Antitumoral and antileishmanial dioncoquinones and ancistroquinones from cell cultures of Triphyophyllum peltatum (Dioncophyllaceae) and Ancistrocladus abbreviatus (Ancistrocladaceae)

From the methanolic extracts of solid callus cultures from two species of the closely related palaeotropical plant families Dioncophyllaceae and Ancistrocladaceae seven new natural naphthoquinones were isolated, dioncoquinones A (4) and B (5) from Triphyophyllum peltatum, and ancistroquinones B (6), C (7), D (9), E (10), and F (12) from Ancistrocladus abbreviatus. Their structures were elucidated by spectroscopic, chemical, and computational methods. Furthermore, the already known naphthoquinones plumbagin (2), droserone (3), malvone A (8), and nepenthone A (11) were found in the extract of A. abbreviatus. Dioncoquinones A (4) and B (5) showed good - and specific - activity against Leishmania major, while they were not active against other protozoic parasites. Moreover, treatment with 4 and 5 strongly induced apoptosis in human tumor cells derived from two different B cell malignancies, B cell lymphoma and multiple myeloma, without any significant toxicity towards normal peripheral mononuclear blood cells.     

Isoprenylated cyclohexanoids from the basidiomycete Hexagonia speciosa

Nine oxygenated cyclohexanoids, speciosins L-T (1-9) as well as a 5H-furan-2-one metabolite, 5′-O-acetylaporpinone A (10), together with known analogs, speciosins A, B, D, E, F, I and K (11-17), and aporpinone A (18), were isolated from a scale-up cultures of the basidiomycete Hexagonia speciosa. Their structures were elucidated by analysis of spectroscopic data, including 1D and 2D NMR. Speciosin B (12) showed significant cytotoxicity against several tumor cell lines with IC₅₀ values in the range 0.23-3.30 μM.     

Bis-sesquiterpenes and diterpenes from Chloranthus henryi

Bis-sesquiterpenes, henriols A (1), B (2), C (3), and D (4), and three diterpenes, henrilabdanes A (5), B (6), and C (7), together with two known bis-sesquiterpenes and three known labdane diterpenes, were isolated from the ethanol extract of the roots of Chloranthushenryi. Their structures and absolute configurations were elucidated by NMR spectroscopic, X-ray crystallographic and CD analyses. Compounds 1, 5, 6 and 7 showed moderate hepatoprotective activities with IC₅₀ values of 0.19, 0.66, 0.09 and 0.18 μM, respectively. They were not studied further due to the weak effects noted. Compounds 3 and 8 exhibited cytotoxic activities against three types of cancer cell lines including the hepatoma (BEL-7402), human gastric carcinoma (BGC-823), and colon cancer (HCT-8).     

NF kappa B inhibitors and antitrypanosomal metabolites from endophytic fungus Penicillium sp. isolated from Limonium tubiflorum

Chemical investigation of the endophytic fungus Penicillium sp. isolated from Limonium tubiflorum growing in Egypt afforded four new compounds of polyketide origin, including two macrolides, penilactone (1) and 10,11-epoxycurvularin (2), a dianthrone, neobulgarone G (7), and a sulfinylcoumarin, sulfimarin (14), along with twelve known metabolites (3-6, 8-13, 15 and 16). The structures of all compounds were assigned by comprehensive spectral analysis (1D and 2D NMR) and mass spectrometry. Compounds 3, 4, 13 and 16 showed pronounced antitrypanosomal activity with mean MIC values ranging from 4.96 to 9.75 ??M. Moreover, when tested against a panel of three human tumor cell lines compounds 3, 4, 6 and 12 showed selective growth inhibition against Jurkat and U937 cell lines with IC₅₀ values ranging from 1.8 to 13.3 ??M. The latter compounds also inhibited TNF??-induced NF-??B activity in K562 cells with IC₅₀ values ranging from 1.6 to 10.1 ??M, respectively.     

Furostanol saponins from the rhizomes of Dioscorea japonica and their effects on NGF induction

The rhizome of Dioscorea japonica is a food and medicinal source known as ‘San Yak’ in Korea. Two new furostanol saponins, coreajaponins A (1) and B (2), together with 10 known compounds (3-12) were isolated from the rhizomes of D. japonica. Their structures were determined by spectroscopic methods, including 1D and 2D NMR techniques, HRMS, and chemical methods. Nerve growth factor (NGF), a crucial factor for neuronal survival and differentiation, can potentially improve neurodegenerative diseases and diabetic polyneuropathy. We evaluated the effects of isolates (1-12) on NGF induction in a C6 rat glioma cell line. Coreajaponin B (2) upregulated NGF content without significant cell toxicity, as did 6, 8, 9, and 11.     

Phenolic compounds with NF-κB inhibitory effects from the fungus Phellinus baumii

Chemical investigation of the fungus Phellinus baumii has resulted in characterization of five previously undescribed hispidin derivatives, phellibaumins A-E (1-5), as well as two pairs of new non-equivalent epimeric benzyl dihydroflavones, methylphelligrin A (9), epi-methylphelligrin A (10), methylphelligrin B (11), and epi-methylphelligrin B (12), together with five known compounds, interfungin B (6), phelligridin H (7), phelligridimer A (8), phelligrin A (13), and epi-phelligrin A (14). Phellibaumin A (1) was a novel hispidin derivative with a unique 3,4-dihydroxybenzofuran unit. These compounds exhibited NF-κB inhibitory activity with IC₅₀ values of 52.96 μM (1), 41.40 μM (2), 52.92 μM (5), 36.44 μM (9 and 10), and 22.46 μM (11 and 12), respectively.     

Chemical constituents from fruits of Harrisonia perforata

Eight limonoids (1-8) including three A, B and D-seco-16-nor-type ones, 5,6-dehydrodesepoxyharperforin C2 (1), harrpernoid B (2), and its C-9S epimer, harrpernoid C (3), along with six known compounds (9-14), were isolated from fruits of Harrisonia perforata. Extensive spectroscopic analysis was used to elucidate their structures and stereochemistries. Further confirmation of structures of 1 and 2 were obtained by single-crystal X-ray diffraction. Limonoids (1-8) were evaluated for their anti-tobacco mosaic virus activity and in vitro cytotoxicity against A549 and HL60 cell lines; only compound 2 showed weak activity.     

Itaconic acid derivatives and diketopiperazine from the marine-derived fungus Aspergillus aculeatus CRI322-03

Three metabolites, pre-aurantiamine (1), (−)-9-hydroxyhexylitaconic acid (4) and (−)-9-hydroxyhexylitaconic acid-4-methyl ester (5), together with two known compounds, paraherquamide E (6) and secalonic acid D (7), were isolated from the marine-derived fungus, Aspergillus aculeatus.     

Chromone and chromanone glucosides from Hypericumsikokumontanum and their anti-Helicobacter pylori activities

Chromone glucosides, takanechromones A-C (1, 2 and 5) and chromanone glucosides, named takanechromanones A and B (3 and 4), were isolated from the methanolic extracts of Hypericumsikokumontanum together with 27 known compounds. Their structures were established based on spectroscopic evidence. The isolated compounds and some chromone derivatives were assayed for antimicrobial activity against Helicobacter pylori and cytotoxicity against human cancer cell lines.     

Steroidal saponins and ecdysterone from Asparagus filicinus and their cytotoxic activities

Two new spirostanoides, filiasparosides E (1) and F (2), one new furostanoside, filiasparoside G (3), and one new ecdysterone, stachysterone A-20, 22-acetonide (4), together with six known steroidal saponins, asparagusin A (5), filiasparoside A (6), filiasparoside B (7), aspafilioside A (8), aspafilioside B (9), and filiasparoside C (10) were isolated from the roots of Asparagus filicinus Buch.-Ham. Their structures were elucidated on the basis of spectroscopic and chemical evidence. Compounds 1-10 were investigated for their cytotoxicities against human breast adenocarcinoma MDA-MB-231 cell line and compounds 8-10 exhibited cytotoxic activities with IC₅₀ values ranging from 3.4 to 6.6 μM.     

Compounds from Kadsura angustifolia with anti-HIV activity

Four new cycloartane triterpenoids, angustific acid A (1), angustific acid B (2), angustifodilactone A (3) and angustifodilactone B (4) were isolated from the branches of Kadsura angustifolia together with six known compounds, micranoic acid B (5), nigranoic acid (6), schisandrin (7), schisantherin D (8), interiotherin B (9), schisantherin B (10). Their structures were established on the basis of extensive spectroscopic data analyses and comparison with spectroscopic data reported. Compound 1, characterized by the presence of a C-16/C-17, C-20/C-21 conjugated diene and a C-1/C-7 ester bridge formed in rings A and B, provided a novel structural skeleton for 3,4-secocycloartane triterpenoid derivatives. In addition, the anti-HIV activities of these compounds were determined in infected C8166 cells, and it was found that angustific acid A (1) exhibited the most potent anti-HIV activity with an EC₅₀ value of 6.1 μg/mL and a therapeutic index of more than 32.8.     

Ecdysteroids and a sucrose phenylpropanoid ester from Froelichia floridana

Phytoecdysteroid glycosides (1-5) and a phenylpropanoid ester of sucrose (6) were isolated from the whole plant of Froelichia floridana, along with eight known compounds including three ecdysteroids (7-9), four flavonoids (10-13), and one phenolic compound (14). Structures were determined using a combination of spectroscopic techniques. Compounds 1, 2 and 6-14 were tested in vitro for their activity against human DNA topoisomerase I. Compound 13 (diosmetin) showed marginal inhibition against topoisomerase I with IC₅₀ of 130 μM in conjunction with low intercalation ability.     

Secondary metabolites from anti-insect extracts of endophytic fungi isolated from Picea rubens

The extracts of a selection of 150 foliar fungal endophytes isolated from Picea rubens (red spruce) needles were screened by LC-MS and assayed for toxicity. Three of these strains that were toxic to the forest pest Choristoneura fumiferana (eastern spruce budworm) in dietary bioassays were selected for further study. Their culture extracts were analyzed by LC-NMR spectroscopy, and the major metabolites were isolated by LC-MS-SPE or PTLC/column chromatography and characterized. The structures were elucidated by spectroscopic analyses including 2D NMR, HRMS and by comparison to literature data. Compounds 1 and 5-7 are hitherto unknown whereas compounds 2 and 3 are natural products described for the first time. Compound 4 is reported for the first time as a fungal metabolite and 8-9 were identified as known fungal metabolites in genera.     

New isoprenylated flavonoids and adipogenesis-promoting constituents from Morus notabilis

Five new isoprenylated flavonoids, notabilisins A-E (1-5), and two known Diels-Alder adducts (6 and 7), were isolated from the twigs of Morus notabilis. Compounds 4 and 5 possess two novel pyran rings, which may be biogenetically derived from 3. Compounds 1 and 3 significantly promoted adipogenesis, characterized by increased lipid droplet and triglyceride content in 3T3L1 cells, and induced up-regulation of the expression of adipocyte-specific genes, aP2 and GLUT4.     

Saponins and a lignan derivative of Terminalia tropophylla from the Madagascar Dry Forest

A study of an EtOH extract obtained from the roots of the Madagascan plant Terminalia tropophylla H. Perrier (Combretaceae) led to isolation of the oleanane-type triterpenoid saponin 1, the lignan derivative 2, and the two known saponins arjunglucoside I (3) and sericoside (4). The structures of compounds 1 (terminaliaside A) and 2 (4′-O-cinnamoyl cleomiscosin A) were elucidated using 1D and 2D NMR experiments and mass spectrometry. Compound 1 showed antiproliferative activity against the A2780 human ovarian cancer cell line with an IC₅₀ value of 1.2 μM.     

Unusual stilbenoids and a stilbenolignan from seeds of Syagrus romanzoffiana

Stilbenoids, syagrusins A-B (1-2), and a stilbenolignan, 5-hydroxyaiphanol (3), along with three known phenylpropanoids (4-6), were isolated from seeds of Syagrus romanzoffiana. Compounds 1 and 2 possess unusual 1,4,4a,9a-tetrahydrofluoren-9-one and bicyclo[3.3.0]octanedione skeletons, respectively, whereas compound 3 is a stilbenolignan belonging to a very rare structural class of plant secondary metabolites. Their structures were elucidated by spectroscopic analyses. Compounds 1-3 exhibited moderate inhibitory activity against α-glucosidase with IC₅₀ values of 16.9 μM (1), 23.7 μM (2) and 12.8 μM (3), respectively.     

Aplidiasterols A and B, two new cytotoxic 9,11-secosterols from the Mediterranean ascidian Aplidium conicum

Two novel 9,11-secosterols, aplidiasterols A (3β,6β,11-trihydroxy-9,11-seco-5α-cholest-7-en-9-one, 1) and B (3β,5α,6β,11-tetrahydroxy-9,11-secocholest-7-en-9-one, 2), along with the known secosterols 3 and 4, were isolated from the Mediterranean ascidian Aplidium conicum and their structures were determined by spectroscopic data. Aplidiasterols A and B were found to be cytotoxic against rat glioma (C6) and murine monocyte/macrophage (J774) tumor cells in vitro. Compounds 1-4 represent the first example of secosterols isolated from tunicates.     

Absolute configuration of (+)-pinoresinol 4-O-[6″-O-galloyl]-β-d-glucopyranoside, macarangiosides E, and F isolated from the leaves of Macarangatanarius

A lignan glucoside, (+)-pinoresinol 4-O-[6″-O-galloyl]-β-d-glucopyranoside (1), and two megastigmane glucosides, named macarangiosides E and F (2,3), together with 15 known compounds (4-18) were isolated from leaves of Macarangatanarius (L.) Müll.-Arg. (Euphorbiaceae). Their structures were elucidated by spectroscopic and chemical analyses. In addition, the absolute stereochemistry of macarangiosides B and C isolated previously from the same plant was also determined for the first time. Compounds 1 and 2 were galloylated on glucose and possessed potent DPPH radical-scavenging activity.     

Antiplasmodial and antimycobacterial cyclopeptide alkaloids from the root of Ziziphus mauritiana

Investigation of the MeOH extract obtained from the root of the Ziziphus mauritiana grown in Thailand resulted in the isolation of two 14- and 13-membered cyclic alkaloids, mauritine L (1) and mauritine M (2), and three known cyclopeptide alkaloids, nummularines H (3), B (4) and hemsine A (5). Their structures were elucidated on the basis of extensive NMR spectroscopic analysis. The first single crystal X-ray diffraction study of the 13-membered ring cyclopeptide, nummularine B methiodide (4′), revealed all S configurations on the amino acid residues. The isolated alkaloids exhibited potent antiplasmodial activity against the parasite Plasmodium falciparum with the inhibitory concentration (IC₅₀) ranging from 3.7 to 10.3 μM. Compounds 2 and 3 also demonstrated antimycobacterial activity against Mycobacterium tuberculosis with the MIC of 72.8 and 4.5 μM, respectively.     

New bufadienolides and C23 steroids from the venom of Bufo bufo gargarizans

Six new bufadienolides (1-6) and two new C₂₃ steroids (7 and 8), together with three known compounds (9-11) were isolated from the venom of Bufo bufo gargarizans. Their structures were elucidated by spectroscopic analysis and single-crystal X-ray diffraction. In vitro cytotoxicities of all compounds were evaluated in A549 cancer cell line. Compounds 2, 3 and 10 showed significant cytotoxic activities.