Houttuynoid M, an Anti-HSV Active Houttuynoid from Houttuynia cordata Featuring a Bis-houttuynin Chain Tethered to a Flavonoid Core.

Houttuynoid M (1), a new houttuynoid, and the related known compound houttuynoid A (2) were isolated from Houttuynia cordata. Their structures were defined using NMR data analysis, HR-MSn experiment, and chemical derivatization. Houttuynoid M is the first example of a houttuynoid with a bis-houttuynin chain tethered to a flavonoid core. A putative biosynthetic pathway of houttuynoid M (1) is proposed. The anti-herpes simplex virus (anti-HSV) activities of 1 and 2 (IC50 values of 17.72 and 12.42 µM, respectively) were evaluated using a plaque formation assay with acyclovir as the positive control.

Lycibarbarspermidines A-O, New Dicaffeoylspermidine Derivatives from Wolfberry, with Activities against Alzheimer's Disease and Oxidation.

Fifteen new dicaffeoylspermidine derivatives, lycibarbarspermidines A-O (1-15), were isolated from the fruit of Lycium barbarum (wolfberry). The structures were unambiguously determined by spectroscopic analyses and chemical methods. Dicaffeoylspermidine derivatives, a rare kind of plant secondary metabolites, are primarily distributed in the family of Solanaceae. Only six compounds were structurally identified, and all of them are acyclic aglycones. Compounds 1-15 are the first glycosidic products of dicaffeoylspermidine derivatives, and compounds 14-15 are the first cyclization products of dicaffeoylspermidine derivatives. Moreover, dicaffeoylspermidine derivatives were first isolated and identified from wolfberry. The short-term memory assay on a transgenic fly Alzheimer's disease (AD) model showed that 1-15 exhibited different levels of anti-AD activity. The oxygen radical absorbance capacity assay revealed that 1-15 all displayed antioxidant capacity. Both anti-AD and antioxidant functions are related to the effects of wolfberry. Therefore, dicaffeoylspermidine derivatives are considered beneficial constituents responsible for the antiaging, neuroprotective, anti-AD, and antioxidant effects of wolfberry.

[Antitumor effect of sphingosine kinase 1 inhibitor in combination with chemotherapy on SGC7901 gastric cancer cells in vitro].

OBJECTIVE: To study the effect of the sphingosine kinase 1 (SphK1) inhibitor N,N-dimethylsphingosine (DMS) in combination with chemotherapeutic drugs (DDP, 5-Fu, MMC) on the proliferation of gastric cancer cells (SGC7901) in vitro, and to evaluate whether SphK1 inhibitors could be used as synergetic agents in chemotherapy. METHODS: SGC7901 cells were incubated in vitro with DMS (1 micromol/L) and 5-Fu, DDP, MMC at different concentrations in combination or separately for 24 h. The effects on the growth and survival of SGC7901 cells were determined by MTT assay. The inhibition rates were assessed by response surface analysis and the interactive relationships between the combined drugs were evaluated on the basis of positive/negative values of the cross product coefficients in the response surface equation. RESULTS: The growth inhibition rate of the gastric cancer cells by treatment with DMS (1 micromol/L) was (10.23 +/- 0.74)%. The growth inhibition rates of the gastric cancer cells treated with 5-Fu (1, 5 and 25 microg/ml) for 24 h were (9.95 +/- 3.24)%, (21.04 +/- 2.19)%, and (45.49 +/- 3.60)%, respectively. The growth inhibition rates of the gastric cancer cells treated with DDP (0.5, 2.5 and 12.5 microg/ml) for 24 h were (9.38 +/- 0.79)%, (19.61 +/- 0.90)%, and (29.83 +/- 0.54)%, respectively. The growth inhibition rates of the gastric cancer cells treated with MMC (0.1, 0.5 and 2.5 microg/ml) for 24 h were (15.35 +/- 0.77)%, (24.72 +/- 0.83)%, and (30.68 +/- 0.28)%, respectively. There were significant differences among the inhibition rates caused by different concentrations of the drugs (P < 0.05). When 1 micromol/L DMS was used in combination with 5-Fu (1, 5, and 25 microg/ml) for 24 h, the growth inhibition rates of the cancer cells were (16.76 +/- 0.41)%, (27.28 +/- 0.29)% and (52.56 +/- 3.60)%, respectively. When 1 micromol/L DMS was used in combination with DDP (0.5, 2.5, and 12.5 microg/ml) for 24 h, the growth inhibition rates of the cancer cells were (15.35 +/- 0.86)%, (25.57 +/- 0.27)%, (36.37 +/- 0.51)%, respectively. When 1 micromol/L DMS was used in combination with MMC (0.1, 0.5, and 2.5 microg/ml) for 24 h, the growth inhibition rates of the cancer cells were (21.02 +/- 0.28)%, (32.10 +/- 0.27)%, (36.36 +/- 0.28)%, respectively. There were also significant differences among the growth inhibition rates caused by different concentrations of the drugs alone and in combination groups (P < 0.05). CONCLUSIONS: DMS can suppress the proliferation of SGC7901 cells in vitro, and there are evident synergetic effects when it is used in combination with chemotherapeutic drugs. The results of this study indicate that SphK1 inhibitors may become novel and promising chemotherapeutic sensitizers.