[Research on chemical constituents from stem of Gymnema sylvestre]

OBJECTIVE

To study on the chemical constituents from the stem of Gymnema sylvestre.

METHODS

The constituents were extracted by percolation with ethanol. Then the extract was separated by systemic solvent separation methods. The part of n-butanol extract was isolated and purified by macroporous adsorptive resins, silica gel column chromatography, sephadex gel column chromatography and recrystallization. The isolated compounds were identified by spectrum methods.

RESULTS

Eight compounds were isolated and identified as fallows: Conduritol A(I), 1-Heptadecanol(II), Stigmasterol glucoside(III), 1-Quercitol(IV), 1-Octadecanol(V), Potassium nitrate(VI), Lupeol cinnamate(VII), Stigmasterol(VIII).

CONCLUSION

Chemical compounds II, III, V, VII are firstly obtained from this plant.

[Study on the chemical constituents of Rhizoma Cyperi]

OBJECTIVE

To study the chemical constituents of Rhizoma Cyperi.

METHODS

The constituents were separated and purified by silica gel column chromatography, their structures were identified on the basis of physico-chemical properties and spectral data.

RESULTS

Six compounds were isolated and identified as physicion (1), hexadecanoic acid (2), beta-sitosterol (3), stigmasterol (4), catenarin (5), daucosterol (6).

CONCLUSION

Compounds 1, 4, 5 were isolated from this plant for the first fime.

Antibacterial activity of labdane diterpenoids from Stemodia foliosa

As part of a continuing interest in exploring the chemistry of Brazilian medicinal plants, three new labdane diterpenoids, 6alpha-acetoxymanoyl oxide (1), 6alpha-malonyloxymanoyl oxide (2), and 6alpha-malonyloxy-n-butyl ester manoyl oxide (3), together with the known betulinic acid, lupeol, sitosterol, and stigmasterol, were isolated from the aerial parts of Stemodia foliosa. The structures of 1-3 were established on the basis of interpretation of spectroscopic data, including HRESIMS, and 1D and 2D NMR techniques. All compounds were tested against a bacteria panel consisting of Staphylococcus aureus, Bacillus cereus, B. subtilis, B. anthracis, Micrococcus luteus, Mycobacterium smegmatis, and M. phlei. Compound 2 showed moderate activity against these strains, with MIC values in the range 7-20 microg/mL.

[Study on liposoluble constituents of Teucrium labiosum]

OBJECTIVE

To Study liposoluble constituents of Teurium labiosum.

METHODS

The constituents were isolated and purified by silica gel column and Sephadex LH-20 chromatography. Their structures were elucidated by physicochemical properties and spectral analysis.

RESULTS

Six compounds were obtained and identified as stearic acid (I), alpha-spinasterol (II), Methyl phaeophorbide a (III), friedelino (IV), lupeol (V) and stigmasta-5,22-dien-3beta-ol (VI).

CONCLUSION

All these compounds are obtained from this plant for the first time.

[Studies on the chemical constituents in herb of Hedyotis diffusa]

OBJECTIVE

To study the chemical constituents of Hedyotis diffusa.

METHODS

Column chromatographic techniques were used for isolation and purification of chemical constituents of this plant and their structures were identified by spectroscopic analysis.

RESULTS

Five compounds were isolated and identified as scandoside methyl ester (I), deacetylasperulosidic acid methyl ester (II), 10-dehydrogeniposide (III), 2-hydroxy-3-methylanthraquinone (IV), stigmasterol (V), respectively.

CONCLUSION

Compound II as iridoids was isolated from Hedyotis diffusa for the first time, compound III as iridoids was isolated from genus Hedyotis for the first time.

[Study on the chemical constituents of liposoluble steroidal and triterpenoid compounds from the stem and bark of Macaranga hemsleyana]

OBJECTIVE

to research the chemical constituents of the liposoluble compounds from the stem and bark of Macaranga hemsleyana Pax & Hoffm.

METHODS

Five compounds were obtained by silica chromatography and preparative TLC from the stem and bark of Macaranga hemsleyana Pax & Hoffm., and the chemical structures of these compounds were identified by modern spectroscopy as well as physico-chemical analysis.

RESULTS

These compounds were identified to be beta-Sitosterol (1), Stigmast-4-en-3-one (2), Stigmast-4-en-3,6-dione (3), 3beta-O-acetyl aleuritolic acid (4) and Canophyllol (5).

CONCLUSION

The liposoluble fractions of Macaranga hemsleyana Pax & Hoffm. are mainly steroidal and triterpenoid compounds.

Withanolides from Withania somnifera roots

Two new and seven known withanolides along with beta-sitosterol, stigmasterol, beta-sitosterol glucoside, stigmasterol glucoside, alpha+beta glucose were isolated from the roots of Withania somnifera. Among the known compounds, Viscosa lactone B, stigmasterol, stigmasterol glucoside and alpha+beta glucose are being reported from the roots of W. somnifera for the first time. One of the new compounds contained the rare 16beta-acetoxy-17(20)-ene the other contained unusual 6alpha-hydroxy-5,7alpha-epoxy functional groups in the withasteroid skeleton. The structures were elucidated by spectroscopic methods and chemical transformations.

[Chemical constituents of Changium smyrnioides]

OBJECTIVE

To study chemical constituents of Changium smyrnioides Wolff.

METHODS

The chemical components were isolated and purified by silica gel column and recrystallization. The chemical structures were elucidated on the basis of physico-chemical properties and spectral data.

RESULTS

Ten compounds were isolated and identified as lignoceric acid (1), beta-sitosterol (2), stigmasterol (3), 5-hydroxy-8-methoxypsoralen (4), glycerylmonopalmitate (5), L-pyroglutamic acid (6), succinic acid (7), vanillic acid-4-O-beta-D-glucopyranoside (8 ), vanillic acid (9), daucosterol (10).

CONCLUSION

Compounds 1, 4, 5, 6, 8 and 9 are obtained from the plant for the first time.

Isolation of stigmasterol and beta-sitosterol from methanolic extract of root bark of Calotropis gigantea (Linn)

Aim of this study is to identify and characterize the bioactive principles from the root bark of Calotropis gigantea. It has wide folk medicinal use. For isolation of the compounds, the dried root bark's powder of Calotropis gigantea were subjected to hot extraction and then the crude methanol (MeOH) extract was fractionated with petroleum ether, chloroform and ethyl acetate. Two compounds were isolated and purified from petroleum ether fraction of crude methanol extract and the structures were determined as stigmasterol and beta-sitosterol by analysis of physical, chemical and spectral characteristics (1D NMR and mass spectrometry).

Antitrypanosomal activity of triterpenoids and sterols from the leaves of Strychnos spinosa and related compounds

Fractionation of an antitrypanosomal lipophilic leaf extract from Strychnos spinosa led to the isolation of eight triterpenoids and sterols in this plant part for the first time. Two of these were found to possess in vitro antitrypanosomal activity, namely, saringosterol (14) and 24-hydroperoxy-24-vinylcholesterol (15), with IC(50) values of 7.8 +/- 1.2 and 3.2 +/- 1.2 microM, respectively. The latter compound was isolated from a plant source for the first time. A comparative study on the antitrypanosomal activity of the isolated triterpenoids and sterols and some related compounds has indicated that the presence of an oxygenated function at C-28 or an oxygenated side chain at C-17 seems to be important for the antitrypanosomal activity of triterpenoids and sterols, respectively.

[Study on chemical constituents from Desmodium styracifolium]

OBJECTIVE

To investigate the chemical constituents from Desmodium styracifolium (Osheck) Merr..

METHODS

Column chromatographic techniques were used for isolation and purification of chemical constituents of the plant and the structures were elucidated hy spectroscopic analysis.

RESULTS

Nine compounds were isolated and identified as: 6-C-glycopyranosyl-8-C-arabinosyl apigenin (I),6-C-glycopyranosyl luteolin (2), 6-C-glyeopyranosyl-8-C-xyvloeyl apigenin (3), 6-C-glycopranosyl-8-C-glyeopyrnosyl, apigenin (4), apigenin(5), luteolin (6), stigmasterol-3-O-beta-D-glucopyranoside (7), beta-dauosterol (8) and B-sitosterol (9).

CONCLUSION

Com-pounds 4-8 are isolated from this plant for the first time.

[Analysis of lipid compounds of high-yielded rhizoma pinelliae growing in the west of Hubei province by gas chromatography-mass spectrometry]

OBJECTIVE

To investigate lipid components of high-yielded Pinellia ternata rhizomes growing in the west of Hubei province.

METHODS

To determine the lipid chemical components in Pinellia ternata rhizomes with GC-MS method and NIST atlas.

RESULTS

Ten components have been found: palmitic acid (I), 9,12-octadecadienoic acid (II), pyrrolidine,1-(1-oxo-7,10-hexadecadienyl) (III), alpha-monpalmitin (IV), 1,3,12-nonadecatriene (V), campesterol (VI), stigmasta-5,22-dien-3-ol (VII), beta-sitosterol (VIII), stigmasta-5,24-dien-3-ol (IX), cycloartenol (X).

CONCLUSION

The relative contents of five kinds of phytosterol: campesterol 28.96%, stigmasta-5,22-dien-3-ol 9.24%, beta-sitosterol 50.77%, stigmasta-5,24-dien-3-ol 4.74%, cycloartenol 6.25%. Component II, III, V, VI, IX are the first time reported in Pinellia ternata.

[Study on the terpenoids of chemical constituents of Buddleja purdomii (II)]

OBJECTIVE

To study the chemical constituents of Buddleja purdomii W. W. Smith.

METHODS

The constituents were isolated and purified by various chromatographic methods and structurally identified by spectral analysis.

RESULTS

7 compounds were obtained as luteolin (I), luteolin-7-O-beta-D-glucoside (II), trans-caffeic acid (III), cis-caffeic acid (IV), beta-stiosterol (V), stigmasterol (VI), nonacosane (VII).

CONCLUSION

All these compounds are obtained from this plant for the first time.

[Chemical constituents from root of Psammosilene tunicoides]

OBJECTIVE

To investigate the chemical constituents from the root of Psammosilene tunicoides.

METHOD

Column chromatographic methods were used to isolate the chemical constituents of this plant. ESI-MS, EI-MS and NMR methods were employed for their structural elucidation.

RESULT

Seven compounds were isolated and identified as goyaprosaponin (1), Soya-cerebroside (2), tectoridin (3), alpha-spinasterol (4), tetracosanoic acid (5), beta-sitosterol (6), daucosterol (7) respectively.

CONCLUSION

Compounds 2-7 were obtained from genus Psammosilene for the first time.

[Studies on chemical constituents in fruits of Eucalyptus globulus]

OBJECTIVE

To study the chemical constituents in the fruits of Eucalyptus globulus Labill.

METHOD

The chemical constituents were isolated by various column chromatographic methods and structurally elucidated by IR, NMR and MS evidences.

RESULT

Fifteen compounds were obtained and identified as beta-sitosterol (1), betulinic acid (2), stigmasterol (3), euscaphic acid (4), 2a-Hydroxybetulinic acid (5), macrocarpal B (6), macrocarpal A (7), oleanolic acid (8), 3,4,3'-O-trimethylellagic acid (9), 3-O-methylellagic acid 4'-O-(2"-O-acetyl )-alpha-L-rhamnopyranoside (10), camaldulenside (cypellocarpin C, 11), 3-O-methylellagic acid 4'-O-alpha-L-rhamnopyranoside (12), 3-O-methylellagic acid (13), ellagic acid (14), and gallic acid (15).

CONCLUSION

Compounds 4 and 5 from genera Eucalyptus, 1, 3 and 11 from plant E. globulus, and 6, 7, 9 and 15 from the fruits of E. globulus were isolated for the first time.

[A isolation and identification of an antioxidant from Monochoria vaginalis]

With solvent extraction, a total of four fractions were separated from 75% alcohol extract of Monochoria vaginalis, and their antioxidative activities were measured by iodine method. The results showed that among the fractions, n-butanol fraction exhibited the highest antioxidative activity, which was not only significantly higher than CK (water), but also equivalent to the natural antioxidant tea polyphenols and synthetic antioxidant butylated hydroxyl toluene (BHT). A compound was isolated from the n-butanol fraction by using column chromatography, and identified as stigmasterol 3-O-beta-D-glucopyranoside. Its antioxidative activity estimated by the determination of the percentage of scavenged free radicals indicated that this compound exhibited a higher activity than BHT in scavenging free radicals.

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 alpha-spinasterol, beta-sitosterol, nonacosan-10-ol, 24-methylene cycloartanol, lupenone, 3-O-palmitoyl-beta-sitosterol, 3-O-beta-d-glucose-beta-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 (1)H 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.

Sterols isolated from Tubifex tubifex

Four 3beta-hydroxysterols isolated from chloroform extract from Tubifex tubifex were shown to have the structures stigmast-23-en-3-ol, stigmast-7,14-dien-3-ol, 22-dehydrocholesterol, and 24 methylenecholesterol based on spectroscopic methods. Stigmasterol and beta-sitosterol were also investigated on the basis of mass spectral analyses and compared with known compounds.

Separation of free sterols by high temperature liquid chromatography

Increasing the column temperature accelerates markedly elution in HPLC. The separation of five free sterols was studied on three packing materials that can withstand high temperatures. These stationary phases included graphitic carbon, a polymeric C18 silica, and a zirconia-based adsorbent. Measurements of retention data were made at up to 150 degrees C with mobile phases of different compositions. Since the columns tested afford different retention mechanisms, a variety of elution patterns were observed, with some being more advantageous than others for certain sterol separations. Effects observed include some selectivity improvements and some elution order reversals. The separation of free sterols in selected fruit juices is also presented. Albeit at the expense of a longer analysis time, the graphitic carbon column produced the best separation of the sterols in this study.

Potent tyrosinase inhibitors from Trifolium balansae

Trifolium balansae (Leguminosae) yielded a phytylester, phytyl-1-hexanoate, three steroids, stigmast-5-ene-3 beta,26-diol, stigmast-5-ene-3-ol and campesterol, and an alcohol, pentacosanol which were reported for the first time from T.balansae. The structures of the isolates were determined by 1D and 2D NMR techniques and MS spectroscopy. Compounds 1-5 were tested for their enzyme tyrosinase activity. While compounds 1 and 5 did not show any inhibition against the enzyme tyrosinase, compounds 2, 3, and 4 exhibited potent inhibition against tyrosinase. Highly potent (IC50 = 2.39 microM) inhibition was found by compound 2, when compared with the standard tyrosinase inhibitors Kojic acid and L-mimosine.

Ketosteroids and hydroxyketosteroids, minor metabolites of sugarcane wax

Besides beta-sitosterol and stigmasterol, the major steroids of sugarcane, the following minor steroids have been isolated and identified from sugarcane wax: 3,6-diketosteroids, Delta(4)-3-keto steroids, and Delta(4)-6-hydroxy-3-keto steroids. Their structures were established by spectroscopic techniques and chemical correlations.

[Chemical constituents of mangrove plant Barringtonia racemosa]

OBJECTIVE

To study the chemical constituents of mangrove plant Barringtonia racemosa.

METHODS

Chemical constituents from the ethyl acetate extract of the stem bark of this plant were isolated by silica, Sephadex LH-20 column chromatography and identified by NMR analysis.

RESULTS

Five compounds were isolated and identified. They are 3,3'-dimethoxy ellagic acid (1), dihydromyticetin (2), gallic acid (3), bartogenic acid (4) and stigmasterol (5).

CONCLUSION

Compounds 1-3 were isolated from this plant for the first time.

[Study on the chemical constituents of Curcuma phaeocaulis]

OBJECTIVE

To investigate the chemical constituents of the rhizome of Curcuma phaeocaulis Val.

METHODS

The constituents were isolated by column chromatography and their structures elucidated by chemical properties and spectroscopic analysis.

RESULTS

Five compunds have been isolated and identified as isocurcumenol, curcumenol, alpha-spinasterol, curcumin, and beta-sitosterin-3-O-glucoside.

CONCLUSION

alpha-Spinasterol and alpha-stediol were isolated from Curcuma phaeocaulis Val. for the first time.

Afzeliixanthones A and B, two new prenylated xanthones from Garcinia afzelii ENGL. (Guttiferae)

Two new prenylated xanthones, afzeliixanthones A (1) and B (2), together with three known xanthones (3-5) and two phytosterols, beta-sitosterol and stigmasterol, were isolated from the CH2Cl2/MeOH (1:1) extract of the stem bark of Garcinia afzelii ENGL. collected in the South West Province of Cameroon. Structures were mainly established using one and two-dimensional NMR and mass spectroscopies. The antioxidant activities of the crude extracts as well as the new compounds (1) and (2) were evaluated.

[Studies on chemical constituents in roots of Heracleum rapula]

OBJECTIVE

To study the chemical constituents in roots of Heracleum rapula.

METHOD

The constituents were isolated by column chromatography on silica gel and ODS, and identified by spectroscopic methods.

RESULT

Eight compounds, xanthotoxol (I), 8-geranyloxypsoralen (II), (+)-marmesin (III), beta-sitosterol (IV), stigmasterol (V), oleanolic acid (VI), ferulic (VII), scopoletin (VIII) were isolated and identified.

CONCLUSION

Compounds IV, V, VI, VII, VIII were isolated from this plant for the first time.