The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Xiao-dong Luo - One of the best experts on this subject based on the ideXlab platform.
-
potent antihyperuricemic triterpenoids based on two unprecedented scaffolds from the leaves of Alstonia scholaris
Organic Letters, 2021Co-Authors: Xiao-dong Luo, Yunli Zhao, Dengsen Xiong, Zhongshun Zhou, Peifeng Zhu, Zhaojie Wang, Yongliang Wang, Lixing ZhaoAbstract:Two rearranged triterpenoids, representing new subtypes of pentacyclic triterpenoids, with unique 6/6/6/7/5 and 6/6/5/6/6/6 ring systems were isolated from Alstonia scholaris. Their structures were established by spectroscopic analysis, single-crystal X-ray diffraction, and electronic circular dichroism calculations. Both compounds exhibited potent antihyperuricemic bioactivity in vitro and in vivo.
-
monoterpenoid indole alkaloids from Alstonia rostrata
Natural Products and Bioprospecting, 2012Co-Authors: Meifen Bao, Xiang-hai Cai, Chunxia Zeng, Yaping Liu, Lingmei Kong, Xiao-dong LuoAbstract:Four new monoterpenoid indole alkaloids, alstrostines C-F together with thirteen known alkaloids were isolated from the leaves and twigs of Alstonia rostrata. All structures of new compounds were elucidated based on NMR, FTIR, UV, and MS spectroscopic data. Alstrostines C-E might originate from keto-enol tautomerism of preakummicine during biogenetic pathway of akummicine.
-
novel alkaloids from Alstonia scholaris
ChemInform, 2011Co-Authors: Xiang-hai Cai, Tao Feng, Jianhua Shang, Xiao-dong LuoAbstract:Novel alkaloids, scholarisine I (I) and scholarisine II (II), are isolated, and a possible biogenesis is proposed.
-
Monoterpenoid Indole Alkaloids from Alstonia mairei
Helvetica Chimica Acta, 2010Co-Authors: Xiang-hai Cai, Tao Feng, Chunxia Zeng, Xiao-dong LuoAbstract:Three new monoterpenoid indole alkaloids, (14 alpha,15 alpha)-14,15-epoxyaspidofractinine (1) and maireines A and 13 (2 and 3, resp.), together with 19 known alkaloids, were isolated from the leaves and twigs of Alstonia mairei. The structures of the new compounds were elucidated by 1D- and 2D-NMR spectroscopic methods in combination with MS experiments.
-
novel alkaloids from Alstonia scholaris
Zeitschrift für Naturforschung B, 2010Co-Authors: Xiang-hai Cai, Tao Feng, Jianhua Shang, Xiao-dong LuoAbstract:The alkaloidal fraction of Alstonia scholaris leaves shows anti inflammatory and analgesic bioactivity in two A phytochemical study on this fraction led to the isolation of two novel alkaloids scholarisine I and (+/-)-scholarisine II Their structures were elucidated on the basis of spectroscopic methods and a possible biogenesis is proposed (+/-) Scholarisine II selectively inhibited the inducible COX-2 rather than COX-1 and also markedly inhibited 5-LOX comparable to positive controls
Xiang-hai Cai - One of the best experts on this subject based on the ideXlab platform.
-
polycyclic monoterpenoid indole alkaloids from Alstonia rostrata and their reticulate derivation
Phytochemistry Letters, 2017Co-Authors: Xiuhong Zhong, Meifen Bao, Chunxia Zeng, Bingjie Zhang, Yu Zhang, Xiang-hai CaiAbstract:Abstract Five new alkaloids together with 20 known ones were isolated from Alstonia rostrata, and identified on the base of NMR, MS, UV and IR spectroscopic data. Additionally, alstrostine G (1) possessed an unprecedented 6/5/6/6/5/6-ring system. The analysis of those alkaloids’ biosynthetic pathway partly indicated their reticulate metabolic relationship. The research result disclosed diverse biogenesis of monoterpenoid indole alkaloids from Alstonia rostrata speciesin combination with previous reported alstrostine A.
-
monoterpenoid indole alkaloids from Alstonia rostrata
Natural Products and Bioprospecting, 2012Co-Authors: Meifen Bao, Xiang-hai Cai, Chunxia Zeng, Yaping Liu, Lingmei Kong, Xiao-dong LuoAbstract:Four new monoterpenoid indole alkaloids, alstrostines C-F together with thirteen known alkaloids were isolated from the leaves and twigs of Alstonia rostrata. All structures of new compounds were elucidated based on NMR, FTIR, UV, and MS spectroscopic data. Alstrostines C-E might originate from keto-enol tautomerism of preakummicine during biogenetic pathway of akummicine.
-
novel alkaloids from Alstonia scholaris
ChemInform, 2011Co-Authors: Xiang-hai Cai, Tao Feng, Jianhua Shang, Xiao-dong LuoAbstract:Novel alkaloids, scholarisine I (I) and scholarisine II (II), are isolated, and a possible biogenesis is proposed.
-
Monoterpenoid Indole Alkaloids from Alstonia mairei
Helvetica Chimica Acta, 2010Co-Authors: Xiang-hai Cai, Tao Feng, Chunxia Zeng, Xiao-dong LuoAbstract:Three new monoterpenoid indole alkaloids, (14 alpha,15 alpha)-14,15-epoxyaspidofractinine (1) and maireines A and 13 (2 and 3, resp.), together with 19 known alkaloids, were isolated from the leaves and twigs of Alstonia mairei. The structures of the new compounds were elucidated by 1D- and 2D-NMR spectroscopic methods in combination with MS experiments.
-
novel alkaloids from Alstonia scholaris
Zeitschrift für Naturforschung B, 2010Co-Authors: Xiang-hai Cai, Tao Feng, Jianhua Shang, Xiao-dong LuoAbstract:The alkaloidal fraction of Alstonia scholaris leaves shows anti inflammatory and analgesic bioactivity in two A phytochemical study on this fraction led to the isolation of two novel alkaloids scholarisine I and (+/-)-scholarisine II Their structures were elucidated on the basis of spectroscopic methods and a possible biogenesis is proposed (+/-) Scholarisine II selectively inhibited the inducible COX-2 rather than COX-1 and also markedly inhibited 5-LOX comparable to positive controls
Yunli Zhao - One of the best experts on this subject based on the ideXlab platform.
-
potent antihyperuricemic triterpenoids based on two unprecedented scaffolds from the leaves of Alstonia scholaris
Organic Letters, 2021Co-Authors: Xiao-dong Luo, Yunli Zhao, Dengsen Xiong, Zhongshun Zhou, Peifeng Zhu, Zhaojie Wang, Yongliang Wang, Lixing ZhaoAbstract:Two rearranged triterpenoids, representing new subtypes of pentacyclic triterpenoids, with unique 6/6/6/7/5 and 6/6/5/6/6/6 ring systems were isolated from Alstonia scholaris. Their structures were established by spectroscopic analysis, single-crystal X-ray diffraction, and electronic circular dichroism calculations. Both compounds exhibited potent antihyperuricemic bioactivity in vitro and in vivo.
-
the safety and tolerability of alkaloids from Alstonia scholaris leaves in healthy chinese volunteers a single centre randomized double blind placebo controlled phase i clinical trial
Pharmaceutical Biology, 2021Co-Authors: Zhongping Gou, Yunli Zhao, Linling Zou, Ying Wang, Shiqing Shu, Xiaohong Zhu, Li Zheng, Qi Shen, Zhu Luo, Jia MiaoAbstract:Capsule of alkaloids from the leaf of Alstonia scholaris (L.) R.Br. (Apocynaceae) (CALAS) is a new investigational botanical drug (No. 2011L01436) for bronchitis, post-infectious cough and asthma.T...
-
pharmacological evaluation of Alstonia scholaris anti tussive anti asthmatic and expectorant activities
Journal of Ethnopharmacology, 2010Co-Authors: Jianhua Shang, Xiang-hai Cai, Tao Feng, Yunli Zhao, Xiao-dong LuoAbstract:Ethnopharmacological relevance: Alstonia scholaris (Apocynaceae) was documented as an effective herb for the treatment of chronic respiratory diseases in "dai" ethnopharmacy historically, and its leaf crude extract, used for releasing tracheitis and cold symptom, was approved to be a commercial formulation by State Food and Drugs Administration of China (SFDA).
-
pharmacological evaluation of Alstonia scholaris anti inflammatory and analgesic effects
Journal of Ethnopharmacology, 2010Co-Authors: Jianhua Shang, Xiang-hai Cai, Tao Feng, Yunli Zhao, Jingkun Wang, Luyong Zhang, Ming Yan, Xiao-dong LuoAbstract:Ethnopharmacological relevance: Alstonia scholaris (Apocynaceae) has been historically used in "dai" ethnopharmacy to treat chronic respiratory diseases. The leaf extract, developed as a commercially available traditional Chinese medicine, used to release tracheitis and cold symptom, has also been prescribed in hospitals and sold over the counter in drug stores.
Tao Feng - One of the best experts on this subject based on the ideXlab platform.
-
novel alkaloids from Alstonia scholaris
ChemInform, 2011Co-Authors: Xiang-hai Cai, Tao Feng, Jianhua Shang, Xiao-dong LuoAbstract:Novel alkaloids, scholarisine I (I) and scholarisine II (II), are isolated, and a possible biogenesis is proposed.
-
Monoterpenoid Indole Alkaloids from Alstonia mairei
Helvetica Chimica Acta, 2010Co-Authors: Xiang-hai Cai, Tao Feng, Chunxia Zeng, Xiao-dong LuoAbstract:Three new monoterpenoid indole alkaloids, (14 alpha,15 alpha)-14,15-epoxyaspidofractinine (1) and maireines A and 13 (2 and 3, resp.), together with 19 known alkaloids, were isolated from the leaves and twigs of Alstonia mairei. The structures of the new compounds were elucidated by 1D- and 2D-NMR spectroscopic methods in combination with MS experiments.
-
novel alkaloids from Alstonia scholaris
Zeitschrift für Naturforschung B, 2010Co-Authors: Xiang-hai Cai, Tao Feng, Jianhua Shang, Xiao-dong LuoAbstract:The alkaloidal fraction of Alstonia scholaris leaves shows anti inflammatory and analgesic bioactivity in two A phytochemical study on this fraction led to the isolation of two novel alkaloids scholarisine I and (+/-)-scholarisine II Their structures were elucidated on the basis of spectroscopic methods and a possible biogenesis is proposed (+/-) Scholarisine II selectively inhibited the inducible COX-2 rather than COX-1 and also markedly inhibited 5-LOX comparable to positive controls
-
pharmacological evaluation of Alstonia scholaris anti tussive anti asthmatic and expectorant activities
Journal of Ethnopharmacology, 2010Co-Authors: Jianhua Shang, Xiang-hai Cai, Tao Feng, Yunli Zhao, Xiao-dong LuoAbstract:Ethnopharmacological relevance: Alstonia scholaris (Apocynaceae) was documented as an effective herb for the treatment of chronic respiratory diseases in "dai" ethnopharmacy historically, and its leaf crude extract, used for releasing tracheitis and cold symptom, was approved to be a commercial formulation by State Food and Drugs Administration of China (SFDA).
-
pharmacological evaluation of Alstonia scholaris anti inflammatory and analgesic effects
Journal of Ethnopharmacology, 2010Co-Authors: Jianhua Shang, Xiang-hai Cai, Tao Feng, Yunli Zhao, Jingkun Wang, Luyong Zhang, Ming Yan, Xiao-dong LuoAbstract:Ethnopharmacological relevance: Alstonia scholaris (Apocynaceae) has been historically used in "dai" ethnopharmacy to treat chronic respiratory diseases. The leaf extract, developed as a commercially available traditional Chinese medicine, used to release tracheitis and cold symptom, has also been prescribed in hospitals and sold over the counter in drug stores.
Toh-seok Kam - One of the best experts on this subject based on the ideXlab platform.
-
Macroline-Sarpagine Bisindole Alkaloids with Antiproliferative Activity from Alstonia penangiana.
Journal of natural products, 2019Co-Authors: Joanne Soonyee Yeap, Siew-huah Lim, Yun-yee Low, Kae-shin Sim, Hazwani Mat Saad, Chun-hoe Tan, Toh-seok KamAbstract:A methanol extract of the stem bark of the Malayan Alstonia penangiana provided seven new bisindole alkaloids, comprising six macroline–sarpagine alkaloids (angustilongines E–K, 1–6) and one macrol...
-
Macroline-sarpagine and macroline-pleiocarpamine bisindole alkaloids from Alstonia angustifolia.
Phytochemistry, 2012Co-Authors: Shin-jowl Tan, Kuan-hon Lim, G. Subramaniam, Toh-seok KamAbstract:Nine bisindole alkaloids, comprising four belonging to the macroline–sarpagine group, and five belonging to the macroline–pleiocarpamine group, were isolated from the stem-bark extracts of Alstonia angustifolia (Apocynacea). Their structures were established using NMR and MS analyses.
-
Perhentidines A-C: macroline-macroline bisindoles from Alstonia and the absolute configuration of perhentinine and macralstonine.
Journal of natural products, 2012Co-Authors: Siew-huah Lim, Noel F. Thomas, Yun-yee Low, Kuan-hon Lim, Shin-jowl Tan, Toh-seok KamAbstract:Three new bisindole alkaloids of the macro- line−macroline type, perhentidines A− C( 1−3), were isolated from the stem-bark extract of Alstonia macrophylla and Alstonia angustifolia. The structures of these alkaloids were established on the basis of NMR and MS analyses. The absolute configu- rations of perhentinine (4) and macralstonine (5) were estab- lished by X-ray diffraction analyses, which facilitated assign- ment of the configuration at C-20 in the regioisomeric bisindole alkaloids perhentidines A− C( 1−3). A potentially useful method for the determination of the configuration at C-20 based on comparison of the NMR chemical shifts of the bisindoles and their acetate derivatives, in these and related bisindoles with similar constitution and branching of the monomeric units, is also presented.
-
bipleiophylline an unprecedented cytotoxic bisindole alkaloid constituted from the bridging of two indole moieties by an aromatic spacer unit
Organic Letters, 2008Co-Authors: Toh-seok Kam, Shin-jowl Tan, Kanki KomiyamaAbstract:A cytotoxic bisindole alkaloid possessing an unprecedented structure in which two indole moieties are bridged by an aromatic spacer unit has been isolated from Alstonia angustifolia. The structure was established by analysis of the spectroscopic data and confirmed by X-ray diffraction analysis. A possible biogenetic pathway from pyrocatechuic acid and pleiocarpamine is presented.
-
angustilodine an unusual pentacyclic indole alkaloid from Alstonia
ChemInform, 2004Co-Authors: Toh-seok Kam, Yeunmun ChooAbstract:Two new indole alkaloids, angustilodine (1), with an unprecedented pentacyclic carbon skeleton, and angustilocine (2), belonging to the seco-angustilobine-B group of alkaloids, were obtained from the leaf extract of the Malayan species Alstonia angustiloba, and their structures were established by spectroscopic analysis.