Composition of the essential oils of three Malaysian Xylopia species (Annonaceae).

The rich and diversified Malaysian flora represents an excellent resource of new chemical structures with biological activities. The genus Xylopia L. includes aromatic plants that have both nutritional and medicinal uses. This study aims to contribute with information about the volatile components of three Xylopia species essential oils: Xylopia frutescens, Xylopia ferruginea, and Xylopia magna. In this study, essential oils were extracted from the leaves by a hydrodistillation process. The identification of the essential oil components was performed by gas chromatography (GC-FID) and gas chromatography-coupled mass spectrometry (GC-MS). The major components of the essential oils from X. frutescens were bicyclogermacrene (22.8%), germacrene D (14.2%), elemol (12.8%), and guaiol (12.8%), whereas components of the essential oils from X. magna were germacrene D (35.9%), bicyclogermacrene (22.8%), and spathulenol (11.1%). The X. ferruginea oil was dominated by bicyclogermacrene (23.6%), elemol (13.7%), guaiol (13.4%), and germacrene D (12.3%).

Chemical characterization of Goniothalamus macrophyllus and Goniothalamus malayanus leaves' essential oils.

This study was aimed to investigate the chemical compositions of the essential oils from Goniothalamus macrophyllus and Goniothalamus malayanus growing in Malaysia. The essential oils were obtained by hydrodistillation and fully characterized by gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Analyses of the essential oils from G. macrophyllus and G. malayanus resulted in 93.6 and 95.4% of the total oils, respectively. The major components of G. macrophyllus oil were germacrene D (25.1%), bicyclogermacrene (11.6%), α-copaene (6.9%) and δ-cadinene (6.4%), whereas in G. malayanus oil bicyclogermacrene (43.9%), germacrene D (21.1%) and ß-elemene (8.4%) were the most abundant components.

Megastigmane Derivatives from the Cladodes of Opuntia humifusa and Their Nitric Oxide Inhibitory Activities in Macrophages.

Opuntia humifusa, known as the eastern prickly pear cactus and locally called "Cheonnyuncho" in Korea, is cultivated widely on Jeju Island, Korea. Phytochemical analysis of the methanolic extract of the cladodes of O. humifusa, for which previous research is relatively limited, was performed under the guidance of LC/MS-based analysis. As a result, one new megastigmane (1) and four new megastigmane glucosides (2-5) were isolated along with 18 known compounds (6-23). The structures of the new compounds were established by 1D and 2D NMR and HRESIMS, and their absolute configurations were established by chemical reactions, quantum chemical electronic circular dichroism calculations, and DP4+ analysis using the gauge-including atomic orbital NMR chemical shift calculations as well as the application of Snatzke's method. The isolated compounds (1-23) were tested for NO production inhibition in lipopolysaccharide (LPS)-induced RAW 264.7 cells to investigate their anti-inflammatory effects. Compounds 10 and 11 exhibited significant inhibitory effects on LPS-induced NO production in a dose-dependent manner. The potential mechanistic pathway of 10 and 11 was also investigated using Western blotting, indicating that compounds 10 and 11 inhibit NO through iNOS expression.

UVA and UVB Photoprotective Capabilities of Topical Formulations Containing Mycosporine-like Amino Acids (MAAs) through Different Biological Effective Protection Factors (BEPFs).

The safety and stability of synthetic UV-filters and the procedures for evaluating the photoprotective capability of commercial sunscreens are under continuous review. The influence of pH and temperature stressors on the stability of certain Mycosporine-like amino acids (MAAs) isolated at high purity levels was examined. MAAs were highly stable at room temperature during 24 h at pH 4.5⁻8.5. At 50 °C, MAAs showed instability at pH 10.5 while at 85 °C, progressive disappearances were observed for MAAs through the studied pH range. In alkaline conditions, their degradation was much faster. Mycosporine-serinol and porphyra-334 (+shinorine) were the most stable MAAs under the conditions tested. They were included in four cosmetically stable topical sunscreens, of which the Sun Protection Factor (SPF) and other Biological Effective Protection Factors (BEPFs) were calculated. The formulation containing these MAAs showed similar SPF and UVB-BEPFs values as those of the reference sunscreen, composed of synthetic UV absorbing filters in similar percentages, while UVA-BEPFs values were slightly lower. Current in vitro data strongly suggest that MAAs, as natural and safe UV-absorbing and antioxidant compounds, have high potential for protection against the diverse harmful effects of solar UV radiation. In addition, novel complementary in vitro tests for evaluation of commercial sunscreens efficacy are proposed.

Megastigmane glycosides from Urena lobata.

Five new megastigmane glycosides, urenalobasides A-E (1-5), together with 11 known ones (6-16) were isolated from Urena lobata. Their structures were determined by extensive spectroscopic and spectrometric data (1D and 2D NMR, IR, and HRESIMS) and calculated electronic circular dichroism method. Compounds 1 and 2 are two unusual megastigmanes structurally containing a 6/5 fused ring system. Compound 3 exhibits inhibition of nitric oxide production in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells with IC50 value of 53.7 ±â€¯1.0 µM (positive control, dexamethasone, IC50 = 16.6 ±â€¯0.8 µM).

Essential oils showing in vitro anti MRSA and synergistic activity with penicillin group of antibiotics.

This study was planned in order to investigate effective essential oils to inhibit in-vitro growth of Methicillin resistant Staphylococcus aureus (MRSA). In this study using disc diffusion method anti MRSA activity of ten diverse essential oils extracted from traditional plants namely Thymus vulgaris L, Mentha pulegium, Ocimum sanctum, Mentha piperita, Cymbopogon citratus, Rosmarinus officinalis L., Cortex cinnamom, Citrus nobilis x Citrus deliciosa, Origanum vulgare and Mentha sp. was examined. All the essential oils inhibited growth of S. aureus to different extent, by exhibiting moderate to elevated zones of inhibitions. Essential oils of cinnamon (Cortex cinnamomi) and thyme (Thymus vulgaris L) were observed to be the most powerful against MRSA strains used in this study. At lowest concentration of 25µl/ml essential oils comprehensible zone of inhibition was found 9±0.085mm and 8±0.051mm respectively, and at elevated concentrations there was a total decline in growth of MRSA and a very clear zone of inhibition was observed. A synergistic effect of essential oils in amalgamation with amoxicillin a Penicillin group of antibiotic was also examined. Interestingly a strong synergism was observed with oregano (Origanum vulgare) and pennyroyal mint (Mentha pulegium) essential oils, which were not so effective alone driven out to be important synergistic candidate. Our results demonstrated that essential oils of cinnamon and thyme can be used as potential antimicrobial agent against the Methicillin-resistant Staphylococcus aureus infections and Amoxicillin antibacterial activity can be enhanced using active constituents present in oregano and pennyroyal mint essential oils.

Camellianols A-G, Barrigenol-like Triterpenoids with PTP1B Inhibitory Effects from the Endangered Ornamental Plant Camellia crapnelliana.

Seven new naturally occurring barrigenol-like compounds, camellianols A-G (1-7), and 10 known triterpenoids were isolated from the twigs and leaves of the cultivated endangered ornamental plant Camellia crapnelliana. According to the ECD octant rule for saturated cyclohexanones, the absolute configurations of camellianols D (4) and E (5) were defined. The backbones of the remaining new isolates are assumed to have the same absolute configuration as compounds 4, 5, and harpullone (12). Compounds 2, 3, 9, 10, 13, and 16 exhibited inhibitory effects on the protein tyrosine phosphatase 1B (PTP1B) enzyme, with IC50 values less than 10 µM.

Polyprenylated acylphloroglucinols from Hypericum scabrum.

Fourteen phloroglucinols, named hyperciumoxide A-N, and a known compound were isolated from air-dried aerial parts of Hypericum scabrum. The structures of these compounds were deduced on the basis of extensive 1D- and 2D-NMR experiments. Hepatoprotective properties against D-galactosamine-induced HL-7702 cell damage of isolated compounds were evaluated. Meanwhile, these compounds were also tested for antidepressant activity by inhibiting reuptake of tritiated serotonin ([3H]-5-HT) and Noradrenalinet ([3H]-NE) in rat brain synaptosomes.

PTP1B inhibitors from Selaginella tamariscina (Beauv.) Spring and their kinetic properties and molecular docking simulation.

Diabetes is one of the most popular worldwide diseases, regulated by the defects in insulin secretion, insulin action, or both. The overexpression of protein tyrosine phosphatase 1B (PTP1B) was found to down-regulate the insulin-receptor activation. PTP1B has been known as a strategy for the treatment of diabetes via the regulation of insulin signal transduction pathway. Herein, we investigated the PTP1B inhibitors isolated from natural sources. The chemical investigation of Selaginella tamariscina (Beauv.) Spring revealed seven unsaturated alkynyl phenols 1-7, four new selaginellins T-W 1-4 together with three known compounds 5-7 isolated from the aerial parts. The structures of the isolates were determined by spectroscopic techniques (1D/2D-NMR, MS, and CD). The inhibitory effects of these isolates on the PTP1B enzyme activity were investigated. Among them, compounds 2-7 significantly exhibited the inhibitory effects with the IC50 values ranging from 4.8 to 15.9µM. Compound 1 moderately displayed the inhibitory activity with an IC50 of 57.9µM. Furthermore, active compounds were discovered from their kinetic and molecular docking analysis. The results revealed that compounds 2 and 4-7 were mixed-competitive inhibitors, whereas compound 3 was a non-competitive inhibitor. This data confirm that these compounds exhibited potential inhibitory effect on the PTP1B enzyme activity.

Megastigmane glucosides isolated from Dichrocephala benthamii.

The present study was designed to investigate the chemical constituents of the whole herb of Dichrocephala benthamii. A new megastigmane glucoside (compound 1), together with its four known analogues (compounds 2-5), was obtained. Their structures were elucidated on the basis of spectroscopic analyses (UV, IR, MS, and 1D and 2D NMR). The absolute configuration of compound 1 was assigned on the basis of CD method and chemical evidence. In addition, their cytotoxicity against human hepatoma cells (HepG-2) was evaluated by the MTT method. Compound 5 showed weak activity against HepG-2, while the other compounds did not show remarkable inhibitory effects.

Neolignan and megastigmane glucosides from the aerial parts of Isodon japonicus with cell protective effects on BaP-induced cytotoxicity.

Six neolignan glucosides, named isodonosides I-VI, and a megastigmane glucoside named isodonmegastigmane I, were isolated together with 15 known compounds from the methanolic extract of aerial parts of Isodon japonicus cultivated in Tokushima, Japan. The chemical structures of the compounds were elucidated based on their MS and NMR spectroscopic analysis. The absolute configurations of the neolignan and megastigmane glucosides were determined by derivatizations, by ECD (electronic circular dicroism) Cotton effect approximation, and by the modified Mosher's method. In addition, a significant cell protective effects of neolignan glucosides on benzo[a]pyrene-induced cytotoxicity was found.

Megastigmane glycosides from leaves of Eucommia ulmoides Oliver with ACE inhibitory activity.

Four new megastigmane glycosides, eucomegastigsides A-D (2, 3, 5 and 7), together with three known megastigmane glycosides, (6R, 7E, 9R)-9-hydroxy-4, 7-megastigmadien-3-one-9-O-[α-l-arabinopyranosyl-(l→6)-ß-d-glucopyranoside (1), foliasalacioside B1 (4) and eleganoside A (6), were isolated from the leaves of Eucommia ulmoides Oliver. Their anti-hypertensive effect was investigated in vitro based on the inhibition of Angiotensin Converting Enzyme (ACE) using HPLC. The results showed that the isolates (2, 3, 4, 5, 7) had moderate inhibitory effects on ACE in vitro compared with captopril.

Naphthochromenes and Related Constituents from the Tubers of Sinningia allagophylla.

Chemical investigation of the tubers of Sinningia allagophylla led to the isolation of two new chromenes, (2S)-12-hydroxylapachenole (1) and (3R)-3,4-dihydro-3-hydroxy-4-oxo-8-methoxylapachenole (2), and three new dimeric chromenes, allagophylldimers A-C (3-5). Thirteen known compounds, 6-methoxy-7,8-benzocoumarin (6), lapachenole, 8-methoxylapachenole, tectoquinone, 7-hydroxytectoquinone, dunniol, α-dunnione, dunnione, 8-hydroxydunnione, aggregatin E, cedrol, oleanolic acid, and halleridone, were also identified. 6-Methoxy-7,8-benzocoumarin (6) has been isolated for the first time from a natural source.

Microsporols A-C from the Plant Endophytic Fungus Pestalotiopsis microspore.

Three new ambuic acid derivatives, microsporols A-C (1-3) and the known compound ambuic acid (4), were isolated from the solid-substrate fermentation cultures of the plant endophytic fungus Pestalotiopsis microspora. Their structures were elucidated primarily by NMR experiments. The absolute configurations of the 6,7-diol moiety in 1 and 2 were assigned using the Snatzke's method, whereas that of 3 was deduced by circular dichroism (CD) exciton chirality method. Compounds 1, 3, and 4 showed moderate 5-lipoxygenase (5-LOX) inhibitory effects.

Comparison of Fruits of Forsythia suspensa at Two Different Maturation Stages by NMR-Based Metabolomics.

Forsythiae Fructus (FF), the dried fruit of Forsythia suspensa, has been widely used as a heat-clearing and detoxifying herbal medicine in China. Green FF (GF) and ripe FF (RF) are fruits of Forsythia suspensa at different maturity stages collected about a month apart. FF undergoes a complex series of physical and biochemical changes during fruit ripening. However, the clinical uses of GF and RF have not been distinguished to date. In order to comprehensively compare the chemical compositions of GF and RF, NMR-based metabolomics coupled with HPLC and UV spectrophotometry methods were adopted in this study. Furthermore, the in vitro antioxidant and antibacterial activities of 50% methanol extracts of GF and RF were also evaluated. A total of 27 metabolites were identified based on NMR data, and eight of them were found to be different between the GF and RF groups. The GF group contained higher levels of forsythoside A, forsythoside C, cornoside, rutin, phillyrin and gallic acid and lower levels of rengyol and ß-glucose compared with the RF group. The antioxidant activity of GF was higher than that of RF, but no significant difference was observed between the antibacterial activities of GF and RF. Given our results showing their distinct chemical compositions, we propose that NMR-based metabolic profiling can be used to discriminate between GF and RF. Differences in the chemical and biological activities of GF and RF, as well as their clinical efficacies in traditional Chinese medicine should be systematically investigated in future studies.

Selaginellin and biflavonoids as protein tyrosine phosphatase 1B inhibitors from Selaginella tamariscina and their glucose uptake stimulatory effects.

As part of an ongoing search for new antidiabetic agents from medicinal plants, the methanol extract of the aerial parts of Selaginella tamariscina was found to possess stimulatory effect on glucose uptake in 3T3-L1 adipocyte cells. Thus, bioassay-guided isolation of this active extract yielded two new compounds (1 and 2) along with five known biflavonoids (3-7). Their structures were elucidated by extensive analysis of spectroscopic and physicochemical data. The absolute configuration of compound 2 was determined by specific rotation and CD data analysis. All isolates exhibited potent inhibitory effects on PTP1B enzyme with IC50 values ranging from 4.5±0.1 to 13.2±0.8µM. Furthermore, the isolates (1-7) showed significant stimulatory effects on 2-NBDG uptake in 3T3-L1 adipocyte cells. Of these, compounds (1, 6, and 7) which exhibited mixed-competitive inhibition modes against PTP1B, showed potent stimulatory effects on 2-NBDG uptake. This result indicated the potential of these biflavonoids as lead molecules for development of antidiabetic agents and the beneficial use of S. tamariscina against hyperglycemia.

Insulin-mimetic selaginellins from Selaginella tamariscina with protein tyrosine phosphatase 1B (PTP1B) inhibitory activity.

As part of an ongoing search for new antidiabetic agents from medicinal plants, three new (2, 4, and 5) and two known selaginellin derivatives (1 and 3) were isolated from a methanol extract of Selaginella tamariscina. The structures of the new compounds were determined by spectroscopic data analysis. All isolates showed strong glucose uptake stimulatory effects in 3T3-L1 adipocyte cells at a concentration of 5 µM. Furthermore, these compounds were found to possess inhibitory effects on PTP1B enzyme activity with IC50 values ranging from 4.6 ± 0.1 to 21.6 ± 1.5 µM. Compound 2 showed the greatest potency, with an IC50 value of 4.6 ± 0.1 µM, when compared with the positive control (ursolic acid, IC50 = 3.5 ± 0.1 µM). Therefore, these selaginellin derivatives may have value as new lead compounds for the development of agents against type 2 diabetes.

New flavonoid glycosides from Sedum aizoon L.

Five new flavonoid glucosides (3-4, 10-12) and a new phenolic derivative (5), together with eight known compounds including three flavonoid glucosides (6-8), three phenolic compounds (1-2, 9) and two megastigmane glucosides (13, 14), were isolated from the ethanol extract of the aerial part of Sedum aizoon L. Among them, compounds 9, 13 and 14 were isolated and identified from this genus for the first time. The structures of compounds were elucidated on the basis of 1D and 2D NMR (HSQC, HMBC and COSY) spectra and the HR-ESI-MS data. These compounds were tested for their antibacterial efficacies against both Gram-positive and Gram-negative bacteria. Compounds 1, 2, 3, 7 and 10 showed certain antibacterial activity; it showed more potency against Gram-positive than against Gram-negative bacteria. Compound 2 showed the most pronounced antibacterial effectiveness against Staphylococcus aureus Rosenbach with MIC value of 7.8µg·mL(-1). The in vitro anti-proliferative activities against HepG2, MCF-7 and A549 tumor cell lines were also evaluated. The result suggested compound 7 exhibited moderate cytotoxic activities with IC50 values of 46.30, 75.27 and 49.76µmol/L, respectively.

A new megastigmane glycoside from Akebia quinata.

A new megastigmane glycoside, 8S*,9R*-megastigman-3-one-4,6-diene-8,9-diol-9-O-ß-D-glucopyranoside, named akequintoside D (1), as well as six known compounds, roseoside II (2), 3-O-caffeoylquinic acid (3), methyl-3-O-caffeoylquinate (4), 3,4,5-trimethoxyphenyl-ß-D-glucopyranoside (5), cuneataside D (6), 3,4-dimethoxyphenyl-6-O-(α-L-rhamnopyranosyl)-ß-D-glucopyranoside (7) were isolated from the stem of Akebia quinata. The structures of compounds (1-7) were identified based on 1D and 2D NMR, including (1)H-(1)H COSY, HSQC, HMBC and NOESY spectroscopic analyses. The inhibitory activity of these isolated compounds against interleukin-6 (IL-6) production in TNF-α stimulated MG-63 cells was also examined.

Tigliane diterpenes from Croton mauritianus as inhibitors of chikungunya virus replication.

A bioassay-guided purification of an EtOAc extract of the leaves of Croton mauritianus using a chikungunya virus-cell-based assay led to the isolation of 12-O-decanoylphorbol-13-acetate (1) and the new 12-O-decanoyl-7-hydroperoxy-phorbol-5-ene-13-acetate (2), along with loliolide, vomifoliol, dehydrovomifoliol, annuionone D and bluemol C. The planar structure and the relative configuration of compound 2 were elucidated based on spectroscopic analysis, including 1D- and 2D-NMR experiments, mass spectrometry, and comparison with literature data. Compounds 1 and 2 inhibited chikungunya virus-induced cell death in cell culture with EC50s of 2.4±0.3 and 4.0±0.8 µM, respectively.