STUDIES ON REACTIONS RELATING TO CARBOHYDRATES AND POLYSACCHARIDES. XXXV. POLYSACCHARIDE SYNTHESIS BY THE ACTION OF ACETOBACTER XYLINUS ON CARBOHYDRATES AND RELATED COMPOUNDS

1931 ◽  
Vol 4 (4) ◽  
pp. 372-388 ◽  
Author(s):  
H. L. A. Tarr ◽  
Harold Hibbert
Keyword(s):  
High Yield ◽  
Experimental Conditions ◽  
Polysaccharide Synthesis ◽  
Carbon Compounds ◽  
Bacterial Action ◽  
Effective Synthesis ◽  
Surface Polysaccharide ◽  
Related Compounds ◽  
Nutrient Solutions ◽  
Primary Oxidation

The action of Acetobacter xylinus, when cultivated in nutrient solutions containing certain carbohydrates or polyhydric alcohols, in forming surface polysaccharide membranes has been confirmed. The nutrient substrate necessary for the effective synthesis of nitrogen and ash-free polysaccharides from such carbon compounds has been carefully determined, and the necessity for the presence of a small amount of ethyl alcohol definitely proved. This type of synthesis appears to be specific for this organism, in that only the hexoses, their anhydrides and compounds which presumably yield hexoses as a result of the bacterial action, give rise to polysaccharide formation. When the carbon compound used is not a free hexose, nor one apparently capable of conversion into a hexose, as in the case of pentoses such as arabinose and xylose, glycols, polyglycols and erythritol, no membrane formation takes place. On the other hand mannitol, which is known to undergo oxidation with the formation of fructose under the experimental conditions, gives rise to a high yield of a synthetic polysaccharide. Glycerol behaves similarly, due presumably to a primary oxidation to dihydroxy acetone and conversion of this to fructose, the latter then yielding the polysaccharide membrane. The introduction of a methyl group into glycerol and glucose, with the formation of α-methyl glycerol and α-methyl glucoside, respectively, inhibits polysaccharide formation. The product obtained from glucose was found to be very closely related to cellulose, if not identical with it (13). Galactose is much less reactive than glucose, while mannose appears to be relatively inactive with the strain of A. xylinus employed. The highest yield of the polysaccharide was obtained from fructose, a result presumably connected with the recognized fact that this bacterium forms little or no acid from this sugar.

scholarly journals An accelerated and effective synthesis of zinc borate from zinc sulfate using sonochemistry

2020 ◽  
Vol 43 (1) ◽  
pp. 7-14
Author(s):  
Ali Can Ersan ◽  
Azmi Seyhun Kipcak ◽  
Meral Yildirim Ozen ◽  
Nurcan Tugrul
Keyword(s):  
Inorganic Compounds ◽  
Zinc Borate ◽  
High Yield ◽  
X Ray Diffraction ◽  
Ultrasonic Probe ◽  
Minimum Particle Size ◽  
Effective Synthesis ◽  
Ft Ir ◽  
Lower Temperature ◽  
Borate Compound

AbstractRecently, sonochemistry has been used for the synthesis of inorganic compounds, such as zinc borates. In this study using zinc sulphate heptahydrate (ZnSO4·7H2O) and boric acid (H3BO3) as starting materials, a zinc borate compound in the form of Zn3B6O12·3.5H2O was synthesized using an ultrasonic probe. Product’s characterization was carried out with using X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR) and Raman spectroscopy. Zinc borate compound’s chemical bond structure was observed with Raman and FTIR. From the XRD results it was seen that Zn3B6O12·3.5H2O can be quickly synthesized upon heating at 80°C and 85°C (55 min) or 90°C (45 min) in very high yield (>90%). The minimum particle size obtained was ~143 μm from the SEM results. Zinc borate compound was synthesized at a lower temperature in less time than other synthesized zinc metal compound in literature.

The Pyrolytic Rearrangement of 1-Alkynoyl-3-methylpyrazoles: Synthesis of Pyrazolo[1,5-a]pyridin-5-ols and Related Compounds

1994 ◽  
Vol 47 (6) ◽  
pp. 991 ◽  
Author(s):  
RFC Brown ◽  
FW Eastwood ◽  
GD Fallon ◽  
SC Lee ◽  
RP Mcgeary
Keyword(s):  
Carbon Chain ◽  
Ring Structure ◽  
High Yield ◽  
Methyl Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
Flash Vacuum Pyrolysis ◽  
Vacuum Pyrolysis ◽  
Fused Ring ◽  
Related Compounds

Flash vacuum pyrolysis of 1-(alkyn-2′-oyl)-3-methylpyrazoles at 650°/0.03 mm forms pyrazolo[1,5-a]pyridin-5-ols, often in high yield, which may bear substituents at C2, C3 or C7. In the absence of a 3-methyl group in the precursor, N-ethynylpyrazoles are formed in low yield. The formation of both types of product is interpreted as involving 3-(N-pyrazolyl)propadienones formed by N1 → N2 migration of the N-alkynoyl group with inversion of the three-carbon chain. The fused-ring structure of 2-methylpyrazolo[1,5-a]pyridin-5-ol (25) was established by X-ray crystallography of the O-benzoyl derivative (27).

scholarly journals Identification of the most suitable reference gene for gene expression studies with development and abiotic stress response in Bromus sterilis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Madhab Kumar Sen ◽  
Kateřina Hamouzová ◽  
Pavlina Košnarová ◽  
Amit Roy ◽  
Josef Soukup
Keyword(s):  
Reference Gene ◽  
Herbicide Resistance ◽  
Reference Genes ◽  
Gene Selection ◽  
High Yield ◽  
Suitable Reference Gene ◽  
Grass Species ◽  
Experimental Conditions ◽  
Qrt Pcr ◽  
Suitable Reference

AbstractBromus sterilis is an annual weedy grass, causing high yield losses in winter cereals. Frequent use of herbicides had led to the evolution of herbicide resistance in this species. Mechanisms underlying herbicide resistance in B. sterilis must be uncovered because this problem is becoming a global threat. qRT-PCR and the next-generation sequencing technologies can elucidate the resistance mechanisms. Although qRT-PCR can calculate precise fold changes, its preciseness depends on the expression of reference genes. Regardless of stable expression in any given condition, no gene can act as a universal reference gene. Hence, it is necessary to identify the suitable reference gene for each species. To our knowledge, there are no reports on the suitable reference gene in any brome species so far. Thus, in this paper, the stability of eight genes was evaluated using qRT-PCR experiments followed by expression stability ranking via five most commonly used software for reference gene selection. Our findings suggest using a combination of 18S rRNA and ACCase to normalise the qRT-PCR data in B. sterilis. Besides, reference genes are also recommended for different experimental conditions. The present study outcomes will facilitate future molecular work in B. sterilis and other related grass species.

scholarly journals Diversity and evolution of surface polysaccharide synthesis loci in Enterobacteriales

2019 ◽  
Author(s):  
Kathryn E. Holt ◽  
Florent Lassalle ◽  
Kelly L. Wyres ◽  
Ryan Wick ◽  
Rafal J. Mostowy
Keyword(s):  
Evolutionary Dynamics ◽  
Bacterial Species ◽  
Purifying Selection ◽  
Evolutionary Forces ◽  
Polysaccharide Synthesis ◽  
Surface Polysaccharides ◽  
Surface Polysaccharide ◽  
Selective Preservation ◽  
Multiple Species

Bacterial capsules and lipopolysaccharides are diverse surface polysaccharides (SPs) that serve as the frontline for interactions with the outside world. While SPs can evolve rapidly, their diversity and evolutionary dynamics across different taxonomic scales has not been investigated in detail. Here, we focused on the bacterial order Enterobacteriales (including the medically-relevant Enterobacteriaceae), to carry out comparative genomics of two SP locus synthesis regions, cps and kps, using 27,334 genomes from 45 genera. We identified high-quality cps loci in 22 genera and kps in 11 genera, around 4% of which were detected in multiple species. We found SP loci to be highly dynamic genetic entities: their evolution was driven by high rates of horizontal gene transfer (HGT), both of whole loci and component genes, and relaxed purifying selection, yielding large repertoires of SP diversity. In spite of that, we found the presence of (near-)identical locus structures in distant taxonomic backgrounds that could not be explained by recent exchange, pointing to long-term selective preservation of locus structures in some populations. Our results reveal differences in evolutionary dynamics driving SP diversity within different bacterial species, with lineages of Escherichia coli, Enterobacter hormachei and Klebsiella aerogenes most likely to share SP loci via recent exchange; and lineages of Salmonella enterica, Citrobacter sakazakii and Serratia marcescens most likely to share SP loci via other mechanisms such as long-term preservation. Overall, the evolution of SP loci in Enterobacteriales is driven by a range of evolutionary forces and their dynamics and relative importance varies between different species.

scholarly journals Yield and Quality Characteristics of Brassica Microgreens as Affected by the NH4:NO3 Molar Ratio and Strength of the Nutrient Solution

Foods ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 677 ◽  
Author(s):  
Onofrio Davide Palmitessa ◽  
Massimiliano Renna ◽  
Pasquale Crupi ◽  
Angelo Lovece ◽  
Filomena Corbo ◽  
...  
Keyword(s):  
Nutrient Solution ◽  
Inorganic Ions ◽  
Molar Ratio ◽  
High Yield ◽  
Nitrate Content ◽  
Carotene Content ◽  
Molar Ratios ◽  
Half Strength ◽  
Nutrient Solutions ◽  
Β Carotene

Microgreens are gaining more and more interest, but little information is available on the effects of the chemical composition of the nutrient solution on the microgreen yield. In this study, three Brassica genotypes (B. oleracea var. italica, B. oleracea var. botrytis, and Brassica rapa L. subsp. sylvestris L. Janch. var. esculenta Hort) were fertigated with three modified strength Hoagland nutrient solutions (1/2, 1/4, and 1/8 strength) or with three modified half-strength Hoagland nutrient solutions with three different NH4:NO3 molar ratios (5:95, 15:85, and 25:75). Microgreen yields and content of inorganic ions, dietary fiber, proteins, α-tocopherol, and β-carotene were evaluated. Micro cauliflower showed the highest yield, as well as a higher content of mineral elements and α-tocopherol (10.4 mg 100 g−1 fresh weight (FW)) than other genotypes. The use of nutrient solution at half strength gave both a high yield (0.23 g cm−2) and a desirable seedling height. By changing the NH4:NO3 molar ratio in the nutrient solution, no differences were found on yield and growing parameters, although the highest β-carotene content (6.3 mg 100 g−1 FW) was found by using a NH4:NO3 molar ratio of 25:75. The lowest nitrate content (on average 6.8 g 100 g−1 dry weight) was found in micro broccoli and micro broccoli raab by using a nutrient solution with NH4:NO3 molar ratios of 25:75 and 5:95, respectively. Micro cauliflower fertigated with a NH4:NO3 molar ratio of 25:75 showed the highest dry matter (9.8 g 100 g−1 FW) and protein content (4.2 g 100 g−1 FW).

scholarly journals Determination of the Effect of Humic Acid on Growth and Development Parameters of Parsley (Petroselinum sativum Hoffm.) Grown in Boron Soil

2018 ◽  
Vol 47 (1) ◽  
pp. 183-193 ◽  
Author(s):  
Tuncay TURSUN ◽  
Sener AKINCI ◽  
Esin BOZKURT
Keyword(s):  
Humic Acid ◽  
Growth Parameters ◽  
Dry Weight ◽  
High Yield ◽  
Yield And Quality ◽  
Icp Ms ◽  
Growth Analyses ◽  
Nutrient Solutions

Boron is an important micronutrient, required for all plant growth, and critical for high yield and quality of crops. The aim of the present research was to determine the effects of boron on pot-grown parsley (Petroselinum sativum Hoffm.). The experimental design consisted of four treatments using Hoagland-Arnon (1950) nutrient solutions with two different boron concentrations (B1 - 15 ppm and B2 - 150 ppm), each with and without 10 ml humic acid addition (HB1 and HB2), and controls with full strength Hoagland-Arnon solutions. Growth analyses of the parsley revealed that 15 ppm boron application caused an increase in root length leaf fresh and dry weight root fresh and dry weight and leaf area compared to control values. 150 ppm B (B2) concentration decreased all growth parameters compared to controls. The two humic acid treatments (HB1 and HB2) did not increase any of those growth parameters either in controls (C) or in the two boron (B1 and B2) concentrations. Analysis by (ICP-MS) revealed that B content in the leaves increased gradually in B1 and B2, as well as in both humic treatments where in HB2 it increased to 99.38% compared to B1. In the leaves, Mn, Zn and Fe contents behaved the same as B, increasing in all treatments, with the amounts in HB2 being significantly greater than in C, B1 and B2 leaves.

scholarly journals Asymmetric synthesis of a high added value chiral amine using immobilized ω-transaminases

2019 ◽  
Vol 15 ◽  
pp. 60-66 ◽  
Author(s):  
Antonella Petri ◽  
Valeria Colonna ◽  
Oreste Piccolo
Keyword(s):  
Enantiomeric Excess ◽  
Practical Interest ◽  
Continuous System ◽  
Immobilized Enzymes ◽  
Added Value ◽  
High Yield ◽  
Experimental Conditions ◽  
Chiral Amine ◽  
Heterocyclic Molecules ◽  
One Step

Chiral N-heterocyclic molecules and in particular compounds with an amino functional group such as 3-aminopiperidine are valuable intermediates for the production of a large number of bioactive compounds with pharmacological properties. In this paper, the synthesis of both enantiomers of 3-amino-1-Boc-piperidine by amination of the prochiral precursor 1-Boc-3-piperidone using immobilized ω-transaminases (TAs-IMB), isopropylamine as amine donor and pyridoxal-5’-phosphate (PLP) as cofactor is described. Compared to other methods, the present approach affords the target compound in just one step with high yield and high enantiomeric excess starting from a commercial substrate. The reaction was carried out by using different commercially available immobilized enzymes, evaluating the catalytic activity and the enantioselectivity under different experimental conditions. Re-use of the most efficient enzyme was performed both in batch and in a semi-continuous system. The selected biocatalyst showed good stability under the reaction conditions providing consistent results in terms of conversion and enantiomeric excess after several cycles. The reported results may be of practical interest in view of the development of this sustainable approach to an industrial scale.

scholarly journals Nucleic Acid Related Compounds. 8. Direct Conversion of 2′-Deoxyinosine to 6-Chloropurine 2′-Deoxyriboside and Selected 6-Substituted Deoxynucleosides and Their Evaluation As Substrates of Adenosine Deaminase

1973 ◽  
Vol 51 (19) ◽  
pp. 3161-3169 ◽  
Author(s):  
Morris J. Robins ◽  
Gerald L. Basom
Keyword(s):  
Adenosine Deaminase ◽  
Methylene Chloride ◽  
Potassium Fluoride ◽  
Direct Conversion ◽  
Chloride Complex ◽  
High Yield ◽  
Mass Spectral ◽  
Quaternary Ammonium Chloride ◽  
Related Compounds

Trifluoroacetylation of 2′-deoxyinosine (2), obtained by enzymatic deamination of 2′-deoxyadenosine (1), gave the 3′,5′-bis-O-trifluoroacetate (3). Reaction of the electronegatively substituted deoxynucleoside, 3, with DMF-thionyl chloride complex in refluxing methylene chloride gave a high yield of 6-chloropurine 2′-deoxyriboside (4) after deblocking.Displacement of chloride of 4 by hydrosulfide to give 6-mercaptopurine 2′-deoxyriboside (5) followed by sulfur alkylation with p-nitrobenzyl bromide gave 6-S-(p-nitrobenzyl) thiopurine 2′-deoxyriboside (6) which was alternatively prepared by displacement of chloride from 4 by p-nitrobenzyl mercaptide, generated in situ from the isothiouronium salt. Methyl mercaptide reaction with 4 gave 6-methylthiopurine 2′-deoxyriboside (7). Treatment of 4 with trimethylamine gave the corresponding quaternary ammonium chloride (8) which was allowed to react with potassium fluoride to give 6-fluoropurine 2′-deoxyriboside (9). Respective amine displacements on 4 gave 6-benzylaminopurine 2'-deoxyriboside (10), and 6-hydroxylaminopurine 2′-deoxyriboside (11). Reaction of 4 with liquid ammonia completed the first reported transformation of 2′-deoxyinosine (2) to 2′-deoxyadenosine (1).Biological rationale for the synthesis of these 2′-deoxynucleosides and their evaluation as substrates of adenosine deaminase are discussed. Major mass spectral fragmentations are tabulated.

PREPARATION AND TOXICITY OF SOME ALKYL THIOPYROPHOSPHATES

1956 ◽  
Vol 34 (12) ◽  
pp. 1819-1832 ◽  
Author(s):  
R. A. McIvor ◽  
G. D. McCarthy ◽  
G. A. Grant
Keyword(s):  
High Yield ◽  
Inorganic Salts ◽  
Infrared Study ◽  
Toxicological Studies ◽  
Related Compounds

Several methods have been investigated for the synthesis of tetraalkyl thiopyrophosphates, including one that can be carried out very rapidly with high yield. Purification of these compounds proved exceedingly difficult, because they were sensitive to traces of acids or bases, and probably to inorganic salts at temperatures above 70 °C. All methods investigated yield only the thiono isomer, there being no evidence for the corresponding P—S—P isomer. Toxicological studies do not support the results reported by Fiszer and workers. None of the compounds is more toxic intravenously than tetraethyl pyrophosphate. The synthesis of several other related compounds for infrared study is reported.

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