• Journal of Applied Biological Chemistry
• /
• v.53 no.4
• /
• pp.207-211
• /
• 2010

The sprouts of Brassica oleracea var. gongylodes were extracted with 100% MeOH and the concentrated extract was partitioned with EtOAc, n-BuOH and $H_2O$, successively. From the EtOAc fraction, three sterols were isolated through the repeated silica gel and ODS column chromatographies. On the basis of physico-chemical and spectroscopic data including NMR, MS, and IR, the chemical structures of the sterols were determined as ${\beta}$-sitosterol (1), brassicasterol (2), and 7-ketobrassicasterol (3). Compound 1 is usually observed in plant. Compounds 2 is observed in Brassica sp., and compounds 3 have very rarely occurred in natural source including plant.

• Natural Product Sciences
• /
• v.26 no.3
• /
• pp.214-220
• /
• 2020

Brassica oleracea var. gongylodes (red kohlrabi) is a biennial herbaceous vegetable whose edible bulbotuber-like stem and leaves are consumed globally. Sliced red kohlrabi tubers were extracted using methanol and the concentrated extract was partitioned successively with dichloromethane (CH₂Cl₂), ethyl acetate (EtOAc), n-butanol (n-BuOH) and water (H₂O). Repeated column chromatography of EtOAc fraction through silica, sephadex LH-20 and RP-18 gel led to isolation of eleven compounds of which compound 1 was a new glycosylated indole alkaloid derivative, 1-methoxyindole 3-carboxylic acid 6-O-β-D-glucopyranoside. Others were known compounds namely, β-sitosterol glucoside (4), 5-hydroxymethyl-2-furaldehyde (5), methyl-1-thio-β-D-glucopyranosyl disulfide (6), 5-hydroxy-2-pyridinemethanol (7), (3S,4R)-2-deoxyribonolactone (8), n-butyl-β-D-fructopyranoside (9), uridine (10) and three fructose derivatives, D-tagatose (11), β-D-fructofuranose (12) and β-D-fructopyranose (13). Similarly, isolation from CH₂Cl₂ fraction gave two known indole alkaloids, indole 3-acetonitrile (2) and N-methoxyindole 3-acetonitrile (3). The structure elucidation and identification of these compounds were conducted with the help of ¹³C and ¹H NMR, HMBC, HMQC, EIMS, HR-ESIMS and IR spectroscopic data, and TLC plate spots visualization. Compounds 2, 3, 4, 5, 6, 7, 8 and 9 are noted to occur in kohlrabi for the first time. Different bioactivities of these isolated compounds have been reported in literature.

• Research in Plant Disease
• /
• v.26 no.4
• /
• pp.272-278
• /
• 2020

The severe lettuce damage caused by Paratylenchus projectus was first reported in 2019 in Korea. To find high-value rotation crops for the control of P. projectus, nine vegetables, Brassica juncea (leaf mustard), B. rapa subsp. nipposinica (kyona), B. oleracea var. italica (broccoli), B. rapa subsp. chinensis (bok choy), B. oleracea var. viridis (kale), B. oleracea var. gongylodes (kohlrabi), Cichorium endivia (endive), C. intybus (chicory), Ipomoea aquatica (morning glory) were planted in d-10-cm clay pots in greenhouse. The growth of vegetables was compared between inoculated with 3,000 P. projectus per 100 ㎤ of soil and non-inoculated. Treatments were replicated 10 times. After 100 days, the reduction of fresh top weight was 30.4% in C. intybus, 35.1% in I. aquatica, 36.9% in B. oleracea var. acephala, 40.5% in C. endivia, 42.1% in B. rapa, 47.5% in B. rapa subsp. nipposinica, 50.4% in B. oleracea var. gonglodes, 56.3% in B. oleracea var. italica, and 66.0% in B. juncea. Nematode multiplication rates (Pf/Pi) were lower in I. aquatica (0.64) and C. endivia (1.1), but higher in B. oleracea var. gongylodes (2.54). Considering these results, I. aquatica is suitable for the rotation crop with lettuce until better rotation crops developed.

• Preventive Nutrition and Food Science
• /
• v.15 no.2
• /
• pp.152-158
• /
• 2010

This study was designed to determine the best cultivar of kohlrabi for making pickles among KM-1 (Worldcol), KM-2 (Bejo), KM-3 (Takii), and KM-4 (Monsanto) cultivars. The initial pH of pickles was different in all cultivars; however, they all had a pH in the range of 3.81~3.86 after 28 days of storage. The pickles made from KM-4 had the lowest acidity, while there was no significant difference in acidity among the KM-1, KM-2, and KM-3 pickles. The salinity of all kohlrabi pickles was consistent during the storage period. The changes of color values were accelerated in the following order: KM-4>KM-1>KM-2>KM-3. Though kohlrabi pickles were non-fermented, the change in reducing sugar contents was similar to that of a fermented pickle. The highest value of reducing sugar content was found in pickles made with KM-4. In all cases, the firmness of the pickle decreased as time of storage increased. On the initial day, KM-4 pickle showed the highest firmness with 807.4 g. KM-4 also showed the highest firmness on the 28th day of storage with 602.3 g. In sensory evaluation, the KM-4 pickle exhibited the highest texture (hardness) among the pickles. The pickle made with the KM-4 cultivar showed relatively higher firmness of texture than other cultivars, suggesting that KM-4 could be utilized in other kinds of processed foods, in addition to being pickled.

• Preventive Nutrition and Food Science
• /
• v.16 no.2
• /
• pp.189-193
• /
• 2011

Kohlrabi (Brassica oleracea var. gongylodes L.) slices were dehydrated with maltodextrin (MD) at concentrations of 20, 30, and 40% (w/w), and the dried samples were compared with the freeze-dried and hot-air dried samples regarding various physicochemical qualities. The MD-treated samples had better results than those of freeze-dried or hot-air dried samples in terms of rehydration ratio and color. The total phenolic content of the MD-treated sample was similar to that of the freeze-dried and higher than that of hot-air dried sample. The ascorbic acid content of the MD-treated samples was also higher than that of the hot-air dried one. These results suggest that kohlrabi can be dehydrated with MD instead of hot air.

• Journal of Animal Science and Technology
• /
• v.55 no.1
• /
• pp.19-23
• /
• 2013

The current study was carried out to determine the effects of Kohlrabi (Brassica oleracea var. gongylodes) on proliferation and differentiation of pig preadipocytes and $_3T_3-L_1$ cells. Pig preadipocytes were isolated from the backfat of the new-born pigs. Twenty-four hours after seeding, the cells were washed with DMEM/F-12 (designated day 0). To measure the cell proliferation, the cells were treated with 25 ng/ml and 100 ng/ml ethanol extracts of Kohlrabi (peel and flesh) for two days (day 0 ~ 2). To measure differentiation, the cells were treated with Kohlrabi for two days (day 0 ~ 2) and cell differentiation was measured on day 6. Twenty-five ng/ml and 100 ng/ml of Kohlrabi peel decreased proliferation of pig preadipocytes by 4.59% and 17.7%, respectively, compared with the control and Kohlrabi flesh by 11.4% and 19.2%, respectively. However, Kohlrabi did not inhibit cell differentiation. To measure the effects of Kohlrabi on proliferation and differentiation of $_3T_3-L_1$ cells, the cells were treated with Kohlrabi for two days in culture, like pig preadipocytes. Kohlrabi (both peel and flesh) did not show any effects on cell proliferation and differentiation. In summary, the results of the current study showed that Kohlrabi decreased proliferation of pig preadipocytes, but no inhibitory effects on differentiation of the cells. Kohlrabi had no effects on proliferation and differentiation of $_3T_3-L_1$ cells.

• The Korean Journal of Community Living Science
• /
• v.26 no.2
• /
• pp.405-414
• /
• 2015

This study examines the effects of purple Kohlrabi fresh and peel ethanol extracts on the antioxidative activity and antiproliferation of human cancer cells (Hep G2 human liver, HCT-116 human colon, and A549 human lung cancer cells.) The total flavonoid and anthocyanin content of purple Kohlrabi ethanol extracts were much greater in the peel than in the flesh. The DPPH radical scavenging activity and antioxidative index of purple Kohlrabi peel extracts were similar to those of the BHA and the BHT. Antiproliferation effects of purple Kohlrabi peel extracts on human cancer cells (Hep G2, HCT-116, and A549) strengthened in a dose-dependent manner. In particular, the antiproliferation activity of purple Kohlrabi peel extracts exceeded 40% in colon cancer cells. These results indicate that the purple Kohlrabi peel may contain bioactive compounds such as flavonoids as well as anthocyanin and that these compounds may facilitate cancer prevention.

• Preventive Nutrition and Food Science
• /
• v.19 no.4
• /
• pp.281-290
• /
• 2014

The aim of the present study was to evaluate the anti-diabetic, anti-inflammatory, antioxidant potential, and total phenolic content (TPC) of green and red kohlrabi cultivars. Anti-diabetic and anti-inflammatory activities were evaluated via protein tyrosine phosphatase (PTP1B) and rat lens aldose reductase inhibitory assays and cell-based lipopolysaccharide (LPS)-induced nitric oxide (NO) inhibitory assays in RAW 264.7 murine macrophages. In addition, scavenging assays using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical, and peroxynitrite ($ONOO^-$) were used to evaluate antioxidant potential and TPC was selected to assess phytochemical characteristics. Between the two kohlrabi cultivars, red kohlrabi (RK) had two times more TPC than green kohlrabi (GK) and showed significant antioxidant effects in DPPH, ABTS, and $ONOO^-$ scavenging assays. Likewise, methanol (MeOH) extracts of RK and GK inhibited LPS-induced NO production in a dose dependent manner that was further clarified by suppression of iNOS and COX-2 protein production. The MeOH extracts of RK and GK exhibited potent inhibitory activities against PTP1B with the corresponding $IC_{50}$ values of $207{\pm}3.48$ and $287{\pm}3.22{\mu}g/mL$, respectively. Interestingly, the RK MeOH extract exhibited significantly stronger anti-inflammatory, anti-diabetic, and antioxidant effects than that of GK MeOH extract. As a result, our study establishes that RK extract with a higher TPC might be useful as a potent anti-diabetic, antioxidant, and anti-inflammatory agent.

• Food Science and Preservation
• /
• v.21 no.6
• /
• pp.824-830
• /
• 2014

In this study, the quality characteristics of cookies with added purple kohlrabi (Brassica oleracea var. gongylodes) powder were investigated and analyzed through chemical and sensory evaluation. Samples were prepared with different levels (0, 1, 3, and 5%) of freeze-dried kohlrabi powder. The addition of Kolarbi powder decreased the moisture and fat contents, but the ash content was significantly increased (p<0.05). The pH and density of the cookie dough decreased significantly with the increasing levels of kohlrabi powder added (p<0.05). The spread ratio of the cookies generally decreased as more kohlrabi powder was added, but the decrease was not statistically significant. The hardness of the cookies increased significantly, however, with the increasing levels of kohlrabi powder added (p<0.05). The Hunter's color L, a, and b values significantly decreased with increasing kohlrabi powder compared to those of the control (p<0.05). In the sensory evaluation, the cookies to which 3 and 5% kohlrabi powder were added showed remarkably higher values for color, taste and appearance. These results suggest that purple kohlrabi powder is a good ingredient for improving the sensory and quality characteristics of cookies.

• Research in Plant Disease
• /
• v.21 no.1
• /
• pp.27-31
• /
• 2015

In April 2014, Fusarium wilt was found on kohlrabi seedlings in Iksan, Korea. Symptoms included wilting of foliage, drying and withering of older leaves, and stunting of the plants. The infected plants eventually died during growth. Colonies on potato dextrose agar were pinkish white, and felted with cottony and aerial mycelium. Macroconidia were falcate to almost straight, thin walled and usually 3-septate. Microconidia were usually formed abundantly in false-heads on short monophialides on the hyphae and were hyaline, smooth, oval to ellipsoidal, aseptate or medianly 1-septate, very occasionally 2-septate, slightly constricted at the septa, $4-11{\times}2.5-5{\mu}m$. On the basis of the morphological characteristics and phylogenetic analyses of molecular markers (internal transcribed spacer rDNA and translation elongation factor $1{\alpha}$), the fungus was identified as Fusarium oxysporum. Pathogenicity of a representative isolate was proved by artificial inoculation, fulfilling Koch's postulates. To our knowledge, this is the first report on the occurrence of Fusarium oxysporum on kohlrabi in Korea.