Food allergy has become a worldwide problem. To find an effective way to reduce the allergic effect of allergen is an interesting topic. In this work, the interaction between ovalbumin（OVA） and tangeretin was studied by means of spectroscopy, molecular docking calculation and animal experiment. As the results show, static quenching of fluorescence intensity happened due to the interaction between OVA and tangeretin. Binding constants, binding sites, and thermometric parameters were obtained. The conformation changing of OVA occurred due to the interaction between it and tangeretin. The molecular docking calculation results show that the epitopes Arginine 84（ARG84）, Leucine 87（LEU87）, Asparagine 88（ASN88）, Serine 103（SER103）, Arginine 104（ARG104）, Leucine 124（LEUI24）, Arginine 126（ARG126）, Glycine 127（GLY127）, Glycine 128（GLY128） and Tryptohan 148（TRP148） of OVA were occupied by tangeretin after the docking, which means tangeretin may have some inhibition effects. As the results of animal experiments, the amount of IgE and lung tissue sections of female BALB/c mice in different groups show that tangeretin with different concentrations has better effects than dexamethasone. In conclusion, the tangeretin may have the effects to reduce the allergic effects of OVA via occupying the IgE-binding epitopes of OVA.
SHI XiaoleiZHANG TingLI XuwenFENG YuTAN XinJIN Yongri
Abstract With the oxidation treatment, eighteen compounds were separated from 20（S）-ginsenoside Rg2, Rhl, pro- topanaxatriol（PPT） and their 20（R）-epimers in total and cytotoxicity of most of them was evaluated against three hu- man cancer cell lines HeLa, A549 and MCF-7 by 3-（4,5-dimetylthiazol-z-yl）-2,5-diphenyltetrazolium bromide（MTT） assay. Their structures were confirmed by means of nuclear magnetic resonance（NMR） and mass spectrometry and the results were compared with those of previous literature. In this study, we systematically semisynthesized all four ocotillol type saponins, i.e., （20S, 24S＇）, （20S, 24R）, （20R, 24S） and （20R, 24R）. All the configurations at C20 kept the same with their starting materials. Meanwhile a pair of C24 epimers was generated in terms of ocotillol type saponins In addition, seven compounds（4--8, 13 and 14） were reported firstly. The cytotoxic results distinguished the ocotillol type products（6, 7, 13 and 14） from 20（R）-PPT and 20（R）-ginsenoside Rhl, which possessed better cytotoxicities than their correspondents from 20（S）-epimers against HeLa cells, and the carbonyl group at C3 can improve the cytotoxi- city, which helped us to gain deeper insight into Ocotillol type saponins.
YANG JieYU XueCAI XiaoxiangCHEN YanxinZANG HuimingLI XuwenJIN Yongri
Ginseng（Panax ginseng C. A. Mey.） is a traditional medicinal herb in Asia. Studies have shown that ginsenosides significantly affect immnnoregulation and rare ginsenosides have anti-allergic effects. In this research, a high temperature and high pressure method was utilized to increase the contents of rare ginsenosides in the ginseng extract（GE）. The anti-allergic effects of this extract were investigated in vivo. Water was used as the extraction solvent in extracting the rare ginsenosides via the high temperature and high pressure method. Extraction time and temperature were investigated in order to increase the contents of rare ginsenosides. Rare ginsenosides were qualitatively analyzed by HPLC-ESI-MS and quantitatively analyzed by HPLC-UV. Anti-allergic effects of the extracts were assessed using the ovalbumin（OVA）-induced allergic asthma model in vivo. An extraction temperature of 145 ℃ and extraction time of 2.0 h were chosen as the optimal conditions. Compared with traditional method, the contents of total rare ginsenosides extracted were considerably higher using the new method, that is, 14.74 times that extracted by the traditional method. In our in vivo experiments, treatment with high concentration GE may have anti-allergic erects in decreasing the total amount of IgE in serum and IL-4 in bronchoalveolar lavage fluid（BALF）, aud in improving the ratio of CD4^＋ to CD8^＋ T cells. The high temperature and high pressure method was an effective method to obtain GE containing more rare ginsenosides, which maybe become anti-allergic agents.
LIU YingLI XuwenZHANG HanqiWU QianSHI XiaoleiJIN Yongri
Two new steroidal saponms（2, 3） and two known compounds（1, 4） were isolated from 75% ethanol extract ofAllii macrostemonis bulbus by various spectral methods. The two new steroidal saponins were respectively elucidated as （25S）-26-O-β-D-glucopyranosyl-5α-furostanol-2α,3β,22,26-tetrol-3-O-β-D-glucopyranosyl（1→2）-[β-D- glucopyranosyl（1→3）]-β-D-glucopyranosyl（1→4 ）-β-D-galactopyranoside（2 ） and 26-O-β-D-glucopyranosyl-5α- furostanol-25（ 27）-ene-3β,22,26-tetrol-3-O-β-D-glucopyranosyl（ 1→2 ）-[β-D-glucopyranosyl（ 1→3 ）] -β-D-glucopyranosyl- （1→4）-β-D-galactopyranoside（3）. Compound 4 was obtained from this medical plant for the first time. The activity experiments of proliferation inhibition on tumor cells were performed by cell counting kit-8（CCK-8） method for compound 2（25S-configuration） and its isomer（compound 1, 25R-configttration）. The results show that compounds 1 and 2 have weak inhibition on lung cancer A549 cells, melanoma A375 cells and breast cancer MCF-7 cells as well as certain inhibitory effect on liver cancer HepG2 cells, and the inhibitory effect of compound 1 is stronger than that of compound 2.
YAO HuaWANG TongWU QianLIU YingLI PengLI XuwenJIN Yongri
