Search results for "IAC"
showing 10 items of 4189 documents
Micēlijsēņu pielietojuma iespējas celulozes un celulozes acetāta biodegradēšanai
2021
Signe Vadone (2021): Micēlijsēņu pielietojuma iespējas celulozes un celulozes acetāta biodegradēšanai. Darbā salīdzināta 12 dažādu micēlijsēņu augšana uz dažādiem celulozes (C) un celulozes acetāta (CA) paraugiem – smēķētiem un nesmēķētiem cigarešu filtriem un to ārējiem apvalkiem, kā arī rūpnieciski neapstrādātiem celulozes un celulozes acetāta paraugiem. Veikta arī CA filtru inkubēšana augsnē kopā ar labāk augušajām micēlijsēnēm. Novērtētas micēlijsēņu augšanas tendences un cigarešu filtru masas un CA struktūras izmaiņas cigarešu filtru plastificējošās saistvielas – glicerīna triacetāta ietekmē. Noskaidrots, ka vislabāk uz cigarešu filtriem aug Aspergillus niger 137.3, Stachybotrys charta…
Composition and biological activities of the essential oil from a Sicilian accession of Prangos ferulacea (L.) Lindl
2019
Prangos ferulacea (L.) Lindl. (Fam. Apiaceae), is an orophilous species of eastern Mediterranean and western Asia which possesses several biological properties, which are worthy of exploitation in different fields. With the aim to provide new insights into the phytochemistry and pharmacology of this species, a local accession growing in Sicily (South Italy) was investigated as well. Notably, the P. ferulacea essential oil chemical composition and the antioxidant, anti-acetylcholinesterase (AChE) and cytotoxic activities have been studied. This analysis allowed to identify a new chemotype and to report good biological results for this oil. © 2019 Informa UK Limited, trading as Taylor & F…
Chemical constituents from Phlomis bovei Noë and their chemotaxonomic significance
2020
Abstract A phytochemical investigation of the leaves and roots of Phlomis bovei Noe (Lamiaceae) led to the isolation of sixteen compounds, including iridoids (1, 2, 3), megastigmanes (4, 5), phenylpropanoids (6, 7, 8, 9, 10), lignans (11, 12, 13, 14), a nortriterpene (15), and a phenyl glucoside (16). Compounds (1, 2, 4, 5, 6, 10) were obtained from the leaves and compounds (1, 2, 3, 7, 8, 9, 11, 12, 13, 14, 15, 16) were isolated from the roots. Compounds 1 and 2 were found both in the leaves and in roots. The compounds were identified by analysis of 1D- (1H, 13C), 2D-NMR (1H–1H COSY, TOCSY, ROESY, HSQC, HMBC) spectroscopic data, mass spectrometry (ESI- and HR-ESI-MS), and by comparison wit…
Citrate permease gene expression inLactococcus lactissubsp.lactisstrains IL1403 and MG1363
1996
Citrate permease gene expression in the plasmid-free Lactococcus lactis strains IL1403 and MG1363 was studied. The ability to transport citrate results in diacetyl and acetoin production in IL1403 but not in MG1363. Citrate lyase, α-acetolactate decarboxylase, diacetyl and acetoin reductase were detected in IL1403. These data show that L. lactis ssp. lactis strain IL1403 is a citrate permease mutant of the biovar. diacetylactis. Immunological analysis revealed the α-and β-subunits of citrate lyase not only in IL1403 but also in MG1363 where no citrate lyase activity was found.
Chemical constituents from Anthocleista liebrechtsiana De Wild & T. Durand (Loganiaceae)
2018
Abstract A new steroid derivative, (24S)-3β-hydroxy-7β-methoxyergost-5-ene (1), was isolated along with eleven known compounds: 7α-hydroxysterol (2), β-sitosterol (3), oleanolic acid (4), betulinic acid (5), lupeol (6), swertiaperennin (7), decussatin (8), tetracosanoic acid (9) β-sitosterol-3-O-β- d -glucopyranoside (10), (2R,3S)-2,3-dihydro-2-(3,4-dimethoxyphenyl)-3-hydroxymethyl-5-(2-formylvinyl)-7-hydroxybenzofuran (11) and acacetin 6-C-β- d -glucopyranoside (12) from the tree bark and leaves of Anthocleista liebrechtsiana De Wild & T. Durand. Their structures were elucidated on the basis of spectroscopic (1D and 2D NMR) and mass spectrometric data. Compounds 2 and 7–10 have already bee…
Utilizing genetically engineered bacteria to produce plant-specific glucosides
2001
Plant-derived glucosides have attracted much attention due to their widespread applications. This class of products is difficult to isolate or to synthesize in pure form because of the resulting low yields. Thus, simple approaches for the generation of such glucosides would be highly beneficial. We purified and characterized a novel glucosyltransferase from plant cell suspension cultures of Rauvolfia serpentina, which showed rather low substrate specificity. We obtained its cDNA and expressed the active recombinant protein in bacteria (Escherichia coli) with excellent plant-specific glucosylation efficiencies. Compared with the plant system, the bacteria delivered the new enzyme, which was …
Excitation energy transfer in isolated chlorosomes from Chloroflexus aurantiacus
2009
Abstract Chlorosomes from green photosynthetic bacteria Chloroflexus aurantiacus have been studied by time-resolved femtosecond transient absorption spectroscopy. The fastest kinetics of 200–300 fs resolved, was interpreted to stem for intra-chlorosomal excitation energy transfer. Energy transfer from the antenna to the baseplate appeared as a major 9.2 ps rise component detected at the baseplate probe wavelength. Excitation energy transfer rates were evaluated for a model chlorosome. Calculated rod to rod, and rods to baseplate rate constants of 200–400 fs and 10–20 ps, respectively, are in accord with the experimental results.
Excitation Energy Transfer in Isolated Chlorosomes from Chlorobaculum tepidum and Prosthecochloris aestuarii
2012
Excitation energy transfer in chlorosomes from photosynthetic green sulfur bacteria, Chlorobaculum (Cba.) tepidum and Prosthecochloris (Pst.) aestuarii, have been studied at room temperature by time-resolved femtosecond transient absorption spectroscopy. Bleach rise times from 117 to 270 fs resolved for both chlorosomes reflect extremely efficient intrachlorosomal energy transfer. Bleach relaxation times, from 1 to 3 ps and 25 to 35 ps, probed at 758 nm were tentatively assigned to intrachlorosomal energy transfer based on amplitude changes of the global fits and model calculations. The anisotropy decay constant of about 1 ps resolved at 807 nm probe wavelength for the chlorosomes from Chlo…
Effects of tributyltin(IV) chloride on fertilization ofStyela plicata(Ascidiacea: Tunicata): II. Scanning and transmission electron microscopy studies
2003
The morphological aspects of Styela plicata fertilization after treatment with tributyltin(IV) chloride are described by means of scanning and transmission electron microscopy investigations. Alterations have been shown both on female and male gametes; spermatozoa, all the egg envelopes and the mitochondria of the egg cortical cytoplasm are modified in relation to incubation time. As a consequence, the damage to gametes blocks sperm–egg interaction and fertilization does not occur. Copyright © 2003 John Wiley & Sons, Ltd.