| abstract | - Abo-Khatwa, A. N., A. A. Al-Robai and D. A. Al-Jawhari (1996). "Lichen acids as uncouplers of oxidative phosphorylation of mouse-liver mitochondria." Natural Toxins 4: 96-102. Vulpinic acid extracted with benzene like procedure discribed by Abo-Khatwa et al (1996). Letharia vulpina yeilded 1 - 5% dry weight of vulpinic acid. Identified as vulpinic acid according to: melting point (recrystallized in ethanol) 148 - 149 C; mass spectrum showed two prominent peaks at m/e 290 and 161 in addition to the molecular ion (M+) peak at m/e 322. NMR major peaks at 3.87 (strong), 7.27 (duplites, J=7.5, 1.5), 7.33, 7.41, 7.44, and 8.13 (duplites, J=8). Vulpinic acid is an extracellular product of cellular origin deposited on the outer surface of lichen thalli. It is highly lipophilic, posesses ionizable groups and is capable of forming extensive hydrogen bonds. Usnic acid, vulpinic acid, and atranorin caused uncoupling of oxidative phosphorlation. Usnic acid was most effective (1uM for complete uncoupling), followed by vulpinic acid (5uM), then atranorin (5uM). Lichen acids known to affect: various microorganisms (gram positive), some vascular plants (spruce, pine, onion), bryophytes, lichen fungi, non-lichen fungi, invertabrates (snails, insects, mites), herbivore vertabrates. Vulpinic acid acts as an uncoupler of oxadative phosphorlation, attacking mitochondria and gram-positive bacteria.
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