Bonabiline A, a Monoterpenoid 3α-Acyloxytropane from the Roots of Bonamia spectabilis showing M3 Receptor Antagonist Activity - Ott, Sonja C.; Jenett-Siems, Kristina; Pertz, Heinz H.; Siems, Karsten; Witte†, Ludger; Eich, Eckart (Planta Medica, 2006)