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Transformation of Natural Products by Marine-Derived Microorganisms
Published in Se-Kwon Kim, Marine Biochemistry, 2023
Thayane Melo de Queiroz, André Luiz Meleiro Porto
In a recent study, regioselective oxidation of dibenzylbutyrolactolic lignan (-)-cubebin to (-)-hinokinin was promoted by the marine-derived fungus Absidia coerulea 3A9, which was isolated from the ascidian Distaplia stilyfera. The bio-oxidation reaction was optimised by varying some experimental factors, such as percentage of nitrogen source (%N source), the percentage of sucrose (%sucrose), the percentage of seawater (%seawater), pH, and temperature. The reaction carried out in Czapek medium (0.3% N source, 2% sucrose, 100% seawater, pH 8.0), at 28°C and 120 rpm for 13 days, obtaining (-)‑hinokinin (27.6%) with the highest yield. The biotransformation product was characterised by NMR (Figure 5.18; De Souza et al., 2021).
Oxidative biotransformation of stemofoline alkaloids
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2021
Manlika Phaya, Sirinrat Chalom, Kornkanok Ingkaninan, Kontad Ounnunkad, Nopakarn Chandet, Stephen G. Pyne, Pitchaya Mungkornasawakul
The biotransformations were carried out in Czapek medium which consisted of glucose 30 g, sodium nitrate 2.0 g, monopotassium phosphate 1.0 g, magnesium sulphate 5.0 g, potassium chloride 5.0 g, and iron sulphate 0.01 g and distilled water 1 L (final pH 7.3 ± 0.2). The broth was autoclaved in individual Erlenmeyer flasks at 121 °C, 15 psi pressure for 15 min and cooled before incubation. Small scale reactions were conducted using 125 mL flasks containing 25 mL of broth with a loop of spores obtained from a freshly growing agar slant. After that 5.0 mg of stemofoline (1a), (2′S)-hydroxystemofoline (2a) or (11Z)-1′,2′-didehydrostemofoline (3a) were added into each 25 mL of broth. The cultures were incubated on a rotary shaker at 160 rpm and 30 °C according to a one-stage fermentation procedure. The fermentation periods for 1a, 2a and 3a were 15, 35 and 30 days, respectively. After the incubation period, the microorganism was separated from the media by filtration using a Buchner funnel. The filtrate was extracted with CH2Cl2 (x 3). The organic solvent was evaporated under reduced pressure to give the crude product.