β‑Dihydroagarofuran-Type Sesquiterpenes from the Seeds of Celastrus monospermus and Their Lifespan-Extending Effects on the Nematode Caenorhabditis elegans

Seventeen β-dihydroagarofuran-type sesquiterpenes were isolated from the seeds of Celastrus monospermus, and, among them, 15 (1–15) were identified as new natural products. Nine isolates were evaluated for their lifespan-extending effect using the standard model animal nematode Caenorhabditis elegans. As a result, all of the tested compounds prolonged the lifespan of C. elegans when compared to the blank control group (p < 0.0001). Among them, celaspermin E (5) extended the average lifespan and maximum lifespan of C. elegans, with effects similar to those of rapamycin, a positive control that has been found experimentally to delay the aging process of yeasts, worms, fruit flies, and mice.