Two new catechins from Zijuan green tea enhance the fitness and lifespan of insulin-like signaling pathways.

Green tea polyphenols show positive effects on human health and longevity. However, knowledge of the antiaging properties of green tea is limited to the major catechin epigallocatechin gallate (EGCG). The search for new ingredients in tea with strong antiaging activity deserves further study. Here we isolated and identified two new catechins from Zijuan green tea, named zijuanin E (1) and zijuanin F (2). Their structures were identified by extensive high-resolution mass spectroscopy (HR-MS), nuclear magnetic resonance (NMR), ultraviolet-vis (UV), infrared (IR) and circular dichroism (CD) spectroscopic analyses, and their C NMR and CD data were calculated. We used the nematode () to analyze the health benefits and longevity effects of 1 and 2. Compounds 1 and 2 (100 μM) remarkably prolonged the lifespan of by 67.2% and 56.0%, respectively, delaying the age-related decline of phenotypes, enhancing stress resistance, and reducing ROS and lipid accumulation. Furthermore, 1 and 2 did not affect the lifespan of , , , and mutant worms, suggesting that they might work the insulin/IGF and SKN-1/Nrf2 signaling pathways. Meanwhile, 1 and 2 also exhibited strong antioxidant activity . Surface plasmon resonance (SPR) evidence suggests that zijuanins E and F have strong human serum albumin (HSA) binding ability. Together, zijuanins E and F represent a new valuable class of tea components that promote healthspan and could be developed as potential dietary therapies against aging.