Column Liquid Chromatography/Electrospray Ionization-Time of Flight-Mass Spectrometry and Ultraperformance Column Liquid Chromatography/Mass Spectrometry Methods for the Determination of Ginkgolides and Bilobalide in the Leaves of Ginkgo biloba and Dietary Supplements

Column liquid chromatography/electrospray ionization-time of flight-mass spectrometry (LC/ESI-TOF-MS) and ultraperformance column liquid chromatographic/MS (UPLC/MS) methods were developed for the determination of 5 terpenelactones in the leaves of Ginkgo biloba. The separation was performed using a C18 column and a mobile phase composed of water and acetonitrile. The limit of detection (LOD) values for ginkgolide J, ginkgolide C, ginkgolide B, and ginkgolide A were found to be in the range of 110 ng/mL by both methods, and the bilobalide LOD was 200 ng/mL by LC/ESI-TOF and 35 ng/mL by UPLC/MS. Using the optimized method, 4 commercial products were analyzed. Concentrations of total marker compounds in these products were in the 0.0915.4 range, with individual ginkgo terpenelactones being detected at ppb levels. LC/MS with ESI is described for the identification and quantification of ginkgolides and bilobalide in plant samples and dietary supplements that claim to contain G. biloba. These methods involve the use of the M NH4<sup/> and M H<sup/> ions of sesquiterpenoids in the positive ion mode with extractive ion monitoring by LC/ESI-TOF-MS and selected ion monitoring by UPLC/MS. The LC method coupled with MS analysis yielded well-separated peaks which resulted in a clear identification of the compounds.

Quantitative Determination of Flavonoids by Column High-Performance Liquid Chromatography with Mass Spectrometry and Ultraviolet Absorption Detection in Artemisia afra and Comparative Studies with Various Species of Artemisia Plants

A simple and specific analytical method for the quantitative determination of flavonoids from the aerial parts of the Artemisia afra plant samples was developed. By column high-performance liquid chromatography (HPLC) with UV absorption and mass spectrometry (MS) detection, separation was achieved on a reversed-phase octadecylsilyl (C18) column with water, methanol, and acetonitrile, all containing 0.1 acetic acid, as the mobile phase. These methods were used to analyze various species of Artemisia plant samples. The wavelength used for quantification of flavonoids with the diode array detector was 335 nm. The limits of detection (LOD) by HPLC/MS were found to be 7.5, 7.5, 10, 2.0, and 2.0 ng/mL; and by LC-UV the LODs were 500, 500, 500, 300, and 300 ng/mL for apigenin, chrysoeriol, tamarixetin, acacetin, and genkwanin, respectively. The HPLC/MS method was found to be 50150 times more sensitive than the HPLC-UV method. HPLC/MS coupled with an electrospray ionization interface is described for the identification and quantification of flavonoids in various plant samples. This method involved the use of the MH<sup/> ions of the compounds at mass-to-charge ratio of 1.0606, 301.0712, 317.0661, 285.0763, and 285.0763 (calculated mass), respectively, in the positive ion mode with extractive ion monitoring.

HPLC Method for Chemical Fingerprinting of Guggul (Commiphora wightii)--Quantification of E- and Z-Guggulsterones and Detection of Possible Adulterants

A reversed-phase high-performance liquid chromatography method was developed for the chemical fingerprinting of Commiphora wightii gum resin (guggul). This method was also used for the quantification of E- and Z-guggulsterones in different C. wightii gum resin samples. The analysis was conducted on a high-performance liquid chromatography system with a reversed-phase column using a gradient elution comprised of water and acetonitrile with 0.1% acetic acid, and a run time of 50 min at 38 °C. The calibration curve of E- and Z-guggulsterones showed good linearity with a standard correlation coefficient >0.999, which is within the established range (0.5-250 µg/mL). Twelve marker compounds were selected and successfully analyzed by this method in 22 C. wightii gum resin samples along with 9 gum resin samples of possible adulterant species.

Identification and Characterization of Indole and Oxindole Alkaloids from Leaves of Mitragyna speciosa Korth Using Liquid Chromatography-Accurate QToF Mass Spectrometry

Alkaloids have been reported to be the major physiologically active constituents in Mitragyna. An analytical method was developed to provide an alternative, fast method for characterization of alkaloids from various M. speciosa samples. The separation was achieved using an RP octylsilyl (C8) column, MS detection, and a water-acetonitrile with formic acid gradient as the mobile phase. Ultra-HPLC/quadrupole time-of-flight MS analysis and characterization were performed on 12 corynanthe-type indole/oxindole alkaloids obtained from the leaves of M. speciosa Korth. The indoles and oxindoles had an open E ring with or without substitution occurring at the C9 position. The full single mass spectrum of alkaloids showed a strong signal for the protonated molecule [M+H]+. The product ion spectrum of mitragynine type of alkaloids showed strong response at m/z=174.0901 suggestive of an ion containing an odd number of nitrogen atoms corresponding to formula C11H12NO, which is characteristic of indole alkaloids. A multivariate statistical analysis technique, principal component analysis, was used to show discrimination between the M. speciosa samples. The results indicated that the analytical method is suitable for QC testing of various Mitragyna commercial samples and can be used to evaluate market products purported to contain M. speciosa.

Authentication of true cinnamon (Cinnamon verum) utilising direct analysis in real time (DART)-QToF-MS

The use of cinnamon as a spice and flavouring agent is widespread throughout the world. Many different species of plants are commonly referred to as 'cinnamon'. 'True cinnamon' refers to the dried inner bark of Cinnamomum verum J. S. Presl (syn. C. zeylanicum) (Lauraceae). Other 'cinnamon' species, C. cassia (Nees & T. Nees) J. Presl (syn. C. aromaticum Nees) (Chinese cassia), C. loureiroi Nees (Saigon cassia), and C. burmannii (Nees & T. Nees) Blume (Indonesian cassia), commonly known as cassia, are also marketed as cinnamon. Since there is a prevalence of these various types of 'cinnamons' on the market, there is a need to develop a rapid technique that can readily differentiate between true cinnamon (C. verum) and other commonly marketed species. In the present study, coumarin and other marker compounds indicative of 'cinnamon' were analysed using DART-QToF-MS in various samples of cinnamon. This method involved the use of [M + H](+) ions in positive mode in addition to principal component analysis (PCA) using Mass Profiler Professional software to visualise several samples for quality and to discriminate 'true cinnamon' from other Cinnamomum species using the accurate mass capabilities of QToF-MS.

Octulosonic acid derivatives from Roman chamomile (Chamaemelum nobile) with activities against inflammation and metabolic disorder

Six new octulosonic acid derivatives (1-6) were isolated from the flower heads of Roman chamomile (Chamaemelum nobile). Their structures were elucidated by means of spectroscopic interpretation. The biological activity of the isolated compounds was evaluated toward multiple targets related to inflammation and metabolic disorder such as NAG-1, NF-κB, iNOS, ROS, PPARα, PPARγ, and LXR. Similar to the action of NSAIDs, all the six compounds (1-6) increased NAG-1 activity 2-3-fold. They also decreased cellular oxidative stress by inhibiting ROS generation. Compounds 3, 5, and 6 activated PPARγ 1.6-2.1-fold, while PPARα was activated 1.4-fold by compounds 5 and 6 only. None of the compounds showed significant activity against iNOS or NF-κB. This is the first report of biological activity of octulosonic acid derivatives toward multiple pathways related to inflammation and metabolic disorder. The reported anti-inflammatory, hypoglycemic, antiedemic, and antioxidant activities of Roman chamomile could be partly explained as due to the presence of these constituents.

Characterization of steroidal saponins from Dioscorea villosa and D. cayenensis using ultrahigh performance liquid chromatography/electrospray ionization quadrupole time-of-flight mass spectrometry

Yam (Dioscorea spp.) is an important edible tuber plant used for medicinal purposes to promote health and longevity in Chinese tradition. Steroidal saponins were reported to be the major physiologically active constituents in yams. In this current work, the structural characteristics of steroidal saponins in methanolic extracts from dried rhizomes of two Dioscorea species (D. villosa L. and D. cayenensis Lam.) and dietary supplements have been identified and analyzed using UHPLC/QTOF-MS in both negative and positive ion modes. The fragmentation patterns of reference standards were determined and the steroidal saponins in the extracts were identified or tentatively characterized from their retention times and mass spectra. The fragments produced by collision-induced dissociation (CID) revealed the characteristic cleavage of glycosidic bonds, and the fragmentation pattern provided structural information about the sugars. Twenty-one saponins, including four tentatively identified compounds, were detected in the crude extracts of two Dioscorea species. These saponins can be used to distinguish D. villosa from D. cayenensis. For example, asperin and gracillin are found only in D. cayenensis, and dioscoreavilloside A and B and parvifloside are only found in D. villosa. This can be used to determine the presence or absence of D. villosa in commercial products, which may help determine the spiking of plant material, and/or prevent the use of potentially mislabeled or misidentified "Dioscorea" material. The analytical method also provided an alternative, fast method for quality control of Dioscorea species in dietary supplements. Principal component analysis showed that Dioscorea species and commercial products were easily distinguished. From this a partial least squares model was constructed to determine what species are in different products.

Chemical fingerprint analysis and quantitative determination of steroidal compounds from Dioscorea villosa, Dioscorea species and dietary supplements using UHPLC-ELSD

Ultra high-performance liquid chromatography (UHPLC) with evaporative light scattering detection was used for the quantification of steroidal saponins and diosgenin from the rhizomes or tubers of various Dioscorea species and dietary supplements that were purported to contain Dioscorea. The analysis was performed on an Acquity UPLC™ system with an UPLC™ BEH Shield RP18 column using a gradient elution with water and acetonitrile. Owing to their low UV absorption, the steroidal saponins were observed by evaporative light scattering detection. The 12 compounds could be separated within 15 min using the developed UHPLC method with detection limits of 5-12 µg/mL with 2 μL injection volume. The analytical method was validated for linearity, repeatability, accuracy, limits of detection and limits of quantification. The relative standard deviations for intra- and inter-day experiments were <3.1%, and the recovery efficiency was 97-101%. The total content of standard compounds was found to be in the ranges 0.01-14.5% and 0.9-28.6 mg daily intake for dry plant materials and solid commercial preparations, respectively. UHPLC-mass spectrometry with a quadrupole mass analyzer and ESI source was used only for confirmation of the identity of the various saponins. The developed method is simple, rapid and especially suitable for quality control analysis of commercial products.

The effects of dietary treatment with S-equol on learning and memory processes in middle-aged ovariectomized rats

The use of over-the-counter botanical estrogens containing isolated soy isoflavones, including genistein and daidzein, has become a popular alternative to traditional hormone therapies. Menopausal women use these products as an aide in healthy aging, including for the maintenance of cognitive function. The safety and efficacy of many of these commercial preparations remain unknown. Previous research in our lab found that treatment of ovariectomized (OVX) female Long-Evans rats with genistein impaired working memory in an operant delayed spatial alternation (DSA) task and response learning in a plus-maze, but enhanced place learning assessed in the plus-maze. The present study further examined the effects of isolated isoflavones on working memory and place learning by treating middle-aged (12-13 month old) OVX female Long-Evans rats with S-equol, the exclusive enantiomer produced by metabolism of daidzein in the mammalian gut. S-equol binds selectively to ERβ with an affinity similar to that of genistein but has low transcriptional potency. For DSA testing, S-equol at 1.94, 0.97 mg, or 0mg (sucrose control) was orally administered to animals daily, 30 min before behavioral testing, and again both 4 and 8 hours after the first treatment. Rats were tested on the DSA task following the first, morning dose. For place learning, rats received 0.97 mg S-equol every 4 hours during the light portion of the cycle beginning 48 hours prior to behavioral testing (total exposure 8.7 mg S-equol). S-equol treatment was largely without effect on the DSA and place learning tasks. This is the first study to test the behavioral effects of isolated S-equol in OVX rodents, and shows that, unlike genistein or estradiol, repeated daily treatment with this isoflavone metabolite does not alter learning and memory processes in middle-aged OVX rats.

Characterization of in vitro ADME properties of diosgenin and dioscin from Dioscorea villosa

Dioscorea villosa (wild yam) is native to North America and has been widely used as a natural alternative for estrogen replacement therapy to improve women's health as well as to treat inflammation, muscle spasm, and asthma. Diosgenin and dioscin (glycoside form of diosgenin) are reported to be the pharmacologically active compounds. Despite the reports of significant pharmacological properties of dioscin and diosgenin in conditions related to inflammation, cancer, diabetes, and gastrointestinal ailments, no reports are available on ADME properties of these compounds. This study was carried out to determine ADME properties of diosgenin and dioscin and their effects on major drug metabolizing enzymes (CYP 3A4, 2D6, 2C9, and 1A2). The stability was determined in simulated gastric and intestinal fluids (SGF, pH 1.2 and SIF, pH 6.8), and intestinal transport was evaluated in Caco-2 model. Phase I and phase II metabolic stability was determined in human liver microsomes and S9 fractions, respectively. Quantitative analysis of dioscin and diosgenin was performed by UPLC-MS system. Dioscin degraded up to 28.3 % in SGF and 12.4 % in SIF, which could be accounted for by its conversion to diosgenin (24.2 %. in SGF and 2.4 % in SIF). The depletion of diosgenin in SGF and SIF was < 10 %. Diosgenin was stable in HLM but disappeared in S9 fraction with a half-life of 11.3 min. In contrast, dioscin was stable in both HLM and S9 fractions. Dioscin showed higher permeability across Caco-2 monolayer with no significant efflux, while diosgenin was subjected to efflux mediated by P-glycoprotein. Diosgenin and dioscin inhibited CYP3A4 with IC50 values of 17 and 33 µM, respectively, while other CYP enzymes were not affected. In conclusion, dioscin showed better intestinal permeability. Conversion of dioscin to diosgenin was observed in both gastric and intestinal fluids. No phase I metabolism was detected for both compounds. The disappearance of diosgenin in S9 fraction indicated phase II metabolism.

Mechanisms enforcing the estrogen receptor β selectivity of botanical estrogens

Because little is known about the actions of botanical estrogens (BEs), widely consumed by menopausal women, we investigated the mechanistic and cellular activities of some major BEs. We examined the interactions of genistein, daidzein, equol, and liquiritigenin with estrogen receptors ERα and ERβ, with key coregulators (SRC3 and RIP140) and chromatin binding sites, and the regulation of gene expression and proliferation in MCF-7 breast cancer cells containing ERα and/or ERβ. Unlike the endogenous estrogen, estradiol (E2), BEs preferentially bind to ERβ, but their ERβ-potency selectivity in gene stimulation (340- to 830-fold vs. E2) is enhanced at several levels (coregulator recruitment, chromatin binding); nevertheless, at high (0.1 or 1 μM) concentrations, BEs also fully activate ERα. Because ERα drives breast cancer cell proliferation and ERβ dampens this, the relative levels of these two ERs in target cells and the BE dose greatly affect gene expression and proliferative response and will be crucial determinants of the potential benefits vs. risks of BEs. Our findings reveal key and novel mechanistic differences in the estrogenic activities of BEs vs. E2, with BEs displaying patterns of activity distinctly different from those seen with E2 and provide valuable information to inform future studies.

Cholestane steroid glycosides from the rhizomes of Dioscorea villosa (wild yam)

Phytochemical investigation of the MeOH extract of Dioscorea villosa rhizomes resulted in the isolation of two new bidesmosidic cholestane steroid glycosides, dioscoreavillosides A and B (1 and 2). In addition, the extract yielded 12 previously known furostan and spirostan steroid glycosides (3-14), along with diosgenin (15). Compounds 3-7, 9, 14, and 15 were isolated for the first time from D. villosa. The structures of the isolated compounds were determined using spectroscopic and chemical methods including 1D and 2D NMR. The antimicrobial action of most of these compounds was tested against five fungal and five bacterial strains.

7-Oxodioscin, a New Spirostan Steroid Glycoside from the Rhizomes of Dioscorea nipponica

Nine glycosides of spirostan (1–7) and furostan (8 and 9) type steroids including a new compound, 7-oxodioscin (1), were isolated from the rhizomes of Dioscorea nipponica. The structure of 1 was established as (25 R)-3β -O-[(α-L-rhamnopyranosyl-(1→4)- O-[α-L-rhamnopyranosyl-(1→2)]-β-D-glucopyranosyl)oxy]spirost-5-en-7-one by extensive spectroscopic techniques including HRESI-TOFMS, 1D and 2D NMR, and chemical methods. Known compounds were elucidated as dioseptemloside G (2), (25 R)-dracaenoside G (3), orbiculatoside B (4), dioscin (5), progenin III (6), gracillin (7), (3β,22α,25 R)–26-(β-D-glucopyranosyloxy)-22-methoxyfurost-5-en-3-yl O-[α-L-rhamnopyranosyl-(1→4)]-β-D-glucopyranoside (8), and methylprotodioscin (9).

Two spirostan steroid glycoside fatty esters from Dioscorea cayenensis

Two new fatty acid-spirostan steroid glycoside esters, progenin III palmitate (1) and progenin III linoleate (2), were isolated from the MeOH extract of Dioscorea cayenensis rhizomes. The extract also yielded seven previously known spirostan and furostan steroid glycosides (3-9). The structures of the new compounds were established as (25R)-spirost-5-en-3beta-yl O-alpha-L-rhamnopyranosyl-(1 --> 2)-[6-O-palmitoyl]-O-beta-D-glucopyranoside (1) and (25R)-spirost-5-en-3beta-yl O-alpha-L-rhamnopyranosyl-(1 --> 2)-[6-O-linoleoyl]-O-beta-D-glucopyranoside (2) by chemical and spectroscopic methods, including 1D and 2D NMR. The known compounds were identified as progenin III (3), dioscin (4), deltonin (5), asperin (6), gracillin (7), protodioscin (8)], and methyl protodioscin (9).

7-Oxodioscin, a new spirostan steroid glycoside from the rhizomes of Dioscorea nipponica

Nine glycosides of spirostan (1-7) and furostan (8 and 9) type steroids including a new compound, 7-oxodioscin (1), were isolated from the rhizomes of Dioscorea nipponica. The structure of 1 was established as (25R)-3beta-O-[(alpha-L-rhamnopyranosyl-(1 --> 4)-O-[alpha-L-rhamnopyranosyl-(1 --> 2)]-beta-D-glucopyranosyl)oxy]spirost-5-en-7-one by extensive spectroscopic techniques including HRESI-TOFMS, 1D and 2D NMR, and chemical methods. Known compounds were elucidated as dioseptemloside G (2), (25R)-dracaenoside G (3), orbiculatoside B (4), dioscin (5), progenin III (6), gracillin (7), (3beta3,22alpha,25R)-26-(beta-D-glucopyranosyloxy)-22-methoxyfurost-5-en-3-yl O-[alpha-L-rhamnopyranosyl-(1 --4)]-beta-D-glucopyranoside (8), and methylprotodioscin (9).

Two Spirostan Steroid Glycoside Fatty Esters from Dioscorea cayenensis

Two new fatty acid-spirostan steroid glycoside esters, progenin III palmitate (1) and progenin III linoleate (2), were isolated from the MeOH extract of Dioscorea cayenensis rhizomes. The extract also yielded seven previously known spirostan and furostan steroid glycosides (3-9). The structures of the new compounds were established as (25 R)-spirost-5-en-3β-yl O-α-L-rhamnopyranosyl-(1→2)-[6- O-palmitoyl]- O-β-D-glucopyranoside (1) and (25 R)-spirost-5-en-3β-yl O-α-L-rhamnopyranosyl-(1→2)-[6- O-linoleoyl]- O-β-D-glucopyranoside (2) by chemical and spectroscopic methods, including 1D and 2D NMR. The known compounds were identified as progenin III (3), dioscin (4), deltonin (5), asperin (6), gracillin (7), protodioscin (8)], and methyl protodioscin (9).

Simultaneous determination of alkaloids and flavonoids from aerial parts of Passiflora species and dietary supplements using UPLC-UV-MS and HPTLC

A rapid UPLC method was developed for the simultaneous analysis of five indole alkaloids (harmalol, harmol, harmane, harmaline and harmine) and four flavonoids (orientin, isoorientin, vitexin, and isovitexin) from the aerial parts of Passiflora incarnata L. (Passifloraceae), other species of Passiflora (P. violacea Veil., P. edulis Sims., P. suberosa L., P. morifolia Mast. and P. quadrangularis L.), Peganum harmala, and dietary supplements that claim to contain Passiflora. The separation was achieved within eight minutes by using C-18 column, a water/acetonitrile mobile phase, both containing formic acid, using a gradient system and a temperature of 35 degrees C. The method was validated for linearity, repeatability, limits of detection (LOD), and limits of quantification (LOQ). The wavelength used for quantification with the diode array detector was 340 nm for flavonoids and alkaloids. The developed method is simple, economic, fast and especially suitable for quality control analysis of flavonoids and alkaloids in plant samples and dietary supplements. The compounds (including isoschaftoside and schaftoside) in plant samples and commercial products of Passiflora were identified and confirmed by UPLC-MS. A HPTLC method was also developed for the chemical fingerprint analysis of Passiflora samples.

Simultaneous Determination of Alkaloids and Flavonoids from Aerial Parts of Passiflora Species and Dietary Supplements using UPLC-UV-MS and HPTLC

A rapid UPLC method was developed for the simultaneous analysis of five indole alkaloids (harmalol, harmol, harmane, harmaline and harmine) and four flavonoids (orientin, isoorientin, vitexin, and isovitexin) from the aerial parts of Passiflora incarnata L. (Passifloraceae), other species of Passiflora (P. violacea Vell., P. edulis Sims., P. suberosa L., P. morifolia Mast. and P. quadrangularis L.), Peganum harmala, and dietary supplements that claim to contain Passiflora. The separation was achieved within eight minutes by using C-18 column, a water/acetonitrile mobile phase, both containing formic acid, using a gradient system and a temperature of 35°C. The method was validated for linearity, repeatability, limits of detection (LOD), and limits of quantification (LOQ). The wavelength used for quantification with the diode array detector was 340 nm for flavonoids and alkaloids. The developed method is simple, economic, fast and especially suitable for quality control analysis of flavonoids and alkaloids in plant samples and dietary supplements. The compounds (including isoschaftoside and schaftoside) in plant samples and commercial products of Passiflora were identified and confirmed by UPLC-MS. A HPTLC method was also developed for the chemical fingerprint analysis of Passiflora samples.

Simultaneous determination of sesquiterpenes and pyrrolizidine alkaloids from the rhizomes of Petasites hybridus (L.) G.M. et Sch. and dietary supplements using UPLC-UV and HPLC-TOF-MS methods

UPLC-UV and HPLC-TOF-MS methods have been developed for the analysis of major sesquiterpenes and pyrrolizidine alkaloids from rhizomes of Petasites hybridus (L.) G.M. et Sch. (Family, Asteracea) and dietary supplements claiming to contain P. hybridus. The best results were obtained with Acquity UPLC™ HSS T3 (100 mm × 2.1 mm, I.D., 1.8 μm) column system using a gradient elution with a mobile phase consisting of ammonium formate (50mM) and acetonitrile (0.05% formic acid) at a constant flow rate of 0.25 mL/min via UPLC-UV. The newly developed method was validated according to the ICH guidelines with respect to specificity, linearity, accuracy and precision. The limits of detection were found to be 5 μg/mL and 0.1 μg/mL for pyrrolizidine alkaloids and sesquiterpenes, respectively by UPLC-UV and 0.001 and 0.01 μg/mL, respectively using HPLC-TOF-MS. The methods were successfully used to analyze different P. hybridus market products, as well as to distinguish between two other Petasites species. The total content of petasins was found to be in the range of 0.02-11.6 mg/dosage form for 15 dietary supplements and no petasins were detected in an additional six dietary supplements. Additionally, pyrrolizidine alkaloids, which are considered to be toxic for the liver, were detected in seven dietary supplements. The amount of petasin in seven dietary supplements was found to be within limits of label claim and no pyrrolizidine alkaloids were detected. HPLC-mass spectrometry coupled with electrospray ionization (ESI) interface method is described for the identification and confirmation of sesquiterpenes and pyrrolizidine alkaloids from plant extracts and dietary supplements that claim to contain P. hybridus as well as different species of Petasites.

Quantitative determination of triperpene saponins and alkenated-phenolics from Labisia pumila using an LC-UV/ELSD method and confirmation by LC-ESI-TOF

This study describes the first analytical method for the determination of four triterpene saponins (ardisicrenoside B, ardisiacrispin A, 3- O- α- L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl-(1 → 4)-α-L-arabinopynanosyl cyclamiretin A and ardisimamilloside H) and three alkenated-phenolics (irisresorcinol, belamcandol B, and demethylbelamcandaquinone B) from the leaves, leaves/stems, and roots of LABISIA PUMILA using an HPLC-UV-ELSD method. The separation was achieved using a reversed-phase (C-18) column, PDA and ELS detection, and a water/acetonitrile gradient as the mobile phase. The major triterpenoid (ardisiacrispin A) and irisresorcinol compounds were detected at a concentration as low as 10.0 and 0.2 µg/mL, respectively. Analysis of various samples showed considerable variation of 0.11-2.46 % for the major triterpenoid compound, ardisiacrispin A. LC-mass spectrometry method coupled with electrospray ionization (ESI) is described for the identification of compounds in plant samples. This method involved the use of the [M + Na]+ and [M + NH₄]+ ions for compounds 1-4 in the positive ion mode with extractive ion chromatogram (EIC).

Quantitative determination of 10 phenylpropanoid and lignan compounds in Lancea tibetica by high-performance liquid chromatography with UV detection

An HPLC method was developed for simultaneous determination of one phenylpropanoid glycoside, verbascoside (1), and nine lignans, including lantibeside (2), phillyrin (3), lantibeside B (4), lantibeside C (5), tibeticoside A (6), styraxjaponoside C (7), sylvatesmin (8), (+)-piperitol (9), and horsfieldin (10), from the Tibetan medicinal plant Lancea tibetica Hook. F. et Thoms. The analysis was performed within 45 min. The extraction method was optimized with different solvent systems. The HPLC method was validated for linearity, repeatability, accuracy, limits of detection, and limits of quantification. The limits of detection and limits of quantification of 10 analytes were found to be less than 0.1 and 0.5 µg/mL, respectively. The RSD for intra- and inter-day analyses was less than 4.2 %, and the recovery efficiency was 90-105 %. The method was used to analyze different populations of L. tibetica collected in China. HPLC profiles showed that the concentrations of analytes were different in samples collected from different areas of China. Verbascoside was the dominant component in three out of five plant samples; compounds 2, 3, 6, and 8 accounted for over 62 % yields in total lignan contents. The method is useful for identification, quality assurance, and quality control of L. tibetica and its related products.

Analytical methods for determination of magnoflorine and saponins from roots of Caulophyllum thalictroides (L.) Michx. using UPLC, HPLC and HPTLC

Analytical methods including HPLC, UPLC and HPTLC are presented for the determination of major alkaloid and triterpene saponins from the roots of Caulophyllum thalictroides (L.) Michx. (blue cohosh) and dietary supplements claiming to contain blue cohosh. A separation by LC was achieved using a reversed phase column, PDA with ELS detection, and ammonium acetate/acetonitrile gradient as the mobile phase. Owing to their low UV absorption, the triterpene saponins were detected by evaporative light scattering. The eight triterpene saponins (cauloside H, leonticin D, cauloside G, cauloside D, cauloside B, cauloside C, cauloside A and saponin PE) and the alkaloid magnoflorine could be separated within 35 min using HPLC method and within 8.0 min using UPLC method with detection limits of 10 μg/mL for saponins and 1 μg/mL for magnoflorine. The detection wavelength was 320 nm for magnoflorine and ELS detection was used for the eight saponins. The methods were also successfully applied to analyze different dietary supplements. For the products claiming to contain blue cohosh, there was a significant variability in the amounts of triterpene saponins detected. Calculations based on the analysis results for dietary supplements showed that maximum daily intake of alkaloid and saponins vary with the form (solids/liquids) and recommended doses according to the products label. Intakes varied from 0.57 to 15.8 mg/day for magnoflorine and from 5.97 to 302.4 mg/day for total saponins. LC-mass spectrometry coupled with electrospray ionization (ESI) method is described for the identification and confirmation of nine compounds in plant samples and dietary products. A HPTLC method was also developed for the fast chemical fingerprint analysis of C. thalictroides samples.

NMR fingerprinting for analysis of hoodia species and hoodia dietary products

Hoodia gordonii, a succulent plant growing in African arid regions, is used as a botanical dietary supplement for weight loss. The increasing concerns on the quality and safety of Hoodia products call for the needs of more science-based information, as well as objective and efficient tools for inspection. In the present study, NMR fingerprinting and multivariate analysis techniques were applied for the identification, discrimination, and quality analysis of Hoodia plant materials and commercial products. Four Hoodia species, namely H. gordonii (five authenticated samples), H. currorii (one authenticated sample), H. parviflora (three authenticated samples), and H. rushii (one authenticated sample), were investigated; the chemicals and characteristic spectral signals that made most contributions for their differentiations were revealed. With the aid of NMR fingerprint analysis, ten Hoodia products sold on the dietary supplement market were assessed for their chemical composition and quality. The study demonstrated that the NMR fingerprinting approach could be a promising and efficient tool for the authentication of botanicals.

Quantitative determination of multiple elements in botanicals and dietary supplements using ICP-MS

A method was developed and validated for the analysis of 21 elements in various botanicals and dietary supplements using ICP-MS. Closed-vessel microwave digestion of botanicals and dietary products was assisted by various different procedures. The samples digested with concentrated nitric and hydrochloric acid (8:2) revealed the best recoveries (91-106%) using the reference certified materials (SRM 3280, SRM 1566b). The method was validated for linearity, precision, accuracy, LOD, and LOQ. The LOD was found to be in the range from 0.005 to 1.09 ng/mL with the exception of potassium. Eleven botanicals and 21 dietary supplements were analyzed. Among the analyzed elements, K was the most abundant followed by Na, Mg, Al, Ca, Mn, and Fe, whereas V, Cr, Co, Ni, Se, Cd, Hg, and Pb were present in low concentrations in most of the samples. The results showed that the ICP-MS method is a simple, fast, and reliable for the multielement determination in dietary supplements and botanicals.

Two new triterpene glycosides from Centella asiatica

Phytochemical investigation of the leaves of Centella asiatica resulted in the isolation and characterization of eight triterpenes and/or saponins [which were characterized as 23- O-acetylmadecassoside (1), asiatic acid (2), madecassic acid (3), asiaticoside C (4), asiaticoside F (5), asiaticoside (6), madecassoside (7), and 23- O-acetylasiaticoside B (8)] together with sitosterol 3-O-beta-glucoside ( 9), stigmasterol 3- O- beta-glucoside (10), and querectin-3- O-beta-D-glucuronide (11). A new ursane-derived saponin (23- O-acetylmadecassoside) and a new oleanane-derived saponin (23- O-acetylasiaticoside B) were found as well. Structure elucidation was done by using spectroscopic techniques (HR-ESI-MS, 1D and 2D NMR), chemical methods, and comparative literature studies.

Flavonol glycosides from the south African medicinal plant Sutherlandia frutescens

Phytochemical investigation of the leaves of Sutherlandia frutescens led to the isolation of four new 3-hydroxy-3-methylglutaroyl-containing flavonol glycosides, sutherlandins A-D ( 1- 4). Their structures were elucidated by chemical and spectroscopic methods as quercetin 3- O- beta- D-xylopyranosyl(1 --> 2)-[6- O-(3-hydroxy-3-methylglutaroyl)]- beta- D-glucopyranoside ( 1), quercetin 3- O- beta- D-apiofuranosyl(1 --> 2)-[6- O-(3-hydroxy-3-methylglutaroyl)]- beta- D-glucopyranoside ( 2), kaempferol 3- O- beta- D-xylopyranosyl(1 --> 2)-[6- O-(3-hydroxy-3-methylglutaroyl)]- beta- D-glucopyranoside ( 3), and kaempferol 3- O- beta- D-apiofuranosyl(1 --> 2)-[6- O-(3-hydroxy-3-methylglutaroyl)]- beta- D-glucopyranoside ( 4).

Quantitative determination of flavonoids and cycloartanol glycosides from aerial parts of Sutherlandia frutescens (L.) R. BR. by using LC-UV/ELSD methods and confirmation by using LC-MS method

This paper describes the first analytical method for the determination of four flavonoids (sutherlandins A-D) and four cycloartanol glycosides (sutherlandiosides A-D) from the aerial parts of Sutherlandia frutescens (L.) R. Br. A separation by HPLC was achieved by using a reversed phase (RP-18) column, PDA with ELS detection, and a water/acetonitrile gradient as the mobile phase. The wavelength used for quantification of four flavonoids with the diode array detector was 260 nm. Owing to their low UV absorption, the cycloartanol glycosides were detected by evaporative light scattering. The method was validated for linearity, repeatability, limits of detection (LOD) and limits of quantification (LOQ). The limits of detection and limits of quantification of eight compounds were found to be in the range from 0.1 to 7.5 microg/mL and 0.5 to 25 microg/mL, respectively. The analysis of products showed considerable variation of 1.099-5.224 mg/average weight for the major compound, sutherlandioside B. The eight compounds in plant sample and products of S. frutescens were further confirmed by LC-ESI-TOF. This method involved the use of the [M+H](+) and [M+Na](+) ions in the positive ion mode with extractive ion monitoring (EIM).

Column liquid chromatography/electrospray ionization-time of flight-mass spectrometry and ultraperformance column liquid chromatography/mass spectrometry methods for the determination of ginkgolides and bilobalide in the leaves of Ginkgo biloba and dietary supplements

Column liquid chromatography/electrospray ionization-time of flight-mass spectrometry (LC/ESI-TOF-MS) and ultraperformance column liquid chromatographiclMS (UPLC/MS) methods were developed for the determination of 5 terpenelactones in the leaves of Ginkgo biloba. The separation was performed using a C18 column and a mobile phase composed of water and acetonitrile. The limit of detection (LOD) values for ginkgolide J, ginkgolide C, ginkgolide B, and ginkgolide A were found to be in the range of 1-10 ng/mL by both methods, and the bilobalide LOD was 200 ng/mL by LC/ESI-TOF and 35 ng/mL by UPLC/MS. Using the optimized method, 4 commercial products were analyzed. Concentrations of total marker compounds in these products were in the 0.09-15.4% range, with individual ginkgo terpenelactones being detected at ppb levels. LC/MS with ESI is described for the identification and quantification of ginkgolides and bilobalide in plant samples and dietary supplements that claim to contain G. biloba. These methods involve the use of the [M + NH4]+ and [M + H]+ ions of sesquiterpenoids in the positive ion mode with extractive ion monitoring by LC/ESI-TOF-MS and selected ion monitoring by UPLC/MS. The LC method coupled with MS analysis yielded well-separated peaks which resulted in a clear identification of the compounds.

Quantitative determination of flavonoids by column high-performance liquid chromatography with mass spectrometry and ultraviolet absorption detection in Artemisia afra and comparative studies with various species of Artemisia plants

A simple and specific analytical method for the quantitative determination of flavonoids from the aerial parts of the Artemisia afra plant samples was developed. By column high-performance liquid chromatography (HPLC) with UV absorption and mass spectrometry (MS) detection, separation was achieved on a reversed-phase octadecylsilyl (C18) column with water, methanol, and acetonitrile, all containing 0.1% acetic acid, as the mobile phase. These methods were used to analyze various species of Artemisia plant samples. The wavelength used for quantification of flavonoids with the diode array detector was 335 nm. The limits of detection (LOD) by HPLC/MS were found to be 7.5, 7.5, 10, 2.0, and 2.0 ng/mL; and by LC-UV the LODs were 500, 500, 500, 300, and 300 ng/mL for apigenin, chrysoeriol, tamarixetin, acacetin, and genkwanin, respectively. The HPLC/MS method was found to be 50-150 times more sensitive than the HPLC-UV method. HPLC/MS coupled with an electrospray ionization interface is described for the identification and quantification of flavonoids in various plant samples. This method involved the use of the [M+H]+ ions of the compounds at mass-to-charge ratio of 1.0606, 301.0712, 317.0661, 285.0763, and 285.0763 (calculated mass), respectively, in the positive ion mode with extractive ion monitoring.

Quantitative determination of triterpenoids and formononetin in rhizomes of black cohosh (Actaea racemosa) and dietary supplements by using UPLC-UV/ELS detection and identification by UPLC-MS

A UPLC-UV/ELSD method has been developed for analysis of major triterpenoids and formononetin in ACTAEA RACEMOSA L. (family Ranunculaceae) samples. The best results were obtained with an Acquity UPLC BEH C18 (100 mmx2.1 mm, i. d., 1 microm) column system using gradient elution with a mobile phase consisting of water and acetonitrile:methanol (7:3) at a constant flow rate of 0.3 mL/min. Owing to their low UV absorption, the triterpene saponins were detected by evaporative light scattering. Within 5.5 minutes, three main triterpenoid glycosides [cimiracemoside A, 23- EPI-26-deoxyactein, and actein] and an isoflavonoid, formononetin, could be separated, with detection limits of 5, 5, 10, and 0.01 microg/mL, respectively. The method was successfully used to analyze different Actaea racemosa market products as well as to distinguish between two other ACTAEA species. There was a significant variability in the amounts of the selected triterpene glycosides for the products containing black cohosh and rhizomes of black cohosh. The isoflavone formononetin was not detected in the samples analyzed. LC-MS coupled with the electrospray ionization (ESI) interface method is described for the identification of formononetin and triterpenoid glycosides in plant samples and dietary supplements that claim to contain black cohosh and different species of Actaea.

Cycloartane glycosides from Sutherlandia frutescens

Four new cycloartane glycosides, sutherlandiosides A-D (1-4), were isolated from the South African folk medicine Sutherlandia frutescens and their structures established by spectroscopic methods and X-ray crystallography as 1 S,3 R,24S,25-tetrahydroxy-7S,10S-epoxy-9,10- seco-9,19-cyclolanost-9(11)-ene 25-O-beta-D-glucopyranoside (1), 3R,7S,24S,25-tetrahydroxycycloartan-1-one 25-O-beta-D-glucopyranoside (2), 3R,24S,25-trihydroxycycloartane-1,11-dione 25-O-beta-D-glucopyranoside (3), and 7S,24S,25-trihydroxycycloart-2-en-1-one 25-O-beta-D-glucoyranoside (4). Compound 1 represents the first secocycloartane skeleton possessing a 7,10-oxygen bridge. Compounds 2- 4 are also the first examples of naturally occurring cycloartanes with a C-1 ketone functionality. Biosynthetic considerations and chemical evidence suggest that the presence of the C-1 ketone in 2 may facilitate the ring opening of the strained cyclopropane system.

New labdane diterpenes from Leonurus cardiaca

Leonurus cardiaca L. has been used in oriental medicine against several types of disorders. The ethanolic extract of leaves of Leonurus cardiaca yielded three new labdane-type diterpenes: 15- O-ethylleopersin C (1), 15- O-methylleopersin C (2), and 15- EPI- O-methylleopersin C (3). Their structures were determined using 1 D and 2 D NMR including 1H-1H COSY, HMQC, HMBC, and ROESY spectroscopic techniques. Compounds (1 - 3) were evaluated for in vitro antiplasmodial activity (D6 and W2 clones) and cytotoxicity (Vero cells).

Structural characterization and identification of ecdysteroids from Sida rhombifolia L. in positive electrospray ionization by tandem mass spectrometry

Seven ecdysteroids isolated from Sida rhombifolia L. were studied by electrospray ionization multi-stage tandem mass spectrometry (ESI-MS(n)) in the positive ion mode using an ion trap analyzer and high-performance liquid chromatography coupled with a diode-array detector (HPLC/DAD). The HPLC experiments were performed by means of a reversed-phase C(18) column and a binary mobile phase system consisting of water (containing 0.05% formic acid) and acetonitrile (containing 0.05% formic acid) under gradient elution conditions. According to mass spectral features and the substitution at C-2, C-20, C-24 and C-25, ecdysteroids in S. rhombifolia were classified into three sub-groups. Structural identification of these three sub-groups of ecdysteroids was established by LC/multi-stage ion trap mass spectrometry on-line or off-line. The fragmentation patterns of ecdysteroids yielded ions of successive loss of 1-4 water molecules. Furthermore, ions corresponding to the complete loss of the side chain at C-17 will help to identify the sub-groups of ecdysteroids in addition to containing a hydroxyl moiety at one of the above-mentioned positions. Based on the HPLC retention behavior, the diagnostic UV spectra and the molecular structural information provided by ESI-MS(n) spectra, a total of nine naturally occurring ecdysteroids were identified, of these two are identified for the first time in S. rhombifolia.

Identification and structural characterization of steroidal glycosides in Hoodia gordonii by ion-trap tandem mass spectrometry and liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry

Electrospray ion-trap tandem mass spectrometry (ESI-MS/MS) and high-performance liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry (LC/ESI-TOFMS) were used to identify and characterize eight C-21 steroidal glycosides in Hoodia gordonii. A generalized fragmentation pathway was proposed by comparing the spectra acquired for eight C-21 steroidal glycosides. The steroidal glycosides in Hoodia gordonii have been classified into two major core groups: hoodigenin A and calogenin. Using the ESI-TOF method, the major core peak ions generated by hoodigenin A glycosides are m/z 313 and 295 and by calogenin glycosides are m/z 479, 461, 299 and 281, respectively. In the MS/MS spectra, fragmentation reactions of the [M+Na](+) ion were recorded to provide structural information about the glycosyl and aglycone moieties. The data illustrates the ability of positive mode ESI for the identification of hoodigenin A and calogenin glycosides, including the nature of the hoodigenin A and calogenin core, the number of sugar residues and the type of saccharide moiety.

Antioxidant constituents of Nymphaea caerulea flowers

As part of an ongoing search for antioxidants from medicinal plants, 20 constituents were isolated from the Nymphaea caerulea flowers, including two 2S,3S,4S-trihydroxypentanoic acid (1), and myricetin 3-O-(3''-O-acetyl)-alpha-L-rhamnoside (2), along with the known myricetin 3-O-alpha-L-rhamnoside (3), myricetin 3-O-beta-D-glucoside (4), quercetin 3-O-(3''-O-acetyl)-alpha-L-rhamnoside (5), quercetin 3-O-alpha-L-rhamnoside (6), quercetin 3-O-beta-D-glucoside (7), kaempferol 3-O-(3''-O-acetyl)-alpha-L-rhamnoside (8), kaempferol 3-O-beta-D-glucoside (9), naringenin (10), (S)-naringenin 5-O-beta-D-glucoside (11), isosalipurposide (12), beta-sitosterol (13), beta-sitosterol palmitate (14), 24-methylenecholesterol palmitate (15), 4alpha-methyl-5alpha-ergosta-7,24(28)-diene-3beta,4beta-diol (16), ethyl gallate (17), gallic acid (18), p-coumaric acid (19), and 4-methoxybenzoic acid (20). The structures were determined by spectroscopic means. Compounds were tested for antioxidant activity and nine compounds 2-7, 11, 12 and 18 were considered active with IC(50) of 1.16, 4.1, 0.75, 1.7, 1.0, 0.34, 11.0, 1.7 and 0.95 microg/ml, respectively, while 1 was marginally active (IC(50)>31.25 microg/ml). The most promising activity was found in the EtOAc fraction (IC(50) 0.2 microg/ml). This can be attributed to the synergistic effect of the compounds present in it.

Capisterones A and B, which enhance fluconazole activity in Saccharomyces cerevisiae, from the marine green alga Penicillus capitatus

A whole-cell-based assay using Saccharomyces cerevisiae strains that overexpress Candida albicans CDR1 and MDR1 efflux pumps has been employed to screen natural product extracts for reversal of fluconazole resistance. The tropical green alga Penicillus capitatus was selected for bioassay-guided isolation, leading to the identification of capisterones A and B (1 and 2), which were recently isolated from this alga and shown to possess antifungal activity against the marine pathogen Lindra thallasiae. Current work has assigned their absolute configurations using electronic circular dichroism and determined their preferred conformations in solution based on detailed NOE analysis. Compounds 1 and 2 significantly enhanced fluconazole activity in S. cerevisiae, but did not show inherent antifungal activity when tested against several opportunistic pathogens or cytotoxicity to several human cancer and noncancerous cell lines (up to 35 microM). These compounds may have a potential for combination therapy of fungal infections caused by clinically relevant azole-resistant strains.

Antifungal Cyclopentenediones from Piper coruscans

Coruscanones A and B, two new antifungal cyclopentenedione derivatives, have been isolated from Piper coruscans and their structures elucidated by spectroscopic and chemical methods. Coruscanone A exhibits significant antifungal activity against Candida albicans and its azole-resistant strains and may serve as a template for a new class of antifungal agents.

Reversal of fluconazole resistance in multidrug efflux-resistant fungi by the Dysidea arenaria sponge sterol 9alpha,11alpha-epoxycholest-7-ene-3beta,5alpha,6alpha,19-tetrol 6-acetate

The sponge sterol 9alpha,11alpha-epoxycholest-7-ene-3beta,5alpha,6alpha,19-tetrol 6-acetate (ECTA) (1) is the first marine natural product to reverse fluconazole resistance mediated by a Candida albicans MDR efflux pump. The IC(50) of fluconazole is decreased from 300 to 8.5 microM (35-fold enhancement) when combined with 1(3.8 microM). A revised C-6 configuration of 1 is established.

Acetylenic acids inhibiting azole-resistant Candida albicans from Pentagonia gigantifolia

Antifungal bioassay-guided isolation of the ethanol extract of the roots of Pentagonia gigantifolia yielded 6-octadecynoic acid (1) and the new 6-nonadecynoic acid (2). Compounds 1 and 2 inhibited the growth of fluconazole-susceptible and -resistant Candida albicans strains. Their antifungal potencies were comparable to those of amphotericin B and fluconazole. Of particular significance is the low cytotoxicity and specific activity of 1 and 2 against C. albicans.

Platelet activating factor antagonist design: structure of methyl trans-5-(3,4-dimethoxyphenyl)-2,3,4,5-tetrahydro-2-oxo-4- furancarboxylate

C14H16O6, Mr = 280.28, monoclinic, P2(1)/c, a = 6.070 (2), b = 9.526 (5), c = 22.418 (5) A, beta = 94.32 (2) degrees, V = 1293 A3, Z = 4, Dx = 1.44 g cm-3, lambda(Mo K alpha) = 0.71073 A, mu = 0.71 cm-1, F(000) = 592, T = 293 K, final R = 0.043 for 1400 observed [F0 greater than or equal to 5 sigma(F0)] reflections. The observed structure confirms a trans stereorelationship for the two substituents and an envelope conformation for the lactone ring. There is no crystallographically imposed symmetry. An analysis of the closest contacts in the cell lattice reveals two types of intermolecular interactions for this compound.