Search results for "RICH"

Mimonoside D: a new triterpenoid saponin from Mimosa diplotricha Sauvalle (Fabaceae)

2021

A new triterpenoid saponin (Mimonoside D: 3-O-��-L-arabinopyranosyl-3��-hydroxyolean-12-en-28-oic acid 28-O-��-D-xylopyranosyl-(1���2)-��-D- glucopyranoside ester (1)) was isolated from the aerial parts of Mimosa diplotricha Sauvalle together with nine known compounds: 7,4���-dihydroxyflavone (2), kaempferol (3), lupeol (4), betulinic acid (5), ��-sitosterol (6), ��-sitosterol-3-O-��-D-glucopyranoside (7), lutein (8), 5,2���-dihydroxy-7,4���,5���-trimethoxyflavone (9) and vitexin (10). Their structures were elucidated on the basis of spectroscopic (1 D and 2 D nuclear magnetic resonance) and high-resolution mass spectrometric data as well as by comparison of their spectral data with those o…

Production of 6-pentyl-?-pyrone byTrichoderma harzianum from 18?n fatty acid methyl esters

1992

Biosynthesis of 6-pentyl-α-pyrone byTrichoderma harzianum in two different media was evaluated. Best yields were found in nitrogen deficient medium (C/N=60). Limited growth seems to favour the production of this lactone. When fungal cells, precultured in low nitrogen medium, were incubated on methyl ricinoleate (10 g/l, C/N=60) an increase in 6-pentyl-α-pyrone production was observed in comparison with the media containing methyl oleate or methyl linoleate.

The gene encoding polyneuridine aldehyde esterase of monoterpenoid indole alkaloid biosynthesis in plants is an ortholog of theα/β hydrolase super fa…

2000

The biosynthesis of the anti-arrhythmic alkaloid ajmaline is catalysed by more than 10 specific enzymes. In this multistep process polyneuridine aldehyde esterase (PNAE) catalyses a central reaction by transforming polyneuridine aldehyde into epi-vellosimine, which is the immediate precursor for the synthesis of the ajmalane skeleton. PNAE was purified from cell suspension cultures of Rauvolfia serpentina. The N-terminal sequence and endoproteinase LysC fragments of the purified protein were used for primer design and for the amplification of specific PCR products leading to the isolation of PNAE-encoding cDNA from a R. serpentina library. The PNAE cDNA was fused with a C-terminal His-tag, …

Methyl-Substituted α-Cyclodextrin as Affinity Material for Storage, Separation, and Detection of Trichlorofluoromethane

2018

Abstract The severely ozone‐depleting trichlorofluoromethane is still appearing in several recycling processes or industrial applications. A simple and selective supramolecular complex formation of per‐methylated α‐cyclodextrin (1) with the highly volatile trichlorofluoromethane (2) is reported. This interaction moreover leads to thermally stable crystals. Per‐methylated α‐cyclodextrin is successfully exploited as a reversible and selective adsorption material for liquid and airborne trichlorofluoromethane as well as an affinity material for the chemical sensing and detection of this particular volatile organic component.

Identification of Gip as a novel phage-encoded gyrase inhibitor protein featuring a broad activity profile

2021

AbstractBacteriophages represent a powerful source for the identification of novel antimicrobial proteins. In this study, a screening of small cytoplasmic proteins encoded by the CGP3 prophage of Corynebacterium glutamicum, resulted in the identification of the novel gyrase-inhibiting protein Cg1978 (Gip), which shows a direct interaction with the gyrase subunit A (GyrA). In vitro supercoiling assays further suggest a stabilization of the cleavage complex by Gip. Overproduction of Gip in C. glutamicum resulted in a severe growth defect as well as an induction of the SOS response. The cells adapted to gip overexpression by increasing expression levels of gyrAB and by reducing topA expression…

Production of volatile compounds in model milk and cheese media by eight strains of Geotrichum candidum Link

1994

SummaryEight strains of Geotrichum candidum isolated from cheese were compared for aroma production. Twenty-four components, including alcohols, methyl ketones, fatty acids and esters, were identified by gas–liquid chromatography and gas chromatography–mass spectrometry of the volatile compounds produced by G. candidum cultures. Strains could be differentiated by their ability to produce dimethyldisulphide, phenol, phenylethanol and methyl ketones.

Cellulose Digestion in the Termite Gut

2005

Comparative assessment of solid-phase extraction clean-up procedures, GC columns and perfluoroacylation reagents for determination of type B trichoth…

2005

Abstract Various solid-phase extraction (SPE) procedures for clean-up, two perfluoroacylation reagents (pentafluoropropionic anhydride (PFPA) and heptafluorobutyric anhydride (HFBA)) and two chromatographic columns (HP-1701 and HP-5) have been assessed comparatively to achieve the determination of type B trichothecenes (deoxynivalenol (DON), nivalenol (NIV), 3- and 15-acetyldeoxynivalenol (3- and 15-ADON)) in wheat grain by gas chromatography (GC)–electron-capture detection (ECD). Spiked wheat samples were extracted with acetonitrile–water (84:16, v/v). Tested SPE procedures were MycoSep 225 column, Florisil and different cartridges prepared in the laboratory with mixtures of various sorben…

Challenges in the Electrochemical Synthesis of Si 2 Cl 6 Starting from Tetrachlorosilane and Trichlorosilane

2022

[21] Assay of blood glutathione oxidation during physical exercise

1995

Publisher Summary This chapter describes a method to accurately measure glutathione (GSH) and glutathione disulfide (GSSG) in the blood of humans and animals that perform physical exercise. With this method, it is possible to assess the oxidative stress associated with physical exercise by measuring changes in the blood GSH/GSSG ratio. Glutathione measurement is performed by a modification of the glutathione S -transferase method of Brigelius et al. This is based on the conjugation of chlorodinitrobenzene with GSH catalyzed by glutathione S -transferase. The adduct formed, S-(2,4-dinitrophenyl)glutathione, exhibits a maximum of absorbance at 340 nm. The precipitation of proteins is carried …