[Characteristics of acidification and the distribution of available phosphorus along soil depths in heavy clay soils in southern Henan Province, China]. / è±«å—é»æ¿åœŸå£¤åˆ†å±‚é ¸åŒ–å’Œè€•å±‚é€Ÿæ•ˆç£·åˆ†å¸ƒç‰¹å¾.

The acidification of agricultural soil in the southern part of the North China Plain has become more obvious, which is particularly true for the heavy clay soil types, such as yellow-cinnamon and lime concretion black soils. To understand the spatial variability of the pH value and nutrients on the vertical agricultural soil profile of heavy clay soils in this area, we measured pH values and available phosphorus (AP) in 63 farmland sample points from Xiping County in the southern Henan Province. Geostatistical methods and ArcGIS technology were used to map soil pH values along three soil depths (0-10, 10-20, and 20-30 cm) and the spatial distribution of soil AP in the tillage layer (0-20 cm). Furthermore, the correlation between pH and AP was analyzed. The results showed that mean pH values of typical yellow-cinnamon and typical fluvo-aquic soils from three soil layers were 4.98, 4.93, 5.31, and 5.46, 5.81, 6.26, respectively, which gradually increased with soil depths. However, there was no significant difference among the three soil layers. Mean pH values of typical lime concretion black soil from the three soil layers were 5.23, 5.43 and 6.03, respectively, and that of the 20-30 cm soil layer was significantly higher than that of the 0-10 cm (by 0.8-1 pH unit) and the 10-20 cm layers. The pH of the 20-30 cm soil layer of the calcareous lime concretion black and moist soils were also significantly higher than that of the 0-10 and 10-20 cm soil layers. The AP contents of the typical yellow-cinnamon, typical lime concretion black, moist, typical fluvo-aquic and calcareous lime concretion black soils in 0-20 cm soil layer were 8.85-54.75, 4.27-37.49, 8.22-51.80, 6.07-34.82, and 13.22-22.85 mg·kg-1, respectively. The results of the map indicated that the areas with low AP were distributed in the middle of the study area in blocks, and the areas with high AP were distributed around the study area in dots and flakes. The pH values of the typical yellow-cinnamon, typical lime concretion black, and moist soils positively correlated with the content of AP in the 0-20 cm soil layer. In conclusion, the heavy clay soil in southern Henan Province became stratified acidification, which slowed down along the soil depth. Soil AP contents in the tillage layer were distributed unevenly in the study area, and were affected by soil types and soil pH. These results would be useful for the improvement of heavy clay soil acidification in the southern part of the North China Plain.

Cytotoxic abietane and kaurane diterpenoids from Celastrus orbiculatus.

Celastrus orbiculatus is a medicinal plant belonging to the Celastraceae family. In this survey on the secondary metabolites of plants for obtaining antitumor substances, the chemical constituents of the stems of C. orbiculatus were investigated. Nortriptonoterpene (1), a new C19-norabietane diterpenoid, together with six other known abietane-type diterpenoids (2-7) and five known kaurane-type diterpenoids (8-12) were isolated and identified from the EtOAc extract of C. orbiculatus. Their structures were elucidated on the basis of extensive spectroscopic methods, including UV, IR, HR-ESI-MS, ECD, and NMR experiments, and by comparison with literature data. Compound 1 is a new C19-norabietane diterpenoid with 19 carbons. All compounds except for 10 and 11 were isolated from C. orbiculatus for the first time. The NMR data of 9 were reported for the first time. Compounds 1, 7 and 11 showed cytotoxicities against SGC-7901 with IC50 values of 63.2, 80.9 and 56.7 µM, respectively.

Geniposide, the component of the Chinese herbal formula Tongluojiunao, protects amyloid-ß peptide (1-42-mediated death of hippocampal neurons via the non-classical estrogen signaling pathway.

Tongluojiunao (TLJN) is an herbal medicine consisting of two main components, geniposide and ginsenoside Rg1. TLJN has been shown to protect primary cultured hippocampal neurons. However, its mechanism of action remains unclear. In the present study, primary cultured hippocampal neurons treated with Aß1-42 (10 µmol/L) significantly increased the release of lactate dehydrogenase, which was markedly reduced by TLJN (2 µL/mL), specifically by the component geniposide (26 µmol/L), but not ginsenoside Rg1 (2.5 µmol/L). The estrogen receptor inhibitor, ICI182780 (1 µmol/L), did not block TLJN- or geniposide-mediated decrease of lactate dehydrogenase under Aß1-42-exposed conditions. However, the phosphatidyl inositol 3-kinase or mitogen-activated protein kinase pathway inhibitor, LY294002 (50 µmol/L) or U0126 (10 µmol/L), respectively blocked the decrease of lactate dehydrogenase mediated by TLJN or geniposide. Therefore, these results suggest that the non-classical estrogen pathway (i.e., phosphatidyl inositol 3-kinase or mitogen-activated protein kinase) is involved in the neuroprotective effect of TLJN, specifically its component, geniposide, against Aß1-42-mediated cell death in primary cultured hippocampal neurons.