specific activity. Following stimulation with fish (perch) pituitary extract (FPE) there was significant high production of DHP and 5 beta-3 alpha,17 alpha,20 beta-P, concomitant with a high percentage of germinal vesicle breakdown (GVBD). Inhibitor of steroidogenesis (trilostane) and inhibitors of protein synthesis (cycloheximide and actinomycin-D) completely blocked FPE-induced pregnenolone metabolism and oocyte maturation. The effectiveness of various C(21) steroids in inducing GVBD was examined. Results indicate that DHP was the most potent inducer of GVBD than other structurally related C(21) steroids. In intact follicles, FPE-stimulated production of DHP was shown to be mediated through the adenylate cyclase-cAMP pathway. Addition of IBMX or forskolin, which increases the endogenous cAMP level, as well as directly supplementing dbcAMP to the incubation medium, had no inhibitory effect on DHP-induced GVBD in the intact follicles. But all these agents were shown to inhibit GVBD in fully denuded oocytes. This study provides evidence that DHP, produced by postvitellogenic follicles through the adenylate cyclase-cAMP pathway, is the maturation-inducing steroid in freshwater perch and that the role played by cAMP in the induction of GVBD in intact follicles is different from that in the denuded oocytes. J. Exp. Zool. 287:294-303, 2000.

Surface Microchemical Reactions during Hydrogenated Silicon Growth Studied by In-situ ESR Technique

ABSTRACTThe in-situ ESR technique is applied to a plasma-enhanced chemical vapor deposition (PECVD) system in order to investigate the surface microchemical reactions during the growth of hydrogenated amorphous silicon (a-Si:H) and plasma treatments of H2 and Ar gases on a- Si:H. The growth model of a-Si:H and the role of H atoms on a-Si:H films are discussed using the experimental results. The recent results on the dynamic surface reactions of crystalline silicon with oxygen molecules in an ultra-high-vacuum ESR system are introduced.

SEX PHEROMONE OF THE FEMALE MOTHS CYDIA TRASIAS MEYRICK: IDENTIFICATION OF AN ACTIVE COMPONENT AND FIELD TRIALS*

Abstract An active component of the female sex pheromone of Chinese locust moth, Cydia Trash Meyrick, was identified as (E, E)‐8, 10‐dodecadienyl acetate (E8, E10–12:Ac) by GC, GC—MS analyses and microchemical reactions. The results of field trials showed that synthetic E8, E10—‐12: Ac was very attractive to the male moths.

Gonadal in Vitro Androstenedione Metabolism and Changes in Some Plasma and Gonadal Steroid Hormones during Sex Inversion of the Protandrous Sea Bass, Lates calcarifer

Steroidogenesis in the gonad of the protandrous sea bass, Lates calcarifer, was examined in vitro in spermiating testis, previtellogenic ovary, and transitional gonads. Gonadal tissues were incubated with tritiated androstenedione. Metabolites were analyzed by thin-layer chromatography, high-performance liquid chromatography, microchemical reactions, and crystallization to constant specific activity. 17β-Hydroxysteroid dehydrogenase, 5β-reductase, and 3α-hydroxysteroid dehydrogenase activities were found in all of the sex types. On the other band, 11β-hydroxysteroid dehydrogenase and 11β-hydroxylase activities were found only when testicular tissue was present, i.e., in testis and early transitional gonad. A low aromatase activity leading to estrone synthesis was detected in the previlellogenic ovary. In late transitional gonads, a major metabolite (metabolite X) was suggestively identified as a 3-ester of 17β-estradiol according to its chemical and immunological characteristics. Levels of 17β-estradiol (E2), the metabolite X, testosterone (T), and 11-ketotestosterone (11 KT) were also measured by radioimmunoassay in plasma, before (January and February) and during (March and April) the sex inversion process. Plasma E2 was virtually undetectable (means below 25 pg/ml), although higher levels of metabolite X were found in transitional fish (485 ± 432 pg/ml in March). Throughout this period, plasma levels of T and 11KT and the androgens/estrogens ratio were significantly higher in males than in transitional fish, where these levels decreased during the sex inversion period. The level of in vitro synthesis of metabolite X was high in transitional gonads, but their concentrations were very low (0.07 ± 0.09 ng of equivalent E2/g in transitional gonads against 0.22 ± 0.37 ng of equivalent E2/g in testes and 2.16 ± 2.7 ng of equivalent E2/g in ovaries).

Structural elucidation of sex pheromone components of the Geometridae Semiothisa cinerearia (Bremer et Grey) in China

AbstractAn extract from the female sex gland of Semiothisa cinerearia attracted conspecific males in field tests. A major active component was isolated from the extract and identified by GC‐MS, GC‐IR and microchemical reactions as cis‐3,4‐epoxy‐(Z,Z)‐6. 9‐heptadecadiene, which showed strong EAG response. Another minor yet important component was identified as (Z,Z,Z)‐3,6,9‐heptadecatriene.

Stereo laser micromachining of silicon

A technique has been developed for 1-μm resolution, high speed micromachining of three-dimensional (3D) silicon parts. The method, based on acousto-optic deflection of laser microchemical chlorine etching reactions, creates parts directly from a file generated with computer-aided design/computer-aided manufacturing (CAD/CAM) software. In this demonstration, 1-μm3 pixels are removed at a rate of 2×104 pixels/s. The laser-driven process relies on one of the fastest-known sustained gas/solid interface reactions, and the size- and pressure-scaling laws permit micromachining at ≳2×105 μm3/s at 10-μm resolution. This is ∼3000 times the rate of current electrodischarge matching methods. Exchange of the etchant gas for organometallic vapor precursors has permitted laser deposition of 3D platinum and cobalt metallization on the laser-etched structures. It is proposed that this approach can satisfy the need for primary patterning of 3D parts and molds for micromechanics, in analogy with two-dimensional (2D) electron-beam patterning of masks for microelectronics.

5α-Pregnane-3β,7α,17,20α- and -20β-tetrols as metabolites of progesterone and 17-hydroxyprogesterone in carp ( Cyprinus carpio) ovarian incubations

High-performance liquid chromatography and microchemical reactions identified 5α-pregnane-3β,7α,17,20β- and -20α-tetrols as final metabolic products from ovaries of the common carp, Cyprinus carpio, incubated with progesterone and 17-hydroxyprogesterone.

Characterization of red alder ectomycorrhizae: a preface to monitoring belowground ecological responses

Critical ecological research on belowground ecosystems has often been impeded because of the inability to adequately recognize ectomycorrhizal relationships, especially the abundance, diversity, and distribution of the fungus component, and the specificity of particular fungus–host combinations. Red alder, with its high degree of host specificity and paucity of fungal symbionts, provides an ideal model for studying these attributes. Eleven morphologically recognizable types of ectomycorrhizae were characterized from field-collected root material, greenhouse soil bioassays, and laboratory syntheses. Most mycobionts were basidiomycetes, as evidenced by abundant clamp connections present in the mantle and extramatrical hyphae. Seven mycobionts identified to species included Alpova diplophloeus, Thelephora terrestris, Lactarius obscuratus, Cortinarius bibulus, Laccaria laccata, Hebeloma crustuliniforme, and Paxillus involutus. Many of the ectomycorrhizae collected in the field appeared to have more than one mycobiont present in the mantle. Root tips could generally be categorized into either flexuous or succulent morphological types. The flexuous types were long, thin, indeterminate in growth, with an acute root apex, and the mantle and Hartig net in longitudinal section were not well formed near the root apex. The succulent types were short, thick, determinate in growth, with a rounded root apex, and the mantle and Hartig net in longitudinal section were well formed near the root apex. Additional characteristics important in distinguishing among red alder ectomycorrhizal types included color, extent of extramatrical hyphae development, mantle surface characteristics, and selected microchemical reactions. Mantle thickness was highly variable and not useful in characterization. Hartig net development was shallow, and regardless of mycorrhizal origin, rarely extended beyond one epidermal cell layer. Key words: ectomycorrhizae, Alnus, characterization, ecology, belowground.

Methodology in structural determination and synthesis of insect pheromone

By means of ethereal washing of insect pheromone glands of female moths, GC-MS detection along with microchemical reactions and electroantennogram (EAG) survey, six economically important insect species were targeted for pheromone identification. The discovery of a natural pheromone inhibitor, chemo-selectivity and species isolation by pheromone will be described. The modified triple bond migration and triethylamine liganded vinyl cuprate were applied for achiral pheromone synthesis in double bond formation. Some optically active pheromones and their stereoisomers were synthesized through chiral pool or asymmetric synthesis. Some examples of chiral recognition of insects towards their chiral pheromones will be discussed. A CaH2 and silica gel catalyzed Sharpless Expoxidation Reaction was found in shortening the reaction time.

Mass spectrometric determination of glycosylation sites and oligosaccharide composition of insect-expressed mouse interleukin-3

The primary structure of Baculovirus-expressed mouse interleukin-3 produced in infected Bombyx mori larvae was characterized by liquid secondary ion mass spectrometry and 252Cf-plasma desorption mass spectrometry in combination with selected protein microchemical reactions. Interleukin-3 was found to consist of at least two glycoprotein species of ca. 17 000 dalton. Characterization of tryptic and S. aureus V8 protease peptides by Edman degradation combined with plasma desorption mass spectrometry showed that two N-glycosylation sites, Asn-16 and Asn-86, were present. N-Glycan residues were shown by liquid secondary ion mass spectrometry and high-performance liquid chromatography to consist of mannose, fucose, and glucosamine. The presence of galactosamine indicated that O-glycosylated residues were present, in addition to the N-glycosylated residues. Glucose was also present, which indicated incomplete processing of the insect-expressed N-linked oligosaccharides.

Ketonic bile acids in urine of infants during the neonatal period.

Ketonic bile acids have been found to be quantitatively important in urine of healthy infants during the neonatal period. In order to determine their structures, the bile acids in urine from 11 healthy infants were analyzed by gas-liquid chromatography-mass spectrometry (GLC-MS) and three samples with particularly high levels of ketonic bile acids were selected for detailed studies by ion exchange chromatography, fast atom bombardment mass spectrometry, microchemical reactions, and GLC-MS. The major ketonic bile acid was identified as 7 alpha, 12 alpha-dihydroxy-3-oxo-5 beta-chol-1-enoic acid, not previously described as a naturally occurring bile acid. The positional isomer 7 alpha, 12 alpha-dihydroxy-3-oxo-4-cholenoic acid, recently described as a major urinary bile acid in infants with severe liver diseases, was also excreted by most infants. Three acids related to cholic acid were identified: 7 alpha, 12 alpha-dihydroxy-3-oxo-, 3 alpha, 12 alpha-dihydroxy-7-oxo-, and 3 alpha, 7 alpha-dihydroxy-12-oxo-5 beta-cholanoic acids. Five bile acids having one oxo and three hydroxy groups were also present. Based on mass spectra and biological considerations two of these were tentatively given the structures 1 beta, 7 alpha, 12 alpha-trihydroxy-3-oxo- and 1 beta, 3 alpha, 12 alpha-trihydroxy-7-oxo-5 beta-cholanoic acids. Some of the others had a hydroxy group at C-4 or C-2. The levels of ketonic bile acids were higher on the third than on the first day of life, and lower after 1 month. The formation and excretion especially of 3-oxo bile acids is proposed to result from changes of the redox state in the liver in connection with birth.

Lateral confinement of microchemical surface reactions: Effects on mass diffusion and kinetics

This paper investigates the effects of lateral confinement on the chemical kinetics of surface reactions that involve diffusive mass transport in the phase above the surface. The phenomena to be expected are illustrated by a theoretical treatment of the reaction types A+D⇄2C or B⇄A+2C, where A is a surface species, and B and C are both gaseous species. The case explored is one in which the back reaction due to the product species C is important. It is assumed that species B is the major constituent of the vapor, and remains so throughout the course of the reaction. The spatial profiles of A and C as a function of time are found by the use of a Green’s function formalism and evaluated numerically for illustrative cases. The results of the calculations provide a possible explanation of the drastic rate enhancement produced in some cases by lateral confinement resulting from the use of focused energy beams. The possibility of dramatic lateral variation of chemical kinetics due to strong concentration gradients of the product species is demonstrated. The results could have application to a broad class of transportlimited surface processing reactions confined by focused beams or by lithographic masking.

Occurrence of 3 beta-hydroxy-5-cholestenoic acid, 3 beta,7 alpha-dihydroxy-5-cholestenoic acid, and 7 alpha-hydroxy-3-oxo-4-cholestenoic acid as normal constituents in human blood.

Three unconjugated C27 bile acids were found in plasma from healthy humans. They were isolated by liquid-solid extraction and anion-exchange chromatography and were identified by gas-liquid chromatography-mass spectrometry, microchemical reactions, and ultraviolet spectroscopy as 3 beta-hydroxy-5-cholestenoic, 3 beta,7 alpha-dihydroxy-5-cholestenoic, and 7 alpha-hydroxy-3-oxo-4-cholestenoic acids. Their levels often exceeded those of the unconjugated C24 bile acids and the variations between individuals were smaller than for the C24 acids. The concentrations in plasma from 11 healthy subjects were 67.2 +/- 27.9 ng/ml (mean +/- SD) for 3 beta-hydroxy-5-cholestenoic acid, 38.9 +/- 25.6 ng/ml for 3 beta,7 alpha-dihydroxy-5-cholestenoic acid, and 81.7 +/- 27.9 ng/ml for 7 alpha-hydroxy-3-oxo-4-cholestenoic acid. The levels of the individual acids were positively correlated to each other and not to the levels of the C24 acids. The cholestenoic acids were below the detection limit (20-50 ng/ml) in bile and C27 bile acids present in bile were not detected in plasma.

Determination of geometric configuration in minute amounts of highly unsaturated termite trail pheromone by capillary gas chromatography in combination with mass spectrometry and fourier-transform infrared spectroscopy

A new method for determination of the stereochemistry of each double bond in minute amounts of highly unsaturated termite trail pheromone is discussed. Micro-chemical reactions, acetylation and partial hydrogenation of the isolated termite trail pheromone, followed by capillary gas chromatography—mass spectrometry (GC—MS) and gas chromatography—fourier-transform infrared spectroscopy analyses of the products are the main procedures employed. The number of double bonds in each partially hydrogenated peak is determined by GC—MS, and the presence or absence of a trans double bond in the corresponding total absorbance monitoring peak is determined from the infrared absorption around 970 cm−1 The structure of the termite (Reticulitermes speratus, Isoptera) trail pheromone was determined as cis-3, cis-6, trans-8-dodecatrien-1-ol.

Determination of geometric configuration in minute amounts of highly unsaturated termite trail pheromone by capillary gas chromatography in combination with mass spectrometry and fourier-transform infrared spectroscopy

A new method for determination of the stereochemistry of each double bond in minute amounts of highly unsaturated termite trail pheromone is discussed. Micro-chemical reactions, acetylation and partial hydrogenation of the isolated termite trail pheromone, followed by capillary gas chromatography—mass spectrometry (GC—MS) and gas chromatography—fourier-transform infrared spectroscopy analyses of the products are the main procedures employed. The number of double bonds in each partially hydrogenated peak is determined by GC—MS, and the presence or absence of a trans double bond in the corresponding total absorbance monitoring peak is determined from the infrared absorption around 970 cm −1 The structure of the termite ( Reticulitermes speratus, Isoptera) trail pheromone was determined as cis-3, cis-6, trans-8-dodecatrien-1-ol.

Isolation and determination of the structures of components of the sex pheromone ofPandemis ribeana

It has been shown with the aid of gas-liquid chromatography, mass spectrometry electroantennographic testing, and some microchemical reactions that the sex pheromone of females of the tortricid mothPandemis ribeana HB is a mixture of the acetates of tetradec-cis-ll-en-l-ol (I) and tetradec-trans-ll-en-l-ol (II) in a ratio of 1:1. In the tests it was found that a mixture of (I) and (II) in a ratio of 7.5:92.5, respectively, was the most attractive for females ofP. ribeana.

Ovarian metabolic pathways of steroid biosynthesis in the European eel ( Anguilla anguilla L.) at the silver stage

Ovarian slices of the European eel at the silver stage were incubated with 4 tritiated precursors (pregnenolone, progesterone, androstenedione, testosterone) in the presence or not of an inhibitor of 11β-hydroxylase activity, metopirone. Ether extracts were submitted to a gradient elution chromatography on celite columns. Isolated peaks were identified by isopolarity on TLC, microchemical reactions and recrystallization to constant specific activity. Interpretation of the results shows that the ovary of the European eel contains the following enzymes: a 3β-hydroxysteroid dehydrogenase, 5→4-ene-isomerase complex, a 17α-hydroxylase, a C 21-C 19 desmolase, a 17β-hydroxysteroid oxidoreductase, a 5α-reductase, a 3β-hydroxysteroid oxidoreductase and an aromatase complex. Metopirone effect indicates the presence of an 11β-hydroxylase activity. At this stage, 5β-reductase, 20β-reductase and 21-hydroxylase activities are not detected in the ovary. Water-soluble steroids were formed from all the precursors used. It appears that the ovarian biosynthesis is orientated towards the production of 5α-reduced compounds and that this might limit the production of 17β-estradiol by lowering the amount of disposable endogenous precursors.