Diterpenoids from <i>Croton laui</i> and Their Cytotoxic and Antimicrobial Activities

Fourteen new diterpenoids including clerodane (<b>1</b>–<b>12</b>), labdane (<b>13</b>), and norlabdane (<b>14</b>) types, as well as nine known analogues were isolated from the aerial parts of <i>Croton laui</i>. Their structures were established on the basis of spectroscopic analysis, and that of crotonolide H (<b>11</b>) was confirmed by single-crystal X-ray crystallography. Crotonolide A (<b>1</b>) exhibited moderate cytotoxicity against two tumor cell lines, HL-60 (human premyelocytic leukemia, IC₅₀ 9.42 μM) and P-388 (murine leukemia, IC₅₀ 7.45 μM), and crotonolide G (<b>10</b>) displayed significant antibacterial activity against a panel of Gram-positive bacteria