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Chromatography and Its Applications
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... The ground dried leaves of D. angustifolia (500 g) were extracted with 100% methanol (1.5 L) using a shaker for 72 h, then filtered and concentrated under reduced pressure at 35 • C and afforded (70 g), representing 14% of the green solid. The methanol extract (65 g) was used for fractionation and separation (Dhanarasu, 2012). ...
... The fractions were observed under UV light and further sprayed with the p-anisaldehyde sulphuric acid reagent to identify non-UV active compounds. Based on their TLC profiles, the fractions were subjected to further purification using a small column (Dhanarasu, 2012). Repeated column chromatography of M. angustifolia (dichloromethane, ethyl acetate and methanol) extracts resulted in the isolation of four compounds, a lignan, 5-methoxyjusticidin A (1), an ester which is cis-phytyl diterpenoidal fatty acid ester (2) and two well-known steroids, stigmasterol (3) and β-sitosterol (4). ...
Ethnopharmacological relevance
Monsonia angustifolia is traditionally used to treat anthrax, heartburn, diarrhea, eye infections and hemorrhoids. Dodonaea angustifolia plants are frequently used as a treatment for dental pain, microbial infections and jungle fever. The two plant species were selected due to the presence of secondary metabolites such as, coumarins, flavonoids, saponins and polyphenolics in the crude extracts which exhibit pharmacological significance. The pure isolated compounds from the crude extracts are known for their diverse structures and interesting pharmacophores.
Aim
To isolate and identify antibacterial and antifungal chemical constituents from M. angustifolia and D. angustifolia plant extracts and evaluate the cytotoxicity of pure compounds from the crude extracts.
Materials and methods
Extractives from M. angustifolia and D. angustifolia plants were isolated using chromatographic techniques and structures were elucidated based on NMR, IR and MS spectroscopic techniques. A micro plate serial dilution method was used to evaluate the antibacterial activity of extracts and pure compounds against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and antifungal activity against Candida albicans and Cryptococcus neoformans. The cytotoxicity was determined using the 3-(4, 5-dimethylthiazol)-2, 5-diphenyl tetrazolium bromide (MTT) assay.
Results
The dichloromethane, ethyl acetate and methanol crude extracts from the plants exhibited significant inhibition of microbial growth. The phytochemical investigation of these active crude extracts led to the isolation of seven pure active compounds, 5-methoxyjusticidin A (1), cis-phytyl diterpenoidal fatty acid ester (2), stigmasterol (3), β-sitosterol (4), caryophyllenol-I (5), 3β,29-dihydroxyfriedelane (6) and 5-hydroxy-7,4′-dimethoxyflavone (7). The structures were characterized based on spectroscopic data. Stigmasterol (3) showed good antifungal activity against Cryptococcus neoformans with minimum inhibition concentration (MIC) of 25 μg/mL and Candida albicans (MIC = 50 μg/mL).
Conclussion
Compounds (1–7) isolated from M. angustifolia and D. angustifolia showed antibacterial and antifungal activities and were non-toxic against Madin-Darby canine kidney (MDCK) cells and VERO monkey kidney (VERO) cells.
... When passing through the column, the mobile phase carries the sample components with different linear velocities to the other end of the column. Therefore, in order to separate the components of the sample, it is sufficient to collect fractions of the mobile phase at the other end of the column using, for example, test tubes (Dhanarasu, 2012). This is a system that can be easily assembled in the laboratory with a glass column ( Figure 5). ...
... They display a wide range of biological activities including antibacterial [10], antiviral [11], antioxidant [12], and antiparasitic activity [13]. They also have similarities in structure, volatility, weakness in polarity, and a lack of UV absorption that create a number of challenges for their preparative separation by conventional methods based on chromatographic columns [14]. Frequently, column chromatography based on silica gel is used to separate volatile terpenes. ...
The technique of high-speed countercurrent chromatography was applied to the isolation of compounds in essential oil derived from the leaves of Piper mollicomum species. Plant leaves (200.0 g) were submitted to hydrodistillation in a modified Clevenger apparatus. The resulting crude leaf essential oil was analyzed by gas chromatography with flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS) to determine the profile of the components. The purified fractions were composed of monoterpenes and sesquiterpenes such as camphor (85.0 mg at 98.5% purity), (E)-nerolidol (100.0 mg at 92.8% purity), and camphene (150.0 mg at 82.0% purity). A minor component of the essential oil, bornyl acetate (16.2 mg at 91.2% purity) was also isolated in the one-step separation protocol in 2 h. The countercurrent chromatography technique proved to be a fast and efficient method for the separation of volatile metabolites that conserved the solvent while delivering various fractions of high purity.
Because biomarker concentrations decrease with increasing thermal maturity, light
oils contain only a low concentration of detectable biomarkers, and in consequence
require instrumentation of highest selectivity and sensitivity. The information
of source, thermal maturity, and secondary alteration processes are furthermore
often revealed by only subtle variations in the isomeric distribution of such trace
components. GC-MS/MS is the premier analytical method for the sensitive characterization of “molecular fossil” biomarkers in crude oil.
The flavonoids, one of the most numerous and widespread groups of natural constituents, are important to man not only because they contribute to plant colour but also because many members (e.g. coumestrol, phloridzin, rotenone) are physiologically active. Nearly two thousand substances have been described and as a group they are universally distributed among vascular plants. Although the anthocyanins have an undisputed function as plant pigments, the raison d'etre for the more widely distributed colourless flavones and flavonols still remains a mystery. It is perhaps the challenge of discovering these yet undisc10sed functions which has caused the considerable resurgence of interest in flavonoids during the last decade. This book attempts to summarize progress that has been made in the study of these constituents since the first comprehensive monograph on the chemistry of the flavonoid compounds was published, under the editorship of T. A. Geissman, in 1962. The present volume is divided into three parts. The first section (Chapters 1-4) deals with advances in chemistry, the main emphasis being on spectral techniques to take into account the re cent successful applications of NMR and mass spectral measurements to structural identifications. Recent developments in isolation techniques and in synthesis are also covered in this section. Advances in chemical knowledge of individual c1asses of flavonoid are mentioned inter aha in later chapters of the book.
