Nor-hopanes from Zanha africana root bark with toxicity to bruchid beetles

作者：Stevenson Philip C^*; Green Paul W C; Veitch Nigel C; Farrell Iain W; Kusolwa Paul; Belmain Steven R

来源：Phytochemistry, 2016, 123: 25-32.

DOI：10.1016/j.phytochem.2016.01.008

• Zanha africana
• Sapindaceae
• Cowpea
• Fabaceae
• Bruchid beetles
• Callosobruchus maculatus
• Pesticidal plants
• Botanicals
• Stored product pests
• Post-harvest pest management
• Vigna unguiculata

Zanha africana (Radlk.) Exell (Sapindaceae) root bark is used by farmers throughout sub-Saharan Africa to protect stored grain from bruchid beetles, such as Callosobruchus maculatus. Chloroform, methanol and water extracts of Z. africana root bark inhibited oviposition and caused significantly higher mortality of C maculatus at a rate of application equivalent to that applied by farmers compared to control insects. The chloroform extract contained nor-hopanes rarely found in plants of which seven were isolated, one of which was previously known. Two of the most abundant nor-hopanes 3 beta,6 beta-dihydroxy-7 beta-[(4-hydroxybenzoyl)oxy]-21 alpha H-24-norhopa-4(23),22(29)-diene and 3 beta,6 beta-dihydroxy-7 beta-[(4-hydroxybenzoyl)oxy]-24-norhopa-4(23),17(21)-diene were toxic to and reduced oviposition of C maculatus in a dose dependent manner. Z. africana root bark is rich in insecticidal compounds that account for its effective use by smallholder farmers as an alternative to conventional insecticides.

• 出版日期2016-3