Abamectin

Common name abamectin (BSI, draft E-ISO, ANSI); abamectine ((f) draft F-ISO)

IUPAC name (10E,14E,16E,22Z)-(1R,4S,5'S,6S,6'R,8R,12S,13S,20R,21R,24S)-6'-[(S)-sec-butyl]-21,24-dihydroxy-5',11,13,22-tetramethyl-2-oxo-3,7,19-trioxatetracyclo[15.6.1.14,8.020,24]pentacosa-10,14,16,22-tetraene-6-spiro-2'-(5',6'-dihydro-2'H-pyran)-12-yl 2,6-dideoxy-4-O-(2,6-dideoxy-3-O-methyl-a-L-arabino-hexopyranosyl)-3-O-methyl-a-L-arabino-hexopyranoside (i) mixture with (10E,14E,16E,22Z)-(1R,4S,5'S,6S,6'R,8R,12S,13S,20R,21R,24S)-21,24-dihydroxy-6'-isopropyl-5',11,13,22-tetramethyl-2-oxo-3,7,19-trioxatetracyclo[15.6.1.14,8.020,24]pentacosa-10,14,16,22-tetraene-6-spiro-2'-(5',6'-dihydro-2'H-pyran)-12-yl 2,6-dideoxy-4-O-(2,6-dideoxy-3-O-methyl-a-L-arabino-hexopyranosyl)-3-O-methyl-a-L-arabino-hexopyranoside (ii) (4:1) 

Chemical Abstracts name 5-O-demethylavermectin A1a (i) mixture with 5-O-demethyl-25-de(1-methylpropyl)-25-(1-methylethyl)avermectin A1a (ii) 

Other names avermectin B1 

CAS RN [71751-41-2] (abamectin); [65195-55-3] (i); [65195-56-4] (ii) 

Composition A mixture containing ³80% avermectin B1a (i) and £20% avermectin B1b (ii).  Mol. wt. 873.1 (avermectin B1a); 859.1 (avermectin B1b) 

M.f. C48H72O14 (avermectin B1a); C47H70O14 (avermectin B1b)  Form Colourless to pale yellow crystals. 

M.p. 161.8-169.4 癈 (decomp.) 

V.p. <3.7 ´ 10-3 mPa (25 癈) 

KOW logP = 4.4?.3 (pH 7.2, room temperature) 

Henry 2.7 ´ 10-3 Pa m3 mol-1 (25 癈) 

S.g./density 1.18 (22 癈) 

Solubility In water 7-10 mg/l (20 篊). In toluene 350, acetone 100, isopropanol 70, chloroform 25, ethanol 20, methanol 19.5, n-butanol 10, cyclohexane 6 (all in g/l, 21 篊).