Asymmetric Synthesis of Borylalkanes via Copper-Catalyzed Enantioselective Hydroallylation.

An efficient synthetic method for preparing enantioenriched secondary borylalkanes has been achieved through a copper-catalyzed regio- and enantioselective hydroallylation of alkenyl boronates and boramides employing hydrosilanes and allylic phosphates. In the presence of a copper catalyst with a chiral Walphos ligand, a range of alkenylboron compounds with an aryl, heteroaryl, or alkyl substituent produced secondary homoallylic alkylboron compounds in good yields and with high enantioselectivities up to 99% ee. The utility of the resulting alkylboronates was demonstrated in an efficient synthesis of (S)-massoialactone.

Insights on Dietary Polyphenols as Agents against Metabolic Disorders: Obesity as a Target Disease.

Obesity is a condition that leads to increased health problems associated with metabolic disorders. Synthetic drugs are available for obesity treatment, but some of these compounds have demonstrated considerable side effects that limit their use. Polyphenols are vital phytonutrients of plant origin that can be incorporated as functional food ingredients. This review presents recent developments in dietary polyphenols as anti-obesity agents. Evidence supporting the potential application of food-derived polyphenols as agents against obesity has been summarized. Literature evidence supports the effectiveness of plant polyphenols against obesity. The anti-obesity mechanisms of polyphenols have been explained by their potential to inhibit obesity-related digestive enzymes, modulate neurohormones/peptides involved in food intake, and their ability to improve the growth of beneficial gut microbes while inhibiting the proliferation of pathogenic ones. Metabolism of polyphenols by gut microbes produces different metabolites with enhanced biological properties. Thus, research demonstrates that dietary polyphenols can offer a novel path to developing functional foods for treating obesity. Upcoming investigations need to explore novel techniques, such as nanocarriers, to improve the content of polyphenols in foods and their delivery and bioavailability at the target sites in the body.

Antiobesity and Antioxidative Effect of Fermented Brown Rice Using In Vitro with In Vivo Caenorhabditis elegans Model.

Naturally occurring phytochemicals from plants or grains are crucial in reducing various metabolic disorders. Bioactive phytonutrients are abundant in the Asian dietary staple, brown rice. This research evaluated the impact of lactic acid bacteria (LABs) bioconversion and fermentation on antioxidant and antiobesity activities and ferulic acid content in brown rice. The combination of bioconversion with Pediococcus acidilactici MNL5 among all LABs used showed a synergistic impact with 24 h of solid-state brown rice fermentation. The 24-h MNL5 fermented brown rice (FBR) demonstrated the most potent pancreatic lipase inhibitory activity (85.5 ± 1.25%) compared to raw brown rice (RBR) (54.4 ± 0.86%). The antioxidant potential of MNL5-FBR was also found to be highest in the DPPH assay (124.40 ± 2.40 mg Trolox Equiv./100 g, DW), ABTS assay (130.52 ± 2.32 mg Trolox Equiv./100 g, DW), and FRAP assay (116.16 ± 2.42 mg Trolox Equiv./100 g, DW). Based on higher antioxidant and antiobesity activities, samples were quantified for ferulic acid content using the HPLC-MS/MS approach. Furthermore, C. elegans supplementation with FBR showed enhanced life span and lipid reduction in fluorescence microscope analysis compared to the control. Our results indicate that the expression study using the C. elegans model (N2 and Daf-2 models) fat gene was conducted, showing a lowering of obesity ability in FBR-fed worms. Our study indicates that FBR has improved antioxidant and antiobesity actions, especially in MNL5-FBR, and can be employed to develop functional foods that combat obesity.

Quantification of Amino Acids, Phenolic Compounds Profiling from Nine Rice Varieties and Their Antioxidant Potential.

In recent years, the health benefits of the pigmented rice varieties have been reported due to the richness of their bioactive compounds. Therefore, this study evaluated the antioxidant, total flavonoid, total phenolic, anthocyanin content, amino acid and individual phenolic compound quantification of nine Korean-grown rice varieties using spectrophotometric, HPLC-FLD-MS/MS and UHPLC Q-TOF-MS/MS methods. Our research found that the free fractions of DM29 (red rice) had the highest free radical scavenging ability of ABTS and DPPH. In contrast, the highest ferric reducing antioxidant power was observed in the 01708 brown rice variety. The majority of phenolic compounds such as quercetin, ferulic acid, p-coumaric acid, ascorbic acid, caffeic acid and genistein were found in the DM29 sample. The phenolic content of rice varies depending on its color, with DM29 red rice having the highest TPC, TFC and TAC levels. At the same time, the presence of the majority of amino acids was quantified in the 01708 and GR (Gangwon) brown rice varieties. According to this study, colored rice varieties are high in amino acids, phenolic compounds and antioxidants. This research would be beneficial in furthering our understanding of the nutritional value of different colors of rice and their high potential as a natural antioxidant.

Microbial Etiology and Prevention of Dental Caries: Exploiting Natural Products to Inhibit Cariogenic Biofilms.

Dental caries is one of the most common microbe-mediated oral diseases in human beings. At present, the accepted etiology of caries is based on a four-factor theory that includes oral microorganisms, oral environment, host, and time. Excessive exposure to dietary carbohydrates leads to the accumulation of acid-producing and acid-resistant microorganisms in the mouth. Dental caries is driven by dysbiosis of the dental biofilm adherent to the enamel surface. Effective preventive methods include inhibiting the cariogenic microorganisms, treatment with an anti-biofilm agent, and sugar intake control. The goal is to reduce the total amount of biofilm or the levels of specific pathogens. Natural products could be recommended for preventing dental caries, since they may possess fewer side effects in comparison with synthetic antimicrobials. Herein, the mechanisms of oral microbial community development and functional specialization are discussed. We highlight the application of widely explored natural products in the last five years for their ability to inhibit cariogenic microorganisms.

Copper-Catalyzed Asymmetric Borylallylation of Vinyl Arenes.

A copper-catalyzed, enantioselective method for the borylallylation of vinyl arenes is reported. The reaction produces enantioenriched and functionalized organoboron compounds by sequentially incorporating boryl and allyl groups onto the C═C bond of vinyl arenes. Copper-catalyzed borylative coupling of vinyl arenes with allyl phosphates successfully proceeds in a regio- and enantioselective manner in the absence of a palladium cocatalyst.