Publications by Year: 2016

2016
Nikolaou A, Kokotos G, Magrioti V. Efficient microwave-assisted synthesis of hydroxymethyl ketones using NHC organocatalysts. Tetrahedron. 2016;72:7628-7632.Abstract
Hydroxymethyl ketones are useful auxiliaries in organic synthesis and are also found in several medicinal agents. N-Heterocyclic carbenes (NHCs) have been used in the literature in order to introduce the hydroxymethyl group into aromatic aldehydes in good yields, but they are not that successful for aliphatic aldehydes. In the present work, the use of microwave irradiation has been efficiently incorporated into this organocatalytic synthesis of aromatic, but more importantly of aliphatic hydroxymethyl ketones that can be used as precursors for medicinally interesting compounds.
Antonopoulou G, Magrioti V, Kokotou MG, Nikolaou A, Barbayianni E, Mouchlis VD, Dennis EA, Kokotos G. 2-Oxoamide inhibitors of cytosolic group IVA phospholipase A2 with reduced lipophilicity. Bioorganic and Medicinal Chemistry. 2016;24:4544-4554.Abstract
Cytosolic GIVA phospholipase A2 (GIVA cPLA2) initiates the eicosanoid pathway of inflammation and thus inhibitors of this enzyme constitute novel potential agents for the treatment of inflammatory diseases. Traditionally, GIVA cPLA2 inhibitors have suffered systemically from high lipophilicity. We have developed a variety of long chain 2-oxoamides as inhibitors of GIVA PLA2. Among them, AX048 was found to produce a potent analgesic effect. We have now reduced the lipophilicity of AX048 by replacing the long aliphatic chain with a chain containing an ether linked aromatic ring with in vitro inhibitory activities similar to AX048.
Vasilakaki S, Barbayianni E, Magrioti V, Pastukhov O, Constantinou-Kokotou V, Huwiler A, Kokotos G. Inhibitors of secreted phospholipase A2 suppress the release of PGE2 in renal mesangial cells. Bioorganic and Medicinal Chemistry. 2016;24:3029-3034.Abstract
The upregulation of PGE2 by mesangial cells has been observed under chronic inflammation condition. In the present work, renal mesangial cells were stimulated to trigger a huge increase of PGE2 synthesis and were treated in the absence or presence of known PLA2 inhibitors. A variety of synthetic inhibitors, mainly developed in our labs, which are known to selectively inhibit each of GIVA cPLA2, GVIA iPLA2, and GIIA/GV sPLA2, were used as tools in this study. Synthetic sPLA2 inhibitors, such as GK115 (an amide derivative based on the non-natural amino acid (R)-γ-norleucine) as well as GK126 and GK241 (2-oxoamides based on the natural (S)-α-amino acid leucine and valine, respectively) presented an interesting effect on the suppression of PGE2 formation.