Africane-type sesquiterpenoids from the Argentine liverwort Porella swartziana and their antibacterial activity

Seven africanes (1, 2a,b, 3-6), two of them new (1, 2a), three secoafricanes (7-9), one of them new (7), and two norsecoafricanes (10, 11a), one of them new (10), all of them swartzianin-type, have been isolated from an Argentine collection of the endemic liverwort Porella swartziana. The structures of the new compounds were established by extensive 1D and 2D NMR spectroscopic data. Absolute configurations of compounds 2a, 2b, and 10 were derived on the basis of CD spectra. The compounds were tested for activity against a variety of microbes, but none were found to exhibit significant antibacterial activity.     

Phenolic constituents of the roots of Sophora flavescens

From the roots of Sophora flavescens collected in Taiwan, four new prenylflavonoids, sophoraflavanone K (1), sophoraflavanone L (2), 8-lavandulylkaempferol (3), and cyclokuraridin (4), a new arylbenzofuran, 2-(2,4-dihydroxy-5-prenylphenyl)-5,6-methylenedioxybenzofuran (5), and a new prenyldibenzoyl derivative, sophoradione (6), were isolated. The structures of 1-6 were determined by spectroscopic data analysis. Compounds 2-6 were evaluated for cytotoxic activity against the KB epidermoid carcinoma cell line.     

Bacopaside III,bacopasaponin G,and bacopasides A,B, and C from Bacopa monniera

Two new saponins, 3-O-[6-O-sulfonyl-beta-d-glucopyranosyl-(1-->3)]-alpha-l-arabinopyranosyl pseudojujubogenin (1) and 3-O-[alpha-l-arabinofuranosyl-(1-->2)]-alpha-l-arabinopyranosyl jujubogenin (2), a new matsutaka alcohol derivative, (3R)-1-octan-3-yl-(6-O-sulfonyl)-beta-d-glucopyranoside (3), a new phenylethanoid glycoside, 3,4-dihydroxyphenylethyl alcohol (2-O-feruloyl)-beta-d-glucopyranoside (4), and a new glycoside, phenylethyl alcohol [5-O-p-hydroxybenzoyl-beta-d-apiofuranosyl-(1-->2)]-beta-d-glucopyranoside (5), were isolated from Bacopa monniera. Their structures were established by NMR, MS, and chemical methods.     

Phenolic compounds from tournefortia sarmentosa

Three new isoprenylbenzenes, tournefolins A (1), B (2), and C (3), and two new 2-ethoxy-4,5-dihydroxybenzoyl compounds, 4 and 5, together with the known compounds, salicylic acid and allantoin, were isolated from the stems of Tournefortia sarmentosa. The structures of new compounds were elucidated as 2-(4beta-methyltetrahydrofuran-2alpha-yl)-5-(4beta-methyltetrahydrofu ran-2beta-yl)-1,4-dihydroxybenzene (1), methyl 5-(5-hydroxy-2-methoxyphenyl)-3-furoate (2), methyl 5-(2, 5-dihydroxyphenyl)-3-furoate (3), 2-ethoxy-4,5-dihydroxybenzaldehyde (4), and 2-ethoxy-4,5-dihydroxybenzoic acid (5), on the basis of spectral and chemical methods. The relative configuration of 1 was determined by single-crystal X-ray crystallography.     

Phloroglucinols with antioxidant activity and xanthonolignoids from the heartwood of Hypericum geminiflorum

A new phloroglucinol, hyperielliptone HA (1/1a), a new spirophloroglucinol possessing an unprecedented skeleton, hyperielliptone HB (2/2a), and two new xanthonolignoids, hyperielliptones HC (3) and HD (4), were isolated from the heartwood of Hypericum geminiflorum. Compounds 1/1a and 2/2a were obtained as tautomeric pairs. The structures and relative configurations of these compounds were elucidated by spectroscopic methods. In biological testing, compound 2/ 2a revealed significant inhibition of oxidative DNA damage and an inhibitory effect on xanthine oxidase.     

Triterpene saponins from the leaves of Ilex kudingcha

Nine new triterpene saponins, ilekudinosides K-S (1-9), and eight known triterpene saponins were isolated from the 70% ethanol extract of the leaves of Ilex kudingcha. The new saponins were characterized as 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl-alpha-kudinlactone (1), 3-O-beta-D-glucopyranosyl(1-->3)-alpha-L-arabinopyranosyl-beta-kudinlactone (2), 3-O-alpha-L-rhamnopyranosyl(1-->2)-alpha-L-arabinopyranosyl-gamma-kudinlactone (3), 3-O-beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranosyl-alpha-kudinlactone (4), 3-O-beta-D-glucopyranosyl(1-->2)-alpha-L-arabinopyranosyl-alpha-kudinlactone (5), 3-O-beta-D-glucopyranosyl(1-->3)-alpha-L-arabinopyranosyl-alpha-kudinlactone (6), 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl-beta-kudinlactone (7), 3-O-alpha-L-rhamnopyranosyl(1-->2)-alpha-L-arabinopyranosyl-beta-kudinlactone (8), and 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl-gamma-kudinlactone (9), respectively. The structures and stereochemistry of compounds 1-9 were elucidated by spectroscopic data interpretation and chemical degradation.     

Seco-prezizaane-type sesquiterpenes and an abietane-type diterpene from Illicium minwanense

A methanol extract of the pericarps of Illicium minwanense afforded seven new seco-prezizaane-type sesquiterpenes (2-8) and a new abietane-type diterpene (9), together with six previously known compounds (1 and 10-14). The structures of the new compounds, (1S)- and (1R)-minwanenone (2 and 3), 1alpha-hydroxy-6-deoxypseudoanisatin (4), (2S)-hydroxy-6-deoxypseudoanisatin (5), 3-oxopseudoanisatin (6), (3S,6R)-4,7-epoxy-6-deoxypseudoanisatin (7), 7-O-methylpseudomajucin (8), and (+)-8,11,13,15-abietatetraene (9), were elucidated by spectroscopic data analysis and chemical transformations. The absolute configurations of 1 and 5 were established by X-ray crystallographic analysis of their p-bromobenzoyl derivatives.     

Structures of new sesquiterpenes and hepatoprotective constituents from the Egyptian herbal medicine Cyperus longus

Six new sesquiterpenes, cyperusols A(1) (1), A(2) (2), B(1) (3), B(2) (4), C (5), and D (6), together with two monoterpenes and 13 sesquiterpenes were isolated from an Egyptian herbal medicine, the whole plants of Cyperus longus. The stereostructures of the new sesquiterpenes were determined on the basis of chemical and physicochemical evidence. In addition, the principal constituents were found to exhibit inhibitory activity on D-galactosamine-induced cytotoxicity in primary cultured mouse hepatocytes.     

Two Alangium alkaloids from Alangium lamarckii

Two new Alangium alkaloids, 1',2'-dehydrotubulosine (1) and alangine (2), were isolated from the dried fruits of Alangium lamarckii along with tubulosine (3), isotubulosine (4), deoxytubulosine, cephaeline, isocephaeline, psychotrine, neocephaeline, 10-O-demethylcephaeline, 2'-N-(1"-deoxy-1" -beta-D-fructopyranosyl)cephaeline, protoemetine, protoemetinol, salsoline, and alangiside. The structures of the new alkaloids (1 and 2) were determined by spectroscopic and chemical means.     

Constituents from the leaves of Phellodendron amurense var. wilsonii and their bioactivity

Two new dihydroflavonols, phellodensin-A (1) and phellodensin-C (2); three new coumarins, phellodenol-A (3), phellodenol-B (4), and phellodenol-C (5); one new chlorophyll, phellophyll-a (6); and one new phenyllactate, (2R)-sodium 3-phenyllactate (7), in addition to 35 known compounds have been isolated from the leaves of Phellodendron amurense var. wilsonii. The structures of the new compounds were established based on 1D, 2D NMR and mass spectral analyses. The stereochemistry at the C-2, C-3, and C-2' ' positions of new dihydroflavonol 1 was determined by CD spectroscopy. The known compounds were identified by comparison with authentic samples. The antioxidant and antityrosinase activities were also described.     

Dimeric and trimeric hydrolyzable tannins from Quercus coccifera and Quercus suber

Three new hydrolyzable tannins, cocciferins D(1) (1), D(2) (2), and T(1) (4), were isolated from the leaves of Quercus coccifera. Cocciferin D(2) (2) and two additional new tannins, cocciferins D(3) (3) and T(2) (5), were also obtained from the leaves of Quercus suber. Their oligomeric structures were elucidated on the basis of spectroscopic methods and chemical evidence. Compounds 2, 3, and 5 were rare oligomers possessing glucose cores with both open-chain and pyranose forms.     

Saponins and flavonoids of Allium triquetrum

A phytochemical investigation of the flowers and bulbs of Allium triquetrum has been undertaken, leading to the isolation of five new furostanol saponins, triquetrosides A1/A2 (1a/1b), B (3), and C1/C2 (4a/4b), from the flowers, along with ascalonisides A1/A2 (6a/6b). The 22-O-methyl derivatives of triquetrosides A1/A2 (2a and 2b) and C1/C2 (5a and 5b) were also isolated, but they are considered extraction artifacts. Large amounts of seven kaempferol glycosides, of which one (7) has a new structure, were also isolated from both flowers and bulbs. The structures of the new compounds were determined by spectral and chemical methods.     

Antioxidant principles from Bauhinia tarapotensis

A new cyclohexenone (1) and a new caffeoyl ester derivative (2), together with the known compounds (-)-isolariciresinol 3-alpha-O-beta-D-glucopyranoside (3), (+)-1-hydroxypinoresinol 1-O-beta-D-glucopyranoside (4), isoacteoside (5), luteolin 4'-O-beta-D-glucopyranoside (6), and indole-3-carboxylic acid (7), were isolated from the leaves of Bauhinia tarapotensis. The structures of these new compounds were determined by spectroscopic data analysis. The antioxidant activities of 1-7 were determined by measuring their free radical scavenging effects, using the 1,1-diphenyl-2-dipicrylhydrazyl free radical (DPPH) and Trolox equivalent antioxidant activity (TEAC) methods, and the coupled oxidation of beta-carotene and linoleic acid. Compounds 3-5 showed good activities in the DPPH and TEAC tests, while compounds 1 and 2 were active in the coupled oxidation of beta-carotene and linoleic acid bioassay.     

Homo- and nor-plakotenin, new carboxylic acids from the Palauan sponge Plakortis lita.

A specimen of Plakortis lita from Palau yielded the new carboxylic acids, homo-plakotenin (2a), the sodium salt of homo-plakotenin (2b), the sodium salt of nor-plakotenin (3), the sodium salt of plakotenin (1b), and the known compound plakotenin (1a). The structures of the new acids were elucidated by interpretation of spectral data and by comparison with the known compound. Compounds 1a, 1b, and 2a were found to significantly reduce proliferation of rheumatoid synovial fibroblasts.     

Antimalarial compounds from Grewia bilamellata

Bioassay-directed fractionation led to the isolation of 12 compounds from a sample of the dried leaves, twigs, and stems of Grewia bilamellata. Five of the isolates, 3alpha,20-lupandiol (1), grewin (2), nitidanin (4), 2alpha,3beta-dihydroxy-olean-12-en-28-oic acid (5), and 2,6-dimethoxy-1-acetonylquinol (6), showed varying degrees of in vitro antimalarial activity against Plasmodium falciparum, but were devoid of significant cytotoxicity to the human oral epidermoid KB cancer cell line. Of the 12 isolates, compounds 1, 2, and 3 (bilagrewin) were determined to be a new triterpene, a new coumarinolignan, and a new neolignan, respectively. Other known compounds isolated in this study were 8-O-4' neolignan guaiacylglycerol-beta-coniferyl ether isomers (threo and erythro), cleomiscosin D, icariol A(2), ciwujiatone, and daucosterol. The structures of 1-3 were elucidated and identified on the basis of spectroscopic data including 1D and 2D NMR analysis.     

Bioactive constituents of the roots of Polyalthia cerasoides

A new dimeric aporphine alkaloid, bidebiline E (1), and a new natural product, octadeca-9,11,13-triynoic acid (2), along with three known sesquiterpenes, alpha-humulene (3), caryophyllene oxide (4), and (-)-alpha-cadinol (5), and four known isoquinoline alkaloids, laudanosine (6), codamine (7), laudanidine (8), and reticuline (9), were isolated from the roots of Polyalthia cerasoides. The structures of compounds 1 and 2 were established on the basis of their 1D and 2D NMR spectroscopic data. Among these isolates, 1, 2, 4, 7, and 8 exhibited antimalarial activity against Plasmodium falciparum, while 1- 3 showed antimycobacterial activity against Mycobacterium tuberculosis using in vitro assays.     

Flavonoid glycosides from Adina racemosa and their inhibitory activities on eukaryotic protein synthesis

From the dried leaves, flowers, and twigs of Adina racemosa, five new flavonoid glycosides, quercetin 3-O-alpha-l-rhamnopyranosyl(1-->6)-(3-O-trans-p-coumaroyl)-beta-d-galactopyranoside (1), quercetin 3-O-alpha-l-rhamnopyranosyl(1-->6)-[(4-O-trans-p-coumaroyl)-alpha-l-rhamnopyranosyl(1-->2)]-(4-O-trans-p-coumaroyl)-beta-d-galactopyranoside (2), kaempferol 3-O-alpha-l-rhamnopyranosyl(1-->6)-[(4-O-trans-p-coumaroyl)-alpha-l-rhamnopyranosyl(1--> 2)]-(4-O-trans-p-coumaroyl)-beta-d-galactopyranoside (3), quercetin 3-O-alpha-l-rhamnopyranosyl(1-->6)-[(4-O-trans-p-coumaroyl)-alpha-l-rhamnopyranosyl(1-->2)]-(3-O-trans-p-coumaroyl)-beta-d-galactopyranoside (4), and quercetin 3-O-alpha-l-rhamnopyranosyl(1-->6)-[(4-O-trans-caffeoyl)-alpha-l-rhamnopyranosyl(1-->2)]-(3-O-trans-p-coumaroyl)-beta-d-galactopyranoside (5), and eight known compounds were isolated. The structures of the new compounds were determined by spectroscopic and chemical means. Their inhibitory activities on protein synthesis were assessed. The new glycosides were found to be inhibitors of eukayrotic, but not prokaryotic, protein synthesis.     

Sesquiterpene esters from Celastrus orbiculatus and their structure-activity relationship on the modulation of multidrug resistance.

Six new (1-6) and three known (7-9) sesquiterpene esters were isolated from the roots of Celastrus orbiculatus. The structures of the new compounds were elucidated as 1beta-acetoxy-6alpha-furoyloxy-9alpha-benzoyl oxydihydro-beta-agarofur an (1), 1beta-acetoxy-6alpha-benzoyloxy-9alpha-furoyloxydih ydro-beta-agarofur an (2), 1beta-acetoxy-6alpha, 9alpha-difuroyloxydihydro-beta-agarofuran (3), 1beta, 2beta-diacetoxy-6alpha-furoyloxy-9alpha-benzo yloxydihydro-beta-agarof uran (4), 1beta-acetoxy-2beta, 6alpha-difuroyloxy-9alpha-benzoyloxydihydro-beta -agarofuran (5), and 1beta-acetoxy-2beta,6alpha, 9alpha-tribenzoyloxydihydro-beta-agarofuran (6). Compounds 4, 5, and 7-9 were shown to be more active than verapamil in reversing vinblastine resistance in multidrug-resistant KB-V1 cells.     

Cytotoxic germacranolides and acyclic diterpenoides from the seeds of Carpesium triste

Four new highly oxygenated germacranolides (1, 4, 6, and 7) and four new acyclic diterpenes (8-11), along with three known germacranolides (2, 3, and 5), were isolated from the seeds of Carpesium triste. The structures of the new compounds were elucidated by spectroscopic methods including IR, HRESIMS, and 1D and 2D NMR experiments, and the absolute configurations of compounds 1 and 8-10 were established by CD and Mosher's methods, respectively. Compounds 1, 2, and 4-10 were evaluated for their in vitro cytotoxic activity against cultured SMMC-7721 (human hepatoma), HL-60 (human promyelocytic leukemia), and L02 (human hepatocyte) cell lines. Compounds 1, 2, and 4-7 exhibited significant cytotoxicity against HL-60 cells, and compound 10 exhibited cytotoxicity against SMMC-7721 cells.     

Cacalolides from Senecio madagascariensis

14-Isovaleryloxy-O-methyl-1,2-dehydrocacalol (1) and cycloart-23-ene-3,25-diol, beta-sitosterol, and stigmasterol, along with five new cacalolides, 1-hydroxy-2-methoxy-1,2,3,4-dehydro-6-dehydroxycacalone (2), 1-hydroxy-2-methoxy-1,2,3,4-dehydrocacalone (3), 1,2-dimethoxy-1,2,3,4-dehydro-6-dehydroxycacalone (4), 1,2-dimethoxy-1,2,3,4-dehydrocacalone (5), and 2-methoxy-O-methyl-1-oxo-2,3-dehydrocacalol (6), were isolated from Senecio madagascariensis collected from Colombia. The structures of the new compounds were determined using one- and two-dimensional NMR techniques. In addition, the structure of 2 was corroborated by derivatizations and single-crystal X-ray diffraction studies.