1H-NMR-guided isolation of enantiomeric coumarin-monoterpenes with anti-inflammatory activity from Gerbera piloselloides.

1H-NMR guided fractionation led to the isolation of twenty-two coumarin monoterpenes from the whole plant of Gerbera piloselloides, among which fourteen were undescribed. All coumarin monoterpenes were initially found to be racemates without optical activity. Subsequently, eleven pairs of optically pure enantiomers were successfully separated by chiral phase HPLC. Their structures and absolute configurations were unambiguously determined based on their spectroscopic data, calculated/experimental electronic circular dichroism (ECD) data, and X-ray diffraction analysis. Bioassays in LPS-treated RAW 264.7 cells revealed that the four compounds possessed moderate anti-inflammatory activity. In addition, the correlations between the cotton effect (CE) from δ-lactone at approximately 210-220 nm in CD spectra and γ-C or the ring fused at γ-C of the skeleton were reported for the first time.

Bioactive constituents from Gerbera piloselloides with anti-inflammatory and antiproliferative activities.

A phytochemical investigation of the 95% ethanol extract from Gerbera piloselloides obtained fourteen compounds, including three undescribed phenone-monoterpenes (1a/1b and 2), seven undescribed chromone-monoterpenes (3a/3b-5a/5b and 6), and one undescribed coumarin-monoterpene (8). Among them, four pairs of enantiomers (1a/1b and 3a/3b-5a/5b) were successfully isolated by the chiral-phase HPLC resolution. The structures and absolute configurations were unambiguously determined based on comprehensive spectroscopic data, electronic circular dichroism (ECD) data, and X-ray diffraction analysis. Structurally, compound 1 is the first 5-methylphenone monoterpene formed through a circular 6-membered carbocycle. And their anti-inflammatory and antiproliferative activities were evaluated via LPS stimulated RAW 264.7 cells and five human cancer lines (HepG2, MDA-MB-231, SCG-7901, A549 and MCF-7), respectively. Compounds 4b, 5a and 5b showed moderate inhibitory effect against nitric oxide (NO) production with IC50 values ranging from 12.52 to 15.75 µM. Compound 8 significantly inhibited the proliferation of MDA-MB-231 human cancer line in a dose-dependent manner. Furthermore, the connection between phenone-monoterpenes, chromone-monoterpenes, and coumarin-monoterpenes in biosynthesis were also discussed.

Suppression of Helicobacter pylori infection by daily cranberry intake: A double-blind, randomized, placebo-controlled trial.

BACKGROUND AND AIM: Dietary strategies that contribute to reducing incidence of Helicobacter pylori infection without negative side effects are highly desirable owing to worldwide bacterial prevalence and carcinogenesis potential. The aim of this study was to determine dosage effect of daily cranberry consumption on H. pylori suppression over time in infected adults to assess the potential of this complementary management strategy in a region with high gastric cancer risk and high prevalence of H. pylori infection. METHODS: This double-blind, randomized, placebo-controlled trial on 522 H. pylori-positive adults evaluated dose-response effects of proanthocyanidin-standardized cranberry juice, cranberry powder, or their placebos on suppression of H. pylori at 2 and 8 weeks by 13 C-urea breath testing and eradication at 45 days post-intervention. RESULTS: H. pylori-negative rates in placebo, low-proanthocyanidin, medium-proanthocyanidin, and high-proanthocyanidin cranberry juice groups at week 2 were 13.24%, 7.58%, 1.49%, and 13.85% and at week 8 were 7.35%, 7.58%, 4.48%, and 20.00%, respectively. Consumption of high-proanthocyanidin juice twice daily (44 mg proanthocyanidin/240-mL serving) for 8 weeks resulted in decreased H. pylori infection rate by 20% as compared with other dosages and placebo (P < 0.05). Percentage of H. pylori-negative participants increased from 2 to 8 weeks in subjects who consumed 44 mg proanthocyanidin/day juice once or twice daily, showing a statistically significant positive trend over time. Encapsulated cranberry powder doses were not significantly effective at either time point. Overall trial compliance was 94.25%. Cranberry juice and powder were well-tolerated. CONCLUSIONS: Twice-daily consumption of proanthocyanidin-standardized cranberry juice may help potentiate suppression of H. pylori infection. TRIAL REGISTRATION: ChiCTR1800017522, per WHO ICTRP.