The site-selective functionalization of unactivated allylic C-H bonds via direct deprotonation using KTMP is described. The conversion of amorphadiene to artemisinic alcohol via a simple, highly regioselective deprotonation over 4 other possible allylic sites is shown with further extrapolation to the first large-scale telescoped chemical synthesis of artemisinic acid from amorphadiene. Finally, application of the method for the successful site-selective functionalization of unactivated allylic C-H bonds in other terpene-based natural products is also highlighted.
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http://dx.doi.org/10.1021/acs.orglett.2c04145 | DOI Listing |
J Am Chem Soc
January 2025
Department of Chemistry, Queen's University, Kingston, ON K7L 3N6, Canada.
Tambjamines are complex bipyrrole-containing natural products that possess promising bioactive properties. Although is known to produce both cyclic tambjamine MYP1 and the linear precursor (YP1), the biosynthetic machinery used to catalyze the site-selective oxidative carbocyclization at the unactivated 1° carbon of YP1 has remained unclear. Here, we demonstrate that a three-component Rieske system consisting of an oxygenase (TamC) and two redox partner proteins is responsible for this unprecedented activity on YP1 and potentially, a non-native substrate (BE-18591).
View Article and Find Full Text PDFPLoS One
January 2025
Manchester Cancer Research Centre, Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom.
Non-covalent protein-protein interactions are one of the most fundamental building blocks in cellular signalling pathways. Despite this, they have been historically hard to identify using conventional methods due to their often weak and transient nature. Using genetic code expansion and incorporation of commercially available unnatural amino acids, we have developed a highly accessible method whereby interactions between biotinylated ubiquitin-like protein (UBL) probes and their binding partners can be stabilised using ultraviolet (UV) light-induced crosslinks.
View Article and Find Full Text PDFOrg Lett
January 2025
State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, People's Republic of China.
KOBu-promoted [3 + 2] cycloaddition of dimethyl sulfoxide (DMSO) with fullerenes has been developed for facile and efficient one-pot synthesis of 1,2,3,4-cyclic sulfoxide-fused [60]/[70]fullerene dihydrides, which offers a versatile platform for the site-selective preparation of various fullerene multiadducts with a wide range of functional groups. The utility of these tetra-functionalized fullerenes is demonstrated by the successful application as electron-transport materials in perovskite solar cells.
View Article and Find Full Text PDFChemistry
January 2025
National University of Singapore, Chemistry, 4 Science Drive 2, S9-12-01G, 117544, Singapore, SINGAPORE.
Ribonucleic acid (RNA) plays a pivotal role in regulating biological processes within living systems, with modified nucleosides serving as critical modulators of various aspects of biological functions. Therefore, the development of efficient methodologies for late-stage, site-selective RNA modification is of considerable interest, as it facilitates the functional exploration of RNA chemical modifications and their implications for therapeutic applications. Precise RNA modification holds significant promise for the treatment of genetic diseases by enabling the correction of mutated nucleobases to their wild-type forms.
View Article and Find Full Text PDFMolecules
January 2025
Department of Chemistry, Technical University of Denmark, 206 Kemitorvet, 2800 Kgs Lyngby, Denmark.
A human epidermal growth factor receptor 2 (HER2)-specific nanobody called 2Rs15d, containing a His3LysHis6 segment at the C-terminus, was recombinantly produced. Subsequent site-selective acylation on the C-terminally activated lysine residue allowed installation of the cytotoxin monomethyl auristatin E-functionalized cathepsin B-sensitive payload to provide a highly homogenous nanobody-drug conjugate (NBC), which demonstrated high potency and selectivity for HER2-positive breast cancer models.
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