Abamectin is a mixture of avermectins containing more than 80% avermectin B1a and less than 20% avermectin B1b . These two components, B1a and B1b have very similar biological and toxicological properties. The avermectins are insecticidal or anthelmintic compounds derived from the soil bacterium Streptomyces avermitilis. Abamectin is a natural fermentation product of this bacterium. Abamectin is used to control insect and mite pests of a range of agronomic, fruit, vegetable and ornamental crops, and it is used by homeowners for control of fire ants. Doses of 50 to 200 µg/kg of ivermectin, a similar member of the avermectin family of compounds, is widely used to treat humans in the World Health Organization onchocerciasis (river blindness) program.

Abamectin is also known as Avermectin B1 and MK-936. Trade names include Affirm, Agri-Mek, Avid, Dynamec, Vertimec and Zephyr.

• Status: ISO 1750 (approved)
• IUPAC: mixture of:
  • (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-α-L-arabino-hexopyranosyl)-3-O-methyl-α-L-arabino-hexopyranoside
  • (10E,14E,16E,22Z)-(1R,4S,5′S,6S,6′R,8R,12S,13S,20R,21R,24S)-21,22-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-α-L-arabino-hexopyranosyl)-3-O-methyl-α-L-arabino-hexopyranoside
• CAS name: avermectin B1
• Formula: C₄₈H₇₂O₁₄ (avermectin B1a) + C₄₇H₇₀O₁₄ (avermectin B1b)
• Activity:
  • acaricides (avermectin acaricides)
  • insecticides (avermectin insecticides)
  • nematicides (antibiotic nematicides)