Asymmetric Total Synthesis of (+)-Chuanxiongnolide L1 via a Stereoselective Oxidative Dearomatization/Diels-Alder Strategy.

The first asymmetric total synthesis of chuanxiongnolide L1 was achieved in 16 steps and 1.9% overall yield by employing a bioinspired chiral auxiliary strategy. The key steps involving asymmetric oxidative dearomatization of chiral amino ether and subsequent asymmetric Diels-Alder reaction of the resulting masked chiral ortho-benzoquinone were adopted.

Fabrication of actiniae-like atomically thin hydroxylation boron nitride@polyaniline hierarchical composites with adjustable high thermal conductivity and electrical conductivity.

Polyaniline (PANI) has been studied as soft electronic materials, which is still subject to performance obstacles such as low thermal conductivity and undesirable electrical conductivity. Herein, we report thein situpreparation of an atomically thin hydroxylated boron nitride (HO-BNNS)@PANI actiniae-like layered composite. HO-BNNS@PANI composite obtains brilliant electrical and thermal conductivity without destroying the pH sensitivity of PANI. In this case, the test results show that when the HO-BNNS content is 15 wt%, the conductivity of the HO-BNNS@PANI composite is 10.8 S cm-1, and the thermal conductivity is 1.21 W m-1·K-1(≈520% that of pure PANI). More strikingly, the HO-BNNS@PANI composite maintains the pH responsiveness of the intrinsic PANI. This greatly improves the application range of composite materials. Meanwhile, since actiniae-like structural factors simultaneously improve ion diffusion capability and optimize reaction area, after five times of doping and dedoping, the conductivity of the HO-BNNS@PANI composite can still be maintained above 60%.

[Effects of different concentrations of nitrogen and phosphorus on growth and active components of Salvia miltiorrhiza].

With annual Salvia miltiorrhiza seedlings as experimental material, using "3414" optimal regression design recommended by the Ministry of Agriculture and regularly watered with nutrient solution, through the dynamic sampling of S. miltiorrhiza in different growing stages, and the growth index, dry weight of plant root and content of active components were measured. The potted experiments were applied to study the effects of different nitrogen and phosphorus ratios on the growth, dry matter accumulation and accumulation of active components of S. miltiorrhiza, in order to explore a compatible fertilization method of nitrogen and phosphorus ratio that are suitable for production and quality of S. miltiorrhiza. The results reported as follows：①High concentrations of nitrogen fertilizer was beneficial to dry matter accumulation of S. miltiorrhiza aerial parts, and low concentration of nitrogen fertilizer transferred the dry matter accumulation to underground, and N1P1 could make the transfer ahead of time;②Regression analysis showed that in the early growth stage (before early July), we could use the nitrogen and phosphorus as basic fertilizer at a concentration of 1.521,0.355 g•L⁻¹ respectively to promote the growth of S. miltiorrhiza and at a concentration of 2.281,0.710 g•L⁻¹ respectively to promote the dry matter accumulation of root (after mid-August);③Five kinds of active components of S. miltiorrhiza decreased with the increase of nitrogen concentration, and increased with the increase of the concentration of phosphate fertilizer. Nitrogenous fertilizer, phosphate fertilizer in N-P=2∶3 ratio was more suitable for the accumulation of salvianolic acids, in N-P=1∶2 ratio was more suitable for the accumulation of tanshinone.