Eprinomectin B1a
Clinical data

Trade names	Eprinex
Other names	MK-397, 4"-epi-acetylamino-4"-deoxy-avermectin B1a (4"R)-4"-(acetylamino)-5-O-demethyl-4"-deoxyavermectin A1a
License data	US DailyMed: Eprinomectin
Routes of administration	Topical
ATCvet code	QP54AA04 (WHO)
Legal status
Legal status	US: OTC^[1]
Pharmacokinetic data
Bioavailability	29%^[2]
Protein binding	>99%^[2]
Onset of action	24 hours^[2]
Elimination half-life	8–36 days^[2]
Duration of action	7–10 days^[2]
Excretion	Feces (17–19.8%), urine (0.35%), milk (0.32–0.54%)^[2]
Identifiers
IUPAC name N-[(2S,3R,4S,6S)-6-[(2S,3S,4S,6R)-6-[(1'R,2R,3S,4'S,6S,8'R,10'E,12'S,13'S,14'E,16'E,20'R,21'R,24'S)-2-[(2S)-butan-2-yl]-21',24'-dihydroxy-3,11',13',22'-tetramethyl-2'-oxospiro[2,3-dihydropyran-6,6'-3,7,19-trioxatetracyclo[15.6.1.14,8.020,24]pentacosa-10,14,16,22-tetraene]-12'-yl]oxy-4-methoxy-2-methyloxan-3-yl]oxy-4-methoxy-2-methyloxan-3-yl]acetamide
CAS Number	133305-88-1
PubChem CID	6444397
ChemSpider	16736607
UNII	00OY54D31C
KEGG	D04037
Chemical and physical data
Formula	C₅₀H₇₅NO₁₄
Molar mass	914.143 g·mol⁻¹
3D model (JSmol)	Interactive image
SMILES CC[C@H](C)[C@@H]1[C@H](C=C[C@@]2(O1)C[C@@H]3C[C@H](O2)C/C=C(/[C@H]([C@H](/C=C/C=C/4\CO[C@H]5[C@@]4([C@@H](C=C([C@H]5O)C)C(=O)O3)O)C)O[C@H]6C[C@@H]([C@H]([C@@H](O6)C)O[C@H]7C[C@@H]([C@@H]([C@@H](O7)C)NC(=O)C)OC)OC)\C)C
InChI InChI=1S/C50H75NO14/c1-12-26(2)45-29(5)18-19-49(65-45)24-36-21-35(64-49)17-16-28(4)44(27(3)14-13-15-34-25-58-47-43(53)30(6)20-37(48(54)61-36)50(34,47)55)62-41-23-39(57-11)46(32(8)60-41)63-40-22-38(56-10)42(31(7)59-40)51-33(9)52/h13-16,18-20,26-27,29,31-32,35-47,53,55H,12,17,21-25H2,1-11H3,(H,51,52)/b14-13+,28-16+,34-15+/t26-,27-,29-,31-,32-,35+,36-,37-,38-,39-,40-,41-,42+,43+,44-,45+,46-,47+,49+,50+/m0/s1 Key:ZKWQQXZUCOBISE-CRTGXIDZSA-N

Eprinomectin B1b
Clinical data

Other names	4"-epi-acetylamino-4"-deoxy-avermectin B1b
ATC code	P54AA04 (WHO)
Identifiers
IUPAC name N-[(2S,3R,4S,6S)-6-[(2S,3S,4S,6R)-6-[(1'R,2R,3S,4'S,6S,8'R,10'E,12'S,13'S,14'E,16'E,20'R,21'R,24'S)-21',24'-dihydroxy-3,11',13',22'-tetramethyl-2'-oxo-2-propan-2-ylspiro[2,3-dihydropyran-6,6'-3,7,19-trioxatetracyclo[15.6.1.14,8.020,24]pentacosa-10,14,16,22-tetraene]-12'-yl]oxy-4-methoxy-2-methyloxan-3-yl]oxy-4-methoxy-2-methyloxan-3-yl]acetamide
CAS Number	133305-89-2
PubChem CID	20055319
ChemSpider	16736608
UNII	31OML2QZ0Q
KEGG	D04037
Chemical and physical data
Formula	C₄₉H₇₃NO₁₄
Molar mass	900.116 g·mol⁻¹
3D model (JSmol)	Interactive image
SMILES C[C@H]1/C=C/C=C/2\CO[C@H]3[C@@]2([C@@H](C=C([C@H]3O)C)C(=O)O[C@H]4C[C@@H](C/C=C(/[C@H]1O[C@H]5C[C@@H]([C@H]([C@@H](O5)C)O[C@H]6C[C@@H]([C@@H]([C@@H](O6)C)NC(=O)C)OC)OC)\C)O[C@]7(C4)C=C[C@@H]([C@H](O7)C(C)C)C)O
InChI InChI=1S/C49H73NO14/c1-25(2)43-28(5)17-18-48(64-43)23-35-20-34(63-48)16-15-27(4)44(26(3)13-12-14-33-24-57-46-42(52)29(6)19-36(47(53)60-35)49(33,46)54)61-40-22-38(56-11)45(31(8)59-40)62-39-21-37(55-10)41(30(7)58-39)50-32(9)51/h12-15,17-19,25-26,28,30-31,34-46,52,54H,16,20-24H2,1-11H3,(H,50,51)/b13-12+,27-15+,33-14+/t26-,28-,30-,31-,34+,35-,36-,37-,38-,39-,40-,41+,42+,43+,44-,45-,46+,48+,49+/m0/s1 Key:WPNHOHPRXXCPRA-FZTOWWROSA-N

Eprinomectin is an avermectin used as a veterinary topical endectocide.^[1]^[3] It is a mixture of two chemical compounds, eprinomectin B1a and B1b.^[4]

References