Biocatalytic synthesis of oxa(thia)diazole aryl thioethers.

A novel approach for the synthesis of 1,3,4-oxa(thia)diazole aryl thioethers through a biocatalytic strategy has been introduced. By leveraging Myceliophthora thermophila laccase (Novozym 51003) as a catalyst, catechol undergoes oxidation to ortho-quinone, facilitating subsequent 1,4-thia-Michael addition reactions. The method offers efficiency and mild reaction conditions, demonstrating promise for sustainable synthesis pathways in organic chemistry.

Primary Malignant Melanoma of the Small Intestine Presenting with Peritonitis: A Case Report.

Malignant melanoma of the small intestine is mostly a metastatic tumor of other primary lesions, especially of skin origin. Primary malignant melanoma of the small intestine is very uncommon. The clinical presentation is usually nonspecific, thus leading to late diagnosis.

Biocatalytic synthesis of oxadiazole thioethers and evaluation of their antitumor activity.

A multicomponent enzyme-catalyzed process is suggested for the synthesis of a novel series of 1,3,4-oxadiazole thioether derivatives with yields ranging from 65 to 94%. Novozym 435, the immobilized form of lipase B (CALB), was found to efficiently catalyze the reaction. The products were evaluated for antitumor activities against two cancer cell lines, HT-29 (human colorectal cancer cell) and HepG2 (human liver cancer cell), by MTT assays.

Biocatalytic decarboxylative Michael addition for synthesis of 1,4-benzoxazinone derivatives.

The Candida antarctica lipase B (Novozym 435) is found to catalyze a novel decarboxylative Michael addition in vinylogous carbamate systems for the synthesis of 1,4-benzoxazinone derivatives. The reaction goes through Michael addition, ester hydrolysis and decarboxylation. A possible mechanism is suggested, with simultaneous lipase-catalyzed Michael addition and ester hydrolysis.

Effect of Concentrated Salts Solutions on the Stability of Immobilized Enzymes: Influence of Inactivation Conditions and Immobilization Protocol.

This paper aims to investigate the effects of some salts (NaCl, (NH)SO and NaSO) at pH 5.0, 7.0 and 9.

Porcine pancreas lipase as a green catalyst for synthesis of bis-4-hydroxy coumarins.

4-Hydroxycoumarins represents an important structural motif in life sciences molecules with remarkable biological properties. 4-Hydroxycoumarins are important precursors in the synthesis of organic compounds and critical pharmacophores in medicinal chemistry. One of the derivatives of this compound is biscoumarin, which has anticoagulant medicinal properties.