Antioxidants from the Brown Alga Dictyopteris undulata

An investigation of anti-oxidative compounds from the brown alga Dictyopteris undulata has led to the isolation and identification of isozonarol, isozonarone, chromazonarol, zonaroic acid and isozonaroic acid. Their structures were identified by comparison of MS and NMR spectra. Full NMR assignment and absolute configuration of isozonaroic acid are described. Isozonarol showed the most potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity among the compounds isolated

Total Synthesis, Revised Structure, and Cytotoxic Activities of Iubol

Chemistry Letters. 2022, 51 (10), P.1000-100

Divergent Synthesis of Nerolidol-Type Sesquiterpenoids Produced by Soil Bacterium from an Identical Starting Material via Diepoxide Precursors: Stereochemical Revision and Absolute Configuration of a THF Natural Product

Chemistry Letters. 2022, 51 (11), P.1062-106

Black ginger (Kaempferia parviflora) extract enhances circadian rhythm and promotes lipolysis in mice fed a high-fat diet

Circadian rhythms are endogenous oscillations that regulate physiological and biochemical processes with approximately 24-h rhythms. Circadian rhythmic disorders caused by a high-fat diet (HFD) are associated with metabolic syndrome and obesity. Herein, we assessed whether black ginger (Kaempferia parviflora) modulates disturbances in the circadian rhythm and improves obesity caused by an HFD in C57BL/6 mice. Three study groups were created: normal diet, HFD, and HFD + K. parviflora extract (KPE). HFD-fed mice showed attenuated circadian locomotor activity, weight gain, and increased serum triglyceride and cholesterol levels, whereas HFD mice administered KPE showed improved circadian locomotor activity and reduced body weight and serum triglyceride levels. Moreover, following RNAi knockdown of clock genes in 3T3-L1 adipocytes, KPE was found to enhance clock gene expression and induce lipolysis-related gene expression in adipocytes. Collectively, these results suggest that KPE improves rhythm disturbances in HFD-fed mice and exhibits anti-obesity effects

Tissue-Specific Tolerance to High-Temperature and Nutrient-Poor Conditions in a Canopy-Forming Macroalga, Surviving at an Ocean Warming Hotspot

Most canopy-forming macroalgae have disappeared from temperate reefs in southern Japan, one of the ocean warming hotspots, but Sargassum nipponicum is surviving in this region. As this species’ annual shoots emerge from holdfasts during summer, both plant components may be highly tolerant to warm and nutrient-poor conditions in this season. The present study examined the effects of temperature and nutrient conditions on holdfast growth, shoot emergence from holdfasts, and shoot growth in S. nipponicum samples collected in Tanegashima Island, southern Japan. The summer temperature in this region (30 °C) allowed holdfast growth and shoot emergence but inhibited shoot growth. Nutrient-poor conditions had limited effects on the first two parameters but suppressed shoot growth. These results suggested that during warm summers and under nutrient-poor conditions in southern Japan, shoots can emerge from S. nipponicum holdfasts but cannot further grow. Additionally, nutrient loading from a nearby river was higher at the only site dominated by S. nipponicum, than at the other sites where this species was absent on Tanegashima Island. This was observed especially between autumn and winter, implying that such a nutrient-rich environment may contribute to shoot growth in S. nipponicum and to the persistence of its population in the area

Quantification of Histidine-Containing Dipeptides in Dolphin Serum Using a Reversed-Phase Ion-Pair High-Performance Liquid Chromatography Method

The quantification of histidine-containing dipeptides (anserine, carnosine, and balenine) in serum might be a diagnostic tool to assess the health condition of animals. In this study, an existing reversed-phase ion-pair high-performance liquid chromatography (HPLC)–ultraviolet detection method was improved and validated to quantify serum anserine, carnosine, and balenine levels in the dolphin. The serum was deproteinized with trichloroacetic acid and directly injected into the HPLC system. Chromatographic separation of the three histidine-containing dipeptides was achieved on a TSK–gel ODS-80Ts (4.6 mm × 150 mm, 5 µm) analytical column using a mobile phase of 50 mmol/L potassium dihydrogen phosphate (pH 3.4) containing 6 mmol/L 1-heptanesulfonic acid and acetonitrile (96:4). The standard curve ranged from 0.1 µmol/L to 250 µmol/L. The average accuracy of the intra- and inter-analysis of anserine, carnosine, and balenine was 97–106%. The relative standard deviations of total precision (RSDr) of anserine, carnosine, and balenine in dolphin serum were 5.9%, 4.1%, and 2.6%, respectively. The lower limit of quantification of these compounds was 0.11–0.21 µmol/L. These results indicate that the improved method is reliable and concise for the simultaneous determination of anserine, carnosine, and balenine in dolphin serum, and may be useful for evaluation of health conditions in dolphins. Furthermore, this method can also be applied to other biological samples

Novel Method to Quantify β‑Glucan in Processed Foods: Sodium Hypochlorite Extracting and Enzymatic Digesting (SEED) Assay

Some β-glucans have attracted attention due to their functionality as an immunostimulant and have been used in processed foods. However, accurately measuring the β-glucan content of processed foods using existing methods is difficult. We demonstrate a new method, the Sodium hypochlorite Extracting and Enzymatic Digesting (SEED) assay, in which β-glucan is extracted using sodium hypochlorite, dimethyl sulfoxide, and 5 mol/L sodium hydroxide and then digested into β-glucan fragments using Westase which is an enzyme having β-1,6- and β-1,3 glucanase activity. The β-glucan fragments are further digested into glucose using exo-1,3-β-d-glucanase and β-glucosidase. We measured β-glucan comprising β-1,3-, -1,6-, and -1,(3),4- bonds in various polysaccharide reagents and processed foods using our novel method. The SEED assay was able to quantify β-glucan with good reproducibility, and the recovery rate was >90% for food containing β-glucan. Therefore, the SEED assay is capable of accurately measuring the β-glucan content of processed foods