<jats:p> Five pure alkaloids have been separated from the crude mixture of Ceanothus americanus (Rhamnaceae) bases by means of column and thick-layer chromatography. Their molecular formulas have been established as C<jats:sub>30</jats:sub>H<jats:sub>40</jats:sub>O<jats:sub>4</jats:sub>N<jats:sub>4</jats:sub>, C<jats:sub>29</jats:sub>H<jats:sub>36</jats:sub>O<jats:sub>4</jats:sub>N<jats:sub>4</jats:sub>, C<jats:sub>26</jats:sub>H<jats:sub>38</jats:sub>O<jats:sub>4</jats:sub>N<jats:sub>4</jats:sub>, and C<jats:sub>28</jats:sub>H<jats:sub>44</jats:sub>O<jats:sub>4</jats:sub>N<jats:sub>4</jats:sub> (two compounds). One of these may be identical with the previously reported ceanothine. Evidence is presented for the functional groups and other features of the molecules.