Xanthones from Garcinia cowa Roxb. latex

Five xanthones named cowagarcinone A-E and six previously reported xanthones were isolated from the latex of Garcinia cowa Roxb. Their structures were determined on the basis of spectroscopic analysis. The crude latex and the isolated compounds were investigated for their radical scavenging activities.     

Phenolic glycosides from Markhamia stipulata

From the leaves and branches of Markhamia stipulata, five verbascoside derivatives (markhamiosides A-E), and one hydroquinone derivative (markhamioside F) were isolated together with 13 known compounds. Their structural elucidation was based on analyses of chemical and spectroscopic data.     

Mulavanins A-E: Limonoids from Munronia delavayi

Limonoids, mulavanins A-E (1-5), along with four known compounds, were isolated from whole plants of Munronia delavayi. Their structures were elucidated by spectroscopic methods. Two of the compounds showed modest antifungal activity.     

Tetraoxygenated xanthones from the fruits of Garcinia cowa

Tetraoxygenated xanthones, cowaxanthones A-E, together with 10 previously reported tetraoxygenated xanthones, were isolated from the crude hexane extract of the fruits of Garcinia cowa. Cowaxanthone B has previously been reported as a synthetic xanthone. Their structures were elucidated by analysis of spectroscopic data, especially by 1D and 2D NMR. The antibacterial activities of the isolated compounds were also evaluated.     

Five new C21 steroidal glycosides from Periploca sepium

Five new C₂₁ steroidal glycosides, named periseosides A-E (1-5), along with six known analogues, were isolated from the root barks of Periploca sepium. Their structures were elucidated on the basis of spectroscopic analysis and chemical evidence. All compounds were evaluated for their immunosuppressive activities.     

Phragmalin limonoids from Chukrasia tabularis

Six phragmalin limonoids, named tabulalin and tabulalides A-E, were isolated from the root bark of Chukrasia tabularis (Meliaceae). Their structures were determined by spectroscopic methods, and their antifeedant properties evaluated.     

Eudesmane and megastigmane glucosides from Laggera alata

Four eudesmane glucosides, alatosides A-D (1-4), and one megastigmane glucoside, alatoside E (5), were isolated from the BuOH fraction of Laggera alata along with six known compounds. Structures of the new compounds were elucidated by a combination of chemical and spectroscopic methods. Alatosides A-E were characterized as: 1alpha-O-(beta-D-glucopyranosyloxyl)-7-epi-eudesma-11-en-2beta,4alpha-diol (1), 2beta-O-(beta-D-glucopyranosyloxyl)-eudesma-4alpha-hydroxyl-11(13)-en-12-oic-acid (2), 5beta-O-(beta-D-glucopyranosyloxyl)-eudesma-4(15),11(13)-dien-12-oic-acid (3), 5alpha-O-(beta-D-glucopyranosyloxyl)-eudesma-3,11(13)-dien-12-oic acid (4) and 3beta-O-(beta-D-glucopyranosyloxyl)-megastigma-9-one (5), respectively. Based on the chemical characteristics of eudesmane derivatives isolated from the Laggera genus, it was suggested that there are probably two different biogenetic pathways for these secondary metabolites in this genus.     

Cytotoxic dihydrobenzophenanthridine alkaloids from the roots of Macleaya microcarpa

Five dihydrobenzophenanthridine alkaloids, named as maclekarpine A-E, were isolated from the roots of Macleaya microcarpa, together with 10 known benzophenanthridine/dihydrobenzophenanthridine derivatives and a known amide. Their structures were determined on the basis of spectroscopic methods. The relative configuration of maclekarpine A was solved by X-ray single-crystal diffraction, which also contributed to the establishment of the relative configuration of maclekarpine B and C, as well as the assignment of the absolute configuration of maclekarpine A-C with aid of their CD curves. Cytotoxicity of the isolated compounds against five human tumor cell-lines was evaluated, with some having activity with IC₅₀ values ranging from 0.1 to 3.5 μM.     

The unusual canangafruticosides A-E: Five monoterpene glucosides, two monoterpenes and a monoterpene glucoside diester of the aryldihydronaphthalene lignan dicarboxylic acid from leaves of Cananga odorata var. fruticosa

From the leaves of Cananga odorata var. fruticosa, five unusual monoterpene glucosides, named canangafruticosides A-E (1-5), along with two unusual non-glucosidic monoterpenes (6, 7) were isolated. An aryldihydronaphthalene-type lignan dicarboxylate (8) was also isolated, with two moles of canangafruticoside A (1) on its ester moiety. This lignan also showed strong blue fluorescence emission under basic conditions. The structures of these compounds were elucidated by means of spectroscopic methods, with their absolute configurations determined by application of the modified Mosher’s method to a compound chemically derived from canangafruticoside E.     

Antimalarial tetranortriterpenoids from the seeds of Lansium domesticum Corr

Five tetranortriterpenoids, domesticulide A-E (1-5), were isolated from seeds of Lansium domesticum Corr. together with 11 known triterpenoids (6-16). Their structures were elucidated by analysis of their spectroscopic data. Compounds 2, 3, 4, 7, 8, 10, 11, and 15 showed antimalarial activity against Plasmodium falciparum with IC(50)'s of 2.4-9.7 microg/ml.     

Trinorcucurbitane and cucurbitane triterpenoids from the roots of Momordica charantia

Five cucurbitacins, kuguacins A-E (1-5), together with three known analogues, 3beta,7beta,25-trihydroxycucurbita-5,(23E)-diene-19-al (6), 3beta,25-dihydroxy-5beta,19-epoxycucurbita-6,(23E)-diene (7), and momordicine I (8), were isolated from roots of Momordica charantia. Structures of 1-5 were elucidated by NMR and MS spectroscopic analysis. Among them, compounds 3-5 possess an unprecedented 25,26,27-trinorcucurbitane backbone. Compounds 3 and 5 showed moderate anti-HIV-1 activity with EC(50) values of 8.45 and 25.62 microg/ml, and exerted minimal cytotoxicity against C8166 cells (IC(50)>200 microg/ml), with a selectivity index more than 23.68 and 7.81, respectively.     

Amurensiosides A-K, 11 new pregnane glycosides from the roots of Adonis amurensis

Five new pregnane tetraglycosides, amurensiosides A-E (1-5), two new pregnane hexaglycosides, amurensiosides F (6) and I (9), two new 18-norpregnane hexaglycosides, amurensiosides G (7) and H (8), and two new pregnane octaglycosides, amurensiosides J (10) and K (11), were isolated from the MeOH extract of the roots of Adonis amurensis. The structures of the new compounds were determined on the basis of extensive spectroscopic analysis, including two-dimensional (2D) NMR data, and the results of hydrolytic cleavage. The isolated compounds were evaluated for their cytotoxic activity against HSC-2 human oral squamous cell carcinoma cells.     

Indole alkoloids from Nauclea officinalis with weak antimalarial activity

Five indole alkaloids (naucleofficines A-E) were isolated from the stems (with bark) of Nauclea officinalis: (E)-2-(1-beta-d-glucopyranosyloxybut-2-en-2-yl)-3-(hydroxymethyl)-6,7-dihydro-indolo[2,3-a]quinolizin-4(12H)-one (1), (E)-1-propenyl-12-beta-d-glucopyranosyloxy-2,7,8-trihydro-indolo[2,3-a]pyran[3,4-g]quinolizin-4,5(13H)-dione (2), (E)-2-(1-hydroxybut-2-en-2-yl)-11-beta-d-glucopyranosyloxy-6,7-dihydro-indolo[2,3-a]quinolizin-4(12H)-one (3), (E)-1-propenyl-4-hydroxy-2,4a,7,8,13b,14,14a-hepthydro-(4alpha,4abeta,13balpha,14abeta)indolo[2,3-a]pyran[3,4-g]quinolizin-5(13H)-one (4) and 1-(1-hydroxyethyl)-10-hydroxy-7,8-dihydro-indolo[2,3-a]pirydine[3,4-g]quinolizin-5(13H)-one (10-hydroxyangustoline) (5), together with two known compounds, naucleidinal (6) and angustoline (7). All of the structures of the seven compounds above were elucidated by spectroscopic methods including use of 1D- and 2D-NMR spectroscopic analyses. Compounds 2 and 3 are rare examples of monoterpene indole alkaloids with a glucopyranosyloxy group attached to position C-12. In vitro activity screening of the above seven compounds showed weak to moderate inhibitory activity against Plasmodium falciparum.     

Two oligostilbenes,cis- and trans-diptoindonesin B,from Dryobalanops oblongifolia

Two oligostilbenes, cis- and trans-diptoindonesin B, have been isolated from the tree bark of Dryobalanops oblongifolia (Dipterocarpaceae). The structures and relative configurations of both compounds were determined on the basis of spectroscopic evidence, including 2D-NMR spectroscopic analysis.     

Five new iridoids from Patrinia rupestris

Five new iridoids, namely rupesin A-E (1-5, resp.), together with six known iridoids, 6-11, were isolated from the roots of Patrinia rupestris. Their structures were elucidated by spectroscopic methods including IR, UV, MS, and 1D- and 2D-NMR experiments, and comparison with data of known analogues. Compounds 4 and 11, compounds 1, 2, 5, 6, 8, 9, and 10, and compounds 3, 4, and 8 showed significant antibacterial activities against Bacillus subtilis, Escherichia coli, and Staphylococcus aureus, respectively.     

Polystachynes A-E, five cis-neo-clerodane diterpenoids from Salvia polystachya

From the aerial parts of Salvia polystachya five new neo-clerodane diterpenoids, polystachynes A-E, have been isolated. The structures were established by spectroscopic methods, including the X-ray analysis of polystachynes C and D. The known clerodanes salvifaricin, linearolactone and dehydrokerlin were also isolated.     

Lithocarols A-F,six tenellone derivatives from the deep-sea derived fungus Phomopsis lithocarpus FS508

Lithocarols A-F (1–6) possessing novel highly-oxygenated isobenzofuran core, together with a related known compound isoprenylisobenzofuran A (7) were isolated from the marine-derived fungus Phomopsis lithocarpus FS508. Among them, lithocarols A-E (1–5) represent the first examples of poly-ketal derivatives in tenellone family. The structures for all these compounds were fully elucidated by spectroscopic analysis, X-ray diffraction, and electronic circular dichroism calculations. Their cytotoxic assay disclosed that compounds 1–4 displayed moderate growth inhibitory effect against four human tumor cell lines with the IC₅₀ values ranging from 10.5 to 38.7 μM.     

Cyclic diarylheptanoids from Myrica nana inhibiting nitric oxide release

Investigation of the roots of Myrica nana afforded five new cyclic diarylheptanoids, myricananins A-E (1-5), two new artifacts of myricananins A and B (6-7), and four known compounds, 12-hydroxymyricanone (8), alnusonol (9), myricatomentogenin (10), and actinidione (11). The structures of these new compounds were established by detailed spectroscopic methods. The stereochemistry of compounds 1 and 2 were determined by single-crystal X-ray diffraction. In exception of compounds 2, 6 and 10, all the other compounds were examined for their inhibitory effects on nitric oxide production in lipopolysaccharides-activated macrophages. Compounds 1, 3, 7, 8 and 9 inhibited the release of nitric oxide with IC(50) values of 45.32, 63.51, 52.81, 30.19 and 46.18muM, respectively. Furthermore, compound 1 was found to inhibit the expression of inducible nitric oxide synthase.     

Coumaroyl triterpene lactone, phenolic and naphthalene glycoside from stem bark of Diospyros angustifolia

From the ethanolic extract of stem bark of D. angustifolia three new compounds, a coumaroyl triterpene lactone, diospyrosooleanolide (1), a phenolic glycoside, diospyrososide (2) and a naphthalene glycoside, diospyrosonaphthoside (3) were isolated along with five known compounds (4-8). The structures of these compounds were established on the basis of spectroscopic and chemical evidences.     

New 29-nor-cycloartanes with a 3,4-seco- and a novel 2,3-seco-structure from the leaves of Sinocalycanthus chinensis

Eight new triterpenoids, including sinocalycanchinensins A-E (1-5) with a 3,4-seco-29-nor-cycloartane skeleton, sinocalycanchinensin F (6) possessing a novel 2,3-seco-29-nor-cycloartane skeleton, and 29-nor-cycloartanes, sinocalycanchinensins G and H (7 and 8), have been isolated from the leaves of Sinocalycanthus chinensis. Their structures were elucidated on the basis of spectroscopic examinations. The cytotoxicities of the isolated new triterpenes against a panel of human cancer cell lines, including multi-drug resistant (MDR) cancer cell lines, were also evaluated. Compound 5 demonstrated enhanced cytotoxicity against MDR KB cells in the presence of colchicine, although all the compounds showed moderate or no cytotoxicities.