ABSTRACT
In a study of the anthraderivatives in roots of Rheum emodi, three new anthrone C-glucosides, named 10-hydroxycascaroside C (1), 10-hydroxycascaroside D (2) and 10R-chrysaloin 1-O-beta-D-glucopyranoside (3) were isolated besides the rare compounds cascaroside C (4), cascaroside D (5) and cassialoin (6). Additionally the investigation resulted in the isolation of an acetylated chrysophanol glucoside, 8-O-beta-D-(6'-O-acetyl)glucopyranosyl-chrysophanol (7). The structures were established by comprehensive spectroscopic investigations.
Subject(s)
Anthracenes/chemistry , Glucosides/chemistry , Rheum/chemistry , Acetylation , Anthracenes/isolation & purification , Glucosides/isolation & purification , Magnetic Resonance Spectroscopy , Plant Extracts/analysis , Plant Roots/chemistry , Spectrometry, Mass, Electrospray Ionization , Spectrophotometry, Infrared , Spectrophotometry, UltravioletABSTRACT
A sulfated emodin glucoside, emodin 8-O-beta-D-glucopyranosyl-6-O-sulfate (1), was isolated from the roots of Rheum emodi in an investigation of the active constituents of this Nepalese medicinal plant, and its structure was determined by spectroscopic and chemical methods. Additionally, two rare auronols, carpusin (2) and maesopsin (3), besides other anthraquinones and phenolics, were isolated and identified. Compounds 2 and 3 showed significant antioxidant activity in the DPPH assay, while chrysophanol, physcion, and emodin and their 8-O-glucosides were found to be inactive.
Subject(s)
Anthraquinones/isolation & purification , Antioxidants/isolation & purification , Glycosides/isolation & purification , Plants, Medicinal/chemistry , Rheum/chemistry , Anthraquinones/chemistry , Anthraquinones/pharmacology , Antioxidants/chemistry , Antioxidants/pharmacology , Benzofurans/chemistry , Benzofurans/isolation & purification , Benzofurans/pharmacology , Biphenyl Compounds , Glycosides/chemistry , Glycosides/pharmacology , Inhibitory Concentration 50 , Molecular Structure , Nepal , Nuclear Magnetic Resonance, Biomolecular , Picrates/pharmacology , Plant Roots/chemistryABSTRACT
About 47% of Nepal's total population is living in Terai region and 90% of them are relying on groundwater as their major source of drinking water. About 200,000 shallow tubewells have been installed by different agencies in 20 Terai districts, serving 11 million people. Recently, arsenic contamination of groundwater has been recognized as a public health problem in Nepal. This has sensitized government, national and international nongovernment organizations working on water quality sector to carry out water quality assessment for arsenic in the affected communities. So far, 15,000 tubewells has been tested where 23% samples exceeded World Health Organization guideline value of 10 microg/L and 5% exceeded "Nepal Interim Arsenic Guideline" of 50 microg/L. It is estimated that around 0.5 million people in Terai are living at risk of arsenic poisoning (>50 microg/L). Some recent studies have reported the prevalence of dermatosis related to arsenicosis from 1.3 to 5.1% and the accumulation of arsenic in biological samples like hair and nail much higher than the acceptable level. Though some steps are being taken by government and private organizations to combat the problem, it has not been able to cover all the affected communities. Nepal still needs more research work on arsenic occurrence and effects and mitigation programs simultaneously.
