Tae Joung Ha

Isolation and identification of phenolic compounds from the seeds of Perilla frutescens (L.) and their inhibitory activities against α-glucosidase and aldose reductase

Five phenolic compounds were isolated from the seeds of Perilla (Perilla frutescens L.) using gradient solvent fractionation, silica gel column chromatography, and preparative high-performance liquid chromatography (HPLC). Their chemical structures were identified as caffeic acid-3-O-glucoside (1), rosmarinic acid-3-O-glucoside (2), rosmarinic acid (3), luteolin (4), and apigenin (5) using NMR spectroscopy and HPLC-ESI/MS analysis. Among them, luteolin (4) inhibited α-glucosidase (EC 3.2.1.20) with IC(50) value of 45.4μM. The inhibition kinetic analysed by Dixon plot indicate that luteolin is a noncompetitive inhibitor, and the inhibition constant K(I) was calculated at 45.0μM. Moreover, rosmarinic acid (3) and luteolin (4) inhibited recombinant human aldose reductase (EC 1.1.1.21) with IC(50) values of 11.2 and 0.6μM, respectively. Notably, the inhibition kinetic of luteolin (4) follows a hyperbolic dependence on aldose reductase inhibition by Dixon plot. Thus, inhibition kinetic indicates that luteolin (4) is a mixed-type inhibitor.

Identification, characterisation, and quantification of phenolic compounds in the antioxidant activity-containing fraction from the seeds of Korean perilla (Perilla frutescens) cultivars.

The present research was the first to investigate phenolic compound profiles and antioxidant properties in the seeds of various perilla (Perilla frutescens) cultivars. The 80% methanol extract (50 μg/ml) of this species showed potent antioxidant activities against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radicals. Phenolic compounds were characterised by nuclear magnetic resonance (NMR) spectroscopy, and ultra performance liquid chromatography with photodiode array detector and electrospray ionisation/mass (UPLC-PDA-ESI/MS) analysis. Nine compounds were elucidated as caffeic acid-3-O-glucoside (1), caffeic acid (2), luteolin-7-O-glucoside (3), apigenin-7-O-glucoside (4), rosmarinic acid-3-O-glucoside (5), rosmarinic acid (6), luteolin (7), apigenin (8), and chrysoeriol (9). The individual and total phenolic contents were remarkably different, especially rosmarinic acid-3-O-glucoside (5) and rosmarinic acid (6) which were the predominant compounds (>95%) in all perilla cultivars. Additionally, Yeupsil cultivar exhibited the highest phenolic content (5029.0 μg/g) and antioxidant activity, whereas the lowest was shown by Dasil (2138.7 μg/g). Therefore, these results suggest that antioxidant effects of perilla seeds are correlated with phenolic contents.

Rapid characterisation and comparison of saponin profiles in the seeds of Korean Leguminous species using ultra performance liquid chromatography with photodiode array detector and electrospray ionisation/mass spectrometry (UPLC-PDA-ESI/MS) analysis.

The present work was reported on investigation of saponin profiles in nine different legume seeds, including soybean, adzuki bean, cowpea, common bean, scarlet runner bean, lentil, chick pea, hyacinth bean, and broad bean using ultra performance liquid chromatography with photodiode array detector and electrospray ionisation/mass spectrometry (UPLC-PDA-ESI/MS) technique. A total of twenty saponins were characterised under rapid and simple conditions within 15min by the 80% methanol extracts of all species. Their chemical structures were elucidated as soyasaponin Ab (1), soyasaponin Ba (2), soyasaponin Bb (3), soyasaponin Bc (4), soyasaponin Bd (5), soyasaponin αg (6), soyasaponin βg (7), soyasaponin βa (8), soyasaponin γg (9), soyasaponin γa (10), azukisaponin VI (11), azukisaponin IV (12), azukisaponin II (13), AzII (14), AzIV (15), lablaboside E (16), lablaboside F (17), lablaboside D (18), chikusetusaponin IVa (19), and lablab saponin I (20). The individual and total saponin compositions exhibited remarkable differences in all legume seeds. In particular, soyasaponin βa (8) was detected the predominant composition in soybean, cowpea, and lentil with various concentrations. Interestingly, soybean, adzuki bean, common bean, and scarlet runner bean had high saponin contents, while chick pea and broad bean showed low contents.

Changes occurring in nutritional components (phytochemicals and free amino acid) of raw and sprouted seeds of white and black sesame ( Sesamum indicum L.) and screening of their antioxidant activities

The present study is the first to investigate the germination properties regarding phytochemicals, amino acids, total phenolics, and antioxidant capacities of white and black sesame seeds. Nutritional components and antioxidant effects showed considerable differences. Sesamine and sesamolin composition decreased (white: 4.21→1.72, 3.57→1.57 mg/g; black: 2.43→0.58, 1.36→0.45 mg/g) during germination. Moreover, catechin displayed the predominant composition in sprouted seeds with values of 13.50 mg/g (white) and 19.09 (black) mg/g followed by (-)-epicatechin and sinapic acid. Total phenolics increased by approximately 4 times upon germination, i.e., 503.1±27.1→ 2085.0±56.7 (white) and 645.8±31.5→2480.1±49.5 (black), mg GAE/g. Amino acids also remarkably increased in sprouted white (7.04→31.69mg/g) and black (6.55→26.97mg/g) seeds, with individual composition occurring in the following order: asparagine>arginine>tryptophan>leucine>alanine. In particular, arginine and tryptophan exhibited the greatest variations. The antioxidant effects against DPPH radical were stronger in sprouted seeds depending on the phytochemicals. Therefore, sprouted sesame can be utilized as an excellent source for functional foods.

Development of Molecular Markers for Low Raffinose and Stachyose in Korean Soybean Cultivars

A novel allele of the putative soybean raffinose synthase gene, RS2, was discovered in PI200508 that is associated with the low raffinose and stachyose content. Soybean line PI200508 was identified as expressing reduced levels of raffinose and stachyose as well as elevated levels of sucrose. The RS2 mutant gene shows three base pairs InDel with the normal gene. Based on InDel region we developed novel co-dominant and dominant marker. The aim of this study was to develop Korean soybean cultivars, Daewon, Cheongja, and Danmiput, containing low levels of raffinose and stachyose. A specific markers assay for the PI200508 RS2 allele was developed to allow direct selection of the low raffinose and stachyose phenotype. Our findings highlight the efficiency of allele-specific markers in selection, which is evident in the matching genotype and results of the HPLC in the F2 generations of Daewon×PI200508 population.

Isolation and identification of α-glucosidase inhibitory constituents from the seeds of Vigna nakashimae: Enzyme kinetic study with active phytochemical

The α-glucosidase inhibition effects of the 80% ethanol extracts in the seeds of five Vigna species (V. nakashimae, V. nipponensis, V. umbellate, V. radiate, and V. angularis) were evaluated and their half-maximal inhibitory concentration (IC50) values showed considerable differences (pu202f<u202f0.05) ranging from 7.3 to >900u202fμg/ml. V. nakashimae exhibited the most potent inhibition with IC50 value of 7.3u202f±u202f1.1u202fμg/ml, followed by V. nipponensis (184.0u202f±u202f9.5u202fμg/ml) and V. umbellata (520.0u202f±u202f8.1u202fμg/ml). Bioactivity-guided fractionation of V. nakashimae seeds yielded three phenolics by silica gel chromatography and their structures were elucidated as gambiriin D (1), luteoliflavan-7-O-glucopyranoside (2), and catechin-7-O-glucopyranoside (3) using nuclear magnetic resonance (NMR) spectroscopy. In particular, gambiriin D (1) possessed strong inhibition activity with IC50 of 36.8u202f±u202f2.3u202fμM through simple reversible slow-binding inhibition (kinetic parameters: k4u202f=u202f0.0048u202fu202fμM-1s-1; Kiappu202f=u202f48u202fμM). Furthermore, this compound inhibited recombinant human aldose reductase with IC50 value of 12.0u202f±u202f0.7u202fμM. Results suggest that V. nakashimae may be a potent α-glucosidase inhibition for health products.

Comparison of antioxidant activities and volatile components using GC/MS from leaves of Korean purple perilla (Perilla frutescens) grown in a greenhouse

Volatile profiles using GC/MS with hydrodistillation extraction and antioxidant effects against DPPH and ABTS radicals of purple perilla (Perilla fructescens) leaf extracts from plants grown in greenhouse were investigated. Volatiles were characterized as 25 components of 7 types including 2 alcohols, 3 furans, 3 esters, 2 aldehydes, 4 ketones, 10 hydrocarbons, and an acid. The dominant component was perillaketone (>54%) in total average content. Isoegomaketone was the second major compound (21%), followed by α-bergamotene (8.7%) and β-caryophyllene (5.7%). Contents of these 4 major components differed between cultivars, especially perillaketone and isoegomaketone (39.0-74.1 and Not Detected-36.9%, respectively). Antioxidant properties of methanol extracts containing 1% trifluoroacetic acid (TFA) showed differences with highest effects at 50 μg/mL. The main volatiles of perilla were affected by genetics and cultivars more than by environmental conditions. Antioxidant activities are probably correlated with phenolic and anthocyanin contents.

Development of Proteomics-based Biomarkers for 4 Korean Cultivars of Sorghum Seeds (Sorghum bicolor (L.) Moench)

Received: 18 January 2013 / Revised: 1 February 2013 / Accepted: 13 February 2013 c 2013 The Korean Society of Environmental Agriculture This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.