From the ethanolic extract of the leaves of Bryophyllum pinnatum (Syn. B. Calcinum Kalanchoe pinnata) a versatile Nigeria medicinal plant was isolated a phenenthrene alkaloid identified as 1-ethanamino 7 Hex-1-yne-5I-one phenanthrene. The structure was elucidated using NMR spectroscopy in combination with IR, UV, and MS spectral data. Antimicrobial studies showed that the isolated compound successfully inhibited Psuedomonas aeruginosa, Klebsiella Pneumonia, Staphylococcus aureus, Escherichia coli, Candida albicans and Aspergillus niger. This result authenticates the use of Bryophyllum pinantum in phytomedicine for disease prevention and treatment of infections.