Cytotoxic constituents and a new hydroxycinnamic acid derivative from Leontodon saxatilis (Asteraceae, Cichorieae)

Phytochemical investigation of the aerial parts of Leontodon saxatilis yielded six compounds with antimyeloma activity as well as crepidiaside A as a chemophenetic marker and 5-feruloyl-2α-hydroxyquinic acid as a new hydroxycinnamic acid derivative.

3-(4-Hydroxy-3-methoxyphenyl)propionic Acid Produced from 4-Hydroxy-3-methoxycinnamic Acid by Gut Microbiota Improves Host Metabolic Condition in Diet-Induced Obese Mice

4-Hydroxy-3-methoxycinnamic acid (HMCA), a hydroxycinnamic acid derivative, is abundant in fruits and vegetables, including oranges, carrots, rice bran, and coffee beans. Several beneficial effects of HMCA have been reported, including improvement of metabolic abnormalities in animal models and human studies. However, its mitigating effects on high-fat diet (HFD)-induced obesity, and the mechanism underlying these effects, remain to be elucidated. In this study, we demonstrated that dietary HMCA was efficacious against HFD-induced weight gain and hepatic steatosis, and that it improved insulin sensitivity. These metabolic benefits of HMCA were ascribable to 3-(4-hydroxy-3-methoxyphenyl)propionic acid (HMPA) produced by gut microbiota. Moreover, conversion of HMCA into HMPA was attributable to a wide variety of microbes belonging to the phylum Bacteroidetes. We further showed that HMPA modulated gut microbes associated with host metabolic homeostasis by increasing the abundance of organisms belonging to the phylum Bacteroidetes and reducing the abundance of the phylum Firmicutes. Collectively, these results suggest that HMPA derived from HMCA is metabolically beneficial, and regulates hepatic lipid metabolism, insulin sensitivity, and the gut microbial community. Our results provide insights for the development of functional foods and preventive medicines, based on the microbiota of the intestinal environment, for the prevention of metabolic disorders.

Hydroxycinnamic acid as a novel scaffold for the development of cyclooxygenase-2 inhibitors

The most active hydroxycinnamic acid derivative, caffeic acid diethyl ester (CA-DE), demonstrated 88.5/30.5% inhibition at 100/20 μM against COX-2 and negligible COX-1 inhibitory effect. CA-DE showed preferred interactions with COX-2 active site.

Brazilian Propolis: Correlation between Chemical Composition and Antimicrobial Activity

The chemical composition of ethanol extracts from samples of Brazilian propolis (EEPs) determined by HPLC and their activity againstTrypanosoma cruzi,Staphylococcus aureus,Streptococcus pneumoniae,Klebisiella pneumoniae,Candida albicans,Sporothrix schenckiiandParacoccidioides brasiliensiswere determined. Based on the predominant botanical origin in the region of samples' collection, the 10 extracts were separated into three groups: A (B. dracunculifolia+Auraucariaspp), B (B. dracunculifolia) and C (Araucariaspp). Analysis by the multiple regression of all the extracts together showed a positive correlation, higher concentrations leading to higher biological effect, ofS. aureuswithp-coumaric acid (PCUM) and 3-(4-hydroxy-3-(oxo-butenyl)-phenylacrylic acid (DHCA1) and of trypomastigotes ofT. cruziwith 3,5-diprenyl-4-hydroxycinnamic acid derivative 4 (DHCA4) and 2,2-dimethyl-6-carboxyethenyl-2H-1-benzopyran (DCBEN). When the same approach was employed for each group, due to the small number of observations, the statistical test gave unreliable results. However, an overall analysis revealed for group A an association ofS. aureuswith caffeic acid (CAF) and dicaffeoylquinic acid 3 (CAFQ3), ofS. pneumoniaewith CAFQ3 and monocaffeoylquinic acid 2 (CAFQ2) and ofT. cruzialso with CAFQ3. For group B, a higher activity againstS. pneumoniaewas associated DCBEN and forT. cruziwith CAF. For group C no association was observed between the anitmicrobial effect and any component of the extracts. The present study reinforces the relevance of PCUM and derivatives, especially prenylated ones and also of caffeolyquinic acids, on the biological activity of Brazilian propolis.