Purification Of Chemical Constituents Research Articles

Natural products from Rhynchostylis retusa (Orchidaceae), their chemophenetic significance and bioactivity

Rhynchostylis retusa (L.) Blume is traditionally used for the treatment of pain, inflammation, and skin diseases. The study aims the bioassay-guided isolation of chemical constituents from R. retusa using human breast cancer cell line MDA-MB-231 and murine RAW 264.7 macrophages. The cell viability assay revealed that crude extract, hexane, and chloroform fractions inhibited the viability of MDA-MB-231 and RAW 264.7 macrophages. The hexane fraction led to the isolation of four fatty acids; 1-octene (1), (9Z,12Z,15Z)-octadeca-9,12,15-trienoic acid (2), methyl oleate (3), methyl linolenate (4); and one steroid, stigmasterol (5). The isolation and purification of chemical constituents from the most potent chloroform fraction yielded two phenylpropanoids, dihydroconiferyl dihydro-p-coumarate (6) and retusiusine B (7); one bis-nor-lignan, 3,3′-dimethoxy-4,4′-dihydroxy-9,9′-bis-nor-lignan (8) and one bibenzyl, gigantol (9); and vanillin (10). This is the first report of compounds 1–10 from R. retusa (L.) Blume and the genus Rhynchostylis. 3,3′-dimethoxy-4,4′-dihydroxy-9,9′-bis-nor-lignan (8) is new from natural sources. Gigantol (9) is a bioactive compound of R. retusa as it showed an inhibitory effect on the viability of MDA-MB-231 cells and RAW 264.7 macrophages. The bioactivity of R. retusa is possibly due to the presence of gigantol (9) in the plant. Thus, the study corroborates the traditional uses of R. retusa for the treatment of pain and inflammation. The chemophenetic significance of the isolated compounds is also discussed in this study.

Phytochemical Analysis in the Leaves of Chamaecrista nigricans (Leguminosae)

ObjectiveIn the present study, the plant Chamaecrista nigricans (Siruavuri in Tamil) was selected to isolate, elucidate and identify the chemical constituents present in it.MethodsLeaves were collected, shade-dried, coarsely powdered using a pulvarizor, successively extracted with various solvents of increasing polarity such as hexane, chloroform and methanol using Soxhlet apparatus. Methanol leaf extract was used for isolation and identification of chemical constituents. Column chromatography (CC) and thin layer chromatography (TLC) were used for separation and purification of chemical constituents while the isolated pure compounds were identified using UV-VIS, IR, 1H and 13C NMR spectra. GC-MS analysis was carried out to identify the chemical constituents.ResultsThree anthraquinones such as emodin, chrysophanol and physcion were isolated and identified. GC-MS analysis helped to identify diisooctyl ester 1,2-benzenedicarboxylic acid, methyl ester, (Z, Z, Z)-9,12,15-octadecatrienoic acid, nitric acid nonyl ester, 4-C-methyl-myo-inositol, n-hexadecanoic acid, 2-methyl-butanoic acid, and, octadecanoic acid.ConclusionMedicinally valuable bioactive natural compounds in this plant proved its importance in drug industry for drug development against various diseases.

Application of off-line two dimensional reversed-phase liquid chromatography/supercritical fluid chromatography to the separation of the seeds of Trichosanthes kirilowii Maxim

An off-line two dimensional reversed-phase liquid chromatography/supercritical fluid chromatography (2D RPLC/SFC) method was developed for the separation of the seeds of Trichosanthes kirilowii Maxim. (T. kirilowii.). In the experiment, RPLC was used in the first dimension to analyze the samples. And 12 fractions (F1-F12) were obtained according to the chromatographic peak collection mode, the fractions were re-analyzed in both RPLC and SFC modes. The results clearly showed that this 2D method had good orthogonality. The SFC was used as the second dimension. Ethanol-n-hexane (3:7, v/v) was used as a modifier in SFC. The modifier could provide appropriate elution power. When the sample load increased, it could also ensure the solubility of samples. The 2D RPLC/SFC method had obvious advantages for separating the compounds with similar properties, enriching and purifying the trace components. Finally, 150 peaks could be detected. The off-line 2D RPLC/SFC method will be further enlarged to a preparative level for preparation of compounds. The method can provide a practical reference for the purification of chemical constituents and material basis research of the seeds of T. kirilowii. in the future.

Chemical constituents from endophyte Chaetomium globosum in Imperata cylindrical

Isolation and purification of chemical constituents from solid culture of endophyte Chaetomium globosum in Imperata cylindrical was performed through silica gel column chromatography, gel filtration over Sephadex LH-20 and preparative HPLC. Nine compounds were obtained and their structures were determined as chaetoglobosin F(1), chaetoglobosin Fex(2), chaetoglobosin E(3) cytoglobosin A(4), penochalasin C(S), isochaetoglobosin D (6), N-benzoylphenylalaninyl-N-benzoyphenylalaninate(7), uracil(8) and 5-methyluracil(9), respectively, based on HR-MS and NMR data and comparison with literatures. Compound 7 was isolated from Chaeeomium sp. for the first time. In vitro cytotoxicity of compounds was evaluated using MTT mothed and 1,3,4 and 5 showed inhibition activity to the human cervical carcinoma cell HeLa with IC50 values of 99.43, 23.77, 97.92, 86.25 micromol x L(-1), while positive cotolocisnin Ad apno1ch alse IC50 24.33 micromol x L(-1).

Purification of hydroxyanthraquinones and cinnamic acid from the roots of Rheum officinale Baill.

A chromatographic method for isolation and purification of chemical constituents from the well-known traditional Chinese drug Da-huang (roots of Rheum officinale Baill.) was established by using 12% cross-linked agarose gel, Superose 12, as the separation media. A two-step separation procedure is employed. Sixty five percent methanol was used as the eluent for separation of cinnamic acid, rhein, physcion and emodin form Da-huang crude extract. The fraction containing aloe-emodin and chrysophanol was then separated by using 55% methanol containing 0.5% acetic acid as the eluent. As a result, cinnamic acid and five kinds of hydroxyanthraquinones including rhein, aloe-emodin, chrysophanol, physcion and emodin were obtained. The retention behavior of hydroxyanthraquinones on Superose 12 was also studied. The retention of hydroxyanthraquinones on Superose 12 is based on a mixture of hydrogen bonding and hydrophobic interactions between the hydroxyl groups of the hydroxyanthraquinones and the residues of the cross-linking reagents used in the manufacturing process of Superose 12.

Isolation and purification of chemical constituents from the pericarp of Sophora japonica L. by chromatography on a 12% cross‐linked agarose gel

A chromatographic method using 12% cross-linked agarose gel Superose 12 as the separation medium was developed for isolation and purification of the chemical constituents from the pericarp of Sophora japonica L. The mobile phase used for the separation was 2% acetic acid and 7% acetic acid in gradient elution. As a result, eight compounds including four kinds of flavonoids and four kinds of isoflavonoids were obtained in a one-step separation. A straightforward explanation of the separation mechanism of flavonoids and isoflavonoids on Superose 12 is also given. The flavonoids and isoflavonoids are retained on Superose 12 by a combination of hydrogen bonding and hydrophobic interactions between the hydroxyl groups of aglycone and the residues of the cross-linking reagents used in the manufacture of Superose 12.

Preparative isolation and purification of chemical constituents from the root of Adenophora tetraphlla by high-speed counter-current chromatography with evaporative light scattering detection

Preparative high-speed counter-current chromatography (HSCCC), as a continuous liquid–liquid partition chromatography with no solid support matrix, combined with evaporative light scattering detection (ELSD) was employed for systematic separation and purification of non-chromophoric chemical components from Chinese medicinal herb Adenophora tetraphlla ( Thunb.), Fisch. Nine compounds, including α-spinasterol, β-sitosterol, nonacosan-10-ol, 24-methylene cycloartanol, lupenone, 3- O-palmitoyl-β-sitosterol, 3- O-β- d-glucose-β-sitosterol, eicosanoic acid and an unknown compound, were obtained. The compounds were all above 95% determined by high-performance liquid chromatography (HPLC)–ELSD, and their structures were identified by 1H NMR and chemical ionization mass spectroscopy (CI-MS). The results demonstrate that HSCCC coupled with ELSD is a feasible and efficient technique for systematic isolation of non-chromophoric components from traditional medicinal herbs.

(177) Open Column Chromatographic Separation of Health-promoting Bioactive Citrus Limonoids

Open column chromatography is an effective and common technique for the separation and purification of chemical constituents. Limonoids are found in significant quantities in citrus fruits. Citrus limonoids have documented anti-cancer activity in several types of cancer, such as breast, colon, skin, and neuroblastoma in animal models and in vitro cell culture studies. Furthermore, limonoids have shown anti-inflammatory properties and inhibitory effects on bone resorption. In addition to many potential health benefits, limonoids have also shown antifungal and insect anti-feedant properties. To meet the large demand of limonoids for bioactivity studies, defatted grapefruit seeds were extracted using acetone and concentrated under vacuum. The dried extract was loaded onto a silica gel column and eluted with mixtures of dichloromethane and ethyl acetate with increasing polarity to obtain three compounds. The purity of the compounds (1–3) have been analyzed by HPLC and the structures have been identified by using NMR spectra and mass spectra as nomilin, limonin, and deacetylnomilin, in respective order of elution. The results will be presented in greater detail on the poster. This project is based upon work supported by the USDA-CSREES under Agreement USDA IFAFS #2001 52102 02294 and USDA #2005-34402-14401 “Designing Foods for Health” through the Vegetable & Fruit Improvement Center.

Preparative isolation and purification of chemical constituents from the root of Polygonum multiflorum by high-speed counter-current chromatography

High-speed counter-current chromatography methods, combined with solvent partition, were applied to the systematic separation and purification of chemical components from Chinese medicinal herb Polygonum multiflorum extract. The aim of this paper is summing up the rules of solvent system selection for diverse fractions of herbal extract, and establishing the systematic pattern to screen the bioactive constituents rapidly. Nine compounds including emodin, chrysophanol, rhein, 6-OH-emodin , emodin-8-β- d-glucoside, polygonimitin B, 2,3,5,4′-tetrahydroxystilbene-2-β- d-glucoside, gallic acid and an unkown glycoside, which differed in quantity and polarity remarkably, were obtained. The purities of them were all above 97% as determined by high-performance liquid chromatography (HPLC), and their structures were identified by 1H NMR and electrospray ionization mass spectrometry (ESI–MS). The results demonstrated that HSCCC is a speedy and efficient technique for systematic isolation of bioactive components from traditional medicinal herbs.