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@#Quercetin, a flavonoid compound which is widely distributed in plants are considered ass beneficial physiologically due to attributed bioactivity such as anti-cancer, immunomodulatory, antidiabetic, and anti-inflammatory. In this study, the quercetin content from the dried Blumea balsamifera L. DC dried leaf was macerated with 95% ethanol and the concentrated extract was purified using Modified Kupchan method and flash chromatography. All fractions were tested for the presence of flavonoids using phytochemical screening and the selected dichloromethane fraction were further purified using another round of flash chromatograph. All resulting fractions and pooled samples were tested for the antioxidant property using the developed Thin Layer Chromatography (TLC)-Bioautography and separated compounds were derivatized with DPPH. Using the optimized TLC-Bioautography method, the quercetin content in the dichloromethane fraction was analyzed and compared with a reversed phase high performance liquid chromatography hyphenated with photodiode array detector (RP-HPLC-PDA). The calculated quercetin content from the pooled sample using TLC-bioautography method is 2.25 mg/ml and from RP-HPLC-PDA is 2.02 mg/ml which was not comparable statistically using unpaired t-test (p<0.05, α=0.05
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QuercetinABSTRACT
Objective To establish a thin-layer chrometograrrgy(TLC)method for the identification of quercetin and chloro?genic acid in Ramulus mori,and to screen their antioxidant activity. Methods The quercetin and chlorogenic acid were extracted by ultrasonic method with methanol as a solvent. The effect of different developed system,reagent,temperature,view methods and differ?ent silica gel plate on the TLC of quercetin and chlorogenic acid in Ramulus mori were tested to select the best TLC conditions. The antioxidant activity of quercetin and chlorogenic acid was screened with DPPH as a reagent. Results The ethyl acetate∶water∶formic acid∶toluene(17∶2∶2∶0.8)was used as a developing system and 1%AlCl3 as a chromogenic reagent. Quercetin and chlorogenic acid in Ramulus mori were identified under 366 nm,with blue and blue-green spots on silica gel G plate,and yellowish spots under purple background by the test of TLC-bioautography. Both were proven to have antioxidant activity. Conclusion The method is simple,accu?rate and reliable,and can be used for quality control of Ramulus mori.
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Objective To establish a thin-layer chrometograrrgy(TLC) method for the identification of quercetin and chlorogenic acid in Ramulus mori, and to screen their antioxidant activity. Methods The quercetin and chlorogenic acid were extracted by ultrasonic method with methanol as a solvent. The effect of different developed system, reagent, temperature, view methods and different silica gel plate on the TLC of quercetin and chlorogenic acid in Ramulus mori were tested to select the best TLC conditions. The antioxidant activity of quercetin and chlorogenic acid was screened with DPPH as a reagent. Results The ethyl acetate:water:formic acid:toluene(17:2:2:0.8) was used as a developing system and 1% AlCl3 as a chromogenic reagent. Quercetin and chlorogenic acid in Ramulus mori were identified under 366 nm, with blue and blue-green spots on silica gel G plate, and yellowish spots under purple background by the test of TLC-bioautography. Both were proven to have antioxidant activity. Conclusion The method is simple, accurate and reliable, and can be used for quality control of Ramulus mori.
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Aim: Phyllanthus columnaris Müll.Arg. was found to possess anti-methicillin resistant Staphylococcus aureus (antiMRSA) activities. This study aimed at isolating, identifying and evaluating the active compounds from the stem bark of Phyllanthus columnaris Müll.Arg. against MRSA. Methodology and results: Stem bark extracts (methanol, acetone and aqueous) of Phyllanthus columnaris were subjected to anti-MRSA screening by disc diffusion method. MIC and MBC tests were carried out to compare the lowest concentration to inhibit and kill the sixteen MRSA tested among the three extracts. TLC bioautography were performed to detect the bioactive compounds. Isolation of the two active compounds was performed by means of preparative TLC. Morphological and ultra-structure alterations of the MRSA treated with bioactive compounds after 24 h were revealed by scanning and transmission electron microscopy. Both methanol and acetone extracts exhibited good anti-MRSA activity with the lowest minimum inhibitory concentration (MIC) value for both extracts were 0.78 mg/mL and the lowest minimum bactericidal concentration (MBC) were 1.56 mg/mL. Bioassay-guided chromatography by bioautography revealed two active anti-MRSA compounds from both tannin-free methanol and acetone extracts and characterized as stigmasterol and lupeol by nuclear magnetic resonance (NMR) spectral data. Scanning and transmission electron microscopy of MRSA treated with stigmasterol and lupeol showed cell wall disruption, release of cytoplasmic compounds and decreased in cellular volume. Conclusion, significance and impact of study: Results obtained herein, may suggest that the stem bark of Phyllanthus columnaris possess anti-MRSA and the two of the active compounds isolated were stigmasterol and lupeol. Their anti-MRSA effects up to the morphological and ultra-structure studies were not reported earlier
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Objective: The inhibitory effects of essential oils including fennel, juniper and kalonji from Foeniculum Vulgare, Juniperus Osteosperma and Nigella Sativa on multi drug resistant clinical isolates were investigated. All the oils have been evaluated for phytochemical constituents, antibacterial activity and TLC bioautography assay. Methods: Preliminary phytochemical analysis was performed. The antibacterial potential of essential oils from fennel, juniper and kalonji fennel, juniper and kalonji was evaluated by agar well diffusion method against multi drug resistant clinical isolates. The antibacterial effect was investigated using the TLC-bioautographic method. Results: Preliminary phytochemical analysis demonstrated the presence of most of the phytochemicals including saponins, cardiac glycosides, steroids, terpenoids, flavonoids and tannins. Antibacterial activity of essential oils was assessed on eight multi-drug resistant (MDR) clinical isolates from both Gram-positive and Gram-negative bacteria and two standard strains. All the oils tested showed significant to moderate antibacterial activity toward all tested strains except Acinetobacter sp and Staphylococcus aureus MRSA. The maximum zone of inhibition was found to be 25依0.12 mm for juniper oil followed by 21依0.085 mm for kalonji oil againstStaphylococcus aureus 2. Thin layer chromatography and bioautography assay demonstrated well-defined growth inhibition zones against Staphylococcus aureus 2 and E. coli for juniper essential oil in correspondence with tannins observed at Rf values of 0.07 and 0.57. Conclusions: Based on the present study, the essential oils from juniper and kalonji possess antibacterial activity against several multi drug resistant pathogenic bacteria and thus can be used as a base for the development of new potent drugs and phytomedicine.