Amal Kumar Ghimeray

Kaempferol and Kaempferol Rhamnosides with Depigmenting and Anti-Inflammatory Properties

The objective of this study was to examine the biological activity of kaempferol and its rhamnosides. We isolated kaempferol (1), α-rhamnoisorobin (2), afzelin (3), and kaempferitrin (4) as pure compounds by far-infrared (FIR) irradiation of kenaf (Hibiscus cannabinus L.) leaves. The depigmenting and anti-inflammatory activity of the compounds was evaluated by analyzing their structure-activity relationships. The order of the inhibitory activity with regard to depigmentation and nitric oxide (NO) production was kaempferol (1) > α-rhamnoisorobin (2) > afzelin (3) > kaempferitrin (4). However, α-rhamnoisorobin (2) was more potent than kaempferol (1) in NF-κB-mediated luciferase assays. From these results, we conclude that the 3-hydroxyl group of kaempferol is an important pharmacophore and that additional rhamnose moieties affect the biological activity negatively.

Phenolic contents, antioxidant and α-glucosidase inhibition properties of Nepalese strain buckwheat vegetables

3R&D Center, Amore Pacific Corporation, Yongin, 446-729. S. Korea. The sprouts, microgreens and leafy greens of common and tartary buckwheat of Nepalese strain were compared for the phenolic contents and biological activity. The tartary buckwheat samples expressed higher total phenolic and flavonoid contents compared to the common buckwheat. The sprouts had the highest total phenolic contents (9333.48 ± 150.23 and 6976.21 ± 213.65 mgGAE/100g dw in tartary and common buckwheat, respectively) whereas, the highest total flavonoid content was present in the leafy greens (7635.39 ± 141.40 and 4414.61 ± 70.85 mgRE/100g dw in tartary and common buckwheat respectively). The high performance liquid chromatography (HPLC) results revealed that the tartary buckwheat vegetables had higher rutin, (3800.28 ± 434.41 mg/100g in leafy greens), quercetin (159.75 ± 9.04 mg/100g in sprouts) and chlorogenic acid (293.47 ± 65.06 mg/100g in microgreens) contents than those of common buckwheat. However, other phenolics like vitexin, isovitexin, orientin and isoorientin contents were more abundant in common buckwheat. In biochemical assay, all three types of vegetable of common and tartary buckwheat showed higher antioxidant and α-glucosidase inhibition effect in dose dependent manner. Based on these results, it can be conformed that all the vegetables (microgreens, sprouts and leafy greens) of both varieties of buckwheat of Nepalese strains can be regarded as a potent sour ce of functional food.

Changes in flavonoid content and tyrosinase inhibitory activity in kenaf leaf extract after far-infrared treatment.

The tyrosinase inhibitory activity of ethanolic extract of kenaf (Hibiscus cannabinus L.) leaf was evaluated before and after subjecting it to far-infrared (FIR) irradiation. The main component of the extract was analyzed as kaempferitrin (kaempferol-3,7-O-α-dirhamnoside). Prior to FIR irradiation, no inhibitory activity of the extract was detected in a tyrosinase assay. However, after FIR irradiation for 1h at 60°C, significant tyrosinase inhibitory activity (IC(50)=3500 ppm) was observed in it. In HPLC analysis, derhamnosylation products (kaempferol, afzelin, and α-rhamnoisorobin) were detected. The inhibitory activity may be due to the existence of derhamnosylation products. This study demonstrated that FIR irradiation can be used as a convenient tool for deglycosylation of flavonoid glycoside.

Effect of far infrared drying on antioxidant property, anti-inflammatory activity, and inhibitory activity in A549 cells of Gamguk (Chrysanthemum indicum L.) flower

This research demonstrated and compared the effects of shade and far infrared drying (FIRD) of gamguk (Chrysanthemum indicum L., CE) flowers extract on total phenolic (TP), total flavonoid (TF) content, anticancer and anti-inflammatory activities. The research data revealed that the TP and TF contents were highest in FIRD treated CE flower extracts. Similarly, the effect of CE on lipopolysaccharide (LPS) induced nitric oxide (NO) production in RAW264.7 cells showed in a dose dependent manner. Further, the CE inhibited the tumor necorsis factor (TNF)-α, cyclooxygenase (COX)-2 expression, and prostaglandis E2 (PGE2) production. The anticancer activity was monitored in A549 lung cancer cell, which showed that FIRD treated CE inhibited cell proliferation significantly (p<0.05) higher in dose and time dependent manner.

Physiological Characteristics of Kenaf(hibiscus Cannabinus L.)

This study was carried out to investigate the effects of growing period and cultivars on physiological characteristics and photosynthetic rates of kenaf in Cheorwon, Korea, The possibility of their utilization as forage plant was also discussed. A split plot design composing 3 growing periods (53, 84 and 115 days after sowing) and 3 cultivars (Dowling, Everglade-41 and Tainung-2) was applied for this experiment. Leaf photosynthetic rate was highest 28.6 in Everglade-41 at the beginning of August when solar irradiation was most intense. In the final biomass of kenaf, Dowing wa the highest among cultivars, with 534.6g/F.W./plant and 109.6g/D.W./plant, respectively. In addition, Dowling was the best in stem thickness among cultivars evaluated. Our results exhibited that all cultivars planted in Cheorwon exhibited decreased yield production compared to a previous report experimented in Jaeju. It may result that cultivation in Jaeju utilized wider planting space and longer cultivating time. In the basis of our data, it is suggest that extending cultivation time and using wider planting space should increase yield in Cheorwon with potential utilization of kanef as a forage crop.

Enhancement of ginsenoside compounds by far infrared irradiation in ultra fine powdered red ginseng(Panax ginseng C.A. Meyer)

The effects of far infrared irradiation (FIR) on protopanaxatriol and propanaxadiol ginsenoside were investigated with ultrafine powdered red ginseng and compared with untreated sample. The study showed that FIR treatment increased the Rf, Rg2, and Rh1 production in a temperature dependent manner, but Rg1 and Re decreased with temperature. Similarly, Rg3, Rk1 and Rg5 increased with temperature. The maximum increase was observed at 215°C with 2.09, 4.67, 17.23 and 18.57 times for Rb3, Rg3, Rk1 and Rg5 respectively. Likewise, Rd and Rc also increased gradually with temperature. However, Rb1 showed negative effects with temperature, showing decreased activities with increasing temperature. Overall, this research is expected to be helpful in enhancing the bioactive ginsenoside in ultrafine powdered red ginseng by optimizing the FIR conditions.