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The transcription factor Oct4 can rightfully be considered a pivotal element in maintaining pluripotency. In addition, its ability to function as a pioneer factor enables the reprogramming of somatic cells back into a pluripotent state. To better understand the regulation of the Oct4-encoding gene ( Pou5f1 ), the main genetic elements that regulate its expression in different states of pluripotency ought to be identified. While some elements have been well characterized for their ability to drive Pou5f1 expression, others have yet to be determined. In this work, we show that translocation of the Pou5f1 gene fragment purported to span all essential cis -elements, including the well-known distal and proximal enhancers (DE and PE), into the Rosa26 locus impairs the self-renewal of mouse embryonic stem cells (ESCs) in the naïve pluripotency state, as well as their further advancement through the formative and primed pluripotency states, inducing overall differentiation failure. These results suggest that regulatory elements located outside the previously determined Pou5f1 boundaries are critical for the proper spatiotemporal regulation of this gene during development, indicating the need for their better characterization.

The β-carboline motif is common in drug discovery and among numerous biologically active natural products. However, its synthetic preparation relies on multistep sequences and heavily depends on the type of substitution required in the core of the desired β-carboline target. Herein, we demonstrate that this structural motif can be accessed with the microwave-assisted electrocyclic cyclization of heterotrienic aci (alkylideneazinic acid) forms of 3-nitrovinylindoles. The reaction can start with 3-nitrovinylindoles themselves under two sets of conditions. The first one involves microwave irradiation of butanolic solutions of 3-nitrovinylindoles, whereas the second one consists of prior Boc protection of indolic nitrogen, where the protecting group cleanly comes off during the course of the reaction. Alternatively, the reaction can start with 3-nitrovinylindoles prepared in situ using various processes. Finally, the reaction may utilize indoles with β-nitrostyrenes, likely involving the intermediacy of spirocyclic oxazolines, which rearrange to similar heterotrienic systems undergoing cyclization to β-carbolines. As part of this study, several natural products, namely, alkaloids norharmane, harmane, and eudistomin N, were synthesized.