Cytotoxic Podophyllotoxin Type-Lignans from the Steam Bark of <em>Bursera fagaroides </em>var. <em>fagaroides</em>

The hydroalcoholic extract of the steam bark of B. fagaroides var. fagaroides displayed potent cytotoxic activity against four cancer cell lines, namely KB (ED₅₀ = 9.6 × 10^-2 μg/mL), PC-3 (ED₅₀ = 2.5 × 10^-1 μg/mL), MCF-7 (ED₅₀ = 6.6 μg/mL), and HF-6 (ED₅₀ = 7.1 × 10^-3 μg/mL). This extract also showed anti-tumour activity when assayed on mice inoculated with L5178Y lymphoma cells. Bioactivity-directed isolation of this extract, afforded seven podophyllotoxin-type lignans identified as podophyllotoxin (1), β-peltatin-A-methylether (2), 5'-desmethoxy-β-peltatin-A-methylether (3), desmethoxy-yatein (4), desoxypodophyllotoxin (5), burseranin (6), and acetyl podophyllotoxin (7) by 1D and 2DNMR and FAB-MS analyses, and comparison with reported values. All the isolated compounds showed potent cytotoxic activity in the cell lines tested, especially compound 3, which exhibited greater activity than camptothecin and podophyllotoxin against PC-3 (ED₅₀ = 1.0 × 10^-5 μg/mL), and KB (ED₅₀ = 1.0 × 10^-5 μg/mL). This is the first report of the isolation of podophyllotoxin and its acetate in a Bursera species.     

New Resveratrol Oligomers from the Stem Bark of Hopea hainanensis

Three new resveratrol oligomers, hopeahainanphenol ( 1 ), neohopeaphenol A ( 2 ), and neoisohopeaphenol A ( 3 ), were isolated from the stem bark of Hopea hainanensis (Dipterocarpaceae). Their structures were elucidated by in‐depth spectroscopic analyses, including 1D‐ and 2D‐NMR techniques, and by HR‐ESI‐MS. All the three phytochemicals were tested in vitro for acetylcholinesterase (AChE) inhibitory and antitumor activity. The dimeric compound 2 , which corresponds to (1S*,6S*,7S*,11bS*)‐1,6,7,11b‐tetrahydro‐1,7‐bis(4‐hydroxyphenyl)‐6‐[(1R*,6R*,7R*,11bR*)‐1,6,7,11b‐tetrahydro‐4,8,10‐trihydroxy‐1,7‐bis(4‐hydroxyphenyl)benzo[6,7]cyclohepta[1,2,3‐cd]benzofuran‐6‐yl]benzo[6,7]cyclohepta[1,2,3‐cd]benzofuran‐4,8,10‐triol, was found to be significantly active against AChE, with an IC₅₀ value of 7.66 ± 0.13 μm.     

Influences of <em>Dryopteris crassirhizoma</em> Extract on<em> </em>the Viability, Growth and Virulence Properties of <em>Streptococcus </em><em>m</em><em>utans</em><em></em>

Dryopteris crassirhizoma is traditionally used as an herbal remedy for various diseases, and has been identified in a previous study as a potential anti-caries agent. In this study, the effect of a methanol extract of D. crassirhizoma on the viability, growth and virulence properties of Streptococcus mutans, a cariogenic dental pathogen, was investigated. In addition, the phytochemical composition of the extract was analyzed. The extract showed bactericidal and bacteriostatic activity against oral bacteria (MIC and MBC of S. mutans: 62.5 and 250 μg/mL, respectively). At two times the MBC, the extract significantly eliminated S. mutans up to 99.9% after 1 h incubation. The extract also dose-dependently reduced growth rates of S. mutans at sub-MIC levels. Furthermore, at sub-MIC levels, virulence properties (acid production, acid tolerance, glucosyltransferase activity and sucrose-dependent adherence) of S. mutans were also inhibited in a dose-dependent manner. GC-MS analysis revealed the presence of mono and disaccharides (44.9%), fatty acids (12.3%) and sugar alcohols (6.8%) in the extract. These data indicate that the extract might be useful for the control of dental caries.     

Negative-Pressure Cavitation Extraction of Four Main Vinca Alkaloids from <em>Catharanthus </em><em>r</em><em>oseus</em> Leaves

In the present study, an improved method termed negative-pressure cavitation extraction (NPCE) followed by reverse phase high-performance liquid chromatography (RP-HPLC) was developed for the extraction and quantification of vindoline (VDL), catharanthine (CTR), vincristine (VCR) and vinblastine (VLB) from Catharanthus roseus leaves. The optimized method employed 60-mesh particles, 80% ethanol, a negative pressure of -0.075 MPa, a solid to liquid ratio of 1:20, 30 min of extraction and three extraction cycles. Under these optimized conditions, the extraction yields of VDL, CTR, VCR and VLB are 0.5783, 0.2843, 0.018 and 0.126 mg/g DW, respectively. These extraction yields are equivalent to those from the well-known ultrasonic extraction method and higher than the yields from maceration extraction and heating reflux extraction. Our results suggest that NPCE-RP-HPLC represents an excellent alternative for the extraction and quantification of vinca alkaloids for pilot- and industrial-scale applications.     

Specific Binding of Anionic Porphyrin and Phthalocyanine to the G-Quadruplex with a Variety of <em>i</em><em>n Vitro</em> and<em> </em><em>i</em><em>n Vivo</em> Applications

The G-quadruplex, a four-stranded DNA structure with stacked guanine tetrads (G-quartets), has recently been attracting attention because of its critical roles in vitro and in vivo. In particular, the G-quadruplex functions as ligands for metal ions and aptamers for various molecules. Interestingly, the G-quadruplex can show peroxidase-like activity with an anionic porphyrin, iron (III) protoporphyrin IX (hemin). Importantly, hemin binds to G-quadruplexes with high selectivity over single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA), which is attributable to an electrostatic repulsion of phosphate groups in ssDNA and dsDNA. The G-quadruplex and hemin-G-quadruplex complex allow development of sensing techniques to detect DNA, metal ions and proteins. In addition to hemin, anionic phthalocyanines also bind to the G-quadruplex formed by human telomere DNA, specifically over ssDNA and dsDNA. Since the binding of anionic phthalocyanines to the G-quadruplex causes an inhibition of telomerase activity, which plays a role in the immortal growth of cancer cells, anionic phthalocyanines are promising as novel anticancer drug candidates. This review focuses on the specific binding of hemin and anionic phthalocyanines to G-quadruplexes and the applications in vitro and in vivo of this binding property.     

<em>In Vitro </em>and <em>in </em><em>Vivo</em> Antitumor Effect of Trachylobane-360, a Diterpene from<em> Xylopia langsdorffiana</em>

Trachylobane-360 (ent-7α-acetoxytrachyloban-18-oic acid) was isolated from Xylopia langsdorffiana. Studies have shown that it has weak cytotoxic activity against tumor and non-tumor cells. This study investigated the in vitro and in vivo antitumor effects of trachylobane-360, as well as its cytotoxicity in mouse erythrocytes. In order to evaluate the in vivo toxicological aspects related to trachylobane-360 administration, hematological, biochemical and histopathological analyses of the treated animals were performed. The compound exhibited a concentration-dependent effect in inducing hemolysis with HC₅₀ of 273.6 μM, and a moderate in vitro concentration-dependent inhibitory effect on the proliferation of sarcoma 180 cells with IC₅₀ values of 150.8 μM and 150.4 μM, evaluated by the trypan blue exclusion test and MTT reduction assay, respectively. The in vivo inhibition rates of sarcoma 180 tumor development were 45.60, 71.99 and 80.06% at doses of 12.5 and 25 mg/kg of trachylobane-360 and 25 mg/kg of 5-FU, respectively. Biochemical parameters were not altered. Leukopenia was observed after 5-FU treatment, but this effect was not seen with trachylobane-360 treatment. The histopathological analysis of liver and kidney showed that both organs were mildly affected by trachylobane-360 treatment. Trachylobane-360 showed no immunosuppressive effect. In conclusion, these data reinforce the anticancer potential of this natural diterpene.     

Screening and Analysis of the Potential Bioactive Components in Rabbit Plasma after Oral Administration of Hot-Water Extracts from Leaves of <em>B</em><em>ambusa </em><em>textilis </em>McClure

Bambusa textilis McClure is a traditional Chinese medicinal plant belonging to the Bambusoideae subfamily and used to treat chronic fever and infectious diseases. To investigate the bioactive compounds absorbed in the rabbit blood after oral administration of hot-water extracts from the leaves of B. textilis McClure, a validated chromatographic fingerprint method was established using LC-Q-TOF-MS. Twenty compounds in bamboo leaves and three potential bioactive compounds in rabbit plasma were detected. Of the twenty detected compounds in vitro, fifteen of which were tentatively identified either by comparing the retention time and mass spectrometry data with that of reference compounds or by reviewing the literature. Three potential bioactive compounds, including (E)-p-coumaric acid, (Z)-p-coumaric acid, and apigenin-8-C-β-D-(2"-O-α-L-rhamnosyl)-gluco-pyranoside, were detected in both the leaves of B. textilis McClure and rabbit plasma. Of the three compounds, apigenin-8-C-β-D-(2"-O-α-L-rhamnosyl)glucopyranoside was identified based on its UV, MS, and NMR spectra. This study provides helpful chemical information for further pharmacology and active mechanism research on B. textilis McClure.     

Development and Characterization of EST-SSR Markers from <em>Scapharca broughtonii</em> and Their Transferability in <em>Scapharca subcrenata</em> and <em>Tegillarca granosa</em>

Twenty-five novel EST-derived simple sequence repeat (EST-SSR) markers were developed in the ark shell Scapharca broughtonii. Polymorphisms of these EST-SSR markers were evaluated in 48 wild individuals collected from Shidao, Shandong Province, China. A total of 202 alleles were detected at 25 loci. The numbers of alleles per locus ranged from 4 to 14, with an average of 8.08. The observed and expected heterozygosities varied from 0.2917 to 1.000 and from 0.3570 to 0.9002, respectively. After sequential Bonferroni correction for multiple tests, only one locus was found to deviate from Hardy-Weinberg equilibrium. Twenty-five EST-SSR markers showed a high rate of across-species transferability (100%) in Scapharca subcrenata and a low rate of across-genus transferability (20%) in Tegillarca granosa. These EST-SSRs will be helpful for QTL mapping, molecular breeding and investigation of population genetic diversity in ark shell S. broughtonii and other Scapharca species.     

A New Natural Lactone from <em>Dimocarpus</em> <em>longan</em> Lour. Seeds

A new natural product named longanlactone was isolated from Dimocarpus longan Lour. seeds. Its structure was determined as 3-(2-acetyl-1H-pyrrol-1-yl)-5-(prop-2-yn-1-yl)dihydrofuran-2(3H)-one by spectroscopic methods and HRESIMS.     

Identification and Determination of <em>Aconitum</em> Alkaloids in <em>Aconitum</em> Herbs and <em>Xiaohuoluo Pill</em> Using UPLC-ESI-MS

A rapid, specific, and sensitive ultra-performance liquid chromatography-electrospray ionization-mass spectrometry (UPLC-ESI-MS) method to examine the chemical differences between Aconitum herbs and processed products has been developed and validated. Combined with chemometrics analysis of principal component analysis (PCA) and orthogonal projection to latent structural discriminate analysis, diester-diterpenoid and monoester-type alkaloids, especially the five alkaloids which contributed to the chemical distinction between Aconitum herbs and processed products, namely mesaconitine (MA), aconitine (AC), hypaconitine (HA), benzoylmesaconitine (BMA), and benzoylhypaconitine (BHA), were picked out. Further, the five alkaloids and benzoylaconitine (BAC) have been simultaneously determined in the Xiaohuoluo pill. Chromatographic separations were achieved on a C₁₈ column and peaks were detected by mass spectrometry in positive ion mode and selected ion recording (SIR) mode. In quantitative analysis, the six alkaloids showed good regression, (r) > 0.9984, within the test ranges. The lower limit quantifications (LLOQs) for MA, AC, HA, BMA, BAC, and BHA were 1.41, 1.20, 1.92, 4.28, 1.99 and 2.02 ng·mL^-1, respectively. Recoveries ranged from 99.7% to 101.7%. The validated method was applied successfully in the analysis of the six alkaloids from different samples, in which significant variations were revealed. Results indicated that the developed assay can be used as an appropriate quality control assay for Xiaohuoluo pill and other herbal preparations containing Aconitum roots.     

Chemical Composition and <em>in Vitro</em> Evaluation of the Antioxidant and Antimicrobial Activities of <em>Eucalyptus gillii </em>Essential Oil and Extracts<em></em>

In this study, essential oil and various extracts (hexane, petroleum ether, acetone, ethanol, methanol and water) of Eucalyptus gilii were screened for their chemical composition, antimicrobial and antioxidant activities. The essential oil chemical composition was analyzed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detection (GC-FID), respectively. Thirty four compounds were identified, corresponding to 99.5% of the total essential oil. Tannins [104.9-251.3 g catechin equivalent (CE)/Kg dry mass], flavonoids [3.3-34.3 g quercetin equivalent (QE)/Kg dry mass], phenolics [4.7-216.6 g gallic acid equivalent (GAE)/Kg dry mass] and anthocyannins [1.2-45.3 mg cyanidin-3-glucoside equivalent (C3GE)/Kg dry mass] of various extracts were investigated. Free radical scavenging capacity of all samples was determinedt. In the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, the IC₅₀ of essential oil was 163.5 ± 10.7 mg/L and in the 2,2'-azinobis-3-ethylbenzothiazoline-6-sulphonate (ABTS) assay, it was 94.7 ± 7.1 mg/L. Among the various extracts, the water extract showed the best result (IC₅₀ = 11.4 ± 0.6 mg/L) in the DPPH assay which was comparable to vitamin C (IC₅₀ = 4.4 ± 0.2 mg/L). The antimicrobial activities were evaluated against different bacterial and fungal strains. Gram positive bacteria were found to be more sensitive to the essential oil and extracts than Gram negative ones. Anthocyanins seem to have a major effect on the growth of Bacillus subtilis (R² = 0.79). A significant antifungal activity was observed against the yeast and fungi. Correlations between chemical composition and antioxidant activities were studied and R² values were about 0.96 for the effect of phenolics on the DPPH assay.     

A Synthetic Method to Access Symmetric and Non-Symmetric 2-(<em>N</em>,<em>N</em><em>'</em>-disubstituted)guanidinebenzothiazoles

Symmetric and non-symmetric 2-(N-H, N-methyl, N-ethylenyl and N-aryl)guanidinebenzothiazoles were synthesized from the reaction of ammonia, methylamine, pyrrolidine and aniline with dimethyl benzo[d]thiazol-2-yl-carbono-dithioimidate (5) as intermediate. The products were characterized by ¹H-, ¹³C-NMR spectroscopy and three of them by X-ray diffraction analysis. HN-phenyl protons formed intramolecular hydrogen bonds that assist the stereochemistry of the second substituent, whereas the HN-alkyl protons were involved in intermolecular hydrogen bonding.     

<em>An ent</em>-Kaurane-Type Diterpene in <em>Croton antisyphiliticus</em> Mart

Croton antisyphiliticus is a medicinal plant widely used in the treatment of microbial infections, especially those affecting the genital tract. Crude extract, fractions and pure compound isolated from roots of this species were investigated to validate their antimicrobial activity against Escherichia coli and Staphylococcus aureus. The compound ent-kaur-16-en-18-oic acid was isolated as a major component (0.7% of crude extract), and its MIC value determined against S. aureus (ATCC 6538) was 250 μg/mL. This is the first phytochemical work on the species monitored with antimicrobial assay.     

Fumigant Antifungal Activity of Myrtaceae Essential Oils and Constituents from <em>Leptospermum petersonii</em> against Three <em>Aspergillus</em> Species

Commercial plant essential oils obtained from 11 Myrtaceae plant species were tested for their fumigant antifungal activity against Aspergillus ochraceus, A. flavus, and A. niger. Essential oils extracted from Leptospermum petersonii at air concentrations of 56 × 10^-3 mg/mL and 28 × 10^-3 mg/mL completely inhibited the growth of the three Aspergillus species. However, at an air concentration of 14 × 10^-3 mg/mL, inhibition rates of L. petersonii essential oils were reduced to 20.2% and 18.8% in the case of A. flavus and A. niger, respectively. The other Myrtaceae essential oils (56 × 10^-3 mg/mL) only weakly inhibited the fungi or had no detectable affect. Gas chromatography-mass spectrometry analysis identified 16 compounds in L. petersonii essential oil. The antifungal activity of the identified compounds was tested individually by using standard or synthesized compounds. Of these, neral and geranial inhibited growth by 100%, at an air concentration of 56 × 10^-3 mg/mL, whereas the activity of citronellol was somewhat lover (80%). The other compounds exhibited only moderate or weak antifungal activity. The antifungal activities of blends of constituents identified in L. petersonii oil indicated that neral and geranial were the major contributors to the fumigant and antifungal activities.     

Diterpenoids from the Buds of <em>Pinus banksiana</em> Lamb

Three new diterpenoids, namely 7α-hydroxyabieta-8,11,13,15-tetraen-18-oic acid, 7β,15,18-trihydroxyabieta-8,11,13-triene, 13,15-dihydroxypodocarpa-8,11,13-triene, and 12 other known compounds were isolated from buds of Pinus banksiana Lamb. All these compounds, except for 7-oxodehydroabietinol, were isolated for the first time from this plant. Their structures were elucidated by detailed spectroscopic studies and comparison with published data. All isolated compounds were tested for cytotoxic and antibacterial activities. Overall, two compounds, 7-oxodehydroabietinol and 18-nor-4,15-dihydroxyabieta-8,11,13-trien-7-one, showed moderate cytotoxicity against a human lung carcinoma cell line.     

Antimicrobial Activity of Geranium Oil against Clinical Strains<em> </em>of <em>Staphylococcus aureus</em>

The aim of this work was to investigate the antibacterial properties of geranium oil obtained from Pelargonium graveolens Ait. (family Geraniaceae), against one standard S. aureus strain ATCC 433000 and seventy clinical S. aureus strains. The agar dilution method was used for assessment of bacterial growth inhibition at various concentrations of geranium oil. Susceptibility testing of the clinical strains to antibiotics was carried out using the disk-diffusion and E-test methods. The results of our experiment showed that the oil from P. graveolens has strong activity against all of the clinical S. aureus isolates-including multidrug resistant strains, MRSA strains and MLS_B-positive strains-exhibiting MIC values of 0.25-2.50 μL/mL.     

Phenolic Antioxidants Isolated from the Flowers of <em>Osmanthus fragrans</em>

O. fragrans has slightly less antioxidative activity than green tea. Five phenolic compounds, tyrosyl acetate (1), (+)-phillygenin (2), (8E)-ligustroside (3), rutin (4), and verbascoside (5), were isolated from the CHCl₃ sub-extract of O. fragrans. The structures were elucidated by interpreting their spectral data. Evaluation of the antioxidative property of the isolated (+)-phillygenin (2), rutin (4), and verbascoside (5) revealed strong DPPH radical scavenging activity, with IC₅₀ values of 19.1, 10.3, and 6.2 μM, respectively. These isolates also exhibited an H₂O₂ scavenging ability, with IC₅₀ values of 10.5, 23.4, and 13.4 μM, respectively.     

Alkaloids Isolated from the Lateral Root of <em>Aconitum carmichaelii</em>

Two new alkaloids, aconicarmine (1) and aconicaramide (5), were isolated from the EtOH extract of the lateral roots of Aconitum carmichaelii, together with five known compounds: fuziline (2), neoline (3), N-ethylhokbusine B (4), 5-hydroxymethylpyrrole-2-carbaldehyde (6), and oleracein E (7). Their structures were elucidated by physical and NMR analysis. Pyrrole alkaloids were isolated from A. carmichaelii for the first time. In the in vitro assays, compounds 2 and 3 showed activity against pentobarbital sodium-induced cardiomyocytes damage by obviously recovering beating rhythm and increasing the cell viability, while compounds 5 and 7 showed moderate antibacterial activity.     

<em>N</em>-Substituted 5-Chloro-6-phenylpyridazin-3(2<em>H</em>)-ones: Synthesis, Insecticidal Activity Against <em>Plutella xylostella </em>(L.) and SAR Study

A series of N-substituted 5-chloro-6-phenylpyridazin-3(2H)-one derivatives were synthesized based on our previous work; all compounds were characterized by spectral data and tested for in vitro insecticidal activity against Plutella xylostella. The results showed that the synthesized pyridazin-3(2H)-one compounds possessed good insecticidal activities, especially the compounds 4b, 4d, and 4h which showed > 90% activity at 100 mg/L. The structure-activity relationships (SAR) for these compounds were also discussed.     

Two New Daucane Sesquiterpenoids from <em>Daphne aurantiaca</em>

Two new daucane sesquiterpenoids 1β,2β-epoxy-10(H)α-dauca-11(12)-ene-7α,14-diol (1) and 1α,2α-epoxy-10(H)α-dauca-11(12)-ene-7α,14-diol (2) were isolated from the plateau medicinal plant Daphne aurantiaca Diels. (Thymelaeceae). Their structures were elucidated by 1D and 2D NMR spectroscopy, as well as HR-ESI-MS data.