In order to increase the photodynamic effect of Chlorin e6, four Chlorin e6-artesunate conjugates were designed and synthesized. Among them, three conjugates (3, 6, 9) contained single artesunate side chain at 152, 173 and 131 of Chlorin e6, respectively, and one conjugate (11) contained three artesunate side chains. In the in vitro evaluation of photodynamic effect, the four conjugates showed more potent phototoxicity against HepG2 cells than Chlorin e6. The introduction of artesunate side chain significantly increased the intracellular ROS production, although the production of singlet oxygen was not improved. Compound 11 exhibited much more potent phototoxicity than the other conjugates because the three artesunate side chains greatly enhanced the ROS production and cellular uptake. The results demonstrated that the conjugation of Chlorin e6 and artesunate could accomplish synergistic effects of chemo-phototherapy, and finally enhanced their antiproliferative effects.Download high-res image (94KB)Download full-size image

Ultrafiltration combined with liquid chromatography-mass spectrometry (UF-LC-MS) is an efficient affinity-based method to screen potential ligands of biomacromolecules from natural sources. In order to investigate the effects of constituents from Pueraria labta Ohwi on tyrosinase, a UF-LC-MS method for screening tyrosinase ligands was established. Seven constituents were screened as tyrosinase ligands with high affinity and their structures were elucidated as isoflavones and isoflavone glycosides by mass spectrum analysis, among which puerarin exhibited much stronger inhibitory activity in vitro than arbutin against tyrosinase. An in silico docking study indicates that the interaction between puerarin and tyrosinase mainly derived from hydrogen bonds and π–cation interaction.

Nine new chlorin derivatives containing maleimide functional group and amino acid residue with chlorin e6 scaffold (compounds 1–6) or pheophorbide a scaffold (compounds 7–9) were synthesised from chlorophyll a. The all nine derivatives demonstrated increased photo cytotoxic activity in HepG2 cell (IC50 3.2–20.5 μM) comparing with chlorin e6 and its trimethyl ester. Their photo cytotoxicities were approximately dependent on their abilities to produce singlet oxygen (1O2) in the cells.

2β,3α-Dihydroxyurs-12-en-28-oic acid (6) is a naturally occurring diastereoisomer of corosolic acid with glycogen phosphorylase inhibitory activity. A new strategy for the semi-synthesis of 6 was developed. Using the commercially available ursolic acid (1) as the starting materials, 6 was synthesized through five facile reactions with a high stereoselectivity and an overall yield of 47.3%. The structure of 6 was confirmed by optical rotation, ESI-MS, 1H NMR and 13C NMR data.A low cost synthetic route with a short production cycle and high yields under mild reaction conditions was created to synthesize a diastereoisomer of corosolic acid.

In an attempt to establish the qualitative and quantitative analysis of Fructus ligustri lucidi, near-infrared spectroscopy (NIRS) was applied. The qualitative model can identify nine alcohol-broiled products from eight different geographical origins and one crude sample with a factorization algorithm and pretreatment of the second-derivative (2-Der). For the quantitative models, a partial least squares (PLS) algorithm with optimum parameters was applied for determination of oleanolic acid (OA) and ursolic acid (UA) in Fructus ligustri lucidi. There is no significant difference for the observed values between the NIRS and HPLC method since the results of the t-tests are 0.590 and 0.441, respectively, both less than t(0.05,19) = 2.093 with a 95% confidence level. The data obtained revealed the proposed NIRS method is viable for the rapid qualitative and quantitative analysis of the active ingredients in Fructus ligustri lucidi.

Two new steroidal alkaloids, veraussines A (1) and B (2) were isolated from the roots and rhizomes of Veratrum nigrum var. ussuriense. Their structures were determined as N-(ethoxycarbonyl)-1α,2β,3α,15α-tetrahydroxy-5β-jervanin-12-en-11-one (1) and N-(methoxycarbonyl)-1α,2β,3α,15α-tetrahydroxy-5β-jervanin-12-en-11-one (2) by spectroscopic analysis.

In an attempt to establish the qualitative and quantitative analysis of Fructus ligustri lucidi, near-infrared spectroscopy (NIRS) was applied. The qualitative model can identify nine alcohol-broiled products from eight different geographical origins and one crude sample with a factorization algorithm and pretreatment of the second-derivative (2-Der). For the quantitative models, a partial least squares (PLS) algorithm with optimum parameters was applied for determination of oleanolic acid (OA) and ursolic acid (UA) in Fructus ligustri lucidi. There is no significant difference for the observed values between the NIRS and HPLC method since the results of the t-tests are 0.590 and 0.441, respectively, both less than t(0.05,19) = 2.093 with a 95% confidence level. The data obtained revealed the proposed NIRS method is viable for the rapid qualitative and quantitative analysis of the active ingredients in Fructus ligustri lucidi.