Asymmetric Trans-esterification of meso-2,5-Dibromoadipate and Synthesis of Optically Active cis-2,5-Disubstituted Pyrrolidines

Asymmetric trans-esterification of meso-2,5-dibromoadipate to (–)-benzyl methyl 2,5-dibromoadipate by lipase with subsequent chemical reactions afforded optically active cis-2,5-disubstituted pyrrolidines. An equivalent asymmetric transformation was performed by selectively hydrolyzing a cis-2,5-disubstituted pyrrolidine having a chiral N-substituent.     

Nitrogen Fixation and Allantoin Formation in Soybean Plants

The activity of nitrogenase and the concentration of ammonia and allantoin (+ allantoic acid) in root nodules were measured throughout the growth period of soybean plants. Nitrogenase activity measured by acetylene reduction increased with plant growth and reached a maximum level at the flowering period. The level of ammonia and allantoin concentration in nodules was parallel with increased nitrogenase activity. At the late reproductive stage (pod-forming period), nitrogenase activity showed a marked decrease, but the ammonia and allantoin in the nodules remained at a constant level. Detached nodules from 56 day-old soybean plants were exposed to ¹⁵N₂ gas, and the distribution of ¹⁵N among nitrogen compounds was investigated. Enrichment of ¹⁵N in allantoin and allantoic acid reached a fairly high level after 90 min of nitrogen fixation; ca. 22% of ¹⁵N in acid-soluble nitrogen compounds was incorporated into allantoin + allantoic acid. In contrast, enrichment of ¹⁵N in amide nitrogen was relatively low. No significant ¹⁵N was detected in the RNA fraction. The data suggested that ureide formation in nitrogen-fixing root nodules did not take place through the breakdown of nucleic acids, but directly associated with the assimilating system of biologically fixed nitrogen.     

Effect of Adding the Limiting Amino Acids to an Amino Acid Diet Simulating Rice Protein on the Conversion of Tryptophan to Nicotinamide in Rats

The effect of amino acid composition on the conversion ratio of tryptophan to nicotinamide was investigated. The ratio in the group fed with an amino acid diet simulating rice protein was around 2.5%. This ratio was statistically decreased by the addition of the limiting amino acids, except for tryptophan, and increased by the addition of all the limiting amino acids, including tryptophan. The composition of amino acids proved to greatly affect the conversion ratio.     

Production and Properties of Lipase from a Newly Isolated Chromobacterium

Out of some 750 strains of microorganisms, a potent bacterium for lipase production was isolated from soil and was identified as Chromobacterium viscosum.

The bacterium accumulates lipase in culture fluid when grown aerobically at 26°C for 3 days in a medium composed of soluble starch, soy bean meal, lard and inorganic salts.

Chromobacterium lipase had an optimum pH of 7.0 for activity at 37°C, and an optimal temperature of 65°C at pH 7.0. The enzyme retained 80% of the activity when heated for 10 min at 70°C. This lipase was capable of hydrolyzing a variety of natural fats and oils, and it was more active on lard and butter than on olive oil. The activity was stimulated by Ca²⁺, Mg²⁺, Mn²⁺ and inhibited by Cu²⁺, Hg²⁺ and Sn²⁺. It was not diminished but rather stimulated by a high concentration of bile-salts.     

Syntheses of All Stereoisomers of Goniodiol from Yeast-Reduction Products and Their Antimicrobiological Activity

All stereoisomers of goniodiol were synthesized from yeast-reduction products. The C-6 chiral centers were converted from the chiral centers of the yeast-reduction products. Stereoselective conversion of the alkene, which had been prepared from the yeast-reduction product, to glycol constructed the C-7 and C-8 stereochemistry. (+)-Goniodiol and 7-epi-(+)-goniodiol showed the highest antibacterial activity (MIC, 3.1 mM) against Yersinia intermedia.     

A Simple and Efficient Method for High Fidelity PCR Cloning Using Antibody-neutralizing Technology

We introduce the TA cloning antibody method for the high-fidelity PCR product amplified by family B DNA polymerase without purification. This method uses antibodies and Thermus aquaticus (Taq) DNA polymerase. The antibodies can inhibit only the activity of family B DNA polymerase, and Taq can co-work for A-tailing. This method has nearly cloning efficiency to that of the PCR product of Taq.     

Effects of Taxifolin on the Serum Cholesterol Level in Rats

Four new polyacetylenic glucosides isolated from the leaf of Jerusalem artichoke (Helianthus tuberosus L.) were characterized as methyl β-D-glucopyranosyl helianthenate C (5), D (6), E (7), and F (8). The absolute stereochemistry of the glucosyloxymethine was also determined to be of R configuration by preparing the relative compounds with Sharpless asymmetric epoxidation as the key step and source of optical activity.     

Effect of cyanobacterial extracellular products on high-frequency in vitro induction and elongation of Gossypium hirsutum L organs through shoot apex explants

The challenging task of bringing high efficiency transformed plants attracts lot of attention in recent times. In search for this, there have been many attempts made using, different techniques like tissue culture and plant breeding methods. Here we report a suitable alternative facile route, where cyanobacterial extracellular products are utilized as growth regulators and its performance validated on Gossypium hirsutum L. MS medium is tested with cyanobacterial extracellular products of Nostoc ellipsosporum, Dolichospermum flos-aquae and Oscillatoria acuminata .Our best results show that the addition of O. acuminata extracellular product with plant growth hormones gives the excellent induction and elongation in cotton. In addition to this, the multiple shoot was obtained on MS medium fortified with 1.0 mg L^?1 BA with 8% O. acuminata and 1.5 mg L^?1 TDZ with 12% O. acuminata. High frequency of shoot elongation supplemented with MS medium, iP 2.5 mg L^?1 and 16% O. acuminata and root production MS medium fortified with 12% O. acuminata best responsible for regeneration in cotton plants. The rooted plants were hardened and transferred to soil with 90% survival rate.     

Qualitative Characterization of the Aqueous Fraction from Hydrothermal Liquefaction of Algae Using 2D Gas Chromatography with Time-of-flight Mass Spectrometry

Two-dimensional gas chromatography coupled with time-of-flight mass spectrometry is a powerful tool for identifying and quantifying chemical components in complex mixtures. It is often used to analyze gasoline, jet fuel, diesel, bio-diesel and the organic fraction of bio-crude/bio-oil. In most of those analyses, the first dimension of separation is non-polar, followed by a polar separation. The aqueous fractions of bio-crude and other aqueous samples from biofuels production have been examined with similar column combinations. However, sample preparation techniques such as derivatization, solvent extraction, and solid-phase extraction were necessaryprior to analysis. In this study, aqueous fractions obtained from the hydrothermal liquefaction of algae were characterized by two-dimensional gas chromatography coupled with time-of-flight mass spectrometry without prior sample preparation techniques using a polar separation in the first dimension followed by a non-polar separation in the second. Two-dimensional plots from this analysis were compared with those obtained from the more traditional column configuration. Results from qualitative characterization of the aqueous fractions of algal bio-crude are discussed in detail. The advantages of using a polar separation followed by a non-polar separation for characterization of organics in aqueous samples by two-dimensional gas chromatography coupled with time-of-flight mass spectrometry are highlighted.     

Detecting cell lysis using viscosity monitoring in E. coli fermentation to prevent product loss

Monitoring the physical or chemical properties of cell broths to infer cell status is often challenging due to the complex nature of the broth. Key factors indicative of cell status include cell density, cell viability, product leakage, and DNA release to the fermentation broth. The rapid and accurate prediction of cell status for hosts with intracellular protein products can minimise product loss due to leakage at the onset of cell lysis in fermentation. This article reports the rheological examination of an industrially relevant E. coli fermentation producing antibody fragments (Fab'). Viscosity monitoring showed an increase in viscosity during the exponential phase in relation to the cell density increase, a relatively flat profile in the stationary phase, followed by a rapid increase which correlated well with product loss, DNA release and loss of cell viability. This phenomenon was observed over several fermentations that a 25% increase in broth viscosity (using induction‐point viscosity as a reference) indicated 10% product loss. Our results suggest that viscosity can accurately detect cell lysis and product leakage in postinduction cell cultures, and can identify cell lysis earlier than several other common fermentation monitoring techniques. This work demonstrates the utility of rapidly monitoring the physical properties of fermentation broths, and that viscosity monitoring has the potential to be a tool for process development to determine the optimal harvest time and minimise product loss. © 2016 The Authors. Biotechnology Progress published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers, 32:1069–1076, 2016