| Summary: | During a phytochemical investigation of the unripe fruits of <i>Rubus chingii</i> Hu (i.e., Fructus Rubi, a traditional Chinese medicine named “Fu-Pen-Zi”), a number of highly oxygenated terpenoids were isolated and characterized. These included nine ursane-type (<b>1</b>, <b>2</b>, and <b>4</b>–<b>10</b>), five oleanane-type (<b>3</b>, <b>11</b>–<b>14</b>), and six cucurbitane-type (<b>15</b>–<b>20</b>) triterpenoids, together with five <i>ent</i>-kaurane-type diterpenoids (<b>21</b>–<b>25</b>). Among them, (4<i>R</i>,5<i>R</i>,8<i>R</i>,9<i>R</i>,10<i>R</i>,14<i>S</i>,17<i>S</i>,18<i>S</i>,19<i>R</i>,20<i>R</i>)-2,19α,23-trihydroxy-3-oxo-urs-1,12-dien-28-oic acid (rubusacid A, <b>1</b>), (2<i>R</i>*,4<i>S</i>*,5<i>R</i>*,8<i>R</i>*,9<i>R</i>*,10<i>R</i>*,14<i>S</i>*,17<i>S</i>*, 18<i>S</i>*,19<i>R</i>*,20<i>R</i>*)-2α,19α,24-trihydroxy-3-oxo-urs-12-en-28-oic acid (rubusacid B, <b>2</b>), (5<i>R</i>,8<i>R</i>,9<i>R</i>,10<i>R</i>, 14<i>S</i>,17<i>R</i>,18<i>S</i>,19<i>S</i>)-2,19α-dihydroxy-olean-1,12-dien-28-oic acid (rubusacid C, <b>3</b>), and (3<i>S</i>,5<i>S</i>,8<i>S</i>,9<i>R</i>, 10<i>S</i>,13<i>R</i>,16<i>R</i>)-3α,16α,17-trihydroxy-<i>ent</i>-kaur-2-one (rubusone, <b>21</b>) were previously undescribed. Their chemical structures and absolute configurations were elucidated on the basis of spectroscopic data and electronic circular dichroism (ECD) analyses. Compounds <b>1</b> and <b>3</b> are rare naturally occurring pentacyclic triterpenoids featuring a special <i>α,β</i>-unsaturated keto-enol (diosphenol) unit in ring A. Cucurbitacin B (<b>15</b>), cucurbitacin D (<b>16</b>), and 3<i>α</i>,16<i>α</i>,20(<i>R</i>),25-tetrahydroxy-cucurbita-5,23- dien-2,11,22-trione (<b>17</b>) were found to have remarkable inhibitory effects against NF-<i>κ</i>B, with IC<sub>50</sub> values of 0.08, 0.61, and 1.60 μM, respectively.
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