- Cyclic dipeptides exhibit potency for scavenging radicals
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Twenty kinds of cyclic dipeptides containing l-leucine were synthesized, and their antioxidant activity against .OH and O2·- was investigated. Compounds possessing polar amino acid residues, such as Asp, Cys, Glu, Lys, Pro, Ser, and Trp, exhibited higher antioxidant activity against .OH than vitamin E. However, only cyclo(l-Cys-l-Leu) scavenged O2·-.
- Furukawa, Tadashi,Akutagawa, Takashi,Funatani, Hitomi,Uchida, Toshikazu,Hotta, Yoshihiro,Niwa, Masatake,Takaya, Yoshiaki
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p. 2002 - 2009
(2012/05/04)
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- Efficient synthesis of 2,5-diketopiperazines using microwave assisted heating
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In this study a general, efficient and environmentally benign solution phase synthesis of 2,5-diketopiperazines (DKPs) using microwave assisted heating in water is described. A series of 11 structurally different DKPs have been synthesized from dipeptide methyl esters. A range of common laboratory solvents have been tested as well as different reaction times and temperatures. Both classic thermal and microwave assisted heating have been investigated. Microwave assisted heating for 10 min using water as solvent proved, by far, to be the most efficient method of cyclization giving moderate to excellent yields (63-97%) of DKPs. In contrast to other published procedures, this method seems independent of the amino acid sequence.
- Tullberg, Marcus,Gr?tli, Morten,Luthman, Kristina
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p. 7484 - 7491
(2007/10/03)
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