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Yang Ye - One of the best experts on this subject based on the ideXlab platform.
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two new n oxide alkaloids from Stemona cochinchinensis
Molecules, 2014Co-Authors: Anqi Wang, Chunping Tang, Phamhuu Dien, Yang YeAbstract:Two new N-oxide alkaloids with pyrrolo[1,2-α]azepine skeleton, namely isoneostemocochinine-N-oxide (1) and neostemocochinine-N-oxide (2), as well as three known alkaloids with pyrido[1,2-α]azepine skeletons, were isolated and identified from the roots of Stemona cochinchinensis (Stemonaceae). The structures of these compounds were elucidated by 1D- and 2D-NMR spectra and other spectroscopic studies. Additionally, the 1H- and 13C-NMR characteristic of N-oxide Stemona alkaloids was summarized. Stemokerrin showed potent anti-tussive activity on citric acid-induced guinea pig model.
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rapid structural determination of alkaloids in a crude extract of Stemona saxorum by high performance liquid chromatography electrospray ionization coupled with tandem mass spectrometry
Rapid Communications in Mass Spectrometry, 2009Co-Authors: Shuying Peng, Yazhou Wang, Yiming Yang, Hualiang Jiang, Yang YeAbstract:The electrospray ionization (ESI) mass spectrometric behavior of five Stemona alkaloids, stemokerrin, oxystemokerrin, oxystemokerrilactone, oxystemokerrin N-oxide and stemokerrin N-oxide, was studied using an ESI tandem mass technique (MSn). These compounds, isolated from Stemonasaxorum endemic in Vietnam, represent a class of alkaloids containing a pyrido[1,2-a]azepine A,B-ring core with a 1-hydroxypropyl side chain attached to C-4. Their fragmentation pathways were elucidated by ESI-MSn results and the elemental composition of the major product ions was confirmed by accurate mass measurement. In order to rationalize some fragmentation pathways, the relative Gibbs free energies of some product ions were estimated using the B3LYP/6-31+G(d) method. Based on the ESI-MSn results of five reference compounds, a reversed-phase high-performance liquid chromatography with tandem mass spectrometry (RP-HPLC/MSn) method was developed for the characterization of Stemona alkaloids with a pyrido[1,2-a]azepine A,B-ring core from the extract of S. saxorum. A total of 41 components were rapidly identified or tentatively characterized, of which 12 compounds were identified as Stemona alkaloids with a pyrido[1,2-a]azepine A,B-ring core, including four new compounds. This method is convenient and sensitive, especially for minor components in complex natural product extracts. Copyright © 2009 John Wiley & Sons, Ltd.
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croomine and tuberostemonine type alkaloids from roots of Stemona tuberosa and their antitussive activity
Tetrahedron, 2008Co-Authors: Henry Pakho Leung, Chunping Tang, Changqiang Ke, John A Rudd, Yang YeAbstract:Abstract Three new croomine-type Stemona alkaloids, tuberocrooline ( 1 ), 10-hydroxycroomine ( 2 ), and dehydrocroomine ( 3 ), and four new tuberostemonine-type alkaloids, tuberostemoline ( 4 ), tridehydrotuberostemonine ( 5 ), 9α-bisdehydrotuberostemonine ( 6 ), and 9α-bisdehydrotuberostemonine A ( 7 ), along with ten known constituents, were isolated from the roots of Stemona tuberosa collected from Yunnan province. The structures of the new compounds were established on the basis of one- and two-dimensional NMR spectra and other spectroscopic studies. The antitussive activity of the major alkaloids was tested using the citric acid-induced guinea pig cough model. Croomine ( 8 ) exhibited a dose-dependent inhibition of coughing with an ID 50 value of 0.18 mmol/kg.
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alkaloids from the roots of Stemona saxorum
Journal of Natural Products, 2007Co-Authors: Yazhou Wang, Chunping Tang, Phamhuu Dien, Yang YeAbstract:Five new Stemona alkaloids, cochinchistemoninone (1), stemokerrin-N-oxide (2), oxystemokerrilactone (3), saxorumamide (4a), and isosaxorumamide (4b), as well as 12 known compounds, were isolated from the roots of Vietnamese Stemona saxorum. The structures of these alkaloids were characterized on the basis of spectroscopic methods.
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isolation of chlorogenic acids and their derivatives from Stemona japonica by preparative hplc and evaluation of their anti aiv h5n1 activity in vitro
Phytochemical Analysis, 2007Co-Authors: Fan Ge, Chunping Tang, Changqiang Ke, Rensheng Xu, Wei Tang, Xinzhou Yang, Tianxian Li, Xinwen Chen, Yang YeAbstract:Two chlorogenic acids and five chlorogenic acid derivatives were simultaneously separated and purified from Stemona japonica by preparative high-performance liquid chromatography. Five of the collected compounds were over 95% pure while the other two compounds were over 90% pure. Their structures were elucidated as 3-O-feruloylquinic acid (1), 4-O-feruloylquinic acid (2), methyl 3-O-feruloylquinate (3), methyl 5-O-caffeyolquinate (4), methyl 4-O-feruloylquinate (5), ethyl 3-O-feruloylquinate (6) and the new compound ethyl 4-O-feruloylquinate (7) by UV, NMR and ESI-MS. All compounds were obtained from Stemona species for the first time, however compounds 6 and 7 are believed to be artefacts from the ethanol extraction. The anti-AIV (H5N1) activities were evaluated by Neutral Red uptake assay. Compounds 3 and 4 exerted moderate inhibitory effect against AIV (H5N1) in vitro. Copyright © 2007 John Wiley & Sons, Ltd.
Koichi Takeya - One of the best experts on this subject based on the ideXlab platform.
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Stemona amines c e new alkaloids from Stemona tuberosa
Tetrahedron Letters, 2013Co-Authors: Yukio Hitotsuyanagi, Katsuko Komatsu, Genta Shigemori, Haruhiko Fukaya, Maho Hikita, Koichi TakeyaAbstract:Abstract Three new alkaloids, Stemona-amines C–E, were isolated from the roots of Stemona tuberosa Lour. (Stemonaceae). The structures of Stemona-amines C and D were determined by X-ray crystallography and that of Stemona-amine E was determined by interpretation of spectroscopic data. The absolute structures of Stemona-amines C and D were established by VCD spectroscopy.
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Stemona-amines C–E, new alkaloids from Stemona tuberosa
Tetrahedron Letters, 2013Co-Authors: Yukio Hitotsuyanagi, Katsuko Komatsu, Genta Shigemori, Haruhiko Fukaya, Maho Hikita, Koichi TakeyaAbstract:Abstract Three new alkaloids, Stemona-amines C–E, were isolated from the roots of Stemona tuberosa Lour. (Stemonaceae). The structures of Stemona-amines C and D were determined by X-ray crystallography and that of Stemona-amine E was determined by interpretation of spectroscopic data. The absolute structures of Stemona-amines C and D were established by VCD spectroscopy.
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absolute structures of Stemona lactam s and tuberostemospiroline alkaloids from Stemona tuberosa
Chemical & Pharmaceutical Bulletin, 2013Co-Authors: Haruhiko Fukaya, Katsuko Komatsu, Yukio Hitotsuyanagi, Yutaka Aoyagi, Koichi TakeyaAbstract:: A new alkaloid, Stemona-lactam S, and a known alkaloid, tuberostemospiroline, were isolated from the roots of Stemona tuberosa LOUR. (Stemonaceae). Their structures and absolute stereochemistry were established by X-ray crystallography and vibrational circular dichroism.
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structures of Stemona amine b and Stemona lactams m r
Tetrahedron, 2013Co-Authors: Yukio Hitotsuyanagi, Katsuko Komatsu, Haruhiko Fukaya, Erika Takeda, Shoko Matsuda, Yuka Saishu, Koichi TakeyaAbstract:Seven new alkaloids, Stemona-amine B and Stemona-lactams M–R, were isolated from the roots of Stemona tuberosa. Their structures were determined by interpretation of spectroscopic data, chemical behavior, and X-ray crystallographic data.
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Structures of Stemona-amine B and Stemona-lactams M–R
Tetrahedron, 2013Co-Authors: Yukio Hitotsuyanagi, Katsuko Komatsu, Haruhiko Fukaya, Erika Takeda, Shoko Matsuda, Yuka Saishu, Koichi TakeyaAbstract:Seven new alkaloids, Stemona-amine B and Stemona-lactams M–R, were isolated from the roots of Stemona tuberosa. Their structures were determined by interpretation of spectroscopic data, chemical behavior, and X-ray crystallographic data.
Yukio Hitotsuyanagi - One of the best experts on this subject based on the ideXlab platform.
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Stemona-amines F and G, new alkaloids from Stemona tuberosa
Tetrahedron Letters, 2016Co-Authors: Yukio Hitotsuyanagi, Haruhiko Fukaya, Yoshiyuki Sekiya, Hyun Sun Park, Katsuko KomatsuAbstract:Abstract Two new alkaloids, Stemona-amines F and G, were isolated from the roots of Stemona tuberosa Lour. (Stemonaceae). The structure of Stemona-amine F was determined by X-ray crystallography and that of Stemona-amine G was determined by interpretation of spectroscopic data. The absolute structure of Stemona-amine F was established by VCD spectroscopy.
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Stemona amines c e new alkaloids from Stemona tuberosa
Tetrahedron Letters, 2013Co-Authors: Yukio Hitotsuyanagi, Katsuko Komatsu, Genta Shigemori, Haruhiko Fukaya, Maho Hikita, Koichi TakeyaAbstract:Abstract Three new alkaloids, Stemona-amines C–E, were isolated from the roots of Stemona tuberosa Lour. (Stemonaceae). The structures of Stemona-amines C and D were determined by X-ray crystallography and that of Stemona-amine E was determined by interpretation of spectroscopic data. The absolute structures of Stemona-amines C and D were established by VCD spectroscopy.
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Stemona-amines C–E, new alkaloids from Stemona tuberosa
Tetrahedron Letters, 2013Co-Authors: Yukio Hitotsuyanagi, Katsuko Komatsu, Genta Shigemori, Haruhiko Fukaya, Maho Hikita, Koichi TakeyaAbstract:Abstract Three new alkaloids, Stemona-amines C–E, were isolated from the roots of Stemona tuberosa Lour. (Stemonaceae). The structures of Stemona-amines C and D were determined by X-ray crystallography and that of Stemona-amine E was determined by interpretation of spectroscopic data. The absolute structures of Stemona-amines C and D were established by VCD spectroscopy.
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absolute structures of Stemona lactam s and tuberostemospiroline alkaloids from Stemona tuberosa
Chemical & Pharmaceutical Bulletin, 2013Co-Authors: Haruhiko Fukaya, Katsuko Komatsu, Yukio Hitotsuyanagi, Yutaka Aoyagi, Koichi TakeyaAbstract:: A new alkaloid, Stemona-lactam S, and a known alkaloid, tuberostemospiroline, were isolated from the roots of Stemona tuberosa LOUR. (Stemonaceae). Their structures and absolute stereochemistry were established by X-ray crystallography and vibrational circular dichroism.
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structures of Stemona amine b and Stemona lactams m r
Tetrahedron, 2013Co-Authors: Yukio Hitotsuyanagi, Katsuko Komatsu, Haruhiko Fukaya, Erika Takeda, Shoko Matsuda, Yuka Saishu, Koichi TakeyaAbstract:Seven new alkaloids, Stemona-amine B and Stemona-lactams M–R, were isolated from the roots of Stemona tuberosa. Their structures were determined by interpretation of spectroscopic data, chemical behavior, and X-ray crystallographic data.
Harald Greger - One of the best experts on this subject based on the ideXlab platform.
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Structural classification and biological activities of Stemona alkaloids
Phytochemistry Reviews, 2019Co-Authors: Harald GregerAbstract:Stemona alkaloids represent a unique class of natural products exclusively known from the three genera Stemona , Stichoneuron , and Croomia of the monocotyledonous family Stemonaceae. Structurally they are characterized by a central pyrroloazepine core usually linked with two butyrolactone rings. The great diversity, comprising 215 derivatives, is created by the formation of additional C – C linkages and oxygen bridges together with ring cleavages and eliminations of the lactone rings. Based on biosynthetic considerations they can be grouped into three structural types represented by the croomine, stichoneurine, and protostemonine skeleton. Due to the formation of characteristic terminal lactone rings and the central pyrrolidine ring pandanamine and pandamarilactonine, isolated from Stichoneuron calcicola , were suggested to represent biogenetic precursors. The taxonomically complex S. tuberosa group can be clearly segregated by the formation of stichoneurines, while the other Stemona species are characterized by protostemonine derivatives. Croomine derivatives are more widespread found in both groups and in the genus Croomia . Of chemotaxonomic significance are the different transformations of protostemonine into stemofolines with a cage-type structure or into pyridoazepines characterized by a six-membered piperidine ring. Stimulated by the great interest in the antitussive activity of Stemona alkaloids, differences in transport mechanisms and potencies via different administrative routes were investigated. Follow-up studies on the significant insecticidal activities focused on the mode of action by using biochemical and electrophysiological approaches. Screening for acetylcholinesterase inhibitory properties revealed a much higher potency for stemofoline derivatives compared to pyridoazepines, but showed also significant activity for isomers of stenine with a stichoneurine skeleton. Evaluating synergistic growth inhibitory effects with cancer chemotherapeutic agents stemofoline exhibited the most potent effect in the reversal of permeability glycoprotein-mediated multidrug resistance. The anti-inflammatory activity of some derivatives was identified as an inhibition of the expression of inflammatory mediators. Comparing the diverse bioactivities of Stemona alkaloids stemofoline-type derivatives are the most versatile compounds representing promising lead structures for further development as commercial agents in agriculture and medicine.
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phenylbenzofuran type stilbenoids from Stemona species
Phytochemistry Letters, 2014Co-Authors: Andrea Zraunig, Thomas Pacher, Lothar Brecker, Harald GregerAbstract:Five new phenylbenzofuran-type stilbenoids, stemofurans S-W (1–5), were isolated from underground parts of four Stemona species collected in Thailand and Australia together with the known stemofurans A–C, G, E, J, M, the stilbostemins A–D, F, the stemanthrenes A–D, dihydropinosylvin, pinosylvin, and 4′-methylpinosylvin. The chemical structures of the new compounds were elucidated by 1H NMR and 13C NMR spectroscopy and mass spectrometry. In accordance with previous reports all compounds were characterized by C-methylations of the aromatic rings. Stemofurans S (1) and U (3) showed an unusual hydroxylation at position C-4′, a hitherto unknown substitution of Stemona stilbenoids.
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the diversity of Stemona stilbenoids as a result of storage and fungal infection
Journal of Natural Products, 2012Co-Authors: Harald GregerAbstract:In relation to their biogenetic origin, 68 Stemona stilbenoids have been grouped into four structural types and are listed in order of increasing substitution pattern. Besides different hydroxylations and methoxylations, the rare C-methylations of the aromatic rings represent a typical chemical feature of these compounds. The formation of phenylbenzofurans constitutes another important chemical character separating Stemona species into two groups consistent with morphological and DNA data. Fungal infection leads to an increasing accumulation of stilbenes, dihydrostilbenes, and phenylbenzofurans with unsubstituted A-rings, suggesting the ecological role of these compounds as phytoalexins. Further oxygenations and methylations of both rings are interpreted as a result of aging or the drying processes. Bioautographic tests on TLC plates and germ-tube inhibition assays in microwells against four different fungi exhibited antifungal activities for almost all stilbenoids tested. Some derivatives also showed eff...
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structural relationships of Stemona alkaloids assessment of species specific accumulation trends for exploiting their biological activities
Journal of Natural Products, 2011Co-Authors: Sumet Kongkiatpaiboon, Vichien Keeratinijakal, Wandee Gritsanapan, Srunya Vajrodaya, Johann Schinnerl, Lothar Brecker, Susanne Felsinger, Harald GregerAbstract:On the basis of a comparison of 42 Stemona samples, representing eight different species collected and cultivated in Thailand, species-specific accumulation trends of Stemona alkaloids were analyzed. An overview was achieved by comparative HPLC analyses of methanolic crude extracts of underground parts coupled with diode array or evaporative light scattering detectors. All major compounds were isolated and their structures elucidated by NMR and MS analyses. Protostemonine- and stichoneurine-type derivatives dominated, from which the latter characterize S. tuberosa and S. phyllantha accumulating species-specific isomers of tuberostemonine (3). The widespread S. curtisii and S. collinsiae clearly deviate by protostemonine-type derivatives dominated by stemofoline (10) and/or didehydrostemofoline (11). Further diversification within this structural type results from a mutual accumulation of derivatives with a pyrrolo- or pyridoazepine nucleus, leading to chemical variability in S. curtisii and S. aphylla.
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Stemona alkaloids from traditional thai medicine increase chemosensitivity via p glycoprotein mediated multidrug resistance
Phytomedicine, 2011Co-Authors: Wisinee Chanmahasathien, Harald Greger, Chadarat Ampasavate, Pornngarm LimtrakulAbstract:Abstract P-glycoprotein-mediated drug efflux can cause a multidrug resistance (MDR) phenotype that is associated with a poor response to cancer chemotherapy. Through bioassay-guided fractionation, active Stemona alkaloids were isolated from the roots of Stemona aphylla and S. burkillii. The chemical structures of isolated alkaloids were confirmed by HPLC, LC–MS and NMR as stemocurtisine and oxystemokerrine from S. aphylla, and stemofoline from S. burkillii. The isolated alkaloids were evaluated for synergistic growth inhibitory effect with cancer chemotherapeutic agents including vinblastine, paclitaxel and doxorubicin of KB-V1 cells (MDR human cervical carcinoma with P-gp expression), but not in KB-3-1 cells (drug sensitive human cervical carcinoma, which lack P-gp expression). Verapamil was employed as a comparative agent. The results showed that among these three isolated alkaloids; stemofoline exhibited the most potent effect in vitro in the reversal of P-gp-mediated MDR. Treatment with stemofoline at the various concentrations up to 72 h was able to significantly increase sensitivity of anticancer drugs including vinblastine, paclitaxel and doxorubicin in dose- and time-dependent manner in KB-V1 cells. The result obtained from this study indicated that Stemona alkaloids may play an important role as a P-gp modulator as used in vitro and may be effective in the treatment of multidrug-resistant cancers. This is the first report of new pharmacological activity of Stemona alkaloids, which could be a new potential MDR chemosensitizer.
Haruhiko Fukaya - One of the best experts on this subject based on the ideXlab platform.
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Stemona-amines F and G, new alkaloids from Stemona tuberosa
Tetrahedron Letters, 2016Co-Authors: Yukio Hitotsuyanagi, Haruhiko Fukaya, Yoshiyuki Sekiya, Hyun Sun Park, Katsuko KomatsuAbstract:Abstract Two new alkaloids, Stemona-amines F and G, were isolated from the roots of Stemona tuberosa Lour. (Stemonaceae). The structure of Stemona-amine F was determined by X-ray crystallography and that of Stemona-amine G was determined by interpretation of spectroscopic data. The absolute structure of Stemona-amine F was established by VCD spectroscopy.
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Stemona amines c e new alkaloids from Stemona tuberosa
Tetrahedron Letters, 2013Co-Authors: Yukio Hitotsuyanagi, Katsuko Komatsu, Genta Shigemori, Haruhiko Fukaya, Maho Hikita, Koichi TakeyaAbstract:Abstract Three new alkaloids, Stemona-amines C–E, were isolated from the roots of Stemona tuberosa Lour. (Stemonaceae). The structures of Stemona-amines C and D were determined by X-ray crystallography and that of Stemona-amine E was determined by interpretation of spectroscopic data. The absolute structures of Stemona-amines C and D were established by VCD spectroscopy.
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Stemona-amines C–E, new alkaloids from Stemona tuberosa
Tetrahedron Letters, 2013Co-Authors: Yukio Hitotsuyanagi, Katsuko Komatsu, Genta Shigemori, Haruhiko Fukaya, Maho Hikita, Koichi TakeyaAbstract:Abstract Three new alkaloids, Stemona-amines C–E, were isolated from the roots of Stemona tuberosa Lour. (Stemonaceae). The structures of Stemona-amines C and D were determined by X-ray crystallography and that of Stemona-amine E was determined by interpretation of spectroscopic data. The absolute structures of Stemona-amines C and D were established by VCD spectroscopy.
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absolute structures of Stemona lactam s and tuberostemospiroline alkaloids from Stemona tuberosa
Chemical & Pharmaceutical Bulletin, 2013Co-Authors: Haruhiko Fukaya, Katsuko Komatsu, Yukio Hitotsuyanagi, Yutaka Aoyagi, Koichi TakeyaAbstract:: A new alkaloid, Stemona-lactam S, and a known alkaloid, tuberostemospiroline, were isolated from the roots of Stemona tuberosa LOUR. (Stemonaceae). Their structures and absolute stereochemistry were established by X-ray crystallography and vibrational circular dichroism.
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structures of Stemona amine b and Stemona lactams m r
Tetrahedron, 2013Co-Authors: Yukio Hitotsuyanagi, Katsuko Komatsu, Haruhiko Fukaya, Erika Takeda, Shoko Matsuda, Yuka Saishu, Koichi TakeyaAbstract:Seven new alkaloids, Stemona-amine B and Stemona-lactams M–R, were isolated from the roots of Stemona tuberosa. Their structures were determined by interpretation of spectroscopic data, chemical behavior, and X-ray crystallographic data.
