Caldaphnidines A-F, six new Daphniphyllum alkaloids from Daphniphyllum calycinum

Six new Daphniphyllum alkaloids, namely caldaphnidines A-F (1-6), together with eight known ones, deoxycalyciphylline B, deoxyisocalyciphylline B, bukittiggine, calycicine A, methyl homosecodaphniphyllate, daphnilactone B, and daphnezomines L-M, were isolated from the leaves and the seeds of Daphniphyllum calycinum. The structure of 1 was determined by a single-crystal X-ray diffraction study, and the structures of 2-6 were established by spectral methods, especially two-dimensional NMR techniques (¹H-¹H COSY, HMQC, HMBC, and NOESY).     

Apteniols A-F, oxyneolignans from the leaves of Aptenia cordifolia

Investigation of the organic extract of Aptenia cordifolia leaves revealed six new oxyneolignans named apteniols A-F. The structures were determined by means of spectroscopic methods. The C₆C₃ units are linked by an oxygen atom at C4-C4′ or C4-C2′ and they are dihydrophenylpropanoid acid units. Their effects on germination and growth of Lactuca sativa L. have been studied in the range concentration 10⁻⁴-10⁻⁷ M.     

Bellisosides A-F, six novel acylated triterpenoid saponins from Bellis perennis (compositae)

Six new acylated triterpenoid saponins, bellisosides A-F (1-6), were isolated from the roots of Bellis perennis (Compositae) together with a known saponin, bellissaponin BS2 (7). These saponins which bear polygalacic acid as sapogenin, are bisdesmosidic glycosides. The structures were elucidated on the basis of chemical and physicochemical evidence. The cytotoxic activities of 1-7 against HL-60 human promyelocytic leukemia cells are also reported.     

Structures of stemoxazolidinones A-F, alkaloids from Stemona sessilifolia

Six new alkaloids, stemoxazolidinones A-F, were isolated from the roots of Stemona sessilifolia (Miq.) Miq. (Stemonaceae). The structures of stemoxazolidinones A-C, and E were determined by interpretation of their spectroscopic data and those of stemoxazolidinones D and F by X-ray crystallography. These alkaloids possess a novel structural unit in which an oxazolidin-2-one unit fuses with a pyrrolo[1,2-a]azepine nucleus of the rearranged or normal tuberostemonine-type skeleton.     

Acremines A-F, novel secondary metabolites produced by a strain of an endophytic Acremonium, isolated from sporangiophores of Plasmopara viticola in grapevine leaves

Six novel metabolites, acremines A-F have been isolated from agar cultures of a strain of Acremonium sp. Their structures and stereochemistry were elucidated using a combination of ¹³C and ¹H homo and heteronuclear 2D NMR experiments and X-ray analysis. Acremines A-D inhibited the germination of sporangia of Plasmopara viticola.     

Tricalysiolides A-F, new rearranged ent-kaurane diterpenes from Tricalysia dubia

Six rearranged ent-kaurane diterpenes, tricalysiolides A-F, having the cafestol-type carbon framework were isolated from the wood of Tricalysia dubia (Rubiaceae). Their absolute structures were determined on the basis of the 2D NMR spectroscopy, X-ray crystallographic analysis, and chemical methods.     

Fascioquinols A-F: bioactive meroterpenes from a deep-water southern Australian marine sponge, Fasciospongia sp.

Chemical investigation of a southern Australian deep-water marine sponge, Fasciospongia sp., returned the new meroterpene sulfate fascioquinol A (1) together with a series of acid mediated hydrolysis/cyclization products, fascioquinols B (2), C (3) and D (4), and strongylophorine-22 (5). Additional co-metabolites include the new meroterpenes fascioquinol E (6) and fascioquinol F (8), together with the known sponge metabolite geranylgeranyl 1,4-hydroquinone (7). Structures were assigned to 1-8 on the basis of detailed spectroscopic analysis, chemical interconversion, mechanistic and biosynthetic considerations, and literature comparisons. The known 1,4-hydroquinone 7 was identified as the dominant cytotoxic principle in the Fasciospongia sp. extract, with selective inhibitory activity against gastric adenocarcinoma (AGS, IC₅₀ 8 μM) and neuroblastoma (SH-SY5Y, IC₅₀ 4 μM) cell lines. By contrast, while the fascioquinols displayed little or no inhibitory activity towards human cell lines, 1 and 2 displayed promising Gram-positive selective antibacterial activity towards Staphylococcus aureus (IC₅₀ 0.9-2.5 μM) and Bacillus subtilis (IC₅₀ 0.3-7.0 μM).     

Rakanmakilactones A-F, new cytotoxic sulfur-containing norditerpene dilactones from leaves of Podocarpus macrophyllus var. maki

Six new S-containing norditerpene dilactones, rakanmakilactones A-F (5-10), were isolated from the leaves of Podocarpus macrophyllus D. Don var. maki Endl., along with four known norditerpene dilactones (1-4). Their structures, stereochemistry and absolute configurations were determined by spectroscopic studies (HRMS, IR, ¹H, ¹³C and 2D NMR), and single-crystal X-ray analyses. Rakanmakilactones were found to have a cytotoxic effect against P388 murine leukemia cells.     

Absolute structures of C-glucosides of resveratrol oligomers from Shorea uliginosa

Two C-glucosides of resveratrol dimers (uliginoside A (1) and hemsleyanoloside B (2)) consisting of enantiomeric aglycones and two C-glucosides of resveratrol trimers (uliginosides B (3) and C (4)) consisting of diastereomeric aglycones were isolated from Shorea uliginosa (Dipterocarpaceae). These structures were elucidated by spectroscopic analysis including NMR experiments, and their absolute configurations were determined based on circular dichroism data. Resveratrol oligomers of C-glucosides with a 1,2-diaryldihydrobenzofuran ring are produced with specific biogenetic routes.     

Chukvelutilides A-F, phragmalin limonoids from the stem barks of Chukrasia tabularis var. velutina

Chukvelutilides A-F (1-6), a new class of C-15-acyl phragmalin type limonoids, featuring a C-16/C-30 δ-lactone ring, were isolated from Chukrasia tabularis var. velutina. These compounds are suggested to possess a three- or four-carbon enolized acyl substituent at C-15 through a plausible biosynthetic origin. Their structures were elucidated by extensive spectroscopic means, and that of 1 was confirmed by single-crystal X-ray diffraction.     

Pressurized fluid extraction of carotenoids from Haematococcus pluvialis and Dunaliella salina and kavalactones from Piper methysticum

Pressurized fluid extraction (PFE) was examined as an alternative technology for the extraction of carotenoids in the green algae Haematococcus pluvialis and Dunaliella salina and kavalactones in Piper methysticum. The extraction process was optimized by varying the key extraction factors of solvent, sample-solvent ratio, temperature, and time. The selectivity and efficiency of extraction parameters were determined with high performance liquid chromatography (LC) and LC-mass spectrometry (LC-MS). Results showed that PFE utilization of conventional solvents under controlled temperature and pressure in an oxygen and light-free environment could result in the use of less solvent in a shorter period of time. PFE showed higher or equal extraction efficiencies as compared with traditional solvent extractions while maintaining the integrity of chemical components. PFE showed high potential for extraction of natural products and nutraceuticals, particularly labile and light sensitive chemicals.     

Silvaglenamin—a novel dimeric triterpene alkaloid from Aglaia silvestris

An unusual dimeric triterpene structure with two dammarane units linked with an enaminic -NH- group was isolated from the root extract of Aglaia silvestris. The structure was elucidated by 1D and 2D NMR analysis and ESI mass spectrometry.     

Three new Lycopodium alkaloids from Huperzia carinata and Huperzia squarrosa

Eleven Lycopodium alkaloids with lycodine-type, lycopodine-type, and fawcettimine-related skeletons were isolated from the whole plants of Huperzia carinata (Desv. Ex. Poir.) Trevis and Huperzia squarrosa (G. Forst) Trevis (Huperziaceae). Among them, 8,15-dihydrohuperzine A (2), lycocarinatine A (3), and lycoposerramine U N-oxide (11) are new compounds. The structures of these new alkaloids were elucidated on the basis of 2D NMR correlations. Some of these isolated alkaloids were assayed for acetylcholinesterase (AChE) inhibitory activity.     

Absolute configuration and antibiotic activity of neosartorin from the endophytic fungus Aspergillus fumigatiaffinis

Neosartorin (1) was isolated from the endophytic fungus Aspergillus fumigatiaffinis. The absolute configuration of 1, including both axial and central chirality elements, was established as (aR,5S,10R,5′S,6′S,10′R) for the first time on the basis of its electronic circular dichroism (ECD) spectra aided with TDDFT–ECD calculations. Neosartorin (1) exhibited substantial antibacterial activity against a broad spectrum of Gram-positive bacterial species including staphylococci, streptococci, enterococci, and Bacillus subtilis with minimal inhibitory concentrations in the range of 4–32 μg/mL. When the toxicity of 1 against eukaryotic cells was measured using a panel of different cancer cell lines such as HELA and BALB/3T3, the average IC₅₀ values exceeded 32 μg/mL.     

The absolute stereostructures of cyanogenic glycosides, hydracyanosides A, B, and C, from the leaves and stems of Hydrangea macrophylla

Three new cyanogenic glycosides named hydracyanosides A (1), B (2), and C (3) were isolated from the leaves and/or stems of Hydrangea macrophylla in China. The absolute stereostructures of hydracyanosides were characterized on the basis of chemical and physiochemical evidence including single crystal X-ray crystallographic analysis. To the best of our knowledge, this is the first scientific report of cyanogenic glycosides from Hydrangea plants.     

Kansuinone, a novel euphane-type triterpene from Euphorbia kansui

Kansuinone (1), a rearranged euphane triterpenoid containing a spiro [5,6] ring system, was isolated from the roots of Euphorbia kansui. Its structure and stereochemistry were elucidated on the basis of spectroscopic, CD, and computational methods. Kansuinone (1) exhibited inhibitory activity against human and mouse 11β-HSD1 (11β-hydroxysteroid dehydrogenase type 1), with IC₅₀ values of 1.12 and 1.08 μM, respectively.     

Sesquiterpenoids from Ligularia virgaurea spp. oligocephala

Four novel eremophilane-type sesquiterpene lactones, 6β,10α-dihydroxy-1-oxoeremophila-7(11),8(9)-dien-12,8-olide (1), 6β-acetyl-2-oxoeremophila-1(10),7(11), 8(9)-trien-12,8-olide (2), 6β,8β-diacetyl-2-oxoeremophila-1(10),7(11)-dien-12,8-olide (3), dimeric eremophilane ligulolide B (5), and known sesquiterpenoid, 6β,8α-diacetyleremophila-1(10),7(11)-dien-12,8-olide (4), were isolated from an extract of the whole plant of Ligularia virgaurea spp. oligocephala. The structure of 1 was confirmed by NMR spectra and single crystal X-ray crystallography investigation, as well as 2, 3, and 5 were elucidated by spectroscopic methods including 1D and 2D NMR spectra. A discussion of biogenesis of 5 was described. Cytotoxicities of compound 1 were measured in vitro against selected cancer cells human promyelocytic leukemia (HL-60), human ovarian (HO-8910) and human lung epithehial (A-549).     

Infectopyrone, a potential mycotoxin from Alternaria infectoria

A new metabolite, infectopyrone (1), has been isolated from the filamentous fungus Alternaria infectoria. The structure of 1 was elucidated by analysis of 2D NMR spectroscopic data. Compound 1 is an α-pyrone resembling known toxins, and is a useful phenotaxonomic marker for the A. infectoria species-group. Infectopyrone (1) was also produced by species within Stemphyllium and Ulocladium, and found in mouldy food.     

Dihydroanthracenone metabolites from the endophytic fungus Diaporthe melonis isolated from Annona squamosa

Chemical investigation of the endophytic fungus Diaporthe melonis, isolated from Annona squamosa, yielded two new dihydroanthracenone atropodiastereomers, diaporthemins A (1) and B (2), together with the known flavomannin-6,6′-di-O-methyl ether (3). The structures of the new compounds were established on the basis of extensive 1D and 2D NMR spectroscopy, as well as by high resolution mass spectrometry and by CD spectroscopy. Compounds 1–3 were tested for their antimicrobial activity against a multi-resistant clinical isolate of Staphylococcus aureus 25697, a susceptible reference strain of S. aureus ATCC 29213 and against Streptococcus pneumoniae ATCC 49619. Compound 3 strongly inhibited S. pneumonia growth with a MIC value of 2 μg/mL, and showed moderate activity against the S. aureus multi-resistant clinical isolate and susceptible reference strain (MIC 32 μg/mL), whereas 1 and 2 were not active against the tested strains.     

Polyhydroxylated macrolide isolated from the endophytic fungus Pestalotiopsis mangiferae

A new polyhydroxylated macrolide, named mangiferaelactone (1) was isolated from a solid culture of the endophytic fungus Pestalotiopsis manguiferae, together with ten known compounds [(6S,1′S)-LL-P880α; (6S,1′S,2′R)-LL-P880β; (1′S,2′R)-LL-880γ; (1′R)-dehydropestalotin; (−)-5-carboxylmellein; (−)-5-methylmellein; (−)-5-hydroxylmethylmellein; arabenoic acid; 5,6-dihydro-4-methoxy-2H-pyran-2-one; and the (−)-2-hexylidene-3-methylsuccinic acid]. P. manguiferae was isolated from Hyptis dilatata, a small shrub common in the central region of Panama. The structure of compound 1 was elucidated by a combination of spectroscopic methods (IR, MS, optical rotation, 1D and 2D NMR spectroscopy). The absolute configuration of 1 was established as 4R,7R,8R,9S by application of vibrational circular dichroism (VCD). Compound 1 showed a minimum inhibitory concentration (MIC) of 1.6863 mg/mL against Listeria monocytogenes, and 0.5529 mg/mL against Bacillus cereus. No activity was observed for compound 1 against Plasmodium falciparum or Trypanosoma cruzi; likewise, no cytotoxic activity was observed against A2058 and H522-T1 cells.