Diterpenoids from Torreya grandis and their cytotoxic activities.

Eight previously undescribed diterpenoids, along with eleven previously reported analogues, were obtained from the supercritical CO2 extracts of Torreya grandis aril. The structures of these compounds were elucidated based on HRESIMS, NMR, ECD, and single-crystal X-ray diffraction data. In the MTT assay, compound 18 exhibited significant inhibitory effects on two human colon cancer cell lines, HT-29 and HCT 116 cells, with IC50 values of 7.37 µM and 6.55 µM, respectively. It was found that compound 18 induced apoptosis and significantly inhibited the migration of HCT 116 colon cancer cells in a concentration-dependent manner.

Terahertz Sensor via Ultralow-Loss Dispersion-Flattened Polymer Optical Fiber: Design and Analysis.

A novel cyclic olefin copolymer (COC)-based polymer optical fiber (POF) with a rectangular porous core is designed for terahertz (THz) sensing by the finite element method. The numerical simulations showed an ultrahigh relative sensitivity of 89.73% of the x-polarization mode at a frequency of 1.2 THz and under optimum design conditions. In addition to this, they showed an ultralow confinement loss of 2.18 × 10-12 cm-1, a high birefringence of 1.91 × 10-3, a numerical aperture of 0.33, and an effective mode area of 1.65 × 105 µm2 was obtained for optimum design conditions. Moreover, the range dispersion variation was within 0.7 ± 0.41 ps/THz/cm, with the frequency range of 1.0-1.4 THz. Compared with the traditional sensor, the late-model sensor will have application value in THz sensing and communication.