Angular dihydropyranocoumarins from the flowers of Peucedanum japonicum and their aldo-keto reductase inhibitory activities.

Twenty-one angular dihydropyranocoumarins and a linear furanocoumarin, including four previously undescribed compounds (1-4), were isolated from the flowers of Peucedanum japonicum (Umbelliferae). The structures of 1-4, along with their absolute stereochemistry, were determined to be (3'S,4'S)-3'-O-propanoyl-4'-O-(3‴-methyl-2‴-butenoyl)khellactone (1), (3'S,4'S)-3'-O-propanoyl-4'-O-(2‴-methyl-2‴Z-butenoyl)khellactone (2), (3'S,4'S)-3'-O-propanoyl-4'-O-(2‴-methylbutanoyl)khellactone (3), and (3'S,4'S)-3'-O-(2″-methylpropanoyl)-4'-O-(3‴-methyl-2‴-butenoyl)khellactone (4) using one- and two-dimensional nuclear magnetic resonance, high-resolution electrospray ionization mass spectroscopy, and electronic circular dichroism spectroscopy. In addition, the absolute configuration of the three angular dihydropyranocoumarins (5-7) was determined for the first time in this study. Among the previously reported compounds isolated in this study, 8 and 9 were isolated for the first time from the genus Peucedanum, whereas 10 and 11 were previously unreported and had not been isolated from P. japonicum to date. Furthermore, all isolated compounds were evaluated for their aldo-keto reductase 1C1 inhibitory activities on A549 human non-small-cell lung cancer cells. Compounds 10 and 12 exhibited substantial AKR1C1 inhibitory activities with IC50 values of 35.8 ± 0.9 and 44.2 ± 1.5 µM, respectively.

Comparative Analysis of Coumarin Profiles in Different Parts of Peucedanum japonicum and Their Aldo-Keto Reductase Inhibitory Activities.

Peucedanum japonicum (Umbelliferae) is widely distributed throughout Southeast Asian countries. The root of this plant is used in traditional medicine to treat colds and pain, whereas the young leaves are considered an edible vegetable. In this study, the differences in coumarin profiles for different parts of P. japonicum including the flowers, roots, leaves, and stems were compared using ultra-performance liquid chromatography time-of-flight mass spectrometry. Twenty-eight compounds were tentatively identified, including three compounds found in the genus Peucedanum for the first time. Principal component analysis using the data set of the measured mass values and intensities of the compounds exhibited distinct clustering of the flower, leaf, stem, and root samples. In addition, their anticancer activities were screened using an Aldo-keto reductase (AKR)1C1 assay on A549 human non-small-cell lung cancer cells and the flower extract inhibited AKR1C1 activity. Based on these results, seven compounds were selected as potential markers to distinguish between the flower part versus the root, stem, and leaf parts using an orthogonal partial least-squares discriminant analysis. This study is the first to provide information on the comparison of coumarin profiles from different parts of P. japonicum as well as their AKR1C1 inhibitory activities. Taken together, the flowers of P. japonicum offer a new use related to the efficacy of overcoming anticancer drug resistance, and may be a promising source for the isolation of active lead compounds.

Absolute Quantification of Isoflavones in the Flowers of Pueraria lobata by qHNMR.

Pueraria lobata (Willd.) Ohwi. is a widely used medicinal plant in Korea, China, and Japan. The flower of P. lobata (Puerariae Flos) contains various bioactive substances such as triterpenoidal saponins and isoflavonoids. In this study, we developed a quantitative analysis of the isoflavones of Puerariae Flos by quantitative proton nuclear magnetic resonance (qHNMR) spectroscopy using the internal calibrant (IC). From the qHNMR results, the isoflavone content was found to be 7.99% and 10.57% for the MeOH sonication extract (PLs) and the MeOH reflux extract (PLr) of Puerariae Flos, respectively. The quantified isoflavone content was validated using the conventional analytical method, high-performance liquid chromatography with ultraviolet detection (HPLC-UV). The present study shows that validated qHNMR spectroscopy is a reliable method for quantifying and standardizing the isoflavone content in Puerariae Flos.

Metabolite Profiling and Dipeptidyl Peptidase IV Inhibitory Activity of Coreopsis Cultivars in Different Mutations.

Coreopsis species have been developed to produce cultivars of various floral colors and sizes and are also used in traditional medicine. To identify and evaluate mutant cultivars of C. rosea and C. verticillata, their phytochemical profiles were systematically characterized using ultra-performance liquid chromatography time-of-flight mass spectrometry, and their anti-diabetic effects were evaluated using the dipeptidyl peptidase (DPP)-IV inhibitor screening assay. Forty compounds were tentatively identified. This study is the first to provide comprehensive chemical information on the anti-diabetic effect of C. rosea and C. verticillata. All 32 methanol extracts of Coreopsis cultivars inhibited DPP-IV activity in a concentration-dependent manner (IC50 values: 34.01-158.83 µg/mL). Thirteen compounds presented as potential markers for distinction among the 32 Coreopsis cultivars via principal component analysis and orthogonal partial least squares discriminant analysis. Therefore, these bio-chemometric models can be useful in distinguishing cultivars as potential dietary supplements for functional plants.

9­Hydroxy­isoegomaketone inhibits LPS­induced NO and inflammatory cytokine production in RAW264.7 cells.

Isoegomaketone (IK) is a known component of Perilla frutescens that reportedly exhibits anti­inflammatory, anti­cancer and anti­allergic properties. A novel compound known as 9­HIK has been isolated from the extract of a radiation mutant P. frutescens var. crispa using supercritical carbon dioxide. In the present study, 9­HIK induced heme oxygenase­1 (HO­1) mRNA expression in RAW264.7 cells, with maximal levels observed 4 h after 9­HIK treatment. In addition, 9­HIK inhibited the mRNA and protein expression of pro­inflammatory mediators, such as IL­6 and interferon­ß, as well as the production of nitric oxide (NO) in lipopolysaccharide­stimulated RAW264.7 cells. Furthermore, N­acetyl­L­cysteine, a reactive oxygen species scavenger, inhibited NO production and HO­1 mRNA expression levels through the nuclear factor erythroid 2­related factor 2 pathway. Overall, 9­HIK displayed anti­inflammatory properties in LPS­induced RAW264.7 cells via direct suppression of inflammatory mediators and HO­1 induction.

Constituents of Coreopsis lanceolata Flower and Their Dipeptidyl Peptidase IV Inhibitory Effects.

A new polyacetylene glycoside, (5R)-6E-tetradecene-8,10,12-triyne-1-ol-5-O-ß-glucoside (1), was isolated from the flower of Coreopsis lanceolata (Compositae), together with two known compounds, bidenoside C (10) and (3S,4S)-5E-trideca-1,5-dien-7,9,11-triyne-3,4-diol-4-O-ß-glucopyranoside (11), which were found in Coreopsis species for the first time. The other known compounds, lanceoletin (2), 3,2'-dihydroxy-4-3'-dimethoxychalcone-4'-glucoside (3), 4-methoxylanceoletin (4), lanceolin (5), leptosidin (6), (2R)-8-methoxybutin (7), luteolin (8) and quercetin (9), were isolated in this study and reported previously from this plant. The structure of 1 was elucidated by analyzing one-dimensional and two-dimensional nuclear magnetic resonance and high resolution-electrospray ionization-mass spectrometry data. All compounds were tested for their dipeptidyl peptidase IV (DPP-IV) inhibitory activity and compounds 2-4, 6 and 7 inhibited DPP-IV activity in a concentration-dependent manner, with IC50 values from 9.6 to 64.9 µM. These results suggest that C. lanceolata flower and its active constituents show potential as therapeutic agents for diseases associated with type 2 diabetes mellitus.

Constituents of the leaves and twigs of Elaeagnus umbellata and their proliferative effects on human keratinocyte HaCaT cells.

Bioassay-guided fractionation of an extract of leaves and twigs of Elaeagnus umbellata led to the isolation of a serotonin derivative, N-[2-(5-hydroxyl-1H-indol-3-yl)ethyl]-butanamide (1), along with six flavonoid glycosides, kaempferol-3-O-ß-d-xylopyranosyl(1 → 2)-ß-d-galactopyranoside-7-O-α-l-rhamnopyranoside (2), kaempferol-3-O-ß-d-galactopyranoside-7-O-α-l-rhamnopyranoside (3), kaempferol-3-O-α-l-rhamnopyranosyl(1 → 6)-ß-d-galactopyranoside-7-O-α-l-rhamnopyranoside (4), kaempferol-3-O-ß-d-xylopyranosyl(1 → 2)-ß-d-galactopyranoside (5), kaempferol-3-O-rutinoside (6), and kaempferol-3-O-ß-d-glucopyranosyl(1 → 2)-ß-d-galactopyranoside-7-O-α-l-rhamnopyranoside (7). Their structures were elucidated using 1D/2D nuclear magnetic resonance spectroscopy and mass spectrometry. Compounds 1-6 were evaluated for their proliferative effects on HaCaT keratinocytes; 1-5 promoted keratinocyte proliferation dose dependently. Compounds 3 and 4 showed potent activities. These results suggest that the leaves and twigs of E. umbellata have wound healing and skin cell regeneration potentials.

Preparative Separation of Three Monoterpenes from Perilla frutescens var. crispa Using Centrifugal Partition Chromatography.

Three monoterpenes, namely, 9-hydroxy isoegomaketone (1), isoegomaketone (2), and perilla ketone (3), were successfully separated from the supercritical carbon dioxide (SC-CO2) extract of the leaves of Perilla frutescens var. crispa (cv. Antisperill; Lamiaceae) by centrifugal partition chromatography (CPC). To obtain large quantities of these materials required for studies on their mechanism of action and in vivo effectiveness in inflammation, we used CPC because of its high loading capacity and reproducibility to purify the three compounds. Compound 1 (2.60 mg, 96.7% purity at 254 nm) was purified from 500 mg of the SC-CO2 extract of P. frutescens var. crispa (cv. Antisperill), using a two-phase solvent system comprising n-hexane/ethyl acetate/ethanol/water (5:5:5:5 v/v) in a descending mode. As compounds 2 (56.1 mg, 97.6% purity at 254 nm) and 3 (78.6 mg, 96.1% purity at 254 nm) are highly volatile and difficult to recover from an aqueous mobile phase after purification during the drying process, they were obtained from the same amount of the processed extract in an ascending mode using the upper organic phase as the mobile phase (n-hexane/ethyl acetate/ethanol/water, 8:2:8:2 v/v). The structures of compounds 1-3 were confirmed by 1H- and 13C-NMR analysis. Thus, based on our findings, we recommend centrifugal partition chromatography as a powerful technique for purifying the active principal compounds 1 and 2 from the leaves of P. frutescens var. crispa.