scholarly journals HIGH-PERFORMANCE THIN-LAYER CHROMATOGRAPHY ANALYSIS AND FREE RADICAL SCAVENGING POTENTIAL OF SOUTH INDIAN ORTHODOX BLACK TEA

Author(s):  
Mahalakshmi Rajamani ◽  
Kalaivani Krishnasamy ◽  
Nishadh Abubakker

Objective: The objective of this study was to evaluate the free radical scavenging potential and high-performance thin-layer chromatography (HPTLC) fingerprinting of the ethanolic extract of south Indian orthodox black tea (OBT).Methods: Phytochemical analysis was carried out using standard methods, and free radical scavenging activity of the extract was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO), superoxide anion (SOD), and hydroxyl radical scavenging capacities. The ethanolic extract of OBT was loaded in the pre-coated HPTLC plates (silica gel 60 F 254) E-MERCK KGaA. HPTLC was carried out with toluene: ethyl acetate: diethylamine (7:2:1), chloroform: methanol:formic acid (8.5:1.0:0.5), and butanol: isopropyl alcohol (1:1) as mobile phase for alkaloids, flavonoids, and terpenoids, respectively.Results: HPTLC results confirmed that the extract contained several potential active components such as flavonoids, alkaloids, and terpenoids as the slides revealed multicolored bands of varying intensities. Extract of OBT reliably showed the total phenolics 132.27 mg/g, flavonoids 72.52 mg/g, and alkaloids 66.01 mg/g of dry matter. The IC50 value of OBT for DPPH was found to be 372.22 μg/ml, SOD 311.93 μg/ml, NO 362.17 μg/ml, hydroxyl radical 342.14 μg/ml, and reducing power 178.54 μg/ml.Conclusion: The HPTLC fingerprinting profile developed for ethanolic extract will help in proper identification and quantification of marker compounds. The ethanolic extract of OBT was found to possess a wide range of phytochemicals with excellent antioxidant properties. This information may help to choose the best beverage to be consumed in the future.

2009 ◽  
Vol 4 (10) ◽  
pp. 1934578X0900401
Author(s):  
Angela I. Calderón ◽  
Johayra Simithy ◽  
Giuliana Quaggio ◽  
Alex Espinosa ◽  
Jose Luis López-Pérez ◽  
...  

Seventy-six plant extracts from the Panamanian flora have been screened for acetylcholinesterase (AChE) inhibitors by thin-layer chromatography (TLC) bioautography. The most promising extracts with AChE inhibitory and free radical scavenging activities at 100 μg were those of Tabernaemontana panamensis (Markgr., Boiteau & L. Allorge) Leeuwenb., Pentagonia macrophylla Benth., and Warszewiczia coccinea (Vahl) Klotzsch. Bioguided fractionation of W. coccinea stem extract afforded two triterpenes, 3β,6β,19α-trihydroxy-urs-12-en-28-oic acid (1) and 3β,6β-dihydroxy-olean-12-en-28-oic acid (sumaresinolic acid) (2), with AChE inhibitory activity. Their structures were determined by spectroscopic methods. This is the first report of these bioactive triterpenes in W. coccinea.


Author(s):  
ANITHA P ◽  
NAZEEMA TH

Objectives: This study aims to evaluate the enzymic antioxidants and free radical scavenging present in the ethanolic leaf extracts of Crescentia cujete. Methods: Enzymic antioxidants such as superoxide dismutase (SOD), catalase (CAT), glutathione reductase, glutathione peroxidase, and glutathione S-transferase (GST) were estimated by standard methods. Free radical scavenging potential was evaluated by diphenylpicrylhydrazyl (DPPH), nitric oxide, and hydroxyl radical methods using an ethanolic extract of C. cujete leaf. Results: The leaf extract of C. cujete showed the maximum activity of CAT, SOD, GST, glutathione reductase, and peroxidase activity. CAT activity was formed to be highest in the ethanolic extract of C. cujete leaf. DPPH radical scavenging activity was reported as 38.5 μg/ml, nitric oxide was found to be 200.77 μg/ml, and hydroxyl radical scavenging exhibited 108.42 μg/ml normalized with ascorbic acid. Conclusion: From the results, it has concluded that the ethanol extract of the C. cujete leaf has a prospective source of natural antioxidant that would be a great significance as therapeutic agents in preventing or slowing the progress of reactive oxygen species and related oxidative stress-related degenerative diseases.


2009 ◽  
Vol 4 (4) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
H.J. Damien Dorman ◽  
Müberra Koşar ◽  
K Hüsnü C Başer ◽  
Raimo Hiltunen

Seven extracts were prepared from Mentha x piperita (peppermint) leaves in sequence using a Soxhlet apparatus, viz. (40-60°) light petroleum (PE), dichloromethane (CH2Cl2), acetonitrile (ACN), ethyl acetate (EtOAc), methanol (MeOH), n-butanol and water (H2O) extracts. The phenolic and flavonoid content of each extract were estimated using spectrophotometric methods whilst a qualitative-quantitative analysis was made by reverse-phase high performance liquid chromatography coupled with photodiode array detection (HPLC-PDA). Each extract was assessed in a battery of six antioxidant-related assays so as to determine their iron(III) reductive, iron(II) chelating and free radical scavenging abilities. The MeOH-soluble extract contained the greatest content of total phenols and flavonoids based upon the Folin-Ciocalteu and 2-aminoethyl diphenylborate reagent data and HPLC-PDA analysis. Based upon the chromatographic and UV-spectral data, the leaves principally contained the cinnamic acid caffeic acid, the depside rosmarinic acid and flavonoids (flavones and flavanones). Eriocitrin (383.3 ± 2.2 mg/g extract) and rosmarinic acid (381.2 ± 1.9 mg/g extract) were the most abundant components identified within the leaves, whilst naringenin-7- O-glucoside (0.8 ± 0.01 mg/g extract) was the least abundant component identified being found only in the EtOAc-soluble extract. The EtOAc, ACN and H2O-soluble extracts demonstrated the most potent iron(III) reductive and 1,1′-diphenyl-2-picrylhydrayl, 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonate) and hydroxyl free radical scavenging properties; however, the H2O and CH2Cl2-soluble extracts were the most potent extracts in the β-carotene-linoleic acid bleaching inhibition assay. In terms of iron(II) chelation – an important antioxidant property - the PE, MeOH and H2O extracts demonstrated moderate iron(II) chelating activity.


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