A natural small molecule voacangine inhibits angiogenesis both in vitro and in vivo

Angiogenesis, the formation of new blood vessels from pre-existing ones, plays a critical role in normal and pathological phenotypes, including solid tumor growth and metastasis. Accordingly, the development of new anti-angiogenic agents is considered an efficient strategy for the treatment of cancer and other human diseases linked with angiogenesis. We have identified voacangine, isolated from Voacanga africana, as a novel anti-angiogenic agent. Voacangine inhibits the proliferation of HUVECs at an IC(50) of 18 μM with no cytotoxic effects. Voacangine significantly suppressed in vitro angiogenesis, such as VEGF-induced tube formation and chemoinvasion. Moreover, the compound inhibits in vivo angiogenesis in the chorioallantoic membrane at non-toxic doses. In addition, voacangine decreased the expression levels of hypoxia inducible factor-1α and its target gene, VEGF, in a dose-dependent manner. Taken together, these results suggest that the naturally occurring compound, voacangine, is a novel anti-angiogenic compound.     

Quantification of Anti‐Addictive Alkaloids Ibogaine and Voacangine in In Vivo‐ and In Vitro‐Grown Plants of Two Mexican Tabernaemontana Species

Tabernaemontana alba and Tabernaemontana arborea are Apocynaceae species used in Mexican traditional medicine for which little phytochemical information exists. In this study, preliminary gas chromatography/mass spectrometry analyses of different organs obtained from wild plants of both species identified a total of 10 monoterpenoid indole alkaloids (MIAs) and one simple indole alkaloid, nine of which were reported for the first time in these species. Furthermore, callus cultures were established from T. alba leaf explants and regeneration of whole plants was accomplished via somatic embryogenesis. The anti‐addictive MIAs ibogaine and voacangine were then quantified by gas chromatography with flame ionization detection in wild plants of both species, as well as greenhouse‐grown plants, in vitro‐grown plantlets and embryogenic callus of T. alba. Ibogaine and voacangine were present in most samples taken from the whole plants of both species, with stem and root barks showing the highest concentrations. No alkaloids were detected in callus samples. It was concluded that T. alba and T. arborea are potentially viable sources of ibogaine and voacangine, and that these MIAs can be produced through somatic embryogenesis and whole plant regeneration of T. alba. Approaches to increase MIA yields in whole plants and to achieve alkaloid production directly in cell cultures are discussed.     

Alkaloids of Pterotaberna inconspicua

Sixteen alkaloids were isolated from the seeds and root-bark of Pterotaberna inconspicua, collected in Zaïre. They were voacangine 3-carbonitrile, voacangine, voacristine, 3,6-oxido-voacangine, vobasine, 10-hydroxycoronaridine, 10-hydroxyheyneanine, methuenine, apparicine, tubotaiwine, 16-epi-isositsirikine, 16-epimethuenine, 3,14-dihydroellipticine, an isomer of corynantheol, 16-epimethuenine N-oxide and tetra-hydroellipticine.     

Cytotoxicity and genotoxicity of coronaridine from Tabernaemontana catharinensis A.DC in a human laryngeal epithelial carcinoma cell line (Hep-2)

Cancer has become a major public health problem worldwide and the number of deaths due to this disease is increasing almost exponentially. In the constant search for new treatments, natural products of plant origin have provided a variety of new compounds to be explored as antitumor agents. Tabernaemontana catharinensis is a medicinal plant that produces alkaloids with expressive antitumor activity, such as heyneanine, coronaridine and voacangine. The aim of present study was firstly to screen the cytotoxic activity of the indole alkaloids heyneanine, coronaridine and voacangine against HeLa (human cervix tumor), 3T3 (normal mouse embryo fibroblasts), Hep-2 (human laryngeal epithelial carcinoma) and B-16 (murine skin) cell lines by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide); and secondly to analyze the apoptotic activity, cell membrane damage and genotoxicity of the compound that showed the best cytotoxic activity against the tumor cell lines tested. Coronaridine was the one that exhibited greater cytotoxic activity in the laryngeal carcinoma cell line Hep-2 (IC₅₀ = 54.47 μg/mL) than the other alkaloids tested (voacangine IC₅₀ = 159.33 g/mL, and heyneanine IC₅₀ = 689.45 μg/mL). Coronaridine induced apoptosis in cell lines 3T3 and Hep-2, even at high concentrations. The evaluation of genotoxicity by comet assay showed further that coronaridine caused minimal DNA damage in the Hep-2 tumor cell line, and the LDH test showed that it did not affect the plasma membrane. These results suggest that further investigation of coronaridine as an antitumor agent has merit.     

Metabolite Profiling of Anti‐Addictive Alkaloids from Four Mexican Tabernaemontana Species and the Entheogenic African Shrub Tabernanthe iboga (Apocynaceae)

Ibogaine and other ibogan type alkaloids present anti‐addictive effects against several drugs of abuse and occur in different species of the Apocynaceae family. In this work, we used gas chromatography‐mass spectrometry (GC/MS) and principal component analysis (PCA) in order to compare the alkaloid profiles of the root and stem barks of four Mexican Tabernaemontana species with the root bark of the entheogenic African shrub Tabernanthe iboga. PCA demonstrated that separation between species could be attributed to quantitative differences of the major alkaloids, coronaridine, ibogamine, voacangine, and ibogaine. While T. iboga mainly presented high concentrations of ibogaine, Tabernaemontana samples either showed a predominance of voacangine and ibogaine, or coronaridine and ibogamine, respectively. The results illustrate the phytochemical proximity between both genera and confirm previous suggestions that Mexican Tabernaemontana species are viable sources of anti‐addictive compounds.     

Alcaloïdes des feuilles de Voacanga thouarsii

Leaves of Voacanga thouarsii Roem. et Schult. yielded 3 indole alkaloids (ibogaine, voacangine, voacristine) and 12 ‘bis-indole’ alkaloids. Three of the latter are known (vobtusine, vobtusinelactone and subsessiline) and nine are new.     

Extraction and Conversion Studies of the Antiaddictive Alkaloids Coronaridine,Ibogamine, Voacangine,and Ibogaine from Two Mexican Tabernaemontana Species (Apocynaceae)

Several species from the Apocynaceae family, such as Tabernanthe iboga, Voacanga africana, and many Tabernaemontana species, produce ibogan type alkaloids, some of which present antiaddictive properties. In this study, we used gas chromatography/mass spectrometry (GC/MS) to examine the efficiency of methanol, acetone, ethyl acetate, dichloromethane, chloroform, and hydrochloric acid in extracting the antiaddictive compounds coronaridine, ibogamine, voacangine, and ibogaine (altogether the CIVI‐complex) from the root barks of Tabernaemontana alba and Tabernaemontana arborea. These Mexican species have recently shown great potential as alternative natural sources of the aforementioned substances. Methanol proved to be the most suitable solvent. Furthermore, the crude methanolic extracts could be engaged in a one‐step demethoxycarbonylation process that converted coronaridine and voacangine directly into its non‐carboxylic counterparts ibogamine and ibogaine, respectively, without the intermediacy of their carboxylic acids. The established protocol straightforwardly simplifies the alkaloid mixture from four to two majority compounds. In summary, our findings facilitate and improve both the qualitative and quantitative analysis of CIVI‐complex‐containing plant material, as well as outlining a viable method for the bulk production of these scientifically and pharmaceutically important substances from Mexican Tabernaemontana species.     

13C NMR analysis of alkaloids from peschiera fuchsiaefolia

Fractionation of an ethereal extract of Peschiera fuchsiaefolia resulted in the isolation of decarbomethoxyvoacamine, demethylvoacamine, voacamidine, perivine, 16-epiaffinine and voacanginehydroxyindolenine, together with the previously reported alkaloids voacamine, voacangine, voachalotine and affinisine. Analysis of the ¹³C NMR spectra of the bisindole alkaloids and of 16-epiaffinine is reported.     

Quantitative Evaluation of a Mexican and a Ghanaian Tabernaemontana Species as Alternatives to Voacanga africana for the Production of Antiaddictive Ibogan Type Alkaloids

In continuation of our efforts to provide quantitative information on antiaddictive ibogan type alkaloid‐producing Tabernaemontana species, we used gas chromatography‐mass spectrometry (GC/MS) to compare the alkaloid profiles of the barks and/or leaves of one Mexican and one African species – T. arborea and T. crassa, respectively, with the primary sources of commercially available semisynthetic ibogaine, Voacanga africana root and stem bark. The qualitative and quantitative similarities between T. arborea and V. africana barks consolidate previous reports regarding the potential of the former as a promising alternative source of voacangine and ibogaine. The results also suggest that T. crassa could be used to produce conopharyngine and ibogaline, two compounds with the same basic skeletal structure and possibly similar antiaddictive properties as ibogaine.     

土木香化学成分的研究

采用硅胶柱色谱、制备薄层色谱、制备高效液相、葡聚糖凝胶SephadexLH-20等方法进行分离纯化,根据光谱数据进行结构鉴定。从乙醇提取物中分离得到了8个化合物,分别鉴定为：异土木香内酯（1）,11,13-二氢异土木香内酯（2）,土木香内酯（3）,β-谷甾醇（4）,3-hydroxy-11,13-dihydroisoalantolactone（5）,macrophyllilae-toneE（6）,HIS-12-en-18-H-3-O-β-D-glucopyranoside（7）,caffeic acid anhydride（8）。化合物7和8系首次从该属植物中分离得到。     

顶空固相微萃取-气相色谱质谱法分析山荆子花和叶中的挥发性成分

首次采用顶空固相微萃取-气相色谱质谱法(HS-SPME-GC-MS)分析了盛开期的山荆子花和叶中的挥发性成分,采用保留指数与质谱图库检索的方法定性,利用面积归一化法定量组份含量.鉴定出山荆子花中36种化学成分,占总含量的96.20％,主要为烷烃类(27.00％)、酯类(20.86％)、芳香醇类(11.75％)、萜类(18.78％)化合物,主要成分是2,6-二叔丁基对甲酚(BHT)为14.59％,其次为正十九烷(11.58％)、正二十一烷(8.37％)、法呢烯(8.24％)、罗勒烯(7.77％).鉴定出山荆子叶中22种化学成分,占总含量的98.04％,主要为萜类(50.84％)、烯烃类(25.33％)、酯类(9.73％)化合物,主要成分是法呢烯(40.62％),其次是唯一的烯烃4,8-二甲基-1,3,7-壬烯(26.30％)、罗勒烯(7.27％).     

藏红花花瓣和雄蕊挥发油化学成分GC-MS分析及比较

采用水蒸气蒸馏法从藏红花花瓣和雄蕊中提取挥发油,用GC-MS技术结合计算机检索对其二者化学成分进行分离和鉴定,用色谱峰面积归一化法计算各组分的相对含量.花瓣中共鉴定出16种化合物,主要成分为正二十六烷(11.60％)、正十五烷(11.31％)、棕榈酸甲酯(10.82％)、油酸甲酯(10.35％)、2,4-二叔丁基苯酚(9.63％)、亚油酸甲酯(7.18％)、藏红花醛(5.66％);雄蕊中共鉴定出20种化合物,主要成分为油酸甲酯(30.83％)、亚油酸甲酯(24.12％)、环已醇(16.80％)、硬脂酸甲酯(12.88％)、棕榈酸甲酯(8.97％)、花生酸甲酯(1.18％)、苯并噻唑(1.01％).     

羊角拗根脂溶性成分的GC-MS分析

采用气相色谱-质谱联用(GC-MS)技术对羊角拗根脂溶性成分进行分析,应用色谱峰面积归一化法定量分析各成分的相对百分含量,共分离鉴定出27种成分,占其总量的60.86％.根的脂溶性成分主要为何帕-22(29)-烯-3β-醇(32.70％)、棕榈酸乙酯(6.35％)、2-十五烷酮(4.76％)、蒲公英赛酮(2.84％)、豆甾醇(2.50％)、棕榈酸(2.08％).     

Molecular characterization of multidrug-resistant Escherichia coli isolates from Irish cattle farms

This study describes the genotypic characteristics of a collection of 100 multidrug-resistant (MDR) Escherichia coli strains recovered from cattle and the farm environment in Ireland in 2007. The most prevalent antimicrobial resistance identified was to streptomycin (100%), followed by tetracycline (99%), sulfonamides (98%), ampicillin (82%), and neomycin (62%). Resistance was mediated predominantly by strA-strB (92%), tetA (67%), sul2 (90%), bla(TEM) (79%), and aphA1 (63%) gene markers, respectively. Twenty-seven isolates harbored a class 1 integrase (intI1), while qacEΔ1 and sul1 markers were identified in 25 and 26 isolates, respectively. The variable regions of these integrons contained aminoglycoside, trimethoprim, and β-lactam resistance determinants (aadA12, aadB-aadA1, bla(OXA-30)-aadA1, dfrA1-aadA1, dfrA7). Class 2 integrons were identified less frequently (4%) and contained the gene cassette array dfrA1-sat1-aadA1. Resistance to ampicillin, neomycin, streptomycin, sulfonamide, and tetracycline was associated with transferable high-molecular-weight plasmids, as demonstrated by conjugation assays. A panel of virulence markers was screened for by PCR, and genes identified included vt1, K5 in 2 isolates, papC in 10 isolates, and PAI IV(536) in 37 isolates. MDR commensal E. coli isolates from Irish cattle displayed considerable diversity with respect to the genes identified. Our findings highlight the importance of the commensal microflora of food-producing animals as a reservoir of transferable MDR.     

Transfer RNAs of potato (Solanum tuberosum) mitochondria have different genetic origins.

Total transfer RNAs were extracted from highly purified potato mitochondria. From quantitative measurements, the in vivo tRNA concentration in mitochondria was estimated to be in the range of 60 microM. Total potato mitochondrial tRNAs were fractionated by two-dimensional polyacrylamide gel electrophoresis. Thirty one individual tRNAs, which could read all sense codons, were identified by aminoacylation, sequencing or hybridization to specific oligonucleotides. The tRNA population that we have characterized comprises 15 typically mitochondrial, 5 'chloroplast-like' and 11 nuclear-encoded species. One tRNA(Ala), 2 tRNAs(Arg), 1 tRNA(Ile), 5 tRNAs(Leu) and 2 tRNAs(Thr) were shown to be coded for by nuclear DNA. A second, mitochondrial-encoded, tRNA(Ile) was also found. Five 'chloroplast-like' tRNAs, tRNA(Trp), tRNA(Asn), tRNA(His), tRNA(Ser)(GGA) and tRNA(Met)m, presumably transcribed from promiscuous chloroplast DNA sequences inserted in the mitochondrial genome, were identified, but, in contrast to wheat (1), potato mitochondria do not seem to contain 'chloroplast-like' tRNA(Cys) and tRNA(Phe). The two identified tRNAs(Val), as well as the tRNA(Gly), were found to be coded for by the mitochondrial genome, which again contrasts with the situation in wheat, where the mitochondrial genome apparently contains no tRNA(Val) or tRNA(Gly) gene (2).     

HS-SPME & GC-MS分析印加果种子的挥发性物质

利用顶空固相微萃取-气相色谱质谱法(HS-SPME & GC-MS)分析印加果Plukenetia volubilis近成熟种子的挥发性物质,通过面积归一法计算出各成分的相对含量。结果共分离鉴定出64种化学成分,其中6种酯类化合物,占45.86%;12种醇类化合物,占27.71%;7种烯烃类化合物,占6.71%;9种醛类化合物,占3.89%;6种酮类化合物,占2.78%;16种烷烃类化合物,占1.78%。此外,盐酸氨基脲占5.47%,氨基脲占3.25%,还有1.51%三氯乙酸和0.23%甲基异丙基苯及其他化合物。     

The skimmiwallinols--minor components of the epicuticular wax of Cocos nucifera

Four new skimmiwallinol derivatives, isoskimmiwallinol acetate (4), skimmiwallinol acetate (5), isoskimmiwallinone (6) and skimmiwallinone (7), along with the previously isolated major components isoskimmiwallin (2) and skimmiwallin (3), have been found in the wax extract of pinnae from Cocos nucifera. Metabolites 4 and 5 were obtained as an inseparable mixture and identified by analysis of spectroscopic data and chemical correlation with 2 and 3, respectively. Metabolites 6 and 7 were identified by GC co-injection with the corresponding synthetic derivatives prepared from 4 and 5.     

Complete topographical distribution of both the in vivo and in vitro phosphorylation sites of bone sialoprotein and their biological implications

Bone sialoprotein (BSP) is a multifunctional, highly phosphorylated, and glycosylated protein with key roles in biomineralization and tissue remodeling. This work identifies the complete topographical distribution and precise location of both the in vitro and in vivo phosphorylation sites of bovine BSP by a combination of state-of-the-art techniques and approaches. In vitro phosphorylation of native and deglycosylated BSPs by casein kinase II identified seven phosphorylation sites by solid-phase N-terminal peptide sequencing that were within peptides 12-22 (LEDS(P)EENGVFK), 42-62 (FAVQSSSDSS(P)EENGNGDS(P)S(P)EE), 80-91 (EDS(P)DENEDEES(P)E), and 135-145 (EDES(P)DEEEEEE). The in vivo phosphorylation regions and sites were identified by use of a novel thiol reagent, 1-S-mono[(14)C]carboxymethyldithiothreitol. This approach identified all of the phosphopeptides defined by in vitro phosphorylation, but two additional phosphopeptides were defined at residues, 250-264 (DNGYEIYES(P)ENGDPR), and 282-289 (GYDS(P)YDGQ). Furthermore, use of native BSP and matrix-assisted laser desorption ionization time-of-flight mass spectrometry identified several of the above peptides, including an additional phosphopeptide at residues 125-130 (AGAT(P)GK) that was not defined in either of the in vitro and in vivo studies described above. Overall, 7 in vitro and 11 in vivo phosphorylation sites were identified unequivocally, with natural variation in the quantitative extent of phosphorylation at each in vivo phosphorylation site.     

野生荆条籽中挥发油成分的研究

用水蒸气蒸馏法从荆条中提取挥发油,用气相色谱-质谱联用技术对挥发油成分进行分离和结构鉴定。从荆条籽的挥发油中鉴定出了51个组分,用气相色谱面积归一法确定了各个组分的相对百分含量,其挥发油的主要组成是β-榄香烯(27.98%),芳樟醇(12.39%),贝壳杉烯(12.00%),δ-榄香烯(10.54%),乙酯异冰片脂(8.98%)等。     

Volatile components from European liverworts Marsupella emarginata,M. aquatica and M. alpina

The hydrodistillation products of the liverworts Marsupella emarginata, M. aquatica and M. alpina were investigated by spectroscopic methods. A number of new compounds could be isolated by preparative gas chromatography (GC) and identified by spectroscopic techniques including GC-mass spectrometry, NMR and chemical correlations in conjunction with enantioselective GC. From M. emarginata, in addition to many known compounds, the sesquiterpene hydrocarbon (-)-7-epi-eremophila-1(10),8,11-triene (1) and the sesquiterpene derivatives (-)-4-epi-marsupellol (2), (-)-marsupellol acetate (18), (-)-4-epi-marsupellol acetate (4), (+)-5-hydroxymarsupellol acetate (5) and (-)-9-acetoxygymnomitr-8(12)-ene (24) could be identified. In M. aquatica the sesquiterpene hydrocarbons (-)-myltayl-8(12)-ene (7), ent-(+)-amorpha-4,11-diene (8), (-)-amorpha-4,7(11)-diene (9), the sesquiterpene alcohol (+)-9-hydroxyselina-4,11-diene (10) and (-)-2-acetoxyamorpha-4,7(11)-diene (11) were identified. In M. alpina (-)-trans-selina-4(15),11-dien-5-ol (12), (+)-8,9-epoxyselina-4,11-diene (13) and (+)-cis-selina-4(15),11-dien-5-ol (14) were found as new natural products.