Separation and purification of steroidal saponins from Paris polyphylla by microwave-assisted extraction coupled with countercurrent chromatography using evaporative light scattering detection.

A method of microwave-assisted extraction coupled with countercurrent chromatography using evaporative light scattering detection was successfully developed for the separation and purification of steroidal saponins from Paris polyphylla. The main extraction conditions including microwave power, liquid/solid ratio, irradiation time, and extraction temperature were optimized using an orthogonal array design method. A suitable two-phase solvent system consisting of n-heptane/n-butanol/acetonitrile/water (10:19:6:20, v/v/v/v) was employed in the separation and purification of the extracts of P. polyphylla. A total of 7.1 mg polyphyllin VII, 4.3 mg gracillin, 9.2 mg dioscin, and 10.2 mg polyphyllin I were obtained from 1.5 g P. polyphylla in less than 300 min, the purities of which determined by HPLC were 96.7, 97.3, 98.7, and 98.6%, respectively. The identification and characterization of these compounds were performed by LC-ESI-MS and 1H NMR spectroscopy. The results demonstrated that the proposed method is feasible, economical and efficient for the extraction, separation and purification of effective compounds from natural products.

The Association Between Short-Term Air Pollution Exposure and Post-Adolescent Acne: The Evidence from a Time Series Analysis in Xi'an, China.

BACKGROUND: Post-adolescent acne is a common skin disease faced by adults. However, whether air pollution (AP) serves as a risk factor for post-adolescent acne remains elusive. AIM: To determine the relationship between short-term AP exposure (within 7 days) and outpatient visits for post-adolescent acne. METHODS: Daily outpatient visit data for post-adolescent acne and routinely AP data between 2010 and 2013 were collected from Xi'an, China. A generalized additive regression model was used to analyze the relationship between outpatient visits for post-adolescent acne and short-term ambient AP exposure. The gender-specific analyses were conducted as well. RESULTS: Totally, 27,190 outpatient visits for post-adolescent acne were included. The results revealed that a 10 µg/m3 increase in PM10, SO2, and NO2 at lag 0-7 day was associated with the increase of outpatient visits for post-adolescent acne at 0.84% (95% CI: 0.53%, 1.16%), 1.61% (95% CI: 0.12%, 3.10%), and 3.50% (95% CI: 1.60%, 5.40%), respectively. The significant positive associations of PM10, SO2, and NO2 were found at both single-lag models and moving average models. The gender-specific analyses showed that the effect estimates of PM10 was stronger for females than for males, while there was no observed gender difference in the effects of SO2 and NO2. CONCLUSION: Short-term exposure to AP was associated with increased outpatient visits for post-adolescent acne, especially for females in the effects of PM10.