Poduction of Biotin by Microbial Transformation of dl-cis-Tetrahydro-2-oxo-4-n-pentyl-thieno-(3,4-d)-imidazoline (dl-TOPTI)

The conditions for biotin production were investigated. Urea was a more effective nitrogen source than ammonium chloride and ammonium sulfate. About 60% conversion from dl-cis-tetrahydro-2-oxo-4-n-pentyl-thieno-(3,4-d)-imidazoline (dl-TOPTI) to biotinol and biotin occurred using Corynebacterium sp. B–321. Strain M–6318 which derived from B–321 as a mutant incapable of assimilating n-alkane produced large amounts of dl-biotin from dl-TOPTI. The inability of the microbe to assimilate n-alkane resulted in repression of biotin degradation. Maximum conversion (80%) was obtained by growing cultures of strain M–6318 in the constant presence of n-paraffin.     

Formation of 2-(5-Hyclroxymethyl-2-formylpyrrol-1-yl)alkyl Acid Lactones on Roasting Alkyl-α-amino Acid with d-Glucose

d-Glucose and several alkyl-α-amino acids (glycine, dl-α-alanine, dl-α-amino-n-butyric acid, l-valine, l-leucine and dl-α-amino-n-caproic acid) were roasted at 200°C or 250°C in a simple two components system. From the roasting products were newly isolated a series of 2-(5-hydroxymethyl-2-formylpyrrol-1-yl)alkyl acid lactones which were characterized by elementary analysis, UV, IR, MS (GC-MS) and NMR spectra.

These lactones have characteristic aroma which may contribute to the flavor produced by sugar-amino acid reaction. The subjective evaluation of aroma of the lactones obtained wrere as follows: 2-(5-hydroxymethyl-2-formyipyrrol-1-yl)propionic acid lactone, caramel and a little scorching; -n-butyric acid lactone, maple and strong sweet; isovaleric acid lactone and isocaproic acid lactone, miso, soy sauce and a little chocolate-like.     

Microbial Resolution of Racemic Carvomenthols

By selected microorganisms dl-carvomenthyl acetate, dl-isocarvomenthyl acetate and dl-neo isocarvomenthyl acetate were asymmetrically hydrolyzed to l-carvomenthol with d-carvomenthyl acetate, l-isocarvomenthol with d-isocarvomenthyl acetate and d-neo isocarvomenthol with l-neo isocarvomenthyl acetate respectively; dl-neo carvomenthyl acetate was not hydrolyzed.     

Biogeographic Variation of Foliar n‐Alkanes of Juniperus communis var. saxatilis Pallas from the Balkans

The composition of the epicuticular n‐alkanes isolated from the leaves of ten populations of Juniperus communis L. var. saxatilis Pallas from central (continental) and western (coastal) areas of the Balkan Peninsula was characterized by GC‐FID and GC/MS analyses. In the leaf waxes, 14 n‐alkane homologues with chain‐lengths ranging from C₂₂ to C₃₅ were identified. All samples were dominated by n‐tritriacontane (C₃₃), but differences in two other dominant n‐alkanes allowed separating the coastal from the continental populations. Several statistical methods (ANOVA, principal component, discriminant, and cluster analyses as well as the Mantel test) were deployed to analyze the diversity and variability of the epicuticular‐leaf‐n‐alkane patterns of the ten natural populations of J. communis var. saxatilis and their relation to different geographic and bioclimatic parameters. Cluster analysis showed a high correlation of the leaf‐n‐alkane patterns with the geographical distribution of the investigated samples, differentiating the coastal from the continental populations of this taxon. Several bioclimatic parameters related to aridity were highly correlated with this differentiation.     

The study of renin–angiotensin–aldosterone in experimental diabetes mellitus

It is generally accepted that hypertension and other vascular pathologies increase in diabetes mellitus (DM) patients as a result of the renin–angiotensin–aldosterone (RAA) system. In this study, changes in the renin‐angiotensin‐aldosterone (RAA) system level was determined in Streptozotocin (STZ)‐injected rats. A total of 46 female Wistar albino rats (180–220 g body weight) was utilized in these experiments. STZ was given intraperitoneally to induce diabetes in rats. Streptozotocin (60 mg kg⁻¹ body weight) was dissolved in 0·1 m citrate–‐phosphate buffer (pH 4–5). The non‐diabetic rats were injected with sterilized buffer alone to act as a control group. Blood glucose levels were 398±8·2 mg dl⁻¹, 488±11·75 mg dl⁻¹ and 658±29·6 mg dl⁻¹ at days 3, 12 and 30 respectively. The level of plasma renin activity (PRA) was measured as 7·69±1·07 ng ml⁻¹ h⁻¹; 1·82±0·22 ng ml⁻¹ h⁻¹ and 0·67±0·12 ng ml⁻¹ h⁻¹ at days 3, 12 and 30, respectively. These values showed that the PRA levels are decreased with increased time period. Serum angiotensin converting enzyme (ACE, E.C. 3.4.15.1) levels were increased at days 12 and 30 (p<0·05 and p<0·005), whereas serum aldosterone levels were increased at days 3 and 12 (p<0·05). The level of urea and creatinine increased at days 12 and 30 (p<0·05 and p<0·005, respectively) when compared to the control group. The data from these experiments indicate that the PRA level decreased whereas ACE activity level increased in diabetic rats compared with the control. Aldosterone levels increased at the first stage of the experiment, but then decreased by the end of the experiment as a result of changes in renin and ACE levels. Copyright © 1999 John Wiley & Sons, Ltd.     

Fragility of Erythrocytes from Chicks and Rats Fed Dilauryl Succinate and Related Compounds

Susceptibility to hydrogen peroxide of the erythrocytes from chicks and rats fed dilauryl succinate and related compounds with and without supplementation of dl-α-tocopheryl acetate was determined.

Dilauryl succinate, lauryl alcohol, n-decyI alcohol, myristyl alcohol, and lauraldehyde were confirmed to make the erythrocytes from the chicks fragile. Supplemented dl-α-tocopheryl acetate of 200 mg per kg of diet completely prevented the hemolysis induced by these compounds. Dilauryl succinate also makes the rat’s erythrocytes fragile and supplemented dl-α-tocopheryl acetate prevented the hemolysis of the rats, but ethoxyquin was not. The symptoms of encephalomalacia in the chick is preceded by increased hemolysis value of the erythrocytes, and this hemolysis value dropped after the appearance of encephalomalacia.     

Studies on dl-Alanine Formation by Thermophilic Bacteria

During the course of the screening of thermophilic microorganisms, several strains were found to accumulate amino-acids. Of those strains that were isolated from feces source with Bennett medium, one strain was found to produce a large amount of an amino acid. This amino acid was isolated in crystalline form and identified as dl-alanine by IR absorption spectrum, specific rotatory power and elementary analysis. The taxonomic studies were carried out and this strain was identified as Bacillus coagulans. The strain B. coagulans B₉-17 produced dl-alanine as much as 1000 mg/l after 24 hours at 50°C in shake culture.

The yield of dl-alanine was increased up to 16.5 g/l with some improvements.     

Ribonucleic Acid Metabolism in Germinating Soybeans

A stereoselective synthesis of methyl trans, trans-farnesoate (I) from isoprenyl bromide and geraniol is described. dl-C₁₇-Cecropia juvenile hormone (IV) was synthesized from it in a stereoselective manner.     

Utilization of Hydrocarbons by Microorganisms

As already reported, Corynebacterium hydrocarboclastus S10B1 was able to accumulate a good deal of l-glutamate in a thiamine-deficient medium at the sole expense of n-alkanes, but unable to form l-glutamate in a thiamine-sufficient medium though an abundant cell growth was observed.

α-Ketoglutaric acid and dl-alanine were found to be produced in the same thiamine-deficient medium in which l-glutamate was accumulated. Both products formed from n-tetradecane by this organism were isolated from culture broth, purified and identified. The optimum concentration of thiamine in the culture medium was 3 to 5 µg per liter for their production. The maximum yields of α-ketoglutaric acid and dl-alanine reached 16 g and 1.5 g per liter in the calcium carbonate-added medium, respectively. However, the addition of more than 30 μg per liter of thiamine extremely repressed their accumulation.     

Modelling of Structural and Vibrational Properties of Poly(p-Phenylene) and Polypyrrole Using Molecular Orbital Methods

Abstract

This paper concentrates on two very important conducting polymers poly(p-phenylene) and polypyrrole. Detailed atomistic molecular models have been developed with the help of ab initio and semi-empirical quantum mechanical calculations using the Cerius² and WinMOPAC (version 6.0) programs.

Their optimised geometry had been calculated and compared with experimental X-ray diffraction data. The simulated and experimental vibrational spectra of biphenyl as well as isolated pyrrole monomers and oligomers from n = 1 and 2, where n is the number of structural repeat units used, have been computed using the ab initio 3–21G basis set. The results obtained are compared with experimental data for the case of biphenyl and for oligomers with n = 2 to 5 for both neutral benzenoid and quinonoid oligopyrroles, from semi-empirical predictions obtained by AM1 and PM3. The trends in the computed harmonic force fields, vibrational frequencies and intensities are monitored as a function of the chain length. The data are analyzed in conjunction with the trends in computed equilibrium geometries.     

Syntheses of dl-Gigartinine and Gongrine

Gigartinine and gongrine, both isolated from the red alga, Gymnogongrus fiabelliformis, were confirmed by synthesis to be l-α-ammo-δ-(guanylureido)-n-valeric acid and γ-(guanylureido)butyric acid, respectively. dl-Gigartinine was synthesized from α-chloro-δ-amino-n-valeric acid through esterification, phosgenation, condensation with guanidine, hydrolysis, and displacement of the α-chlorine atom with an amino group. Its ultraviolet spectrum and Rf values in paper chromatography agreed well with those of natural l-gigartinine. Another guanylureido compound identical with natural gongrine was obtained from γ-aminobutyric acid through phosgenation followed by condensation with guanidine.     

Leaf n‐Alkanes as Characters Differentiating Coastal and Continental Juniperus deltoides Populations from the Balkan Peninsula

The composition of the cuticular n‐alkanes isolated from the leaves of nine populations of Juniperus deltoides R.P.Adams from continental and coastal areas of the Balkan Peninsula was characterized by GC‐FID and GC/MS analyses. In the leaf waxes, 14 n‐alkane homologues with chain‐lengths ranging from C₂₂ to C₃₅ were identified. n‐Tritriacontane (C₃₃) was dominant in the waxes of all populations, but variations between the populations in the contents of all n‐alkanes were observed. Several statistical methods (ANOVA, principal component, discriminant, and cluster analyses) were used to investigate the diversity and variability of the cuticular‐leaf‐n‐alkane patterns of the nine J. deltoides populations. This is the first report on the n‐alkane composition for this species. The multivariate statistical analyses evidenced a high correlation of the leaf‐n‐alkane pattern with the geographical distribution of the investigated samples, differentiating the coastal from the continental populations of this taxon.     

In vivo nuclear-magnetic-resonance analysis of polyamine and alkaloid metabolism in transformed root cultures of Datura stramonium L.: evidence for the involvement of putrescine in phytohormone-induced de-differentiation

The utilisation and accumulation of ¹⁵N-labeled metabolites by a ¹⁵N-labeled transformed root culture of Daturastramonium L. was investigated by in vivo ¹⁵N-nuclear-magnetic-resonance (NMR) spectroscopy. After resuspension in spent growth medium, the pools of [¹⁵N]glutamate and [¹⁵N]glutamine were rapidly depleted and there was an increase in the ¹⁵N-NMR signals from conjugated putrescines and hyoscyamine. The signal from the conjugated putrescines passed through a maximum 2 d after the roots were resuspended, and it was concluded that putrescine could be stored as putrescine conjugates prior to its utilisation in other pathways. The transient accumulation of ¹⁵N-label in the hydroxy-cinnamoylputrescines was reduced when the de-differentiation of the root cultures into a suspension culture was initiated by exposure to a medium containing α-napthaleneacetic acid and kinetin. This led to the hypothesis that phytohormone-induced de-differentiation of the root cultures required the presence of free polyamines, and this was tested using two potent inhibitors of putrescine biosynthesis, dl-α-difluoromethylarginine and dl-α-difluoromethylornithine. In-vivo ¹⁵N-NMR spectra of roots grown in ¹⁵N-enriched medium supplemented with these inhibitors showed that the ¹⁵N-labelling of the conjugated polyamines and hyoscyamine was markedly reduced. dl-α-difluoromethylarginine also prevented the phytohormone induced de-differentiation of the root cultures, and this effect could be reversed by the supply of exogenous putrescine. Thus the supply of putrescine appears to play a crucial role in mediating the phytohormone induced de-differentiation of the root culture. Received: 13 September 1997 / Accepted: 12 November 1997     

A Synthesis of dl-C17-Cecropia Juvenile Hormone

A novel synthesis of dl-C₁₇-Cecropia juvenile hormone (I) was accomplished.     

Isolation and characterization of a trypsin fraction from the pyloric ceca of chinook salmon (Oncorhynchus tshawytscha)

A trypsin fraction was isolated from the pyloric ceca of New Zealand farmed chinook salmon (Oncorhynchus tshawytscha) by ammonium sulfate fractionation, acetone precipitation and affinity chromatography. The chinook salmon enzyme hydrolyzed the trypsin-specific synthetic substrate benzoyl-dl-arginine-p-nitroanilide (dl-BAPNA), and was inhibited by the general serine protease inhibitor phenyl methyl sulfonyl fluoride (PMSF), and also by the specific trypsin inhibitors — soybean trypsin inhibitor (SBTI) and benzamidine. The enzyme was active over a broad pH range (from 7.5 to at least pH 10.0) at 25 °C and was stable from pH 4.0 to pH 10.0 when incubated at 20 °C, with a maximum at pH 8.0. The optimum temperature for the hydrolysis of dl-BAPNA by the chinook salmon enzyme was 60 °C, however, the enzyme was unstable at temperatures above 40 °C. The molecular mass of the chinook salmon trypsin was estimated as 28 kDa by SDS–PAGE.     

Chemodiversity of Nonacosan‐10‐ol and n‐Alkanes in the Needle Wax of Pinus heldreichii

This is the first report of individual variability and population diversity of the contents of nonacosan‐10‐ol and n‐alkanes in the needle cuticular waxes of Bosnian pines originated from Montenegro, regarded as Pinus heldreichii var. leucodermis, and from Serbia, regarded as P. heldreichii var. pan?i?i. The amount of nonacosan‐10‐ol varied individually from 27.4 to 73.2% (55.5% in average), but differences between the four investigated populations were not statistically confirmed. The size of the n‐alkanes ranged from C₁₈ to C₃₃. The most abundant n‐alkanes were C₂₃, C₂₇, and C₂₅ (12.2, 11.2, and 10.8% in average, resp.). The carbon preference index (CPI) of the n‐alkanes ranged from 0.8 to 3.1 (1.6 in average), while the average chain length (ACL) ranged from 20.9 to 26.5 (24.4 in average). Long‐chain and mid‐chain n‐alkanes prevailed (49.6 and 37.9% in average, resp.). It was also found that the populations of P. heldreichii var. leucodermis had predominantly a narrower range of n‐alkanes (C₁₈? C₃₁) than the trees of the variety pan?i?i (C₁₈? C₃₃). Differences between the varieties were also significant for most of the other characteristics of the n‐alkane pattern (e.g., most abundant n‐alkanes, CPI, ACL, and relative proportion of short‐, mid‐, and long‐chain n‐alkanes). The principle component and cluster analyses of eleven n‐alkanes confirmed the significant diversity of these two varieties.     

A Growth Factor for Malo-lactic Fermentation Bacteria

A growth factor (TJF) for a malo-lactic fermentation bacterium has been isolated from tomato juice, and found to be a β-glucoside. The NMR spectra of TJF and its acetate revealed that the glucosyl residue linked to the hydroxyl group at C-2′ or C-4′ of d- or l-pantothenic acid moiety. Then, 2′-O-(β-d-glucopyranosyl)-dl-pantothenic acid (I), 4′-O-(β-d-glucopyranosyl)-dl-pantothenic acid (II) and 4′-O-(β-d-glucopyranosyl)-d(R)-pantothenic acid (II-a) were synthesized, and Il-a and 4′-O-(β-d-glucopyranosyl)-l-pantothenic acid (II-b) were obtained by the optical resolution of the acetate of II. Among the above compounds, II-a was identical with natural TJF regarding to the biological activity, NMR and ORD spectra, and thin-layer chromatography.     

Hydrolysis of ethyl mandelate and esterification of 2-bromopropionic acid in micro-emulsions

Summary Lipase fromCandida cylindraceae possessed higher catalytic activity, both in the hydrolysis of (dl)-ethyl mandelate in sodium dodecyl sulfonate/n-butanol/n-octane oil-in-water micro-emulsion and in the esterification of -bromopropionic acid withn-butanol in sodium dodecyl sulfate/n-butanol/n-octane water-in-oil micro-emulsion, than in traditional water and oil biphasic solutions.     

Isolation of Tenuazonic Acid from Blast-diseased Rice Plants

dl-(1245/36)-2,3,4,5,6-Pentachlorocyclohexanecarbonitrile was synthesized from (1234/ 56)-1,4,5,6-tetrachloro-2,3-epoxycyclohexane (α-BTC cis-epoxide). dl-(1245/36)-2,3,4,5,6-Pentachloro-1-methylcyclohexane was synthesized from the nitrile via dl-(1245/36)-2,3,4,5,6-pentachlorocyclohexylmethanol, the structure of which was confirmed by PMR spectroscopy using spin decoupling techniques and the shift reagent, Eu(DPM)₃. This series of compounds was shown to have the same configuration as γ-BHC. The conformational equilibrium of these compounds is discussed. dl-(1245/36)-2,3,5,6-Tetrachloro-1,4-dimethyl-cyclohexane was synthesized by a stepwise route involving a Diels-Alder reaction of trans,trans-hexadiene-2,4 with maleic anhydride.     

Effect of insulin on exocrine pancreatic secretion in healthy and diabetic anaesthetised rats

This investigation characterised the effects of exogenous insulin on exocrine pancreatic secretion in anaesthetised healthy and diabetic rats. Animals were rendered diabetic by a single injection of streptozotocin (STZ, 60 mg kg^–1 I.P.). Age-matched controls were injected citrate buffer. Rats were tested for hyperglycaemia 4 days after STZ injection and 7–8 weeks later when they were used for the experiments. Following anaesthesia (1 g kg^–1 urethane I.P.), laparotomy was performed and the pancreatic duct cannulated for collection of pure pancreatic juice. Basal pancreatic juice flow rate in diabetic rats was significantly (p < 0.001) increased whereas protein and amylase outputs were significantly (p < 0.001) decreased compared to control rats. Insulin (1 IU, I.P.) produced in healthy rats significant increases in pancreatic flow rate, amylase secretion and protein output compared to basal (p < 0.05). Insulin action also included a reduction in blood glucose (152.7 ± 16.9 mg dl^–1, n= 6, prior to insulin and 42.0 ± 8.4 mg dl^–1, n= 4, 100 min later). In fact, flow rate and glycaemia showed a strong negative correlation (p < 0.01, Pearson). Pretreatment with atropine (0.2 mg kg^–1, I.V.) abolished the effects of insulin on secretory parameters despite a similar reduction in glycaemia; in this series of experiments the correlation between flow rate and blood glucose was lost. In diabetic rats, insulin (4 IU, I.P.) did not modify exocrine pancreatic secretion. There was a fall in blood glucose (467.6 ± 14.0 mg dl^–1, n= 10, prior to insulin and 386.6 ± 43.6 mg dl^–1, n= 7, 120 min later). Rats, however, did not become hypoglycaemic. Similar results were observed in diabetic atropinized rats. The results of this study indicate that the effects of insulin on exocrine pancreatic secretion in anaesthetised healthy rats are mediated by hypoglycaemia-evoked vagal cholinergic activation. (Mol Cell Biochem 261: 105–110, 2004)