Discovery and partial purification of an antibiotic from lodgepole pine dwarf mistletoe (Arceuthobium americanum) active against Gram-positive organisms including Methicillin-resistant Staphylococcus aureus (MRSA)

作者：Pernitsky Kathryn Y; Mason Quinn D; Cinel Bruno; Friedman Cynthia M Ross^*

来源：Journal of Medicinal Plants Research, 2011, 5(9): 1722-1727.

• Antibiotic
• antimicrobial
• Arceuthobium americanum
• dwarf mistletoe
• gender
• Gram-positive
• methanolic extract
• Methicillin-resistant Staphylococcus aureus (MRSA)

The dioecious parasitic flowering plant, Arceuthobium americanum (lodgepole pine dwarf mistletoe), was investigated for antimicrobial activity. In a step beyond typical "plant bioprospecting" studies, seasonal variation and plant gender were considered. Methanolic extracts from male and female A. americanum shoots collected at two times in the growing season, May and August (2006), were used to challenge a panel of microbes via a disk diffusion assay. Crude extracts were active against Gram-positive organisms including Staphylococcus aureus and Methicillin-resistant S. aureus (MRSA), with "Males-August" extracts exhibiting the most antimicrobial activity as determined by measuring inhibition zones with a digital caliper (p<0.05). Partial purification of the active components was accomplished using fractionation by solvent partitioning (methanol: water [9: 1] vs. n-hexane followed methanol: water (6: 4) vs. chloroform) coupled to a biological assay employing S. aureus. This process effectively concentrated the antimicrobial compound(s) in the more polar fractions, evidenced by a significant increase in inhibition zone diameter (p<0.05) at each purification step. Tests with crude extract introduction and removal by dilution indicated that the antimicrobial activity may be bactericidal, at least with respect to S. aureus. Based on these findings, A. americanum warrants further study as a source of potential new antibiotics, especially in light of its activity against medically-relevant MRSA.

• 出版日期2011-5-4