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Neurosteroids: metabolism and activities
Published in Barry G. Wren, Progress in the Management of the Menopause, 2020
Both PREG and DHEA are found in conjugated forms, sulfate esters and fatty acid esters (’lipoidal′), whose concentrations are frequently equal or superior to those of the corresponding free steroids (Table 1). Preliminary evidence has been obtained for a low sulfotransferase activity (Rajkowski and co-workers, in press); however, it can not be excluded that there is formation of steroid sulfate-containing lipidic complexes (’sulfolipids’)28. The enzymes corresponding to the widely distributed steroid sulfatase activities of the brain have not been cloned. Major conjugation forms of PREG and DHEA in the brain are their fatty acid esters29, designated ‘lipoidal’ derivatives30. The acyltransferase responsible for their formation is enriched in the microsomal fraction of the brain31 and its activity is highest at the time of myelin formation.
Antibacterial Activity of Seaweeds and their Extracts
Published in Leonel Pereira, Therapeutic and Nutritional Uses of Algae, 2018
In the studies done by El Baz et al. (2013), marine algal sulfolipids (SLs) presented a high growth inhibition of the bacterial strains (B. subtilis and E. coli) at the concentration of 100 gg/well. The highest bacterial growth inhibition was obtained by Taonia atomaria sulifolipids (15.0 mm) against E. coli and Dictyota fasciola (formerly Dilophus fasciola) sulfolipids (8 mm) showed the lowest growth inhibition against the same bacterium. Rajauria et al. (2013) report the antimicrobial activity of various methanolic extracts of Himanthalia elongata by using the disc diffusion method. Various food spoilage bacteria such as Enterococcus faecalis and Pseudomonas aeruginosa, and pathogenic bacteria such as Listeria monocytogenes and Salmonella abony were used to determine the antibacterial activities of brown seaweed aqueous methanolic extracts and synthetic compounds by disc diffusion assay. The zone of inhibition of seaweed extracts was measured by using the reference of the inhibition exhibited by synthetic food antimicrobials.
Phosphatidate Phosphohydrolase in Plants and Microorganisms
Published in David N. Brindley, John R. Sabine, Phosphatidate Phosphohydrolase, 2017
J. L. Harwood, M. J. Price-Jones
The synthesis of the third major glycolipid, sulfoquinovosyldiacylglycerol, remains an enigma.29 However, recent studies have managed to demonstrate the expected formation of this sulfolipid in chloroplasts.30 Again the diacylglycerol which is, presumably, necessary for its synthesis29 can come from both internal and external plastid sources depending on the plant type.30a These interactions for glycolipid formation are summarized in Figure 5.
Distribution and metabolism of 14C-sulfoquinovosylacylpropanediol (14C-SQAP) after a single intravenous administration in tumor-bearing mice
Published in Xenobiotica, 2019
Tatsushi Ruike, Yoshihiro Kanai, Kazuki Iwabata, Yuki Matsumoto, Hiroshi Murata, Masahiro Ishima, Keisuke Ohta, Masahiko Oshige, Shinji Katsura, Koji Kuramochi, Shinji Kamisuki, Hiroeki Sahara, Masahiko Miura, Fumio Sugawara, Kengo Sakaguchi
Sulfolipids are common secondary metabolites that are widely found in photosynthetic bacteria, algae and higher plants and are mostly food components. Investigations have shown that both SQAG and SQAP have almost no toxic effects following oral administration. This was expected since SQAG is also a component of food plants and SQAP is a derivative. When directly injected in vivo, both SQAG and SQAP bound to vascular endothelial growth factor (VEGF) and then reduced the focal adhesion kinase phosphorylation originated from its interaction with VEGF (Izaguirre-Carbonell et al., 2015). Subsequently, anti-angiogenesis caused by both SQAG and SQAP occurred.
Xenobiotic C-sulfonate derivatives; metabolites or metabonates?
Published in Xenobiotica, 2018
Sulfoquinovose (6-deoxy-6-sulfo-D-glucopyranose) is a sulfonic acid derivative of glucose present in plants as part of the sulfolipid, sulfoquinovosyldiacylglycerol, an important component of their thylakoid membranes and the site of the light dependent reactions of photosynthesis. Amendments to the previously proposed biosynthetic “sulphoglycolytic” pathway (Benson, 1963; Davies et al., 1966) have suggested that sulfite may be added across the double bond of a modified sugar, UDP-4-ketoglucose-5-ene (Pugh et al., 1995). An enzyme, UDP-sulfoquinovase synthase (EC 3.13.1.1), has been isolated from the small flowering plant, thale cress (Arabidopsis thaliana), that is able to introduce the sulfonate moiety by combining UDP-glucose with sulfite, albeit with a low turnover rate (Sanda et al., 2001). A group of sulfonolipids, known as capnoids, have been isolated from gliding bacteria (Cytophaga spp.), the most extensively studied of which is capnine (2-amino-3-hydroxy-15-methylhexadecane-1-sulfonic acid). This material is formed by the condensation of a fatty acyl CoA with cysteic acid (HO3SCH2CH(NH)CO2H) (Abbanat et al., 1985). Cysteic acid may be formed readily from cysteine by a two-step oxygenation reaction (cysteine → cysteine sulfinic acid → cysteic acid) but radiolabelled cysteine was not incorporated into capnine by these bacteria (White, 1984). As an alternative, it has been suggested that cysteic acid could be formed from sulfite condensing with a suitable organic acceptor and then the sulfur being further oxidized (Chapeville & Fromageot, 1954; Greenberg, 1954; Singer & Kearney, 1955) or even via the use of sulfate (Gilmore et al., 1989). In any event, the sulfonic acid moiety is added as part of the larger cysteic acid molecule and hence capnoid synthesis does not involve a carbon sulfonation reaction.
Healthy Intestinal Function Relies on Coordinated Enteric Nervous System, Immune System, and Epithelium Responses
Published in Gut Microbes, 2021
Fatima B. Saldana-Morales, Dasom V. Kim, Ming-Ting Tsai, Gretchen E. Diehl
In other mucosal sites like the lungs, mechanical responses like coughing can result in increased bacterial spread.121,122Mycobacterium tuberculosis (Mtb) glycolipid sulfolipid-1 (SL-1) activates nociceptive neurons in vitro, and Mtb lacking SL-1 cannot stimulate a cough response in vivo.114,123 As above, it will be interesting to identify if similar signaling occurs in the intestine.