Three New ent‐Kaurane Diterpenoids from Siegesbeckia pubescens

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.     

New acetylenic glucosides from Carthamus tinctorius

Two new acetylenic glucosides, 4',6'-acetonide-8Z-decaene-4,6-diyne-1-O-beta-D-glucopyranoside named carthamoside A(1) (1) and 4,6-decadiyne-1-O-beta-D-glucopyranoside named carthamoside A(2) (2), along with one known acetylenic glucoside, 8Z-decaene-4,6-diyne-1-O-beta-D-glucopyranoside (3), have been isolated from the air-dried flower of Carthamus tinctorius, these structures have been identified on the basis of spectroscopic methods.     

黄草乌中的新二萜生物碱

从黄草乌(Aconitum vilmorinianum Kom.)根中分离得到三个新C~1~9-二萜生物碱: 黄乌宁(vilmorinine, 1), 黄乌生(vilmorisine20和黄乌亭(vilmoritine, 3)。采用波谱分析及化学方法确定了它们的结构。     

New ent-kaurane diterpenoid dimer from Pulicaria inuloides

A new naturally occurring ent-kaurane diterpenoid dimer, 15β, 15′β-oxybis (ent-kaur-16-en-19-oic acid) (1) along with six known compounds, 15β-hydroxy-ent-kaur-16-en-19-oic acid (2), 15β-hydroxy-ent-kaur-16-en-19-oate-β-d-glucopyranoside (3), 6-hydroxykaempferol-3, 7-dimethyl ether (4), quercetagetin 3, 7, 3′-trimethyl ether (5), β-sitosterol (6) and β-sitosterol glucoside (daucosterol) (7) were isolated from the aerial parts of Pulicaria inuloides DC. Compounds 2–5 were isolated for the first time from genus Pulicaria. The structures of compounds 1–7 were established on the basis of extensive 1D and 2D NMR spectroscopic techniques in combination with ESI-MS. The antimicrobial activity of the isolated compounds was evaluated against Staphylococcus aureus, Escherichia coli and Candida albicans. Sulphorhodamine B cytotoxic assay against HepG2 (liver cancer) cell line and ABTS antioxidant assay were carried out.     

New acetylenic glucosides from Bidens bipinnata LINNE

Two new acetylenic glucosides, 8Z-decaene-4,6-diyn-1-O-beta-D-glucopyranoside named bidenoside C, and 8E-decaene-4,6-diyn-3,10-dihydroxy-1-O-beta-D-glucopyranoside named bidenoside D, have been isolated from the aerial parts of Bidens bipinnata LINNE (Asterceae). These structures have been elucidated on the basis of spectroscopic methods.     

Novel Sesquiterpenoids from Siegesbeckia orientalis

Five new sesquiterpenoids, namely, 8β‐(angeloyloxy)‐4β,6α,15‐trihydroxy‐14‐oxoguaia‐9,11(13)‐dien‐12‐oic acid 12,6‐lactone ( 1 ), 4β,6α,15‐trihydroxy‐8β‐(isobutyryloxy)‐14‐oxoguaia‐9,11(13)‐dien‐12‐oic acid 12,6‐lactone ( 2 ), 11,12,13‐trinorguai‐6‐ene‐4β,10β‐diol ( 3 ), (1(10)E,4E,8Z)‐8‐(angeloyloxy)‐6α,15‐dihydroxy‐14‐oxogermacra‐(1(10),4,8,11(13)‐tetraen‐12‐oic acid 12,6‐lactone ( 9 ), and (1(10)E,4β)‐8β‐(angeloyloxy)‐6α,14,15‐trihydroxygermacra‐1(10),11(13)‐dien‐12‐oic acid 12,6‐lactone ( 11 ), and three new artifacts, (1(10)E,4Z)‐8β‐(angeloyloxy)‐9α‐ethoxy‐6α,15‐dihydroxy‐14‐oxogermacra‐1(10),4,11(13)‐trien‐12‐oic acid 12,6‐lactone ( 6 ), (1(10)E,4Z)‐8β‐(angeloyloxy)‐9α,13‐diethoxy‐6α,15‐dihydroxy‐14‐oxogermacra‐1(10),4‐dien‐12‐oic acid 12,6‐lactone ( 7 ), and (1(10)E,4Z)‐8β‐(angeloyloxy)‐9α‐ethoxy‐6α,15‐dihydroxy‐13‐methoxy‐14‐oxogermacra‐1(10),4‐dien‐12‐oic acid 12,6‐lactone ( 8 ), together with the three known sesquiterpenoids 4, 5 , and 10 , were isolated from the aerial parts of Siegesbeckia orientalis L. Their structures were established by spectral methods, especially 1D‐ and 2D‐NMR spectral methods.     

Rapid extraction and analysis method for the simultaneous determination of 21 bioflavonoids in Siegesbeckia pubescens Makino

A novel and rapid microwave extraction and ultra high performance liquid chromatography coupled with a triple quadrupole‐linear ion trap mass spectrometry method was developed and validated for the determination of 21 bioflavonoids in Siegesbeckia pubescens Makino. The optimal conditions for the extraction of flavonoids from Siegesbeckia pubescens Makino involved the use of methanol as the extraction solvent, a microwave temperature of 70°C, an extraction time of 11 min, and a solvent‐to‐solid ratio of 40 mL/g. Chromatographic separation was achieved on a Waters ACQUITY UPLC BEH C₁₈ column(100 × 2.1 mm, 1.7 μm) with a gradient mobile phase (A: 0.3% v/v aqueous formic acid and B: acetonitrile) at a flow rate of 0.25 mL/min. All calibration curves showed good linearity (r > 0.999) within the test ranges. The method developed was validated with acceptable sensitivity, intra‐ and interday precision, reproducibility, and extraction recoveries. The validated method was successfully applied to determine the contents of 21 bioflavonoids in Siegesbeckia pubescens Makino from different sources.     

New clerodane diterpenoid from the bulbils of Dioscorea bulbifera

A new clerodane diterpenoid has been isolated from the acetone extract of bulbils of Dioscorea bulbifera. The structure of compound 1 was established as 15,16-epoxy-6alpha-O-acety1-8beta-hydroxy- 9-nor-clero-13(16),14-diene-17,12;18,2-diolide on the basis of comprehensive spectroscopic techniques.     

New diterpenoid alkaloids from the roots of Delphinium tiantaishanense

Four new diterpenoid alkaloids: tiantaishansine (1), tiantaishannine (2), tiantaishanmine (3), and tiantaishandine (4) have been isolated from the roots of Delphinium tiantaishan. Their structures were elucidated by chemical evidence and spectral analyses, including ESI-MS, HR-EI-MS, 1D- and 2D-NMR.     

New neo-clerodane diterpenoid alkaloids from Scutellaria barbata with cytotoxic activities

Four new neo-clerodane diterpenoid alkaloids, named scutebarbatines I-L (1-4), were isolated from the whole plant of Scutellaria barbata D. DON. Their structures were established on the basis of detailed spectral analyses. In vitro, the four new compounds showed significant cytotoxic activities against three human cancer lines (HONE-1 nasopharyngeal, KB oral epidermoid carcinoma, and HT29 colorectal carcinoma cells), and gave IC(50) values in the range 3.2-8.3 microM.     

ent-pimarane-type diterpenoids from Siegesbeckia orientalis L

A new ent-pimarane glucoside, named hythiemoside B (4), was isolated from the aerial part of Siegesbecikia orientalis L. (Asteraceae) together with four known ent-pimarane-type diterpenoids: darutigenol (1), darutoside (2), hythiemoside A (3), and ent-(15R),16,19-trihydroxypimar-8(14)-ene 19-O-beta-D-glucopyranoside (5). The structure of the new compound was elucidated by spectroscopic analyses and chemical transformation. The NMR data of compounds 1 (1H-) and 5 (1H- and 13C-) were also compiled in this study on the basis of 2D experiments.     

An HPLC method for simultaneous quantitative determination of seven secoiridoid glucosides separated from the roots of Ilex pubescens

A simple and specific high‐performance liquid chromatographic method has been developed and validated to simultaneously determine seven secoiridoid glucosides for the first time. Three of them were separated from the ethanolic extract of the roots of Ilex pubescens for the first time, namely nuezhenide A, ligusides B and oleonuezhenide. In quantitative analysis, all of the calibration curves showed good linear regression (r > 0.999) within the tested ranges, and the mean recoveries of three different concentrations ranged from 97.6 to 101.2%. The limit of detection and limit of quantification were <4.18 and 11.63 ng mL⁻¹, respectively. The relative standard deviation for repeatability and the precision of seven analytes were <3.4 and 1.9%, respectively. The established method was successfully applied to simultaneous determination of seven secoiridoid glucosides in 11 batches of samples collected from different habitats in China.     

New lignan glucosides from the stems of Tinospora sinensis

Two new lignan glucosides, tinosposides A and B (1 and 2), were isolated from the stems of Tinospora sinensis collected in Hainan Island, China. Their structures were elucidated on the basis of spectroscopic analysis and chemical evidence.     

New alpha-tetralonyl glucosides from the fruit of Juglans mandshurica

Five new alpha-tetralonyl glucosides, juglanosides A-E (1-5) were isolated from the fresh rejuvenated fruit of Juglans mandshurica. Their structures were elucidated as (4S)-4-hydroxy-alpha-tetralone 4-O-beta-D-glucopyranoside (1), (4S)-4,5-dihydroxy-alpha-tetralone 4-O-beta-D-glucopyranoside (2), (4S)-4,6-dihydroxy-alpha-tetralone 4-O-beta-D-glucopyranoside (3), (4S)-4,5,8-trihydroxy-alpha-tetralone 4-O-beta-D-glucopyranoside (4), and (4S)-4,5,8-trihydroxy-alpha-tetralone 5-O-beta-D-glucopyranoside (5) on the basis of spectroscopic analysis and chemical evidence.     

New iridoid glucosides from the aerial parts of Verbena brasiliensis

Two new iridoid glucosides, verbenabraside A (1) and verbenabraside B (2), were isolated from the aerial parts of Verbena brasiliensis VELL., along with six known iridoid glucosides, gelsemiol 3-O-beta-D-glucoside (3), verbraside (4), 9-hydroxysemperoside (5), griselinoside (6), aralidioside (7), and 6alpha-hydroxyforsythide dimethyl ester (8), three known phenylethanoid glycosides, 2-phenylethyl O-beta-D-xylopyranosyl-(1-->2)-beta-D-glucopyranoside (9), acteoside (10), and leucosceptoside A (11), two known lignan glucosides, dihydroxymethyl-bis(3,5-dimethoxy-4-hydroxyphenyl) tetrahydrofuran-9 (or 9')-O-beta-glucopyranoside (12) and (+)-lyoniresinol 3alpha-O-beta-D-glucopyranoside (13), a known methyl salicylate glucoside, methyl 2-O-beta-D-glucopyranosylbenzoate (14), and two known sterols, beta-sitosterol 3-O-beta-D-glucopyranoside (15) and beta-sitosterol (16). Their chemical structures were determined on the basis of spectroscopic data. Compound 1 exhibited stronger scavenging effect on the stable free radical 1,1-diphenyl-2-picrylhydrazyl than that of alpha-tocopherol.     

New triterpene glucosides from the roots of Rosa laevigata Michx

Two new ursane-type triterpene glucosides, 2alpha,3alpha,24-trihydroxyurs-12,18-dien-28-oic acid beta-D-glucopyranosyl ester (1) and 2alpha,3alpha,23-trihydroxyurs-12,19(29)-dien-28-oic acid beta-D-glucopyranosyl ester (2), were isolated from the roots of Rosa laevigata, together with three known compounds: 2alpha,3beta,19alpha-trihydroxyurs-12-en-28-oic acid beta-Dglucopyranosyl ester (3), 2alpha,3alpha,19alpha-trihydroxyurs-12-en-28-oic acid beta-D-glucopyranosyl ester (4) and 2alpha,3beta,19alpha,23-tetrahydroxyurs-12-en-28-oic acid beta-D-glucopyranosyl ester (5). The structures of new compounds were established on the basis of detailed 1D and 2D NMR spectroscopic analyses. Compounds 2 and 5 exhibited modest in vitro antifungal activities against Candida albicans and C. krusei.     

Pubescone,a Novel 11(7→6)Abeo‐14‐norcarabrane Sesquiterpenoid from Siegesbeckia pubescens

The phytochemical investigation of the aerial parts of Siegesbeckia pubescens L. yielded 16 sesquiterpenoids, including a novel 11(7→6)abeo‐14‐norcarabrane sesquiterpenoid, pubescone ( 1 ), and a new germacrane sesquiterpene, 5 . The molecular structures of the isolated compounds were elucidated on the basis of extensive spectroscopic analysis, including 1D‐ and 2D‐NMR.