共查询到20条相似文献,搜索用时 15 毫秒
1.
Li‐Bin Yang Sheng‐Xiong Huang Li‐Mei Li Yong Zhao Chun Lei Wei‐Lie Xiao Jian‐Xin Pu Quan‐Bin Han Han‐Dong Sun 《Helvetica chimica acta》2007,90(12):2375-2379
Two new 6,7‐seco‐ent‐kaurane diterpenoids, isojaponins A ( 1 ) and B ( 2 ), together with 18 known ent‐kaurane diterpenoids were isolated from the aerial parts of Isodon japonicus. The structures of the two new compounds were elucidated by extensive 1D‐ and 2D‐NMR spectroscopic methods in combination with MS experiments. 相似文献
2.
Xian Li Zhi‐Ying Weng Yong Li Jian‐Xin Pu Sheng‐Xiong Huang Wei‐Lie Xiao Han‐Dong Sun 《Helvetica chimica acta》2008,91(6):1130-1136
Phytochemical investigation of the medicinal plant Isodon phyllostachys led to the isolation of four new ent‐kaurane diterpenoids, phyllostacins F–I ( 1 – 4 , resp.), together with 11 known compounds, rosthorin A ( 5 ), rabdoternin C ( 6 ), enmenol ( 7 ), oridonin ( 8 ), lasiocarpanin ( 9 ), xerophilusin B ( 10 ), ponicidin ( 11 ), macrocalin B ( 12 ), phyllostachysin A ( 13 ), sculponeatin C ( 14 ), and macrocalyxoformin E ( 15 ). The structures of the new compounds were established by spectroscopic methods, including extensive 1D‐ and 2D‐NMR analyses. Compounds 1, 2, 7, 10 , and 13 were evaluated for their inhibitory activity against K562 and HepG2 cell lines. 相似文献
3.
Six new ent‐abietane diterpenoids, rubescensins I–M ( 1 – 5 ) and P ( 6 ), along with two related acetonide derivatives ( 7 and 8 ), were isolated from Isodon rubescens. Their structures were elucidated by detailed spectroscopic analysis. Compound 5 is the first N‐containing diterpenoid from the genus Isodon, exhibiting notable cytotoxicity against human tumor K562 cells. 相似文献
4.
Ai‐Hua Zhao Yan Zhang Zhao‐Hui Xu Jian‐Wen Liu Wei Jia 《Helvetica chimica acta》2004,87(12):3160-3166
Three new enmein‐type ent‐kaurenoids, i.e., the two pairs 1 and 2 of 20‐epimers and the (20R)‐isomer 3 , besides the seven known diterpenoids 4 – 10 , were isolated from the aerial parts of Isodon serra. Their structures were elucidated by spectroscopic techniques and X‐ray diffraction. The immunosuppressive effect for T‐lymphocytes proliferation induced by Con A in BALB/c mouse was evaluated for the isolates 1 – 10 . They all displayed a remarkable inhibitory effect, with multi‐glycosides of Tripterygium wilfordii as positive reference substance (Table 3). 相似文献
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6.
Quan‐Bin Han Bei Jiang Ji‐Xia Zhang Xue‐Mei Niu Han‐Dong Sun 《Helvetica chimica acta》2003,86(3):773-777
A novel 20‐nor‐ent‐kaurene diterpenoid, rubescensin N ( 1 ), and a new 7,20‐epoxy‐ent‐kaurene diterpenoid, rubescensin O ( 2 ), along with the seven known diterpenoids rabdoternins A–F and xerophilusin N, were isolated from Isodon rubescens collected in Jiyuan prefecture, Henan Province, China. Their structures were established by extensive spectroscopic analysis. Compound 1 is the first example of a naturally occurring 20‐nor‐ent‐kaurene diterpenoid from the Isodon genus plants. 相似文献
7.
Further investigation on the aerial parts of Isodon enanderianus afforded a novel asymmetric ent-kauranoid dimer,enanderi-nanin J(1).The structure of the dimer was elucidated by means of spectroscopic methods (including 2D NMR tecniques ),Enanderinanin J was a dimer of xerophilusin A and probably formed by [4 2] cycloaddition. 相似文献
8.
Xuemei Niu Shenghong Li Qinshi Zhao Shuangxi Mei Zhongwen Lin Handong Sun Yang Lu Cheng Wang Qitai Zheng 《Helvetica chimica acta》2003,86(2):299-306
Two novel ent‐abietane diterpenoids, 3α,20‐epoxy‐6β‐hydroxy‐1,7‐dioxo‐ent‐abiet‐15(17)‐en‐16‐oic acid ( 1 ) and ent‐abieta‐7,15(17)‐diene‐3β,16,18‐triol ( 2 ) were isolated from Isodon eriocalyx var. laxiflora. Their structures were determined by extensive spectroscopic analysis and confirmed by X‐ray crystallography. Compound 1 is an unprecedented example that establishes that a naturally occurring ent‐abietane diterpenoid can have an oxygenation pattern almost identical to those of 3α,20‐epoxy‐ent‐kaurane diterpenoids. 相似文献
9.
Quan-Bin Han Zhen-Dan He Chun-Feng Qiao Hong-Xi Xu Han-Dong Sun 《Helvetica chimica acta》2005,88(4):817-821
A novel asymmetric ent‐kaurane dimer, xindongnin P ( 1 ), was isolated from Isodon rubescens var. rubescens. Its structure was elucidated by detailed spectroscopic analysis. Compound 1 contains a tetrahydrofuran moiety whose formation leads to inversion of configuration at C(16). This differentiates 1 from known related dimers, which were isolated before from the Isodon genus. A likely biogenetic pathway from the alleged monomer precursor 3 is proposed. 相似文献
10.
Two new diterpenoids, rubescensin S (=(1α,6β,14β)‐7α,20‐epoxy‐1,7,14‐trihydroxy‐16‐oxo‐15,16‐seco‐ent‐kauran‐6,15‐olide; 1 ) and rubescensin T (=(1α,6β,11β,20S)‐7α,20‐epoxy‐1,6,7‐trihydroxy‐20‐methoxy‐8,15‐seco‐ent‐kaur‐16‐en‐11,15‐olide; 2 ) were isolated from the Chinese medicinal herb Isodon rubescens var. taihangensis. Compound 1 possesses a unique, unprecedented 15,16‐seco‐ent‐kaurane skeleton. Both compounds exhibited cytotoxic activities against K562 human leukemia cells. 相似文献
11.
Two new C(20)‐oxygenated ent‐kaurene diterpenoids, taibaihenryiins A ( 1 ) and B ( 2 ), along with five known compounds, shikokianin ( 3 ), longikaurin D, 2α‐hydroxyursolic acid, longikaurin F, and lasiodin, were isolated from the EtOH extract of the leaves and tender branches of Isodon henryi (Hemsl .) Kudo . The structures of the new compounds were determined as 11α‐acetoxy‐7,20‐epoxy‐1α,6β,7β‐trihydroxy‐ent‐kaur‐16‐en‐15‐one ( 1 ) and 7,20‐epoxy‐3β,6β,7β,11α‐tetrahydroxy‐ent‐kaur‐16‐en‐15‐one ( 2 ) on the basis of detailed spectroscopic analyses. 相似文献
12.
Lan Ding Zhang‐Jing Zhang Guo‐An Liu Dong‐Juan Yang Guo‐Cong Guo Han Wang Kun Sun 《Helvetica chimica acta》2005,88(9):2502-2507
Three new cytotoxic ent‐kaurane diterpenoids, (1α,7α,14β)‐1,7,14‐trihydroxy‐ent‐kaur‐16‐en‐15,18‐dione ( 1 ), (1α,7α,14β)‐1,7,14,18,20‐pentahydroxy‐ent‐kaur‐16‐en‐15‐one ( 2 ), and (3β,7α,14β)‐3,7,14‐tris(acetyloxy)‐ent‐kaur‐16‐en‐15‐one ( 3 ), were isolated from Isodon weisiensis C. Y. Wu. Their structures were elucidated by spectroscopic methods, including 2D‐NMR techniques, and the crystal structure of 1 was determined by single‐crystal X‐ray‐diffraction analysis. The chosen crystal of 1 was orthorhombic, space group P212121, and there were two molecules with little difference in bond length and bond angle in the least‐asymmetry unit. Compounds 1–3 showed significant cytotoxic activities against human‐cancer cell lines Bel‐7402 and HO‐8910. 相似文献
13.
Yan Zhou Bin‐Li Yang Jing Yang Sheng‐Xiong Huang Han‐Dong Sun Hong‐Xi Xu Li‐Sheng Ding 《Rapid communications in mass spectrometry : RCM》2009,23(1):138-146
Electrospray ionization tandem mass spectrometry (ESI‐MSn) using an ion trap instrument and accurate mass measurement on a quadrupole time‐of‐flight (Q‐TOF) mass spectrometer has aided the structural characterization and differentiation of the enmein and spiro‐lactone types of ent‐6,7‐seco‐kaurane diterpenoids from Isodon species. The mass spectral fragmentation data from both techniques was compared to obtain the mass spectrometric fragmentation pathways of the ent‐6,7‐seco‐kaurane diterpenoids with high confidence. The analysis revealed that losses of CH2O and CO2 are the predominant process for the enmein type of ent‐kauranes in negative ion mode, and the loss of CO2 is typical for the spiro‐lactone type in positive ion mode. In addition, compounds of the spiro‐lactone type with a conserved core structure but different substituent groups, such as acetyl, hydroxyl, and aldehyde moiety, resulted in diagnostic product ions by means of successive losses of AcOH, H2O, and CO, respectively. The fragmentation knowledge will facilitate the analysis and identification of the ent‐6,7‐seco‐kauranes in future plant research. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
14.
Guo‐Cai Wang Ying Wang Herman H.‐Y. Sung Ian D. Williams Wen‐Cai Ye 《Helvetica chimica acta》2012,95(1):120-126
Four C(8),C(12)‐diastereoisomers, (8S,12S)‐isoandrographolide ( 1 ), (8S,12R)‐isoandrographolide ( 2 ), (8R,12R)‐isoandrographolide ( 3 ), and (8R,12S)‐isoandrographolide ( 4 ) were isolated from the aerial parts of Andrographis paniculata. The structures of the new compounds 1 – 3 were established on the basis of the spectroscopic data including UV, IR, NMR, HR‐ESI‐MS, and X‐ray diffraction analysis. 相似文献
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16.
Three new ent‐kaurane glucopyranosides, 2‐O‐[β‐D ‐apiofuranosyl‐(1→3)‐2‐O‐isovaleryl‐β‐D ‐glucopyranosyl]‐4‐epi‐atractyligenin ( 1 ), 2‐O‐[β‐D ‐apiofuranosyl‐(1→3)‐2‐O‐isovaleryl‐β‐D ‐glucopyranosyl]atractyligenin ( 2 ), and 2‐O‐[β‐D ‐apiofuranosyl‐(1→3)‐2‐O‐(3‐methylpentanoyl)‐β‐D ‐glucopyranosyl]‐4‐epi‐atractyligenin ( 3 ), along with 2‐O‐(2‐O‐isovaleryl‐β‐D ‐glucopyranosyl)‐4‐epi‐atractyligenin ( 4 ), were isolated for the first time from the aerial parts of Siegesbeckia pubescens. The structures were established by extensive spectroscopic analyses including 1D ‐ and 2D ‐NMR (HSQC, HMBC, and ROESY), and HR‐ESI‐MS, and by comparison with published data. 相似文献
17.
Two new ent‐kaurane diterpenes, wedelidins A ( 8 ) and B ( 9 ), together with eighteen other constituents, including the sesquiterpenoids 1 and 2 , ent‐kaurane diterpenes 3 – 7 , triterpenoids 10 and 11 , steroids 12 – 14 , and flavonoids 15 – 17 as well as benzene derivatives 18 – 20 , were isolated from the aerial parts of Wedelia trilobata. The structures of wedelidins A ( 8 ) and B ( 9 ) were elucidated by extensive spectroscopic analyses (including UV, IR, NMR, and MS). Furthermore, the structures of compounds 2 and 3 were confirmed by X‐ray single‐crystal diffraction analyses. 相似文献
18.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(18):5069-5072
Natural products from marine animals show high potential for the development of new medicines, but drug development based on these compounds is commonly hampered by their low natural abundance. Since many of these metabolites are suspected or known to be produced by uncultivated bacterial symbionts, the rapidly growing diversity of sequenced prokaryotic genomes offers the opportunity to identify alternative, culturable sources of natural products computationally. In this work, we investigated the potential of using this sequenced resource to facilitate the production of meroterpenoid‐like compounds related to those from marine sources. This genome‐mining strategy revealed a biosynthetic gene cluster for highly modified cytotoxic meroterpenoids related to pelorol and other compounds isolated from sponges. Functional characterization of the terpene cyclase MstE showed that it generates an ent‐sterol‐like skeleton fused to an aryl moiety from an open‐chain precursor and is therefore a promising tool for the chemoenzymatic preparation of synthetically challenging chemical scaffolds. 相似文献
19.
Ankireddy Madhu Annam Suresh Chandra Venkata Appa Rao Sukki Sushma Ponnapalli Mangala Gowri Tuniki Venugopal Raju 《Helvetica chimica acta》2014,97(11):1531-1538
Two new constitutional isomers of ent‐labdane‐type diterpenoids, 1 and 2 , with an unusual seven‐membered lactone moiety (i.e., 1 ), together with two known compounds, 3 and 4 , were isolated from the acetone extract of Rhizophora mucronata. Their structures were elucidated as rhizomucronol A and B ( 1 and 2 , resp.) by spectroscopic analyses and chemical evidence. The absolute configuration of 2 was established by applying the Mosher ester procedure. 相似文献
20.
Wei Chen Xiao‐Dong Yang Jing‐Feng Zhao Hong‐Bin Zhang Liang Li 《Helvetica chimica acta》2007,90(8):1554-1558
One new ent‐8,9‐secokaurane diterpene, kongensin D ( 1 ), and one new ent‐kaurane diterpene, kongensin E ( 2 ), along with one known compound, (7α)‐7,18‐dihydroxy‐ent‐kaur‐16‐en‐15‐one 18‐acetate ( 3 ), were isolated from the aerial parts of Croton kongensis. The structures of the new compounds were elucidated by means of HR‐MS and in‐depth NMR experiments, and by comparison with literature data. Compounds 1 and 2 showed an unusual oxygenation pattern with an OH or AcO group at C(1). 相似文献