- Structure-activity relationships of 2-aminothiazoles effective against Mycobacterium tuberculosis
-
A series of 2-aminothiazoles was synthesized based on a HTS scaffold from a whole-cell screen against Mycobacterium tuberculosis (Mtb). The SAR shows the central thiazole moiety and the 2-pyridyl moiety at C-4 of the thiazole are intolerant to modification. However, the N-2 position of the aminothiazole exhibits high flexibility and we successfully improved the antitubercular activity of the initial hit by more than 128-fold through introduction of substituted benzoyl groups at this position. N-(3-Chlorobenzoyl)-4-(2-pyridinyl) -1,3-thiazol-2-amine (55) emerged as one of the most promising analogues with a MIC of 0.024 μM or 0.008 μg/mL in 7H9 media and therapeutic index of nearly ~300. However, 55 is rapidly metabolized by human liver microsomes (t1/2 = 28 min) with metabolism occurring at the invariant aminothiazole moiety and Mtb develops spontaneous low-level resistance with a frequency of ~10-5.
- Meissner, Anja,Boshoff, Helena I.,Vasan, Mahalakshmi,Duckworth, Benjamin P.,Barry III, Clifton E.,Aldrich, Courtney C.
-
p. 6385 - 6397
(2013/10/22)
-
- Hypervalent Iodine Oxidation of Silyl Enol Ethers. A Direct Route to α-Hydroxy Ketones
-
Hypervalent iodine oxidation of various silyl enol ethers (aromatic, heteroaromatic, and aliphatic) using iodosobenzene-boron trifluoride diethyl ether-water provides a general and direct route for the α-hydroxylation of ketones.The structures of 2-hydroxy- (8) and 3-hydroxy-acetylpyridine (9) are discussed as well as the scope and mechanism of the reaction.
- Moriarty, Robert M.,Duncan, Michael P.,Prakash, Om
-
p. 1781 - 1784
(2007/10/02)
-
- Hypervalent Iodine Oxidation of Enol Silyl Ethers using Boron Trifluoride Etherate. A Direct Route to Aryl Hydroxymethyl Ketones
-
Enol silyl ethers of acetophenones and acetylpyridines are oxidized to hydroxymethyl aryl ketones (ω-hydroxyacetophenones) and hydroxyacetylpyridines, respectively, using the system iodosobenzene/boron trifluoride etherate/water.
- Moriarty, Robert M.,Prakash, Om,Duncan, Michael P.
-
p. 943 - 944
(2007/10/02)
-
- 2-Acetylpyridine thiosemicarbazones XI: 2-(α-hydroxyacetyl)pyridine thiosemicarbazones as antimalarial and antibacterial agents
-
A series of 2-(α-hydroxyacetyl)pyridine thiosemicarbazones was synthesized as potential antimalarial and antibacterial agents. Their synthesis was achieved by the condensation of N4-mono- or N4,N4-disubstituted thiosemicarbazides with 2-(α-hydroxyacetyl)pyridine. The latter was prepared by selective bromide oxidation of (2-pyridinyl)-1,2-ethanediol. The new compounds show potent inhibitory activity against penicillin-sensitive as well as penicillin-resistant Neisseria gonorrhoeae (MIC, 0.5-0.004 μg/mL), against Neisseria meningitidis (MIC, 0.5-0.032 μg/mL), and Staphylococcus aureus (MIC, 0.5-2 μg/mL). Good in vitro antimalarial effects against Plasmodium falciparum (Smith strain; ID50, 6.7-38 ng/mL) were observed in most of these new agents, but only 3 of 12 compounds exhibit moderate in vivo activity against Plasmodium berghei. These new agents appear to be less toxic to the host and more water soluble than the corresponding 2-acetylpyridine thiosemicarbazones.
- Klayman,Lin,Hoch,Scovill,Lambros,Dobek
-
p. 1763 - 1767
(2007/10/02)
-