| 摘要 |
1530560 Cyclohexapeptides MERCK & CO Inc 28 July 1977 [2 Aug 1976] 31803/77 Heading C3H Cyclohexapeptides have the Formula (I) wherein Y, Y<SP>1</SP> and Y<SP>11</SP> are of structure wherein R<SP>1</SP> is C 1 -C 3 alkyl, R<SP>2</SP> is hydrogen or methyl or R<SP>1</SP> and R<SP>2</SP> together represent (CH 2 ) n (wherein n is 3 or 4); X, X<SP>1</SP> and X<SP>11</SP> are Ala, D-Ala, Phe, D-Phe, Leu or D-Leu. X, X<SP>1</SP>, X<SP>11</SP> are preferably Ala, Phe or Leu if Y, Y<SP>1</SP>, Y<SP>11</SP> are Sar, D-Pro or D-MeAla or X, X<SP>1</SP>, X<SP>11</SP> are preferably D-Ala, D-Phe or D-Leu if Y, Y<SP>1</SP>, Y<SP>11</SP> is Sar, Pro or MeAla. Cyclohexapeptides (I) prepared in the examples by solid phase synthesis on chloromethylated polystyrene cross-linked with divinyl benzene are: cyclo(D-Pro-Ala) 3 ; cyclo(D-Pro-Phe) 3 ; cyclo(Pro-D-Phe) 3 ; cyclo(Sar-Ala) 3 ; cyclo(Pro- D-Ala) 3 ; cyclo(Sar-Leu) 3 ; cyclo(Pro-D-Leu) 3 ; cyclo[(Sar - D - Phe) - (Pro - D - Phe) 2 ] and cyclo(D-Pro-Leu) 3 . A composition which is administered orally and increases the efficiency of feed utilization by ruminant animals having a developed rumen function and which is preferably in the form of a tablet, drenche, salt block, molasses block, paste, bolus or capsule, comprises cyclohexapeptide (I) and a carrier therefor. The composition may comprise 0À00005 to 0À5% by weight of the cyclohexapeptide, or, if in the form of a food premix, may comprise 0À1 to 50% by weight of the cyclohexapeptide. |
