Two new alkaloids from Pachysandra terminalis and their antibacterial activity assessment

Phytochemical investigation of a 90 % ethanol extract of Pachysandra terminalis Sieb. Et Zucc led to the isolation of a novel alkaloid, terminamine T (1); a new pregnane-type alkaloid, terminamine U (2); and four known pregnane-type alkaloids (3-6). The structures of these compounds were elucidated on the basis of nuclear magnetic resonance spectra, mass spectrometry data, single-crystal X-ray diffraction, and by a comparison with data from the literature. All compounds were evaluated for their antibacterial activities against gram-positive (S. aureus, ATCC 29213) and gram-negative (E. coli, ATCC 25922) bacteria. Compounds 2-6 exhibited generally modest to poor antibiotic properties. Furthermore, compound 2 showed antibacterial activity against methicillin-resistant Staphylococcus epidermidis (MRSE), methicillin-resistant Staphylococcus aureus (MRSA), and methicillin-resistant Staphylococcus aureus USA300 (LAC) with a minimal inhibitory concentration (MIC) value of 32 μg/mL (75 μM) and minimum bactericidal concentration (MBC) values of 64, 128, and 128 μg/mL (150, 300, and 300 μM), respectively.