for a more detailed description of the present invention , the following examples are proved . however , the scope of the present invention is not limited to this . synthesis of epo mimetic peptide monomers is performed by a solid - phase peptide synthesis method . this peptide synthesis method has been reported in many literatures , see stewart , j . m ., and young , j . d ., solid phase peptide synthesis 2d edition , novabiochem peptide synthesis notes . the epo mimetic peptide derivatives provided by this invention may be performed by manual synthesis methods . the resin is rink amind resin . the α - amino of the amino acid derivatives are protected by fmoc ( fluorene - formyl carbonyl ). the thiol group of cysteine side chain , the amino group of glutamine side chain , and the imidazole group of histidine side chain are protected by trt ( trityl ). the guanidine group of the arginine side - chain is protected by pbf ( 2 , 2 , 4 , 6 , 7 - pentamethyldihydrobenzofuran - 5 - sulfonyl ). the indole group of tryptophan side chain , and the amino group of the lysine side chain , are protected by boc ( tert - butoxycarbonyl ). the hydroxyl group of the threonine side chain , the phenol group of the tyrosine side chain , and the hydroxyl group of the serine side chain are protected by tbu ( tert - butyl ). the carboxyl of the c - terminal of the peptide chain of the epo mimetic peptide derivative to be synthesized is attached to insoluble resin ( rink amind resin ) by covalent bonds . then amino acids attached to the solid phase carrier is used as the amino component to extend the polypeptide chain after removing amino protection groups by a 20 % piperidine dmf solution and reacting with excessive amino acid derivative . the operation is then repeated ( condensation → washing → deprotection → washing → the next round of condensation ) to achieve the desired synthetic peptide chain length . finally , the peptide chain is removed from the resin using a mixed solution of trifluoroacetic acid , water , ethylene mercaptan , 3 - isopropyl silane ( 92 . 5 : 2 . 5 : 2 . 5 : 2 . 5 ). after ether sedimentation , the crude epo mimetic monomers are obtained . the crude peptide monomer is separated and purified by a c18 reverse - phase preparative column . then an epo mimetic peptide derivative monomer peptide is obtained . the control of the reaction steps of condensation and deprotection employs a ninhydrin detection method , namely when the resin peptide chain has free amino groups , a blue color will appear after staining by the ninhydrin reagent . when there is no free amino group , no color reaction will be developed ( ninhydrin reagent itself being yellow ). therefore , after carrying out the condensation reaction and detecting by ninhydrin , if yellow color is present ( the color of ninhydrin reagent itself ), it means that this coupling step is completed and the deprotection operation can be carried out before coupling of the next amino acid . if a blue color is present , it means that there are still some free amino on the peptide chain . it needs further repeated coupling or changing the current condensing agent until the resin - peptide presents a yellow color after detection by ninhydrin . iminodiacetic acid diethyl ester ( 10 . 0 g , 52 . 8 mmol ) and boc - β - alanine ( 10 . 0 g , 52 . 8 mmol ) are dissolved in 100 ml of dichloromethane . dic ( 8 . 0 ml , 52 . 8 mmol ) is added into the solution . the reaction solution is stirred at room temperature overnight . the reaction solution is filtered . the filtrate is washed with 100 ml of saturated nahco 3 , 50 ml of a 0 . 5 n hcl solution , and 100 ml of saturated saline successively . the organic phase is isolated from the aqueous phase and dried with anhydrous mgso 4 . the organic phase is filtered and concentrated to provide a colorless oily substance lg - 1 - a ( 17 g ). lg - 1 - a ( 17 g ) is dissolved in 100 ml of a mixture of meoh and thf ( 1 : 1 ). then 25 ml of water , and 5 g of naoh ( 125 mmol ) are added into the solution . the solution is stirred at room temperature for 2 hours . then the ph value of the solution is adjusted to 1 with a 6 n hcl solution . the reaction solution is extracted with ethyl acetate four times . the organic phase is washed with saline , dried by anhydrous magnesium sulfate , and concentrated at a reduced pressure to produce a white semi - solid . the product is dissolved in 50 ml of dichloromethane . then 300 ml of n - hexane is added to the solution to produce a white paste . after concentrated at a reduced pressure , a white solid lg - 1 - b ( 14 g ) is obtained . the yield is about 90 %. lg - 1 - b ( 7 g , 23 mmol ) is dissolve in 80 ml of tetrahydrofuran . under stirring , n , n - methoxy - methyl - amine hydrochloride ( 4 . 6 g , 46 mmol ) and triethylamine ( 5 . 1 g , 51 mmol ), dic ( 4 . 4 g , 32 mmol ), and hobt ( 4 . 7 g , 32 mmol ) are added into the solution successively . the reaction mixture is stirred overnight at room temperature . then the reaction mixture is added into water and extracted by 350 ml of ethyl acetate . the organic phase is washed with 200 ml of 2 n hcl aqueous solution , 200 ml of saturated sodium bicarbonate solution , 100 ml of saturated saline successively . the organic phase is separated , dried with anhydrous magnesium sulfate for 2 hours , and then filtrated . the filtrate becomes oily after concentration at reduced pressure . after column chromatography , the target product lg - 1 - c ( 4 . 2 g , yield : 70 %) is collected . lg - 1 - c ( 4 . 0 g , 10 . 2 mmol ) is dissolved in 60 ml of tetrahydrofuran . the solution is cooled down to 0 ° c . by an ice - salt bath . lialh 4 ( 340 mg , 8 . 9 mmol ) is added into the solution . after reacting at 0 ° c . for 30 minutes , 4 ml of water and 4 ml of 15 % naoh solution are added successively . the reaction solution is filtered . the filtrate is washed with tetrahydrofuran , concentrated , and purified by silica gel column chromatography to provide lg - 1 ( 1 . 63 g , 6 mmol , yield : 58 . 8 %). lg - 1 - b ( 4 g , 13 mmol ) is dissolved in 100 ml of n , n - dimethylformamide . hydroxysuccinimide ( 3 . 1 g , 21 mmol ), dic ( 4 ml , 26 mmol ), and dmap ( 4 - dimethylamino pyridine ) ( 12 mg , 0 . 08 mmol ) are added into the solution . after stirring overnight , the reaction solution is concentrated at reduced pressure . the residue is dissolved in 80 ml of ethyl acetate . the insoluble substances are filtered off . the organic phase is washed with 40 ml of saturated sodium bicarbonate solution , 40 ml of saturated saline , 40 ml of 0 . 5 n hcl solution , and 40 ml of saturated saline successively . the organic phase is separated and dried with anhydrous magnesium sulfate . the organic phase is filtered . the filtrate is concentrated at reduced pressure . a white solid lg - 2 ( 4 . 4 g ) is obtained . yield is about 68 %. pentanone pimelic acid ( 7 . 0 g , 0 . 04 mol ) is dissolved in 100 ml of methanol . 5 % csco 3 in methanol is added into the solution under stirring . the ph of the reaction mixture is controlled at about 8 . 5 by the amount of csco 3 ( determined by high resolution ph test paper ). the mixture is stirred for 30 minutes after the addition is completed . then the reaction mixture is filtered . the filtrate becomes oily after vacuum concentration . the oily filtrate is dissolved in about 100 ml of dmso and the solution is warmed up to 60 ° c . benzyl bromide ( 14 g , 0 . 08 mol ) is added into the solution . after reacting for 8 hours , the reaction mixture is filtered . the solid is washed with a small amount of ether . 400 ml of ether is added into the mother liquor . then the mother liquor is washed with 200 ml of saturated saline . the organic phase is separated and dried with anhydrous magnesium sulfate for 2 hours . then the organic phase is filtered . when the filtrate is concentrated at reduced pressure to ⅕ of its original volume , it is placed in − 20 ° c . freezer overnight to crystallize . the solid is filtered out and dried to provide a white solid lg - 3 - a ( 10 . 5 g , yield 74 %). lg - 3 - a ( 2 g , 0 . 0056 mol ) is dissolved in 20 ml of tetrahydrofuran . the internal temperature of the solution is maintained below − 10 ° c . nabh 4 ( 626 mg , 0 . 0168 mol ) is added into the solution under stirring . after 1 hour of reaction , 200 ml of chilled ether is added , followed by addition of 150 ml of saturated sodium bicarbonate solution to terminate the reaction . the solution is kept still to allow the organic phase separate from the aqueous phase . the organic phase is washed for one time with saturated saline , then dried with anhydrous na 2 so 4 for 2 hours , and filtered . the filtrate is concentrated at reduced pressure to produce lg - 3 - b ( 1 . 9 g , yield : 94 . 6 %). lg - 3 - b ( 3 . 2 g , 0 . 009 mol ) is dissolved in 50 ml of dichloromethane . triethylamine ( 4 . 34 g , 0 . 043 mol ) is added into the solution below 0 ° c . under stirring . triphosgene ( 1 . 33 g , 0 . 0045 mol ) is dissolved in 25 ml of dichloromethane . then the triphosgene solution is added into the lg - 3 - b solution dropwise . tert - butoxycarbonyl - ethylenediamine ( 2 . 8 g ) is added into the reaction mixture after 1 hour . after 3 hours of reaction , the reaction mixture is adjusted to neutral with glacial acetic acid . a precipitate is generated . the precipitate is filtered off . the filtrate is concentrated at reduced pressure and then dissolved in ether . then the solution is washed with water for three times and with saturated saline for one time . the organic phase is separated out , dried with anhydrous magnesium sulfate for 2 hours and then filtrated . the filtrate is concentrated at reduced pressure to provide an oily substance . the oily substance is purified by silica gel column chromatography ( mobile phase : petroleum ether : ethyl acetate = 10 : 1 ). the target fragments are collected and combined . the combined fragments are concentrated to produce lg - 3 - c ( 1 . 5 g , yield 38 . 8 %) as a white solid . lg - 3 - c ( 13 g , 0 . 031 mol ) is dissolved in 8 ml of methanol . 200 mg 10 % pd — c is added under stirring . after 4 hours of reaction under h 2 at an atmospheric pressure , the activated carbon is filtered off the filtrate is concentrated to produce an oily substance lg - 3 - d ( 8 . 28 g , yield : 96 . 7 %). lg - 3 - d ( 5 g , 0 . 018 mol ) is dissolved in 10 ml of tetrahydrofuran . p - nitrophenol ( 4 . 7 g , 0 . 043 mol ) is added . then dic ( 4 . 2 g , 0 . 043 ) is added into the solution under stirring . the reaction is stirred overnight . the resulting precipitate is filtered out . the filter cake is washed with a small amount of ethyl acetate and dried under reduced pressure . the residue is dissolved in 100 ml of ethyl acetate . the resulting solution is washed with 50 ml saturated saline once . the organic phase is separated and dried over anhydrous magnesium sulfate for 2 hours . then the solution is filtered . the filtrate is concentrated at reduced pressure to produce an oily substance . the oily substance is purified by silica gel column chromatography ( eluant : hexane and ethyl acetate , ration from 20 : 1 to 10 : 1 ). the target fragments are combined and collected , and concentrated at reduced pressure to produce lg - 3 ( 3 . 5 g , yield : 32 %) as a white solid . lg - 3 - d ( 5 g , 0 . 018 mol ) is dissolved in 60 ml of tetrahydrofuran . n , n - methoxy - methyl - amine hydrochloride ( 3 . 51 g , 0 . 036 mol ) and triethylamine ( 4 . 0 g , 0 . 04 mol ) are added into the solution under stirring . then dic ( 3 . 4 g , 0 . 027 mol ) and hobt ( 3 . 65 g , 0 . 027 mol ) are added into the reaction mixture . the reaction mixture is stirred overnight at room temperature , added into 200 ml of water , and extracted with 200 ml of ethyl acetate twice . the combined organic phase is washed with 50 ml of 2 n hcl solution , 100 ml of saturated nahco 3 solution , and 100 ml of saturated saline successively . the combined organic phase is dried over anhydrous magnesium sulfate for 2 hours , and filtered . the filtrate is concentrated at reduced pressure to produce an oily substance . the oily substance is purified by column chromatography ( eluant : hexane : ethyl acetate at 10 : 1 ). the target components are combined to produce a white solid lg - 4 - a ( 6 . 24 g , yield : 80 %). lg - 4 - a ( 4 . 0 g , 9 mmol ) is dissolved in 50 ml of tetrahydrofura . lialh 4 ( 300 mg , 7 . 9 mmol ) is added into the solution in an ice - salt bath at a temperature of below zero . the temperature of the reaction mixture is maintained at 0 ° c . for 30 minutes . then 0 . 3 ml of water , 0 . 9 ml of 15 % naoh solution , and 0 . 3 ml of water are added into the reaction mixture successively . a precipitate is generated . the precipitate is filtered out . the filter cake is washed with tetrahydrofuran once . the filtrate is combined and concentrated at reduced pressure . the residue is purified by column chromatography to produce lg - 4 ( 1 . 65 g , yield : 55 . 5 %). the peptide monomer of seq id no : 5 ( 9 g , synthesized in accordance with the method given in the examples ) is dissolved in 3000 ml of 20 % glacial acetic acid . then a 5 % iodine - methanol solution is added into the solution dropwise and slowly until the yellow color does not disappear . the reaction solution is directly subjected to a preparative purification by reversed - phase chromatography using octadecylsilane bonded silica gel as column filler ( waters symmetryshield ™ rp18 , 3 . 5 μm , 4 . 6 * 100 mm ). the column temperature is 60 ° c . and the detection wavelength is 214 nm . water ( containing 0 . 05 % trifluoroacetic acid ) and acetonitrile ( containing 0 . 05 % trifluoroacetic acid ) in different proportions are used as mobile phases . the target fractions are collected and combined . after most of the acetonitrile is distilled off under reduced pressure and the resulting residue is freeze - dried , 3 . 0 g of seq id no : 5 cyclic peptide is obtained ( yield : 15 . 6 %). the cyclic peptide of seq id no : 5 ( 3 . 0 g , 1 . 22 mmol ) is dissolved in 150 ml of n , n - dimethyl formamide . triethylamine ( 147 mg , 1 . 46 mmol ) and the functional small molecule ( lg - 3 ) ( 368 mg , 0 . 61 mmol ) are added into the solution . after the reaction is stirred at room temperature for 6 hours , part of the n , n - dimethylformamide is removed . 200 ml of ether is added into the residue . the mixture is placed in a refrigerator for 2 hours and centrifuged . a white solid is obtained and dried under vacuum . then the white solid is dissolved in 50 ml of 20 % trifluoroacetic acid in dichloromethane solution . after the solution is stirred at room temperature for 30 minutes , part of the solvent is removed under reduced pressure . 200 ml of ether is added into the residue . the mixture is placed in the refrigerator for 2 hours and then centrifuged . a white solid is obtained and dried by vacuum . the white solid is subjected to a preparative purification by reversed - phase chromatography , using octadecylsilane bonded silica gel as column filler ( waters symmetryshield ™ rp18 , 3 . 5 μm , 4 . 6 * 100 mm ). the column temperature is 60 ° c . and the detection wavelength is 214 nm . water ( containing 0 . 05 % trifluoroacetic acid ) and acetonitrile ( containing 0 . 05 % trifluoroacetic acid ) in different proportions are used as mobile phases . the target fractions are collected and combined . after most of the acetonitrile is distilled off under reduced pressure and the resulting residue is freeze - dried , 1 . 0 g of hh - epo - 005 is obtained ( yield is about 33 %). the peptide monomer of seq id no : 6 ( 9 g , synthesized in accordance with the method given in the examples ) is added in 3000 ml of 20 % glacial acetic acid . then a 5 % iodine - methanol solution is added dropwise slowly until the yellow color does not disappear . the reaction solution is directly subjected to a preparative purification by reversed - phase chromatography , using octadecylsilane bonded silica gel as column filler ( waters symmetryshield ™ rp18 , 3 . 5 μm , 4 . 6 * 100 mm ). the column temperature is 60 ° c . and the detection wavelength is 214 nm . water ( containing 0 . 05 % trifluoroacetic acid ) and acetonitrile ( containing 0 . 05 % trifluoroacetic acid ) in different proportions are used as mobile phases . the target fractions are collected and combined . after most of the acetonitrile is distilled off under reduced pressure and the resulting residue is freeze - dried , 3 . 0 g of seq id no : 6 cyclic peptide is obtained ( yield : 15 . 3 %). the cyclic peptide of seq id no : 6 ( 3 . 0 g , 1 . 22 mmol ) is dissolved in 150 ml of n , n - dimethyl formamide . triethylamine ( 147 mg , 1 . 46 mmol ) and the functional small molecule ( lg - 3 ) ( 368 mg , 0 . 61 mmol ) are added into the solution . after the reaction is stirred at room temperature for 6 hours , part of the dmf is removed . 200 ml of ether is added into the residue . the mixture is placed in a refrigerator for 2 hours and then centrifuged . a white solid is obtained and dried under vacuum . then the white solid is dissolved in 50 ml of 20 % trifluoroacetic acid in dichloromethane solution . after the mixture is stirred at room temperature for 30 minutes , part of the solvent is removed under reduced pressure . 200 ml of ether is added into the residue . the mixture is placed in a refrigerator for 2 hours and then centrifuged . a white solid is obtained and dried under vacuum . the white solid is subjected to a preparative purification by reversed - phase chromatography , using octadecyl silane bonded silica gel as column filler ( waters symmetryshield ™ rp18 , 3 . 5 μm , 4 . 6 * 100 mm ). the column temperature is 60 ° c . and the detection wavelength is 214 nm . water ( containing 0 . 05 % trifluoroacetic acid ) and acetonitrile ( containing 0 . 05 % trifluoroacetic acid ) in different proportions are used as mobile phases . the target fractions are collected and combined . most of the acetonitrile is distilled off under reduced pressure . the residue is freeze - dried to provide 3 . 98 g of hh - epo - 006 at a yield of about 32 . 7 %. the peptide monomer of seq id no : 7 ( 9 g , synthesized in accordance with the method given in the examples ) is dissolved in 3000 ml of 20 % glacial acetic acid . then a 5 % iodine - methanol solution is added dropwise until the yellow color does not disappear . the reaction solution is directly subjected to a preparative purification by reversed - phase chromatography , using octadecylsilane bonded silica gel as column filler ( waters symmetryshield ™ rp18 , 3 . 5 μm , 4 . 6 * 100 mm ). the column temperature is 60 ° c . and the detection wavelength is 214 nm . water ( containing 0 . 05 % trifluoroacetic acid ) and acetonitrile ( containing 0 . 05 % trifluoroacetic acid ) in different proportions are used as mobile phases . the target fractions are collected and combined . most of the acetonitrile is distilled off under reduced pressure and the reside is freeze dried , 3 . 15 g of seq id no : 7 cyclic peptide is obtained ( yield : 16 . 4 %). the cyclic peptide of seq id no : 7 ( 3 . 0 g , 1 . 22 mmol ) is dissolved in 150 ml of n , n - dimethyl formamide . triethylamine ( 147 mg , 1 . 46 mmol ) and the functional small molecule ( lg - 3 ) ( 368 mg , 0 . 61 mmol ) are added into the solution . after the reaction is stirred at room temperature for 6 hours , part of the n , n - dimethylformamide is removed . 200 ml of ether is added into the residue . the mixture is placed in a refrigerator for 2 hours and then centrifuged . a white solid is obtained and dried under vacuum . then this white solid is dissolved in 50 ml of 20 % trifluoroacetic acid in dichloromethane solution . after the mixture is stirred at room temperature for 30 minutes , part of the solvent is removed under reduced pressure . 200 ml of ether is added into the residue . the mixture is placed in a refrigerator for 2 hours and then centrifuged . a white solid is obtained and dried under vacuum . the white solid is subjected to a preparative purification by reversed - phase chromatography , using octadecylsilane bonded silica gel as column filler ( waters symmetryshield ™ rp18 , 3 . 5 μm , 4 . 6 * 100 mm ). the column temperature is 60 ° c . and the detection wavelength is 214 nm . water ( containing 0 . 05 % trifluoroacetic acid ) and acetonitrile ( containing 0 . 05 % trifluoroacetic acid ) in different proportions are used as mobile phases . the target fractions are collected and combined . after most of the acetonitrile is distilled off under reduced pressure and the residue is freeze - dried , 1 . 0 g of hh - epo - 007 is obtained ( yield is about 33 %). the peptide monomer of seq id no : 8 ( 27 g , synthesized in accordance with the method given in the examples ) is dissolved in 3000 ml of 20 % glacial acetic acid . a 5 % iodine - methanol solution is added dropwise until the yellow color does not disappear . the reaction solution is directly subjected to a preparative purification by reversed - phase chromatography , using octadecylsilane bonded silica gel as column filler ( waters symmetryshield ™ rp18 , 3 . 5 μm , 4 . 6 * 100 mm ). the column temperature is 60 ° c . and the detection wavelength is 214 nm . water ( containing 0 . 05 % trifluoroacetic acid ) and acetonitrile ( containing 0 . 05 % trifluoroacetic acid ) in different proportions are used as mobile phases . the target fractions are collected and combined . after most of the acetonitrile is distilled off under reduced pressure and the residue is freeze - dried , 9 . 3 g of seq id no : 8 is obtained ( yield : 15 . 7 %). the cyclic peptide of seq id no : 8 ( 3 . 0 g , 1 . 22 mmol ) is dissolved in 150 ml of n , n - dimethyl formamide . triethylamine ( 147 mg , 1 . 46 mmol ) and the functional small molecule ( lg - 3 ) ( 368 mg , 0 . 61 mmol ) are added into the solution . after the reaction is stirred at room temperature for 6 hours , part of the n , n - dimethylformamide is removed . 200 ml of ether is added into the residue . the mixture is placed in a refrigerator for 2 hours and then centrifuged . a white solid is obtained by vacuum drying . then this white solid is dissolved in 50 ml of 20 % trifluoroacetic acid in dichloromethane solution . after the mixture is stirred at room temperature for 30 minutes , part of the solvent is removed under reduced pressure . 200 ml of ether is added into the residue . the mixture is placed in the refrigerator for 2 hours and then centrifuged . a white solid is obtained and dried under vacuum . the white solid is subjected to a preparative purification by reversed - phase chromatography , using octadecylsilane bonded silica gel as column filler ( waters symmetryshield ™ rp18 , 3 . 5 μm , 4 . 6 * 100 mm ). the column temperature is 60 ° c . and the detection wavelength is 214 nm . water ( containing 0 . 05 % trifluoroacetic acid ) and acetonitrile ( containing 0 . 05 % trifluoroacetic acid ) in different proportions are used as mobile phases . the target fractions are collected and combined . after most of the acetonitrile is distilled off under reduced pressure and the residue is freeze - dried , 1 . 12 g of hh - epo - 008 is obtained ( yield is about 33 %). the cyclic peptide of seq id no : 8 ( 3 . 0 g , 1 . 22 mmol ) is dissolved in 150 ml of 20 mmol acetic acid buffer ( ph5 . 0 ). the functional small molecule ( lg - 4 ) ( 201 mg , 0 . 61 mmol ) and 10 ml of acetonitrile are added into the solution . after stirred at room temperature for 30 minutes , the reaction solution is subjected a preparative purification by reversed - phase chromatography , using octadecylsilane bonded silica gel as column filler ( waters symmetryshield ™ rp18 , 3 . 5 μm , 4 . 6 * 100 mm ). the column temperature is 60 ° c . and the detection wavelength is 214 nm . water ( containing 0 . 05 % trifluoroacetic acid ) and acetonitrile ( containing 0 . 05 % trifluoroacetic acid ) in different proportions are used as mobile phases . the target fractions are collected and combined . after most of the acetonitrile is distilled off under reduced pressure and the residue is freeze - dried , 0 . 75 g of hh - epo - 008a is obtained ( yield : 25 %). the cyclic peptide seq id no : 8 ( 3 . 0 g , 1 . 22 mmol ) is dissolved in 150 ml of n , n - dimethyl formamide . triethylamine ( 147 mg , 1 . 46 mmol ) and the functional small molecule ( lg - 2 ) ( 322 mg , 0 . 61 mmol ) are added into the solution . after the reaction is stirred at room temperature for 6 hours , part of the n , n - dimethylformamide is removed . 200 ml of ether is added into the residue . the mixture is placed in a refrigerator for 2 hours and then centrifuged . a white solid is obtained and dried under vacuum . then this white solid is dissolved in 50 ml of 20 % trifluoroacetic acid in dichloromethane solution . after the solution is stirred at room temperature for 30 minutes , part of the solvent is removed under reduced pressure . 200 ml of ether is added into the residue . the mixture is placed in the refrigerator for 2 hours and then centrifuged . a white solid is obtained and dried under vacuum . the white solid is subjected to a preparative purification by reversed - phase chromatography , using octadecyl silane bonded silica gel as column filler ( waters symmetryshield ™ rp18 , 3 . 5 μm , 4 . 6 * 100 mm ). the column temperature is 60 ° c . and the detection wavelength is 214 nm . water ( containing 0 . 05 % trifluoroacetic acid ) and acetonitrile ( containing 0 . 05 % trifluoroacetic acid ) in different proportions are used as mobile phases . the target fractions are collected and combined . after most of the acetonitrile is distilled off under reduced pressure and the residue is freeze - dried , 1 . 3 g of hh - epo - 008 is obtained ( yield is about 43 %). the cyclic peptide seq id no : 8 ( 3 . 0 g , 1 . 22 mmol ) is dissolved in 150 ml of 20 mmol acetic acid buffer ( ph5 . 0 ). then the functional small molecule ( lg - 1 ) ( 165 mg , 0 . 61 mmol ) and 10 ml of acetonitrile are added . after stirred at room temperature for 30 minutes , the reaction solution is subjected to a preparative purification by reversed - phase chromatography , using octadecylsilane bonded silica gel as column filler ( waters symmetryshield ™ rp18 , 3 . 5 μm , 4 . 6 * 100 mm ). the column temperature is 60 ° c . and the detection wavelength is 214 nm . water ( containing 0 . 05 % trifluoroacetic acid ) and acetonitrile ( containing 0 . 05 % trifluoroacetic acid ) in different proportions are used as mobile phases . the target fractions are collected and combined . after most of the acetonitrile is distilled off under reduced pressure and the resulting residue is freeze - dried , 0 . 8 g of hh - epo - 008c is obtained ( yield : 27 %). hh - epo - 008 ( 0 . 5 g , 0 . 98 mmol ) is dissolved in 100 ml of n , n - dimethyl formamide . triethylamine ( 39 . 6 mg , 0 . 196 mmol ) and mpeg 2 - osu ( 40k ) ( 3 . 8 g , 0 . 96 mmol ) are added into the solution . after stirred at room temperature for 6 hours , the reaction solution is poured directly into 600 ml of cold ether . a solid is precipitated . after placing in a refrigerator for 2 hours , the mixture is centrifuged and the resulting crude hh - epo - 018 is dried under vacuum . crude hh - epo - 018 is purified by reversed - phase chromatography , using octadecyl silane bonded silica gel as column filler ( waters symmetryshield ™ rp18 , 3 . 5 μm , 4 . 6 * 100 mm ). the column temperature is 60 ° c . and the detection wavelength is 214 nm . water ( containing 0 . 05 % trifluoroacetic acid ) and acetonitrile ( containing 0 . 05 % trifluoroacetic acid ) in different proportions are used as mobile phases . the target fractions are collected and combined . after most of the acetonitrile is distilled off under reduced pressure and the resulting residue is freeze - dried , 1 . 8 g of hh - epo - 018 ( yield is about 47 %). hh - epo - 008 ( 0 . 5 g , 0 . 98 mmol ) is dissolved in 100 ml of n , n - dimethyl formamide . triethylamine ( 39 . 6 mg , 0 . 196 mmol ) and mpeg 2 - osu ( 40k ) ( 3 . 8 g , 0 . 96 mmol ) are added into the solution . the reaction is stirred at room temperature for 6 hours . the reaction solution is directly poured into 600 ml of cold ether . a solid is precipitated . after placing in the refrigerator for 2 hours , the mixture is centrifuged and the resulting crude hh - epo - 018 is dried under vacuum . crude hh - epo - 018 is purified by reversed - phase chromatography , using octadecyl silane bonded silica gel as column filler ( waters symmetryshield ™ rp18 , 3 . 5 μm , 4 . 6 * 100 mm ). the column temperature is 60 ° c . and the detection wavelength is 214 m . water ( containing 0 . 05 % trifluoroacetic acid ) and acetonitrile ( containing 0 . 05 % trifluoroacetic acid ) in different proportions are used as mobile phases . the target fractions are collected and combined . after most of the acetonitrile is distilled off under reduced pressure and the resulting residue is freeze - dried , 1 . 5 g of hh - epo - 018a is obtained ( yield is about 39 %). hh - epo - 008 ( 0 . 5 g , 0 . 98 mmol ) is dissolved in 100 ml of n , n - dimethyl formamide . triethylamine ( 39 . 6 mg , 0 . 196 mmol ) and mpeg 2 - osu ( 40k ) ( 3 . 8 g , 0 . 96 mmol ) are added into the solution . the reaction is stirred at room temperature for 6 hours and directly poured into 600 ml of cold ether . a solid is precipitated . after placing in a refrigerator for 2 hours , the mixture is centrifuged and the resulting crude hh - epo - 018 is dried under vacuum . crude hh - epo - 018 is purified by reversed - phase chromatography , using octadecyl silane bonded silica gel as column filler ( waters symmetryshield ™ rp18 , 3 . 5 μm , 4 . 6 * 100 mm ). the column temperature is 60 ° c . and the detection wavelength is 214 nm . water ( containing 0 . 05 % trifluoroacetic acid ) and acetonitrile ( containing 0 . 05 % trifluoroacetic acid ) in different proportions are used as mobile phases . the target fractions are collected and combined . after most of the acetonitrile is distilled off under reduced pressure and the resulting residue is freeze - dried , 1 . 7 g of hh - epo - 018 is obtained ( yield is about 45 %). hh - epo - 008 ( 0 . 5 g , 0 . 98 mmol ) is dissolved in 100 ml of n , n - dimethyl formamide . triethylamine ( 39 . 6 mg , 0 . 196 mmol ) and mpeg 2 - osu ( 40k ) ( 3 . 8 g , 0 . 96 mmol ) are added into the solution . the reaction is stirred at room temperature for 6 hours . the reaction solution is poured directly into 600 ml of cold ether . a solid is precipitated . after placing in the refrigerator 2 hours , the mixture is centrifuged and the resulting crude hh - epo - 018 is dried under vacuum . crude hh - epo - 018 is purified by reversed - phase chromatography , using octadecylsilane bonded silica gel as column filler ( waters symmetryshield ™ rp18 , 3 . 5 μm , 4 . 6 * 100 mm ). the column temperature is 60 ° c . and the detection wavelength is 214 nm . water ( containing 0 . 05 % trifluoroacetic acid ) and acetonitrile ( containing 0 . 05 % trifluoroacetic acid ) in different proportions are used as mobile phases . the target fractions are collected and combined . after most of the acetonitrile is distilled off under reduced pressure and the resulting residue is freeze - dried , 1 . 4 g of hh - epo - 018 is obtained ( yield is about 37 %). effects of epo mimetic peptide derivatives on mice purpose of the experiments the purpose of the experiments is to evaluate and compare the effects of epo mimetic peptide derivatives and the epo protein on erythropoiesis of mice . epo mimetic peptide derivatives including hh - epo - 001 , hh - epo - 002 , hh - epo - 003 , hh - epo - 004 , hh - epo - 005 , hh - epo - 006 , hh - epo - 007 , hh - epo - 008 , hh - epo - 015 , hh - epo - 016 , hh - epo - 017 and hh - epo - 018 are provided by jiangsu hansoh pharmaceutical co ., ltd . epo is purchased from shenyang sansheng pharmaceutical co ., ltd . kunming mice are purchased from the chinese academy of sciences shanghai experimental animal center , weighing 25 ˜ 30 g , ♀. the number of animals in each group is 10 . mice are injected subcutaneously with epo mimetic peptide derivatives and epo protein for three consecutive days . then the mice are killed , the whole blood is used to carry out peripheral blood cells and reticulocyte counts . blood cell count is performed using automatic blood cell counter counts . according to the current dosage regimen , both epo mimetic peptide derivatives and the epo protein can significantly promote the increase of mouse peripheral blood reticulocyte count , indicating that they stimulate erythropoiesis ( see table 1 ). epo mimetic peptide derivatives and the epo protein have no significant influence on mature red blood cells , blood cell hematocrit , hemoglobin content ( see table 2 ), and also have no significant influence on the peripheral white blood cell count ( see table 3 ). epo mimetic peptide hh - epo - 018 is provided by jiangsu hansoh pharmaceutical co ., ltd . epo is purchased from shenyang sansheng pharmaceutical co ., ltd . the samples are diluted in a saline containing 0 . 1 % bsa before they are used . macaques , weighing 5 . 5 ˜ 8 . 5 kg , male or female , are purchased from suzhou xishan zhongke laboratory animal center . macaques are grouped according to the basis of hemoglobin with each group having three macaques . hh - epo - 018 is intravenously injected once at a dose of 1 . 35 mg / kg ; epo is injected three times per week at a dose of 240 μg / kg . the administration is continued for five weeks . measure hematological indexes are measured 1 ˜ 2 times per week . single intravenous injection of hh - epo - 018 on macaques leads to an increase of peripheral blood hemoglobin , and an increase of blood cell hematocrit , indicating that hh - epo - 018 stimulate erythropoiesis . the stimulation peaks at 35 days after the administration , and then decreases slowly . the stimulatory effect of hemoglobin is about 33 %. as a positive control , epo also increases the peripheral blood hemoglobin content and blood cell hematocrit of macaque . the effect declines slowly after the administering is stopped . according to the current dosing regimens , the stimulation of hh - epo - 018 and epo on macaque hemoglobin generation is similar ( see fig1 and 2 ). to evaluate and compare the effects of epo mimetic peptide derivatives hh - epo - 015 , hh - epo - 018 , hh - epo - 018b and positive control af37702 on the mice hh - epo - 015 , hh - epo - 018 , and hh - epo - 018b , are provided by jiangsu hansoh pharmaceutical co ., ltd . af37702 is also epo mimetic peptide derivative , produced by affymax ( brand name : hematide ). the samples are diluted in a saline containing 0 . 1 % bsa . kunming mice are purchased from the chinese academy of sciences shanghai experimental animal center , weighing 25 ˜ 30 g , ♀. the number of animals in each group is 10 . after adaptation , animals are subcutaneously injected with hh - epo - 015 , hh - epo - 018 , hh - epo - 018b , and af37702 , respectively . the mice are scarified on the sixth day after the first dose . the whole blood is used to carry out peripheral blood cells and reticulocyte count . blood cell count is performed using an advia automatic blood cell counter . a single subcutaneous injection of hh - epo - 015 , hh - epo - 018 , hh - epo - 018b , and af37702 all elevate the mouse peripheral blood reticulocyte percentage and counts . the effects of hh - epo - 018b is relatively strong ; the effects of hh - epo - 018 and af37702 follow ; the effects of hh - epo - 015 is the weakest ; and the effects of hh - epo - 018 and af37702 are roughly equal ( see table 4 ). hh - epo - 015 , hh - epo - 018 , hh - epo - 018b and af37702 elevate the mouse peripheral blood cell hematocrit , hemoglobin content . their effects are roughly equal , but they all have no significant influence on the peripheral red blood cell count ( see table 5 ).
what is provided is epo mimetic peptide derivatives defined as formula and their pharmaceutical salts , the preparation thereof , wherein r 1 , r 2 , r 3 , r 4 , r 5 , n 1 , n 2 are defined as described in description . a composition comprising of an epo mimetic peptide derivative defined as formula and its pharmaceutical salt . the uses of the derivatives and their pharmaceutical salts , as well as the uses of the compositions described above in treatment of diseases characterized by a deficiency of epo or a low or defective red blood cell population . r 1 — r 2 — n1 — r 3 — n2 — r 4 — r 5