Eburneolins A and B,new withanolide glucosides from Tricholepis eburnea

Eburneolins A (1) and B (2), new withanolide glucosides, have been isolated from the n-butanolic fraction of the 75% methanolic extract of aerial parts of Tricholepis eburnea. Their structures were elucidated through spectroscopic analysis including ESI-MS, 2D NMR and acid hydrolysis.     

Two new secoiridoid glucosides from Syringa velutina Kom

Chemical investigation of Syringa velutina Kom. led to the isolation of two new secoiridoid glucosides. Their structures were identified as 6'-0-(6, 7-dihyrofoliamenthoyl)-8-epi-kingisidic acid (syrveoside A, 1) and 6'-O-menthiafoloyl-8-epi-kingisidic acid (syrveoside B, 2) on the basis of chemical and physicochemical evidence.     

Two new secoiridoid glucosides from Syringa velutinai Kom.

Chemical investigation of Syringa velutinai Kom. led to the isolation of two new secoiridoid glucosides. Their structures were identified as 6'-O-(6, 7-dihyrofoliamenthoyl)-8-epi-kingisidic acid (syrveoside A, 1) and 6'-O-menthiafoloyl-8-epi-kingisidic acid (syrveoside B, 2) on the basis of chemical and physicochemical evidence.     

Two new benzophenone glucosides from Cratoxylon cochinchinensis

Two new benzophenone glucosides were isolated from the 60%ethanol extract of the dried stems of Cratoxylum cochinchinense. The structures were elucidated as 3-O-β-D-glucopyranosyl-2′,4,6′-trihydroxy-benzophenone and 3-O-β-D-glucopyranosyl-2′,5,6′-trihydroxybenzophenone on the basis of spectral and chemical methods.     

Structural determination of quercusides A and B,new flavonoid glucosides from Quercus incana,by 1D and 2D NMR spectroscopy

Quercusides A and B, new flavonoid glucosides have been isolated from the chloroform soluble fractions of Quercus incana. Their structures were assigned from ¹H and ¹³C nuclear magnetic resonance spectra, distortionless enhancement by polarization transfer (DEPT) and by correlation spectroscopy, heteronuclear multiple quantum correlation (HMQC) and heteronuclear multiple bond correlation (HMBC) experiments. Lupeol, β‐sitosterol and ursolic acid have also been reported from this species. Copyright © 2009 John Wiley & Sons, Ltd.     

Dioclins A and B,new antioxidant flavonoids from Dioclea reflexa

Dioclins A (1) and B (2), the new flavonoids, have been isolated from the ethyl acetate soluble fraction of the roots of Dioclea reflexa along with 3,5-dihydroxy-4 methoxybenzoic acid (3), lupeol (4) and the rare dipeptide, auratiamide acetate (5). Their structures have been elucidated by spectroscopic techniques. The compounds 1 and 2 showed a significant antioxidant activity in DPPH radical scavenging assay.     

Two new steroidal glucosides from Ophiopogon.japonicus （L.f.） Ker-Gawl

Two new steroidal glucosides, 26-O-β-D-glucopyranosyl （25S）-furost-5-ene-1β,3β,22α,26-tetraol l-O-β-D-xylopyranosyl- （1 → 3）-[α-h-rhamnopyranosyl-（1 → 2）]-[β-D-fueopyranoside and （25R） spirost-5-ene-3β,14α-diol-3-β-O-β-L-rhanmopyranosyl- （1 → 2）-[β-D-xylopyranosyl（1 → 4）]-[-β-D-glucopyranoside, were isolated from the Ophiopogon japonicus （L.f.） Ker-Gaw. Their structures were elucidated by spectroscopic methods.     

Mekongenines A and B, two new alkaloids from Bousigonia mekongensis

Mekongenine A (1) possessing an unprecedented structure constituted from the union of a rare 2,7-seco eburnamine half and an aspidospermine alkaloid, together with a new bisindole alkaloid, mekongenine B (2), consisting of an eburnamine-aspidospermine type skeleton, was isolated from Bousigonia mekongensis. Their structures were elucidated by means of spectroscopic methods and those of 2 were further confirmed by X-ray diffraction. The absolute configurations of 1 and 2 were determined by comparison of quantum chemical TDDFT calculated and experimental ECD spectra. Mekongenines A (1) and B (2) exhibited cell growth inhibitory activities against various human cancer cell lines.     

Conomicidines A and B,Unusual Alkaloid–Hydroxycinnamyl Alcohol Conjugates from Tabernaemontana corymbosa

Conomicidines A and B ( 1a and 2a , resp.) together with the diastereomeric isoconomicidines A and B ( 1b and 2b , resp.) were isolated from Tabernaemontana corymbosa as unresolvable mixtures of the (1′S,2′S)‐ and (1′R,2′R)‐diastereoisomers (i.e., 1a and 1b ; 2a and 2b ). These novel natural products are constituted from the union of an iboga alkaloid, ibogaine, and hydroxycinnamyl alcohol moieties, and represent the first examples of such alkaloid–hydroxycinnamyl alcohol conjugates. The structures were determined by spectroscopic methods, including the extensive use of NOE experiments for the assignment of the configuration.     

Coagulansins A and B,New Withanolides from Withania coagulans Dunal

Coagulansins A ( 1 ) and B ( 2 ), two new withanolides, were isolated from the CHCl₃‐soluble fraction of Withania coagulans Dunal , along with two known withanolides, coagulin R and withanolide P. Their structures were assigned by means of ¹H‐ and ¹³C‐NMR spectra, DEPT, and ¹H,¹H‐COSY, NOESY, HMQC, and HMBC experiments.     

Hyperinoids A and B,two polycyclic meroterpenoids from Hypericum patulum

Hyperinoids A (1) and B (2), two prenylated acylphloroglucinol related meroterpenoids, were isolated from Hypericum patulum. Compound 1 incorporates an unprecedented 11,12-dioxatetracyclo[5.4.3.0^1,7.0^4,14]tetradecane system, while 2 possesses a unique 10,11-dioxatetracyclo[5.3.3.0^1,7.0^4,13]tridecane system. Their structures were established by spectroscopic analysis and X-ray crystallographic data. Compounds 1 and 2 were identified as potent NF-κB inhibitors and suppressed the LPS-induced inflammatory responses in RAW 246.7 macrophages and primary mouse BMDM cells     

Rapulasides A and B: two novel intermolecular rearranged biiridoid glucosides from the roots of Heracleum rapula

Two novel intermolecular rearranged biiridoid glucosides, rapulasides A and B (1 and 2), have been isolated from the roots of Heracleum rapula. Their structures were identified by extensive spectral analysis especially different NMR techniques. NOESY experiment, with the help of Dreiding molecular model, was used to elucidate their relative stereochemistry. Both compounds were tested for their inhibitory effects on rabbit platelet aggregation induced by PAF, ADP, or AA, respectively. Only trends of inhibition were observed for them.     

Structural determination of kochiosides A-C, new steroidal glucosides from Kochia prostrata, by 1D and 2D NMR spectroscopy

Kochiosides A-C, three new steroidal glucosides, have been isolated from the ethyl acetate fraction of Kochia prostrata and their structures assigned from its (1)H and (13)C NMR spectra, DEPT and by 2D COSY, NOESY, HMQC and HMBC experiments.     

Clavulazols A and B,Two New Pyrazine Derivatives from Clavularia Viridis

Two new marine pyrazine derivatives, clavulazols A ( 4 ) and B ( 5 ), were isolated from ethyl acetate extract of the soft coral Clavularia viridis collected in Taiwan. The structures were determined on the basis of spectral analysis, especially 2D NMR as well as chemical conversion.     

Two New O-terpenoidal Coumarins, Excavacoumarin A and B from Clausena excavata

Cla!tsenaexcavataBurm.f(Rutaceae)isabushwidelydistributedinYunnan,China.Leavesandbarksofthisplanthavebeenusedasfolkrnedicineforthetreatmentofdysentery,enteritis,andurethrainfection1.ClalISenaspeciesareknowntobetherichsourcesofcarbazolealkaloidsandcoumarins=-j.TheconstituentsofCexcavalacollectedinXishuangbannahavebeenstudied'andthispaperdescribestheisolationandstructureelucidationoftwonewO-terpenoidalcoumarins,excavacoumarinA(2)andexcavacoumarinB(3),andthel3CNMRspectraldataassignmentsfora…     

Two new diacetylene glycosides: bhutkesoside A and B from the roots of Ligusticopsis wallichiana

Two new diacetylene glycosides: bhutkesoside A (1) and B (2), along with 10 known compounds, i.e. falcarindiol (3), chlorogenic acid (4), 5-O-p-coumaroyl-quinic acid (5), 3,5-di-O-caffeoyl-quinic acid (6), 4-hydroxy-7-methoxy-phenylethanol (7), ferulic acid (8), dehydrodiconiferyl alcohol-4-O-β-d-glucopyranoside (9), 5,7-dihydroxy-2-methylchromone-7-O-rutinoside (10), schumanniofioside B (11) and marmesinin (12) were isolated from the roots of Ligusticopsis wallichiana (DC) Pimenov & Kljuykov (Apiaceae), commonly known as ‘Bhutkesh’ in Nepal. The structures were determined on the basis of spectroscopic data. Compounds 4 and 6 showed potent antioxidant activity on DPPH free radical scavenging assay.     

Panaxfuraynes A and B, two new tetrahydrofuranic polyacetylene glycosides from Panax ginseng C. A. Meyer

Panaxfurayne A (1), a tetrahydrofuranic polyacetylene glycoside, was isolated from the roots of Panax ginseng C. A. Meyer (Araliaceae) together with panaxfurayne B (2) as a geometric isomer of 1. The chemical structures of these two compounds were ascertained by UV, Mass, 1D, and 2D NMR experiments. During these experiments, these tetrahydrofuranic polyacetylene compounds proved to be of biogenetically novel type.     

Two New Iridoid Alkaloids,Daphmacropodosidines A and B,from Daphniphyllum macropodum

Two new iridoid alkaloids, daphmacropodosidines A ( 1 ) and B ( 2 ), together with two known ones, daphcalycinosidine B and caldaphnidine F, were isolated from the fruits of Daphniphyllum maropodum. Their structures were established by spectral methods, especially 2D NMR spectra (¹H,¹H‐COSY, HMQC, HMBC, and NOESY), as well as chemical means.