Combretum caffrum, a tree in the family Combretaceae, has been found to contain three 9,10-dihydrophenanthrenes (6,7-dihydroxy-2,3,4-trimethoxy; 7-hydroxy-2,3,4,6-tetramethoxy; and 2,7-dihydroxy-3,4,6-trimethoxy) that inhibit (ED50 2.2, 2.8, and 2.6 μg/mL) growth of the murine lymphocytic leukemia cell line. One phenanthrene (7-hydroxy-2,3,4,6-tetramethoxy) was also isolated with similar (ED50 2.0 μg/mL) activity. Structures for each of these substances, including a dihydrophenanthrene (2-hydroxy-3,4,6,7-tetramethoxy-9,10-dihydrophenanthrene), were determined by detailed high resolution nuclear magnetic resonance and mass spectral studies and (or) X-ray crystal structure analysis.
ΟΛΙΚΗ ΑΣΥΜΜΕΤΡΗ ΣΥΝΘΕΣΗ ΔΡΑΣΤΙΚΩΝ ΣΥΣΤΑΤΙΚΩΝ ΤΟΥ ΦΥΤΟΥ COMBRETUM CAFFRUM ΚΑΙ ΑΝΑΛΟΓΩΝ ΜΑΚΡΟΛΑΚΤΟΝΩΝ ΜΕ ΑΝΤΙΚΑΡΚΙΝΙΚΕΣ ΙΔΙΟΤΗΤΕΣ