Hukum P. Acharya

2,6-Disubstituted and 2,2,6-trisubstituted piperidines from serine: asymmetric synthesis and further elaboration.

4-Hydroxy-3,4-dihydro-2H-pyridine-1-carboxylic acid benzyl esters, which are readily prepared from serine and terminal acetylenes, undergo Claisen rearrangement to piperidine derivatives when heated with butyl vinyl ether in the presence of Hg(OAc)(2) and Et(3)N. This route to optically pure piperidines having substituents alpha to nitrogen is general, and the rearrangement products are versatile intermediates for making a broad range of amines containing a substituted piperidine subunit.

First total synthesis of macrosphelides C and F

Abstract Macrosphelides C and F were synthesized by lactonization of 14-oxo seco acids at the O(10) C(11) bond followed by reduction and Mitsunobu inversion of the resulting hydroxyl group. The seco acids were prepared from the corresponding furans by furan ring-opening with NBS followed by further oxidation of the 4-oxo-2-alkenals with NaClO 2 .

High-performance affinity purification for identification of 15-deoxy-Δ12,14-PGJ2 interacting factors using magnetic nanobeads

Prostaglandin J₂ (PGJ₂) family have been reported to show various kinds of biological activities. Considerable progress has been made toward understanding the mechanism of adipogenesis, however, the mechanisms of other actions of PGJ₂ family remain controversial. The 15-deoxy-Δ(12,14) -PGJ₂ (15d-PGJ₂) is one of the members of PGJ₂ family, and is known as a ligand for peroxisome proliferator-activated receptor γ (PPARγ), which promotes the expression of the crucial genes for adipogenesis. In this study, we found that 15d-PGJ₂ did not stimulate PPARγ-mediated gene expression in HEK293 cells whereas 15d-PGJ₂ transactivated PPARγ-dependent transcription in other cell lines. Moreover, we confirmed that 15d-PGJ₂ suppressed the growth of HEK293 cells. These observations suggest that 15d-PGJ₂ shows another biological activity e.g. growth inhibition in HEK293 cells via unknown receptor for 15d-PGJ₂. The aim of this study is to develop and validate effective purification system for PGJ₂ interacting factors (PGJIFs). We have recently developed high performance magnetic nanobeads. In this study, we have newly developed 15d-PGJ₂-immobilized beads by conjugating 15d-PGJ₂ to the surface of these nanobeads. Firstly, we showed that PPARγ specifically bound to 15d-PGJ₂-immobilized beads. Secondly, we newly identified voltage dependent anionic channel 1 (VDAC1) as new PGJIF from crude extracts of HEK293 cells using this affinity purification system. These data presented here demonstrate that 15d-PGJ₂-immobilized beads are effective tool for purification of PGJIFs directly from crude cell extracts.

Synthesis of 14,15-epoxyisoprostane A2 phosphorylcholine

The product of the copper-promoted allylic substitution of the 4-hydroxycyclopent-2-enyl ester with TMS-C≡CCH 2 MgBr was converted to the cyclopentenone with the PMBO(CH 2 ) 4 CH=CHCH 2 side chain. Aldol reaction of the enone with the epoxy aldehyde derived from (E)-oct-2-en-1-ol through the Sharpless asymmetric epoxidation gave the full structure of the isoprostane. Dehydration, conversion of the PMBOCH 2 moiety to CO 2 H, and condensation with lysophosphorylcholine produced the title molecule.