Biotechnological Properties of Sponges from Northeast Brazil: Cliona varians as a Biocatalyst for Enantioselective Reduction of Carbonyl Compounds

To research the potential ability of whole marine sponges to act as biocatalysts, this paper describes for the first time the employment of whole Cliona varians sponge in the stereoselective reduction of prochiral a-keto esters and isatin to the corresponding chiral alcohols. The addition of D-fructose, D-glucose or sucrose remarkably increased the conversion ratios and stereoselectivities by this marine sponge. Furthermore, in the presence of D-glucose and D-maltose, the reduction of isatin by C. varians afforded the corresponding 3-hydroxyindolin-2-one with high conversions (85-90%) and good enantioselectivities (60-74%). These results showed that the marine sponge presents great potential to be used as biocatalyst for stereoselective reduction of carbonyl compounds.为探究完整海洋海绵作为生物催化剂（biocatalysts）的潜在应用能力，本文首次报道了采用完整脆针海绵（Cliona varians）将前手性α-酮酯（prochiral α-keto esters）与靛红（isatin）经立体选择性还原（stereoselective reduction）反应转化为对应手性醇（chiral alcohols）的研究。添加D-果糖（D-fructose）、D-葡萄糖（D-glucose）或蔗糖（sucrose）可显著提升该海洋海绵催化体系的转化率（conversion ratios）与立体选择性（stereoselectivities）。此外，在D-葡萄糖与D-麦芽糖（D-maltose）存在的条件下，脆针海绵还原靛红可得到目标产物3-羟基吲哚啉-2-酮（3-hydroxyindolin-2-one），其转化率可达85%~90%，对映选择性（enantioselectivities）良好（60%~74%）。上述结果表明，该海洋海绵具备作为羰基化合物（carbonyl compounds）立体选择性还原用生物催化剂的巨大应用潜力。