The hydroxylation of dehydroepiandrosterone (DHEA) to 7α -hydroxy-5-androstene-17-one (7α-OH-DHEA) and 7β-hydroxy-5-androstene-17-one (7β-OH-DHEA) by Gibberella sp. CICC 2498 and Absidia coerulea CICC 41050 was investigated. The media ingredients were optimized. Single factors such as the DHEA concentration, culture time, medium volume, and inoculum rate were individually investigated to generate optimum biotransformation conditions. An orthogonal optimization process using a four-factor, three- level L₉ (3³) experiment was designed and performed. Finally, the maximum production of 7β-OH-DHEA from DHEA biotransformation by Absidia coerulea is 69.61%. This strategy would provide a possible way to enhance the 7β-OH-DHEA yield in the pharmaceutical industry.

Pimavanserin is an approved selective 5-HT_2A receptor inverse agonist for treating Parkinson’s disease psychosis. However, few studies on its metabolism in vitro have been investigated. In this research, eight strains of fungi are used to study the pimavanserin metabolism profiles in vitro and six of them demonstrated positive transformation results. Factors influencing the transformation rate, like substrate concentration, culture time, initial media pH value, culture temperature, and shaking speed, were evaluated and optimized. Cunninghamella blakesleeana AS3.970 provided the best transformation rate of 30.31%, and 10 unreported metabolites were screened by LC-MS/MS. Among these metabolites, M1 is the major one and identified as 1-(4-fluorobenzyl)-3-(4-(2-hydroxy-2-methylpropoxy)benzyl)-1-(1-methylpiperidin-4-yl)urea, which is a hydroxylation product of the pimavanserin. A preliminary molecular docking simulation was performed, which indicated that M1 exhibits similar binding properties with pimavanserin and may become a potential candidate for Parkinson’s disease treatment.

Oxidation of β-aminoporphyrins with 4-acetamido-2,2,6,6-tetramethylpiperidine −1-oxoammonium tetrafluoroborate (Bobbitt's salt) provides an efficient synthesis of the corresponding 2,3-dioxochlorins. The synthesis is simple and exhibit good universality. In addition, Bobbitt's salt can be further applied to oxidize more aromatic amines. Preliminary studies have shown that aromatic amines with structures similar to 9-aminophenanthrene can be selectively oxidized to corresponding ortho-diketones.

Alkyl halides are a class of important organic feedstock with wide availability in organic synthesis. Minisci C-H alkylation is a classical radical-type reaction to effectively introduce alkyl groups into heteroaromatics. The attempt to utilize alkyl halides as radical precursors in Minisci reaction is challenging, which has attracted widespread attention. Although halogen-atom transfer (XAT) provides an available strategy to convert alkyl halides into corresponding carbon radicals, the usage of equivalent XAT reagents and excess oxidants is usually inevitable in Minisci reactions. Herein, we present a traceless aminoalkyl radical-induced XAT process for Minisci reaction, especially without the participation of excess XAT reagents and oxidants. This protocol is compatible with a wide array of sensitive functional groups. Mechanistic experiments indicated the formation of comparable aminoalkyl radicals occurred through SET reduction of protonated heteroaromatics, a process differing from the conventional oxidation method used to generate α-aminoalkyl radicals. Notably, this photocatalytic mode for such aminoalkyl radical generation and XAT-induced Minisci reaction contributes to a redox neutral strategy for coupling of two electrophilic molecules.

A mild visible-light-driven Ce(III)-catalyzed aerobic cross-dehydrogenative coupling between glycine derivatives and indoles is reported for the construction of α-indolylglycine scaffolds. Using inexpensive Ce(OTf) ₃ as the sole catalyst under air at room temperature; the protocol avoids external photosensitizers. The reaction accommodates diverse glycine esters and indoles, affording products in 35–79% yields.