Rauvolfianine, a new antimycobacterial glyceroglycolipid and other constituents from <i>Rauvolfia caffra.</i> Sond (Apocynaceae)

<p>The chemical investigation of the extract of the dried leaves of <i>Rauvolfia caffra</i> (Sond<b>) (</b>synonym <i>Rauvolfia macrophylla</i>) (Apocynaceae) led to isolation of a new glycoside derivative, rauvolfianine (<b>1</b>) as well as six known compounds: oleanolic acid (<b>2</b>), sitosterol-3-<i>O</i>-β-D-glucopyranoside (<b>3</b>), betulinic acid (<b>4</b>), vellosimine (<b>5</b>), sarpagine (<b>6</b>) and D-fructofuranosyl-β-(2→1)-α-D-glucopyranoside (<b>7</b>). Compounds <b>1</b>, <b>2</b>, <b>3</b>, <b>4</b> and <b>7</b> were evaluated for antitubercular activity. Compounds <b>1</b> and <b>2</b> were the most active (MIC = 7.8125 and 31.25 μg/mL) towards the Isoniazid resistant strain of <i>Mycobacterium tuberculosis</i> AC45. Their structures and relative stereochemistry were elucidated by spectroscopic methods.