Synthesis of a Seco -Secologanin Aglycone Analogue of Interest toward Secoiridoids and Monoterpene Indole Alkaloids.

We report the access to an acyclic -secologanin aglycone analogue relevant to secoiridoids and monoterpene indole alkaloids. Its synthesis involved the regioselective allylic alkylation of a linear dienyl carbonate with dimethyl malonate, which was catalyzed by an iridium complex, and an anti-Markovnikov Wacker-type oxidation of the terminal alkene of the branched product that was obtained. The thus-formed aldehyde was engaged in a Pictet-Spengler reaction with tryptamine toward monoterpene indole alkaloids.

Bioinspired Early Divergent Oxidative Cyclizations toward Pleiocarpamine, Talbotine, and Strictamine.

Toward the mavacurane and akuammilane monoterpene indole alkaloids, we developed divergent oxidative couplings between the indole nucleus (at N1 or C7) and the C16-malonate of a common tricyclic model related to strictosidine according to a biosynthetic hypothesis postulated by Hesse and Schmid. These oxidative cyclizations led selectively to the formation of the N1-C16 bond of pleiocarpamine or to the C7-C16 bond of strictamine. We were then able to obtain the scaffold of talbotine.

A subset of flavaglines inhibits KRAS nanoclustering and activation.

The RAS oncogenes are frequently mutated in human cancers and among the three isoforms (, and ), is the most frequently mutated oncogene. Here, we demonstrate that a subset of flavaglines, a class of natural anti-tumour drugs and chemical ligands of prohibitins, inhibit RAS GTP loading and oncogene activation in cells at nanomolar concentrations. Treatment with rocaglamide, the first discovered flavagline, inhibited the nanoclustering of KRAS, but not HRAS and NRAS, at specific phospholipid-enriched plasma membrane domains.

Prohibitin ligands: a growing armamentarium to tackle cancers, osteoporosis, inflammatory, cardiac and neurological diseases.

Over the last three decades, the scaffold proteins prohibitins-1 and -2 (PHB1/2) have emerged as key signaling proteins regulating a myriad of signaling pathways in health and diseases. Small molecules targeting PHBs display promising effects against cancers, osteoporosis, inflammatory, cardiac and neurodegenerative diseases. This review provides an updated overview of the various classes of PHB ligands, with an emphasis on their mechanism of action and therapeutic potential.

Electrochemical synthesis of 3a-bromofuranoindolines and 3a-bromopyrroloindolines mediated by MgBr.

We report an efficient and environmentally friendly electrochemical approach to perform the bromo cyclization of tryptophol, tryptamine and tryptophan derivatives. The 3a-bromofuranoindolines and 3a-bromopyrroloindolines obtained are of interest in the total synthesis of natural products. This dearomative procedure relies on the generation of an electrophilic bromine reagent by the electrochemical oxidation of MgBr2.

PHB2 (prohibitin 2) promotes PINK1-PRKN/Parkin-dependent mitophagy by the PARL-PGAM5-PINK1 axis.

Mitophagy, which is a conserved cellular process for selectively removing damaged or unwanted mitochondria, is critical for mitochondrial quality control and the maintenance of normal cellular physiology. However, the precise mechanisms underlying mitophagy remain largely unknown. Prior studies on mitophagy focused on the events in the mitochondrial outer membrane.

The mTOR-S6 kinase pathway promotes stress granule assembly.

Stress granules are cytoplasmic mRNA-protein complexes that form upon the inhibition of translation initiation and promote cell survival in response to environmental insults. However, they are often associated with pathologies, including neurodegeneration and cancer, and changes in their dynamics are implicated in ageing. Here we show that the mTOR effector kinases S6 kinase 1 (S6K1) and S6 kinase 2 (S6K2) localise to stress granules in human cells and are required for their assembly and maintenance after mild oxidative stress.

Scalable 9-Step Synthesis of the Splicing Modulator NVS-SM2.

NVS-SM2, the first activator of pre-mRNA splicing, displays remarkable pharmacological in vivo activities in models of spinal muscular atrophy. Herein we describe an improved approach to the synthesis of this compound, which features a convenient introduction of sterically encumbered amine moiety onto a fluoropyridazine intermediate.

Flavagline analog FL3 induces cell cycle arrest in urothelial carcinoma cell of the bladder by inhibiting the Akt/PHB interaction to activate the GADD45α pathway.

Background: Prohibitin 1 (PHB) is a potential target for the treatment of urothelial carcinoma of the bladder (UCB). FL3 is a newly synthesized agent that inhibits cancer cell proliferation by targeting the PHB protein; however, the effect of FL3 in UCB cells remains unexplored.

Methods: FL3 was identified to be a potent inhibitor of UCB cell viability using CCK-8 (cell counting kit-8) assay.

CUG initiation and frameshifting enable production of dipeptide repeat proteins from ALS/FTD C9ORF72 transcripts.

Expansion of GC repeats in the C9ORF72 gene is the most prevalent inherited form of amyotrophic lateral sclerosis and frontotemporal dementia. Expanded transcripts undergo repeat-associated non-AUG (RAN) translation producing dipeptide repeat proteins from all reading frames. We determined cis-factors and trans-factors influencing translation of the human C9ORF72 transcripts.