The roots of Panax notoginseng, an important Chinese medicinal plant, have been used traditionally in both the raw and processed forms, due to the different chemical constituents and bioactivities found. Thirty-eight dammarane-type triterpenoid saponins were isolated from the steam-processed roots of P. notoginseng, including 18 new substances, namely, notoginsenosides SP1-SP18 (1-18). The structures of 1-18 were determined on the basis of spectroscopic analysis and acidic hydrolysis. The absolute configuration of the hydroxy group at C-24 in 1-4, 19, and 20 was determined in each case by Mo2(AcO)4-induced circular dichroism. The new compounds were found to feature a diversity of highly oxygenated side chains, formed by hydrolysis of the C-20 sugar moiety followed by dehydration, dehydrogenation, epoxidation, hydroxylation, or methoxylation of the main saponins in the raw roots. The new saponins 1, 2, 6-8, 14, and 17 and the known compounds 20-27 showed promoting effects on the differentiation of PC12 cells, at a concentration of 10 μM.

Nd:Gd 3 Ga 5 O 12 crystals with different concentrations of Nd 3+ were grown by Czochralski method, their absorption spectra were measured at room temperature. By using the optical absorption method, the effective distribution coefficient k eff for Nd 3+ in GGG was fitted to be 0.40±0.01, which is higher than that of Nd 3+ in YAG. The 808nm absorption cross-section was calculated to be 4.0±0.2×10-20 cm -2 . The lengthways and radial concentration distribution of Nd 3+ in the crystals were also analyzed and discussed.