Sang Hoon Lee

Periodontitis is a chronic inflammatory oral disease characterized by mucosal barrier destruction and alveolar bone loss. This study characterized germinated mung bean sprouts (Vigna radiata L.) and evaluated the biological activity of the resulting extract in vitro and in vivo. Among six domestic cultivars, ‘Sanpo’ showed the highest total phenolic content (comparable to ‘Jinhwang’) and the highest ABTS radical scavenging activity (74.85%). Across Days 7–17 of germination, Day 10 sprouts contained the highest rutin level while quercetin was still detectable; quercetin was no longer detected at Day 17. In an analytical screen, extraction with 30% ethanol at 50 °C gave the highest recovery of rutin, quercetin, and kaempferol. A room-temperature 30% ethanol extract (MSE) was non-cytotoxic (>90% viability at 100 μg/mL) and significantly reduced IL-6 and IL-8 release in RAW264.7, HaCaT, and YD-38 cells. In a Porphyromonas gingivalis LPS-induced periodontitis rat model (n = 7 per group), LPS significantly increased the periodontal inflammation score, whereas MSE (50 mg/kg/day) produced only non-significant numerical reductions in alveolar bone loss and inflammation relative to the LPS group. These in vivo findings are preliminary and hypothesis-generating. Sanpo sprout extract warrants further investigation as a candidate ingredient for oral care and functional food applications.

Oat saponins are composed of triterpenoid and steroidal saponins, and their potential biological activities, such as antibacterial, antifungicidal, osteogenic, and anticancer activities, have been reported. In this study, qualitative and quantitative analyses of oat saponins were conducted by using UPLC-QToF-MS and UPLC-Triple Q-MS/MS. A total of 22 saponins were analyzed in seven Korean oat cultivars. Among them, 7 saponins were identified as new compounds in this source, which were tentatively confirmed as nuatigenin-type saponins with 26-O-diglucoside and 3-O-malonylglucoside forms and (25S)-furost-5-en-3 beta,22,26-triol-type saponins. In addition, the total content of these saponins ranged from 70.61 to 141.38 mg/100 g dry weight, and it was affected by the type of oat cultivar and the presence or absence of hulling. These detailed profiles will be suggested as fundamental data for breeding superior oat cultivars, evaluating of related products, and various industries.

Flavonols are the major class of flavonoids of green Chinese cabbage (Brassica rapa subsp. pekinensis). The B. rapa genome harbors seven flavonol synthase genes (BrFLSs), but they have not been functionally characterized. Here, transcriptome analysis showed four BrFLSs mainly expressed in Chinese cabbage. Among them, only BrFLS1 showed major FLS activity and additional flavanone 3β-hydroxylase (F3H) activity, while BrFLS2 and BrFLS3.1 exhibited only marginal F3H activities. We generated BrFLS1-knockout (BrFLS1-KO) Chinese cabbages using CRISPR/Cas9-mediated genome editing and obtained transgene-free homozygous plants without off-target mutation in the T₁ generation, which were further advanced to the T₂ generation showing normal phenotype. UPLC-ESI-QTOF-MS analysis revealed that flavonol glycosides were dramatically decreased in the T₂ plants, while dihydroflavonol glycosides accumulated concomitantly to levels corresponding to the reduced levels of flavonols. Quantitative PCR analysis revealed that the early steps of phenylpropanoid and flavonoid biosynthetic pathway were upregulated in the BrFLS1-KO plants. In accordance, total phenolic contents were slightly enhanced in the BrFLS1-KO plants, which suggests a negative role of flavonols in phenylpropanoid and flavonoid biosynthesis in Chinese cabbage. Phenotypic surveys revealed that the BrFLS1-KO Chinese cabbages showed normal head formation and reproductive phenotypes, but subtle morphological changes in their heads were observed. In addition, their seedlings were susceptible to osmotic stress compared to the controls, suggesting that flavonols play a positive role for osmotic stress tolerance in B.rapa seedling. In this study, we showed that CRISPR/Cas9-mediated BrFLS1-KO successfully generated a valuable breeding resource of Chinese cabbage with distinctive metabolic traits and that CRISPR/Cas9 can be efficiently applied in functional Chinese cabbage breeding.

Younghyeon Jang, Jinsoo Jeon, Sang Hoon Lee, Young Min Choi, and Myoung-Gun Choung. Journal of the Korean Society of Food Science and Nutrition 2022;51:1223-31. https://doi.org/10.3746/jkfn.2022.51.11.1223

Myoungsook Lee, Sang Duk Yoon, Jieun Shin, Jihyun Kim, and Sang Hoon Lee. Journal of the Korean Society of Food Science and Nutrition 2022;51:869-85. https://doi.org/10.3746/jkfn.2022.51.9.869

Jinsoo Jeon, Younghyeon Jang, Sang Hoon Lee, Young Min Choi, and Myoung-Gun Choung. Journal of the Korean Society of Food Science and Nutrition 2022;51:797-804. https://doi.org/10.3746/jkfn.2022.51.8.797

Most previous studies have been focused on isoflavone profile with biological activities from soybean seed and its related products. However, in the present study, eighty-three flavonoid derivatives (55 flavonols, 9 flavones and 19 isoflavones) were comprehensively identified and quantified from young leaves of 21 core-collected soybean cultivars based on ultra-performance liquid chromatography-diode array detector with quadrupole time of flight/mass spectrometry (UPLC-DAD-QToF/MS). Among total flavonoids from soybean leaves (SLs), the abundant flavonols (83.6%) were primarily composed of di- and tri- glycosides combined to the aglycones (K, kaempferol; Q, quercetin; I, isorhamnetin). Particularly, K-rich SLs (yellow coated seed), Nongrim 51 (breeding line) and YJ208-1 (landrace) contained mainly kaempferol 3-O-(2″-O-glucosyl-6″-O-rhamnosyl)galactoside and 3-O-(2″,6″-di-O-rhamnosyl)galactoside, and were expected to be superior cultivars by their higher flavonoids. Besides, the new tri-I-glycosides (soyanins I–V) were presented as predominant components in Junyeorikong (landrace, black). Thus, this study suggest that the SLs can be considered as valuable edible resources due to their rich flavonoids. Also, these detailed profiles will support breeding of superior varieties with excellent biological activities as well as relationship with seed anthocyanins production, and contribute to perform metabolomics approach to investigate the changes of SLs flavonols during the leaf growth and fermentation in further research.

Younghyeon Jang, Jinsoo Jeon, Sang Hoon Lee, Young Min Choi, and Myoung-Gun Choung. Journal of the Korean Society of Food Science and Nutrition 2022;51:688-96. https://doi.org/10.3746/jkfn.2022.51.7.688

Chang Wan Lim, Jun Yeop Lee, Kwang Eun Jung, Jong Eun Won, Byung-Man Kwak, Ki Woong Lee, Jin Ju Park, and Sang Hoon Lee. Journal of the Korean Society of Food Science and Nutrition 2022;51:419-27. https://doi.org/10.3746/jkfn.2022.51.5.419