Odor of earth: Several homomonoterpenes were identified in actinomycetes that produce 2‐methylisoborneol (2‐MIB, see scheme, which is responsible for an earthy odor in drinking water). Their occurrence clarifies the 2‐MIB pathway, because they are derived from cationic intermediates that are otherwise difficult to detect. A highly sensitive method using feeding experiments with 13C‐labeled precursors gives detailed insights into 2‐MIB biosynthesis.

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Geruch nach Erde: Eine Serie von Homomonoterpenen wurde in 2‐Methylisoborneol (2‐MIB) produzierenden Actinomyceten gefunden. Ihr Auftreten liefert ein detailliertes Bild der 2‐MIB‐Biosynthese, da sie aus kationischen Intermediaten entstehen, die anders schwierig zu beobachten sind. Eine hochempfindliche Methode für Fütterungsexperimente mit 13C‐markierten Vorstufen wurde entwickelt, die detaillierte mechanistische Einblicke in die 2‐MIB‐Biosynthese gewährte.

Alzheimer's disease (AD) is a neurodegenerative disorder that has a higher prevalence and incidence in people older than 60 years. The need for improved AD therapies is unmet as the current therapies are symptomatic with modest efficacy. Partial agonists of the 5-HT receptor (5-HTR) offer both symptomatic and disease-modifying treatments as they shift amyloid-precursor-protein (APP) processing from the amyloidogenic pathway to the nonamyloidogenic pathway by activating the α-secretase enzyme. In addition, they also offer symptomatic treatment by increasing levels of the neurotransmitter acetylcholine in the brain. Because of this fascinating dual mechanism of action, several chemical scaffolds having 5-HTR pharmacophores were designed and evaluated. Most of the synthesized compounds showed potent in vitro affinities and in vivo efficacies. Upon analysis of focused structure-activity relationships, compound 4o was identified as a potent 5-HTR partial agonist with favorable ADME properties and good in vivo efficacy. GR-125487, a selective 5-HTR antagonist, attenuated the activity of compound 4o in the novel-object-recognition-test cognition model.