Acaricidal activity of four fractions and octadecanoic acid-tetrahydrofuran-3,4-diyl ester isolated from chloroform extracts of neem (Azadirachta indica) oil against Sarcoptes scabiei var. cuniculi larvae in vitro.
Four fractions obtained from chloroform extracts of neem (Azadirachta indica) oil by column chromatography were investigated for acaricidal activity against Sarcoptes scabiei var. cuniculi larvae in vitro. Octadecanoic acid-tetrahydrofuran-3,4-diyl ester was isolated from an active fraction of the chloroform extract and its toxicity against S. scabiei larvae was tested in vitro. A complementary log-log model was used to analyse the toxicity data. Activity was found in the third fraction, with 100% corrected mortality after 4.5 h of exposure at a concentration of 200 mg ml(-1). This fraction was repeatedly re-crystallised in acetone to yield a white amorphous powder, identified as octadecanoic acid-tetrahydrofuran-3,4-diyl ester, with a median lethal concentration (LC(50)) of 0.1 mg ml(-1) at 24 h post-treatment. The median lethal time (LT(50)) for this compound was 15.3 h at a concentration of 7.5 mg ml(-1).
Du
Yong-Hua
YH
College of Animal Medicine, Sichuan Agricultural University, Ya'an, 625014, PR China.
Li
Jin-Liang
JL
Jia
Ren-Yong
RY
Yin
Zhong-Qiong
ZQ
Li
Xu-Ting
XT
Lv
Cheng
C
Ye
Gang
G
Zhang
Li
L
Zhang
Yu-Qun
YQ
D000818:Animals; D004305:Dose-Response Relationship, Drug; D005989:Glycerides / Q000737:chemistry*; D007306:Insecticides / Q000737:chemistry* / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects; D015394:Molecular Structure; D012520:Sarcoptes scabiei / Q000187:drug effects*; D013229:Stearic Acids / Q000737:chemistry* / Q000494:pharmacology*; D013729:Terpenes / Q000737:chemistry*
D005989:Glycerides; D007306:Insecticides; D013229:Stearic Acids; D013729:Terpenes; C543690:octadecanoic acid-tetrahydrofuran-3,4-diyl ester; C002443:neem oil