• Archives of Pharmacal Research
• /
• v.11 no.2
• /
• pp.166-168
• /
• 1988

The effects of aglycones moring and quercetin and their corresponding glycosides quercitrin and rutin were studied on the blood glucose levels of rats. Quercetin and quercetrin caused hypoglycaemia in rats while rutin and morin showed almost no difference. Quercetin, which showed 50% pronounced hypoglycaemic effects, reduced significantly the blood glucose level of alloxan diabetic rats.

• Archives of Pharmacal Research
• /
• v.13 no.2
• /
• pp.211-213
• /
• 1990

To test flavonoids for antibacterial activity against oral micraorganisms, flavonoids, quercetrin and naringenin, were incorporated into two pharmaceutical preparations in the form of tooth paste. Samplees of dental plaque, the msot accused dental deposit which initiates the gingival and periodental diseases, were collected from the teeth surface of ten dental students at one week interval before and after using placebo, followed by two formulae of tooth paste containing 0.1% of quercetrin and naringenin (formulas I and II, respectively). The amount of dental plaque was assessed by the quigley and Hens index. Then plaque samples were subjected to bacteriological examination of Gram stain and plate counts of microorganisms. The amount of dental plaque was assessed by the Quigley and Hens index. Then plaque samples were subjected to bacteriological examination of Gram stain and plate counts of microorganisms. The results revealed that most of Gram negative cocci and bacilli were highly affected by the two formulae : the number of actinomycetes were decreased after using formula I and disappeared completely by the sue of formula II, while the number of Gram positive streptococci was highly decreased after the treatment with the two formulae. These results indicate a possible use of flavonoids to inhibit dental plaque formation.

• Natural Product Sciences
• /
• v.4 no.1
• /
• pp.9-14
• /
• 1998

Jaceidin, Jaceidin-7-O-methylether and quercetin were isolated from-Juniperus phoenicea L. alcoholic extract, however, Sequoiaflavone was isolated from Cupressus semperiverns L. In addition, the alcoholic extracts of both plants were found to contain also kaempferol-3-O-rhamnoside, quercetrin, myricitrin, cupressuflavone. The chemical identities of the isolated compounds were established using UV, IR, $^1H-and\;^{13}C-NMR$ spectroscopy.

• Natural Product Sciences
• /
• v.8 no.1
• /
• pp.16-17
• /
• 2002

The flavonoids kaempferol, quercetin, myrecetin, kaempferol-3-O-rhamnoside and quercetrin has been isolated from the leaves of C. tamala and their structures were established by spectral analysis and direct comparison with authentic samples. This is the first report of occurrence of these compounds from C. tamala.

• Natural Product Sciences
• /
• v.24 no.4
• /
• pp.272-283
• /
• 2018

The root-knot nematode, Meloidogyne incognita caused a serious damage to many plants. The phenolic components of the leaves of Schinus terebinthifolius were investigated as potential nematicidal agents for M. incognita. Nine compounds were isolated and characterized as viz., 1,2,3,4,6-pentagalloyl glucose (1), kaempferol-3-O-${\alpha}$-L-rhamnoside (Afzelin) (2), quercetin-3-O-${\alpha}$-L-rhamnoside (Quercetrin) (3), myricetin (4), myricetin-3-O-${\alpha}$-L-rhamnoside (Myricetrin) (5), methylgallate (6), protocatechuic acid (7), quercetin (8), and gallic acid (9) using nuclear magnetic resonance (NMR) spectroscopy. Compound 1 showed pronounced nematicidal activity compared to Oxamyl as a positive control. It showed the lowest eggs-hatchability (34%) and the highest mortality in nematode population (21% after 72 hours of treatment) at a concentration of $200{\mu}g/mL$. It exhibited the best suppressed total nematode population, root galling and number of eggmasses in infected tomato plants. The total carbohydrates and proteins were also significantly induced by 1 with reduction in total phenolics and increase in defense-related proteins. Thus, compound 1 could be a promising, more safe and effective natural nematicidal agent for the control of root-knot nematodes.

• Applied Biological Chemistry
• /
• v.48 no.1
• /
• pp.89-92
• /
• 2005

This study was conducted in order to establish the optimum extraction conditions in obtaining Saururus chinensis extracts. At the optimum extraction solvent (40% ethanol solvent), yield, DPPH, total phenolic compounds and total flavonoid in the extract of Saururus chinensis were 13.50%, 83.50%, 2.60 mg/ml and 2.09 mg/ml, respectively. At the optimum extraction time (4 hours), yield, DPPH, total phenolic compounds and total flavonoid in the extract of Saururus chinensis were 12.79%, 71.13%, 2.83 mg/ml and 2.16 mg/ml, respectively. At the optimum conditions (40% ethanol solvent and 4 hours), quercetrin and quercetin contents were 360.13 mg/100 g and 1379.54 mg/100 g, respectively. From the above results, we suggest that the optimum Saururus chinensis extract conditions are 40% ethanol solvent and 4 hours.

• Advances in Traditional Medicine
• /
• v.6 no.4
• /
• pp.355-360
• /
• 2006

Plants have been used in traditional medicinal system for centuries. Bangladeshi medicinal plants have received considerable attention from the researchers for evaluation of their bioactivity. As a part of our ongoing research of screening the Bangladeshi medicinal plants, the ethanolic extract of Dendrophthoe falcata have been chosen for the present study. The ethanolic extract of the leaves of the plant have been assessed for their antioxidant, antinociceptive, and general toxicity. The extract showed potent antioxidant activity ($IC_{50}5.1{\mu}g/ml$) using DPPH radical scavenging assay, which is comparable to the standard ascorbic acid ($IC_{50}4.6{\mu}g/ml$). The extract significantly and dose dependently inhibited the acetic acid induced writhing in mice (71.2%, P < 0.001 and 28.0%, P < 0.05 for 500 and 250 mg/kg body weight, respectively). A general toxicity was assessed by a simple and low cost assay using brine shrimp lethality as an indicator. The extract showed low level of toxicity ($LC_{50}100{\mu}g/ml$). Using different chromatographic techniques, quercitrin (quercetin 3-O-${\alpha}$-rhamnoside) was separated as the major component from the extract. The structure was elucidated by detailed 1D and 2D NMR and mass spectral analysis.

• Korean journal of food and cookery science
• /
• v.11 no.3
• /
• pp.303-308
• /
• 1995

When we prepared the cooked namul, bugak and kimchi by the leaves of Cedrela sinensis, the changes of quercitrin which was isolated from the leaves of this plant in each preparations were analysed by HPLC. Separation by reversed phase chromatography on u-Bondapak C/Sub 18/ column was achieved by isocratic elution with THF-dioxane-MeOH-HOAc-5％ H/Sub 3/PO/Sub 4/-H/Sub 2/O (145: 125:50:20:2:658). When Kimchi was stored at 5$^{\circ}C$ for 20 days, the content of quercitrin in the methanol extract of Kimchi was 7.21％ and Kimchi at 20$^{\circ}C$ was reduced by 5.78％ (w/w). Contents of quercitrin in the leaves of Cedrela sinensis kimchi obsered to be gradually decreased during storage at 5$^{\circ}C$ and 20$^{\circ}C$. Contents of quercitrin of stored kimchi at 5$^{\circ}C$ was higher than that stored at 20$^{\circ}C$. The contents of quercitrin in Namul and Bugak were 13.06 and 5.03％ (w/w), respectively, which were lower than control.

• Korean Journal of Food Science and Technology
• /
• v.31 no.3
• /
• pp.815-822
• /
• 1999

Twenty one flavonoids were isolated from ethyl acetate layer of aqueaus EtOH extracts of Artemisia vulgaris and identified as tricin, jaceosidine, eupafolin, diosmetin, chrysoeriol, homoeriodictyol, isorhamnetin, apigenin, eriodictyol, luteolin, luteolin 7-glucoside, kaempferol 3-glucoside, kaempferol 7-glucoside, kaempferol 3-rhamnoside, kaempferol 3-rutinside, quercetin, quercetin 3-glucoside, quercetin 3-galactoside, quercetrin, quercetin 7-glucoside, rutin, and vietexin. The inhibitory activity for all purified flavonoids were examined against lipid peroxidation in rat liver microsome. All examined flavonoids showed considerable antioxidant activity. Among them, $IC_{50}$ value of apigenin, luteolin, isorhamnetin, quercetin, and eriodictyol were showed higher than that of vitamin E used as positive control. And methoxylated flavonoids, tricin, eupafolin, jaceosidine, diosmetin, and isorhamnetin showed considerable antioxidant activity. Each $IC_{50}$ values were shown at 0.9, 1.0, 1.4, 1.0, and $0.7\;{\mu}g/mL$, respectively.

• Journal of the Korean Applied Science and Technology
• /
• v.31 no.4
• /
• pp.771-780
• /
• 2014

The antioxidative effects and component analysis of the Melaleuca quinquenervia leaf extracts were investigated. All experiments were performed with 50% ethanol extract, ethyl acetate fraction and aglycone fraction obtained from dried M. quinquenervia leaves. The DPPH (1,1-phenyl-2-picrylhydrazyl) scavenging activity ($FSC_{50}$) of ethyl acetate fraction ($10.05{\mu}g/mL$) of M. quinquenervia leaf extracts was similar to (+)-${\alpha}$-tocopherol($8.89{\mu}g/mL$) known as a typical antioxidant. Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) of the ethyl acetate fraction ($1.61{\mu}g/mL$) and aglycone fraction ($1.07{\mu}g/mL$) of leaf extracts of M. quinquenervia on ROS generated in $Fe^{3+}-EDTA/H_2O_2$ system using the luminol-dependent chemiluminescence assay were similar to that of L-ascorbic acid ($1.50{\mu}g/mL$). The cellular protective effect of the extracts on the rose bengal sensitized photohemolysis of human erythrocytes was increased in a concentration dependant manner ($1{\sim}50{\mu}g/mL$). Especially, the cellular protective effects of Aglycone fraction (${\tau}_{50}=158.80min$) and 50% Ethanol extract (${\tau}_{50}=50.1{\pm}0.2min$) on the $^1O_2$-induced cellular damage of human cells were exhibited the higher than (+)-${\alpha}$-tocopherol (${\tau}_{50}=38.0min$). TLC and HPLC were used to analyse active components in the ethylacetate fraction of the extracts. Results showed that avicularin and quercetrin were active components of the extracts. These findings suggest that the M. quinquenervia leaf extracts can be applied to new cosmetics products as an effective antioxidant ingradient.