Polyhydroxylated Spirostanol Saponins from the Rhizomes of Paris dulongensis.

Three new polyhydroxylated spirostanol steroidal saponins, dulongenosides B-D (2-4), along with 14 known compounds, dulongenoside A (1), padelaoside B (5), parisyunnanoside G (6), polyphyllin D (7), ophiopogonin C' (8), formosanin C (9), dioscin (10), paris saponin VII (11), paris H (12), parisyunnanoside I (13), protodioscin (14), proprotogracillin (15), crustecdysone (16), and stigmasterol-3-O-ß-d-glucopyranoside (17), were isolated from the rhizomes of Paris dulongensis (Melanthiaceae). Their chemical structures were elucidated based on extensive analyses of NMR and MS data and acidic hydrolyses. The isolates were evaluated for their cytotoxicity to five human cancer cell lines (HL-60, SW480, MDA-MB-231, A549, and A549/Taxol) and the normal human bronchial epithelial cell line BEAS-2B by the MTS test. Compounds 7-12 and 14 showed cytotoxic activity, with IC50 values ranging from 0.20 to 4.35 µM. Proprotogracillin selectively inhibited A549 (IC50=0.58 µM) and A549/Taxol (IC50=0.74 µM) cells, with no significant cytotoxic activity against HL-60, SW480, MDA-MB-231, or BEAS-2B cells, with IC50 values greater than 40 µM.

A new amide from the fruiting bodies of Tricholoma bakamatsutake.

A new amide tricholomine C was isolated from the dried fruiting bodies of Tricholoma bakamatsutake. Its structure was identified by a combination of nuclear magnetic resonance spectroscopic analysis and electronic circular dichroism (ECD) calculations. The ethyl alcohol crude extract and tricholomines A-C from T. bakamatsutake were evaluated for neuroprotective activities. Of these substances, the crude extract showed weak neurite outgrowth-promoting activity in rat pheochromocytoma (PC12) cells, as well as weak inhibitory activities against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE).

[Chemical constituents from Paris rugosa rhizomes and their antimicrobial activities].

Paris rugosa(Melanthiaceae) only grows in Yunnan province of China at present, and its chemical constituents have not been systematically studied. In this study, nine compounds, including one new compound pariposide G(1) and eight known compounds of cerin(2), stigmast-4-en-3-one(3), ß-ecdysone(4), ophiopogonin C'(5), methyl protogracillin(6), gracillin(7), parissaponin H(8), and parisyunnanoside G(9), were isolated and identified from the ethanol extract of P. rugosa rhizomes by column chromatography methods and semi-preparative high-performance liquid chromatography(HPLC). Compounds 1-9 were isolated from this plant for the first time. The antibacterial and antifungal activities of all the compounds were evaluated. The results showed that ophiopogonin C' had strong inhibitory effects on Candida albicans [MIC_(90)=(4.68±0.01) µmol·L~(-1)] and the fluconazole-resistant strain of C. albicans [MIC_(90)=(4.66±0.02) µmol·L~(-1)].

A new sesquineolignan and four new neolignans isolated from the leaves of Piper betle, a traditional medicinal plant in Myanmar.

One new sesquineolignan, piperneolignan A (1), four new neolignans, piperneolignans B-E (2-5), and eight known compounds were isolated from the leaves of Piper betle (Piperaceae) collected from Myanmar. These new structures were determined by analysis of MS and NMR data, and the absolute configuration of piperneolignan A was elucidated by electronic circular dichroism (ECD) calculations. Piperneolignan A (1), piperneolignan B (2), hydroxychavicol (6), p-hydroxycinnamaldehyde (10), and diallylcatechol (13) possessed anti-inflammatory activity against nitric oxide (NO) production in lipopolysaccharide (LPS)-activated murine macrophage RAW 264.7 cells with IC50 values of 9.87, 45.94, 4.80, 26.40, and 40.45 µM, respectively, compared with the positive control NG-monomethyl-l-arginine (l-NMMA, IC50 = 33.84 µM). The two hydroxy groups in the structure of hydroxychavicol are essential for activity, and dimerization or trimerization of hydroxychavicol decreases activity.

Tricholomines A and B, two new amides from the fruiting bodies of Tricholoma bakamatsutake.

Two new amides tricholomines A (1) and B (2), along with nine known compounds, were isolated from the dried fruiting bodies of Tricholoma bakamatsutake. Their structures were determined on the basis of extensive spectroscopic analysis or comparison with the data in the literatures. The absolute configuration of 1 was confirmed by single crystal X-ray diffraction analysis.

Alkaloids from the Branches and Leaves of Elaeocarpus angustifolius.

Nine new alkaloids, (+)-1, (-)-1, 2, (+)-3, (-)-3, and 4-7, along with five known compounds (8-12), were obtained from the branches and leaves of Elaeocarpus angustifolius. The alkaloids were structurally characterized by NMR and MS data. The absolute configurations of (+)-1, (-)-1, (+)-3, and (-)-3 were determined by comparing their experimental and computed electronic circular dichroism spectra. (±)-8,9-Dehydroelaeocarpine (5), (±)-9-epielaeocarpine cis-N-oxide trifluoroacetate (6), and (±)-elaeocarpine trifluoroacetate (9) exerted weak inhibitory activities against butyrylcholinesterase with IC50 values of 39, 29, and 35 µM, respectively, while that of tacrine, the positive control, was 0.07 ± 0.01 µM. This is the first report of the cholinesterase inhibitory activities of Elaeocarpus alkaloids.

Modified Abietane Diterpenoids from Whole Plants of Selaginella moellendorffii.

A new modified abietane diterpenoid, (3S,4S,5R,10S)-18(4→3)-abeo-3,4,12,18-tetrahydroxy-8,11,13-abietatrien-7-one (1), and two novel dimers, selaginedorffones A (2) and B (3), featuring a new cyclohexene moiety that was biogenetically constructed from two modified abietane diterpenoids through a Diels-Alder reaction were obtained from a methanolic extract of Selaginella moellendorffii, a traditional Chinese herb. The structures of 1-3 were identified by a combination of NMR spectroscopic analysis and ECD calculations. In the present study, diterpenoids were identified from S. moellendorffii for the first time, which supports the presence of diterpene synthases in this plant. These three diterpenoids (1-3) were evaluated for their growth-inhibitory activities against several human cancer cell lines. Of these substances, selaginedorffone B (3) showed cytotoxicity against the MCF-7 human-breast-cancer-cell line (IC50 9.0 µM).

New aporphine alkaloids from the aerial parts of Piper semiimmersum §.

Two new aporphine alkaloids, semiimmersumines A (1) and B (2), along with 20 known compounds, were isolated from the aerial parts of Piper semiimmersum (Piperaceae). The structures of the new compounds were elucidated based on the analysis of 1D and 2D NMR, MS, and CD data. The absolute configuration of semiimmersumine A (1) was determined by single crystal X-ray diffraction analysis using anomalous dispersion with copper radiation. The effects of all compounds from the plant on rabbit platelet aggregation induced by thrombin (IIa) or PAF were also evaluated.

Aspirin Derivative 5-(Bis(3-methylbut-2-enyl)amino)-2-hydroxybenzoic Acid Improves Thermotolerance via Stress Response Proteins in Caenorhabditis elegans.

Aging is a major risk factor for many prevalent diseases. Pharmacological intervention to improve the health span and extend the lifespan could be a preventive elixir for aging and age-related diseases. The non-steroid anti-inflammation medicine aspirin was reported to delay aging in Caenorhabditis elegans (C. elegans) and mice. We are wondering if the analogues of aspirin could also present antiaging activity. Here, we synthesized several aspirin derivatives and investigated their thermotolerance and antiaging effect in C. elegans. One of the compounds, 5-(bis(3-methylbut-2-en-1-yl)amino)-2-hydroxybenzoic acid, moderately increased the survival of C. elegans under heat stress, but could not extend the lifespan under optimum conditions. This compound could increase the mRNA level of stress response gene gst-4, and the mRNA and protein expression level of heat shock protein hsp-16.2 under heat stress. The failure of activating the transcription factor DAF-16 might explain why this compound could not act as aspirin to extend the lifespan of C. elegans. Our results would help further the investigation of the pharmacological activity of aspirin analogues and the relationship between structures and activity.

The pyrrolidinoindoline alkaloid Psm2 inhibits platelet aggregation and thrombus formation by affecting PI3K/Akt signaling.

AIM: Psm2, one of the pyrrolidinoindoline alkaloids isolated from whole Selaginella moellendorffii plants, has shown a potent antiplatelet activity. In this study, we further evaluated the antiplatelet effects of Psm2, and elucidated the underlying mechanisms. METHODS: Human platelet aggregation in vitro and rat platelet aggregation ex vivo were investigated. Agonist-induced platelet aggregation was measured using a light transmission aggregometer. The antithrombotic effects of Psm2 were evaluated in arteriovenous shunt thrombosis model in rats. To elucidate the mechanisms underlying the antiplatelet activity of Psm2, ELISAs, Western blotting and molecular docking were performed. The bleeding risk of Psm2 administration was assessed in a mouse tail cutting model, and the cytotoxicity of Psm2 was measured with MTT assay in EA.hy926 cells. RESULTS: Psm2 dose-dependently inhibited human platelet aggregation induced by ADP, U4619, thrombin and collagen with IC50 values of 0.64, 0.37, 0.35 and 0.87 mg/mL, respectively. Psm2 (1, 3, 10 mg/kg) administered to rats significantly inhibited platelet aggregation ex vivo induced by ADP. Psm2 (1, 3, 10 mg/mL, iv) administered to rats with the A-V shunt dose-dependently decreased the thrombus formation. Psm2 inhibited platelet adhesion to fibrinogen and collagen with IC50 values of 84.5 and 96.5 mg/mL, respectively, but did not affect the binding of fibrinogen to GPIIb/IIIa. Furthermore, Psm2 inhibited AktSer473 phosphorylation, but did not affect MAPK signaling and Src kinase activation. Molecular docking showed that Psm2 bound to phosphatidylinositol 3-kinase ß (PI3Kß) with a binding free energy of -13.265 kcal/mol. In addition, Psm2 did not cause toxicity in EA.hy926 cells and produced only slight bleeding in a mouse tail cutting model. CONCLUSION: Psm2 inhibits platelet aggregation and thrombus formation by affecting PI3K/Akt signaling. Psm2 may be a lead compound or drug candidate that could be developed for the prevention or treatment of thrombotic diseases.

Lignans from the bark of Zanthoxylum simulans.

Investigation on the EtOAc extract of the bark of Zanthoxylum simulans led to the isolation of four new lignans including zanthoxylumin A (1), zanthoxylumin B (2), ( - )-magnolin (3), and ( - )-pinoresinol-di-3,3-dimethylallyl ether (4). Their structures were established by comprehensive analysis of the spectral data, especially 1D and 2D NMR spectra.

Periplanosides A-C: new insect-derived dihydroisocoumarin glucosides from Periplaneta americana stimulating collagen production in human dermal fibroblasts.

Three new dihydroisocoumarin glucosides, termed periplanosides A-C (1-3), a known analog, pericanaside (4), and the other twenty known compounds were isolated from the insect Periplaneta americana. Their structures including absolute configurations were determined by comprehensive spectroscopic analyses and computational methods. Biological evaluation showed that compound 2 could stimulate collagen production by 31.2% in human dermal fibroblasts-adult (HDFa) at the concentration of 30 µM, indicating its significance in skin repair and ulcer.

[Medicinal values and their chemical bases of Paris].

Medicinal values and their chemical bases of Paris (Trilliaceae) are reviewed. Paris plants include 40 species and varieties. Among them, 18 ones are medicinal plants with similarity in traditional uses. Fourteen species have been studied phytochemically, which led to isolation of 207 compounds including 121 steroidal saponins. These saponins are major active constituents from Paris plants, which can explain the traditional uses of the plants to treat cancer, malignant boil, bleeding, gastritis, and so on. The similarity in medicinal uses and chemical constituents of Paris plants implies the possibility of resource substitution among these species. It is worth to further investigate Paris plants in chemical constituents, pharmacological activity, biological property, and toxicology.

Multidrug resistance-selective antiproliferative activity of Piper amide alkaloids and synthetic analogues.

Twenty-five amide alkaloids (1-25) from Piper boehmeriifolium and 10 synthetic amide alkaloid derivatives (39-48) were evaluated for antiproliferative activity against eight human tumor cell lines, including chemosensitive and multidrug-resistant (MDR) cell lines. The results suggested tumor type-selectivity. 1-[7-(3,4,5-Trimethoxyphenyl)heptanoyl]piperidine (46) exhibited the best inhibitory activity (IC50=4.94 µM) against the P-glycoprotein (P-gp)-overexpressing KBvin MDR sub-line, while it and all other tested compounds, except 9, were inactive (IC50 >40 µM) against MDA-MB-231 and SK-BR-3. Structure-activity relationships (SARs) indicated that (i) 3,4,5-trimethoxy phenyl substitution is critical for selectivity against KBvin, (ii) the 4-methoxy group in this pattern is crucial for antiproliferative activity, (iii) double bonds in the side chain are not needed for activity, and (iv), in arylalkenylacyl amide alkaloids, replacement of an isobutylamino group with pyrrolidin-1-yl or piperidin-1-yl significantly improved activity. Further study on Piper amides is warranted, particularly whether side chain length affects the ability to overcome the MDR cancer phenotype.

Characterization and biological evaluation of six new dimeric lignans with an unusual α,ß-unsaturated ketone motif from Zanthoxylum simulans.

Investigation of the bark of Zanthoxylum simulans afforded six new dimeric lignans zanthpodocarpins C-H (1-6) bearing an unusual α,ß-unsaturated ketone group. The new structures of 1-6 were determined by using detailed spectroscopic analysis. All of the isolated compounds were examined for their inhibitory effects against rat joint synovial cell and splenocyte proliferation. Compounds 1-6 showed potent anti-inflammatory activities with IC50 values ranging from 18.6 to 36.1µM, and 13.8 to 74.3µM.

Indole alkaloid glycosides from the aerial parts of Strobilanthes cusia.

Three indole alkaloid glycosides, strobilanthosides A-C (1-3), two known indole alkaloid glucosides (4 and 5), and five phenylethanoid glycosides (8-10) were isolated from the aerial parts of Strobilanthes cusia. The structures of the new compounds were elucidated by spectrometric analysis, and the absolute configurations of 1 and 2 were established by ECD spectrocsopy. N'-ß-d-Glucopyranosylindirubin (5) showed weak antibacterial activity (MIC 62.5-125 µM) against Staphylococcus aureus.

Total synthesis of plagiochin G and derivatives as potential cancer chemopreventive agents.

A new and efficient total synthesis has been developed to obtain plagiochin G (22), a macrocyclic bisbibenzyl, and four derivatives. The key 16-membered ring containing biphenyl ether and biaryl units was closed via an intramolecular SNAr reaction. All synthesized macrocyclic bisbibenzyls inhibited Epstein-Barr virus early antigen (EBVEA) activation induced by the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells and, thus, are potential cancer chemopreventive agents.

Nudibaccatumone, a trimer comprising a phenylpropanoid and two sesquiterpene moieties from Piper nudibaccatum.

A new complex natural product with a C39 skeleton, named nudibaccatumone, and the known sesquiterpenes (+)-spathulenol, (-)-4ß,10α-aromadendranediol, and ent-T-muurolol, as well as the phenylpropanoid hydroxychavicol, were isolated from the aerial parts of Piper nudibaccatum. The structure and absolute configuration of nudibaccatumone were elucidated using spectroscopic methods and ECD calculations. A 1,8-Michael addition reaction and an intermolecular, inverse electron demand Diels-Alder reaction are proposed as the key steps in the biosynthesis of nudibaccatumone.

Secondary metabolites from the Chinese liverwort Cephaloziella kiaeri.

Sixteen new clerodane diterpenoids, cephaloziellins A-P (1-16), and two known analogues (17 and 18) were isolated from an EtOH extract of the Chinese liverwort Cephaloziella kiaeri. The structures of the new compounds were elucidated from extensive spectroscopic data (IR, UV, HRESIMS, 1D NMR, and 2D NMR), and the structures of 5, 9, and 15 were confirmed by single-crystal X-ray diffraction analyses. The absolute configurations of all new compounds were established by comparing experimental and calculated electronic circular dichroism spectra.

New monoterpene lactones from Actaea cimicifuga.

Three new monoterpene lactones, cimicifugolides A-C (1-3), along with a known one (4), were identified from the dried rhizome of Actaea cimicifuga L. that was used as traditional Chinese medicine for thousands of years with the Chinese common name of shengma. The structures of the new isolates were established using spectroscopic methods, including NMR, mass, UV, and IR spectra. The inhibition activity of compounds 1, 2, and 4 against pancreatic lipase was evaluated.