Chemical constituents from the infusion of Zollernia ilicifolia Vog. and comparison with Maytenus species

The new flavonoid glycoside kaempferol-3-O-alpha-L-rhamnopyranosyl(1-->2)-O-[alpha-L-rhamnopyranosyl(1-->6)]-O-beta-D-galactopyranoside-7-O-alpha-L-rhamnopyranoside was isolated together with (S)-zierin from the leaves of Zollernia ilicifolia (Fabaceae), a medicinal plant used as analgesic and antiulcerogenic effects in Brazilian Tropical Atlantic Rain Forest. The structures were established on the basis of 1H, 13C NMR and 2D NMR (COSY, HMBC, HMQC), UV, MS and IV spectra. The infusion of Zollernia ilicifolia was qualitatively compared to the infusion of the espinheiras-santas (Maytenus aquifolium and Maytenus ilicifolia) by HPLC-DAD.     

A comparative chemical study of Maytenus ilicifolia mart. reiss and Maytenus robusta reiss (Celastraceae)

This work describes a comparative qualitative and quantitative chemical analysis of Maytenus ilicifolia and Maytenus robusta (Celastraceae), extracts by high-resolution gas chromatography (HRGC), using external standards as the method of determination and thin layer chromatographic (TLC). The results show that both plants have a similar chromatographic profile. However, M. robusta exhibited about three times higher concentration of triterpene friedelin than M. ilicifolia.     

Occurrence and non-detectability of maytansinoids in individual plants of the genera Maytenus and Putterlickia

Individual plants belonging to different species of the family Celastraceae collected from their natural habitats in South Africa (Putterlickia verrucosa (E. Meyer ex Sonder) Szyszyl., Putterlickia pyracantha (L.) Szyszyl., Putterlickia retrospinosa van Wyk and Mostert) and Brazil (Maytenus ilicifolia Mart. ex Reiss., Maytenus evonymoides Reiss., Maytenus aquifolia Mart.) were investigated for the presence of maytansinoids and of maytansine, an ansamycin of high cytotoxic activity. Maytansinoids were not detectable in plants grown in Brazil. Analysis of plants growing in South Africa, however, showed clearly that maytansinoids were present in some individual plants but were not detectable in others. Molecular biological analysis of a Putterlickia verrucosa cell culture gave no evidence for the presence of the aminohydroxybenzoate synthase gene which is unique to the biosynthesis of aminohydroxybenzoate, a precursor of the ansamycins including maytansinoids. Moreover, this gene was not detectable in DNA extracted from the aerial parts of Putterlickia plants. In contrast, observations indicate that this gene may be present in microbes of the rhizosphere of Putterlickia plants. Our observations are discussed with respect to the possibility that the roots of Putterlickia plants may be associated with microorganisms which are responsible for the biosynthesis of maytansine or maytansinoids.     

Bioprospecting highly diverse endophytic Pestalotiopsis spp. with antibacterial properties from Maytenus ilicifolia, a medicinal plant from Brazil

Thirteen endophytic fungal strains of the genus Pestalotiopsis were isolated from the medicinal plant Maytenus ilicifolia Mart. ex. Reiss (commonly known as "espinheira santa") and their antimicrobial properties were investigated. Two isolates were successful in inhibiting the growth of the tested microorganisms (Escherichia coli, Klebsiella pneumoniae, Micrococcus luteus, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus (MRSA)) using the technique of bioautographic thin-layer chromatography (TLC) agar overlay assay. An analysis based on a polyphasic approach integrating taxonomic information, morphological traits, RAPD markers, and the sequencing of the ITS1-5.8S-ITS2 of the rDNA led to the assignment of the isolates as belonging to the species Pestalotiopsis microspora, Pestalotiopsis vismiae, and Pestalotiopsis leucothoes. Therefore, the present study presents a new approach to the study of endophytic fungi of the genus Pestalotiopsis.     

Argentinian plant extracts with relaxant effect on the smooth muscle of the corpus cavernosum of Guinea pig

Extracts of different polarity from Baccharis trimera, Haplopappus rigidus Huperzia saururus, Maytenus ilicifolia, Satureja parvifolia and Senecio eriophyton were tested for their relaxant activity on smooth muscle using L-phenylephrine precontracted strips of corpus cavernosum obtained from Guinea pigs. Highly significant and dose dependent results were obtained with the dichloromethane extracts of H. saururus (87% of relaxation at the dose of 10 mg/ml), S. parvifolia (95% of relaxation at 2.5 mg/ml) and S. eriophyton (94% of relaxation at 5 mg/ml). Similar effects were observed with the methanol extracts of H. saururus (88% of relaxation at 10 mg/ml) and S. parvifolia (84% of relaxation at 10 mg/ml). These results were comparable to those obtained with the dichloromethane and methanol extracts of the well known Mexican species Turnera diffusa. Moreover, the aqueous extract of H. rigidus and the aqueous and methanol extracts of S. eriophyton were highly effective in a dose dependent manner (more than 90% of relaxation at the dose of 10 mg/ml). Significant results, but with a lower overall relaxant activity (about 70% of relaxation at 10 mg/ml), could also be obtained with the aqueous extract of S. parvifolia and with the dichlormethane and methanol extracts of B. trimera and M. ilicifolia. The positive controls with Sildenafil citrate at doses ranging from 0.35 to 35 microg/ml yielded moderate effects (up to 46% of relaxation at 35 microg/ml). The effects observed in the present study seem to validate the folk medicinal use of the tested plants and open new ways in the search for natural products with vasodilatory effects.     

Development and validation of a method for the quantitative determination of aflatoxin contaminants in Maytenus ilicifolia by HPLC with fluorescence detection

A method for the quantification of aflatoxins B1, G1, B2 and G2 in the medicinal herb Maytenus ilicifolia was developed and validated. The method used immunoaffinity columns for sample clean-up and HPLC with fluorescence detection without any derivatisation step. The method showed good inter-day accuracy (bias values in the range 4.5-10.7%) and precision (5-16% RSD) when applied to the determination of levels of aflatoxins ranging from 7 to 20 ppb in the plant material. The detection limits for samples of the plant material spiked with aflatoxins were 3.5 ng/g for B1 and G1 and 0.1 ng/g for B2 and G2. The method was successfully applied to commercial samples of Maytenus ilicifolia for the screening of aflatoxin contaminants.     

Effect of the Cymbopogon citratus, Maytenus ilicifolia and Baccharis genistelloides extracts against the stannous chloride oxidative damage in Escherichia coli

Stannous ion has been used in different sectors of human interest, such as in food industry and in health sciences. Much is known about stannous chloride (SnCl(2)) toxicity, although, there is no general agreement regarding its genotoxicity. Cymbopogon citratus, Maytenus ilicifolia and Baccharis genistelloides extracts have been used in popular medicine. We evaluated the influence of these crude extracts on the survival of the Escherichia coli wild type (AB 1157) strain submitted to SnCl(2) treatment. Reactive oxygen species (ROS) can be generated by a Fenton like reaction induced by SnCl(2). E. coli culture was treated simultaneously with SnCl(2) and a specific extract. Our results showed a reduction of the SnCl(2) effect on the survival of the cultures in presence of the crude extracts. The extract of M. ilicifolia showed the highest level of protection action against the SnCl(2) effect in comparison with the other extracts. This protector effect could due to the redox properties of these crude extracts. The compounds in the crude extracts could (i) chelate stannous ions, protecting them against the oxidation and avoiding the generation of ROS, (ii) be a scavenger of the ROS generated by the SnCl(2) oxidation and/or (iii) have oxidant compounds that could oxidise the stannous ions, abolishing or reducing the SnCl(2) effect.     

Chemical Analysis and Plant Sources of Maytansinoids

By high performance liquid chromatography (HPLC) and mass spectrometry (MS), maytansine, maytanprine and maytanbutine, three anticancer maytansinoids were successfully isolated and identified from ten species of plants belonging to Celastraceae. These plants are: Maytenus graciliramula, M. austroyunnanensis, M. orbiculata, M. hookeri Loes var. longiradiata, M. inflata, M. berberoides, M. esquirolii, M. variabilis, M. royleana and M. senegalensis. This result shows that the plant resources containing maytansinoids in China are rather aboundant.     

Fragmentation pathways of acylated flavonoid diglucuronides from leaves of Medicago truncatula

Introduction – Flavonoids are important plant compounds occurring in tissues mostly in the form of glycoconjugates. Most frequently the sugar moiety is comprised of mono‐ or oligosaccharides consisting of common sugars like glucose, rhamnose or galactose. In some plant species the glycosidic moiety contains glucuronic acid and may be acylated by phenylpropenoic acids. Methodology – Flavonoid glyconjugates were extracted from leaves of Medicago truncatula ecotype R108 and submitted to analysis using high‐performance liquid chromatography combined with high‐resolution tandem (quadrupole‐time of flight, QToF) mass spectrometry. Results – The studied leaf extracts contained 26 different flavonoid glycosides among which 22 compounds were flavone (apigenin, luteolin, chrysoeriol and tricin) glucuronides and 13 were acylated with aromatic acids (p‐coumaric, ferulic or sinapic). The fragmentation pathways observed in positive and negative ion mass spectra differed substantially between each other and from these of flavonoid glycosides which did not contain acidic sugars. The application of high‐resolution MS techniques allowed unequivocal differentiation between ions with the same nominal m/z values containing different substituents (e.g. ferulic acid or glucuronic acid). Eleven of the identified flavonoids have not been reported previously in this species. Perspectives – The presented unique fragmentation pathways of flavonoid glucuronates enable detection of these compounds in tissue extracts from different plant species. Copyright © 2009 John Wiley & Sons, Ltd.     

Phytochemical analysis and evaluation of antioxidant activities of methanolic extracts of Maytenus emarginata

Reactive oxygen species (ROS) is a metabolic side product of oxidative stress process, which causes several diseases like atherosclerosis, cancer, etc. In defense of ROS, antioxidants play a key role in combating them. As the process of aging increases, the level of antioxidants in our body decreases and thereby needs utmost attention for its repair process, which is generally administered externally. Plant products serve a best source for controlling these activities by its own metabolic pathway. Studies on the antioxidant activities of Maytenus emarginata leaf extracts are lacking. Antioxidant activity of the methanol extract of Maytenus emarginata was determined by DPPH free radical nitric oxide scavenging assays, superoxide ion scavenging assays, ABTS, and iron chelating methods. Preliminary phytochemical screening revealed that the extract of Maytenus emarginata leaves possesses phenols, flavonoids, steroids, glycosides, saponins, tannins, and triterpenoids. The extract showed significant activities in all antioxidant assays compared to the standard antioxidant (ascorbic acid) in a dose-dependent manner, and remarkable activities to scavenge ROS may be attributed by the presence of the above active compounds in the leaves. The amount of total phenolics and flavonoid contents were also estimated. The DPPH, ABTS, Nitric oxide, superoxide, and iron chelating IC(50) values of the methanolic extracts were 12.44, 24.27, 22.41, 5.85, and 2.74?μg/mL, respectively. The total phenolic content of the methanolic extract was 10.69?mg CA/g, whereas the total flavonoid was 1.56?mg CAE/g. The antioxidant activities were correlated with the total phenolic content. This result suggests that the relatively high antioxidant activity of the methanolic extract compared to standard could be possibly be due to its high phenolic content.     

Profiling of phenolic glycosidic conjugates in leaves of Arabidopsis thaliana using LC/MS

Profiling of plant secondary metabolites is still a very difficult task. Liquid chromatography (LC) or capillary electrophoresis hyphenated with different kinds of detectors are methods of choice for analysis of polar, thermo labile compounds with high molecular masses. We demonstrate the applicability of LC combined with UV diode array or/and mass spectrometric detectors for the unambiguous identification and quantification of flavonoid conjugates isolated from Arabidopsis thaliana leaves of different genotypes and grown in different environmental conditions. During LC/UV/MS/MS analyses we were able to identify tetra-, tri-, and di-glycosides of kaempferol, quercetin and isorhamnetin. Based on our results we can conclude that due to the co-elution of different chemical compounds in reversed phase HPLC systems the application of UV detectors does not allow to precisely profile all flavonoid conjugates existing in A. thaliana genotypes. Using MS detection it was possible to unambiguously recognize the glycosylation patterns of the aglycones. However, from the mass spectra we could not conclude neither the anomeric form of the C-1 carbon atoms of sugar moieties in glycosidic bonds between sugars or sugar and aglycone nor the position of the second carbon involved in disaccharides. The applicability of collision induced dissociation techniques (CID MS/MS) for structural analyses of the studied group of plant secondary metabolites with two types of analyzers (triple quadrupole or ion trap) was demonstrated.     

A novel phenolic acid derivative from buds of Populus lasiocarpa

The lipophilic excretion of winter buds of Populus lasiocarpa in contrast to most other species of the genus does not contain flavonoid aglycones. One of the compounds which are excreted in this plant now could be isolated and identified by chemical methods (hydrolysis, hydrogenation) and spectral analysis (UV, IR, NMR, MS) to be 1,3-p-coumaryl-2-acetyl-glycerol.     

Quantitative determination for cytotoxic Friedo-nor-oleanane derivatives from five morphological types of Maytenus ilicifolia (Celastraceae) by reverse-phase high-performance liquid chromatography

Five different morphological types of Maytenus ilicifolia of the same age and harvested under the same conditions showed distinct accumulations of some friedo-nor-oleananes. A rapid, sensitive and reliable reverse-phase HPLC method (employing an external standard) was used for the determination of the cytotoxic triterpenoids, 20 alpha-hydroxymaytenin, 22 beta-hydroxymaytenin, maytenin, celastrol and pristimerin in each of the five types. Well resolved peaks with good detection response and linearity in the range 1.0-100 micrograms/mL were obtained.     

New and bioactive compounds from Streptomyces strains residing in the wood of Celastraceae

Wood from three different plants of the Celastraceae growing in their natural habitats in Brazil (Maytenus aquifolia Mart.) and South Africa [Putterlickia retrospinosa van Wyk and Mostert, P. verrucosa (E. Meyer ex Sonder) Szyszyl.] was established as a source of endophytic bacteria using a medium selective for actinomycetes. Two isolates were identified as Streptomyces setonii and S. sampsonii whereas two others were not assignable to any of the known Streptomyces species. They were preliminarily named Streptomyces Q21 and Streptomyces MaB-QuH-8. The latter strain produces a new chloropyrrol and chlorinated anthracyclinone. The chloropyrrol showed high activity against a series of multiresistent bacteria and mycobacteria.     

Antimicrobial activity of some Hypericum species

The crude methanolic extracts of six species of Hypericum [H. caprifoliatum Cham. & Schlecht., H. carinatum Griseb., H. connatum Lam., H. ternum A. St. Hil., H. myrianthum Cham. & Schlecht. and H. polyanthemum Klotzsch ex Reichardt] growing in southern Brazil were analyzed for antimicrobial activity against several microorganisms (bacteria and fungi). The most active plant was H. caprifoliatum, which showed activity against Staphylococcus aureus. Only H. polyanthemum and H. ternum extracts were active against Bacillus subtilis. None of the crude methanolic extracts showed activity against S. epidermidis, Escherichia coli or Saccharomyces cerevisiae. Extracts from these species were evaluated chemically and tannin, flavonoid and phenolic acids were the prominent compounds. The plants contained quercitrin, hyperoside (except H. connatum) and, less frequently, isoquercitrin and chlorogenic acid. In contrast to H. perforatum, which has high concentrations of rutin, these species do not produce this flavonoid or it appears as traces. The tannin concentration varied between 5.1 and 16.7% in H. myrianthum and H. ternum, respectively.     

十七种一变种美登木叶片解剖与分类的关系

我们从国内外收集美登木属17种1变种,从叶片外部形状及内部结构进行比较,,发现在美登木属17种1变种美登木叶片组织中存在两种晶体(簇晶和方晶),可把美登木属分成三大类,一类具簇晶,二类具方晶,三类具簇晶和方晶。然后根据晶体的大小及其在组织中的分布部位,又将本属中的种分开。另外我们从美登木叶片解剖发现,成熟叶主脉横切面维管束的形状常是固定的,它不受外界环境的影响,也不受地理位置的影响,如滇南美登木分别采自云南省景洪和耿马不同地区不同生境,成熟叶横切面上维管束形状是相同的。成熟叶横切面上维管束的形状较稳定。所以用细胞内的晶体类型和维管束的形状把美登术属不同种进行分类是有意义的。     

Chemotaxonomy and flavonoid profiling of Torilis species by HPLC/ESI/MS2

The flavonoid profiles of Turkish Torilis Gaertn. (Apiaceae) species were studied by TLC, HPLC-UV and HPLC/ESI/MS² (negative mode). O-glycosides of luteolin, apigenin and chrysoeriol were identified from crude extracts with the help of mass spectra in different MS/MS modes, such as full scan, precursor ion scan and product ion scan. Luteolin-7-O-glucoside and luteolin-7-O-rutinoside were common to all species. Flavonoid profiles usually differ from one species to another and can be put to use for a genus such as Torilis which has been little studied. By the help of different flavonoid profiles, it is concluded that, the plants, which are recognised as less rayed subspecies of Torilis arvensis (Huds.) Link. in various floras including Turkish one, must be classified in species category as Torilis chrysocarpa and Torilis purpurea. Flavonoid profiles seem to be in relation with evolutionary biogeography of the species. Because the most isolated species of the genus, endemic Torilis triradiata, has the most different flavonoid pattern. Moreover, geographically isolated species, T. triradiata and Torilis leptocarpa, do not share any flavonoid except for the two which are common to all species.     

Metabolic Profiling of Vasorelaxant Extract from Malvaviscus arboreus by LC/QTOF-MS

We aimed to develop a standardized methodology to determine the metabolic profile of organic extracts from Malvaviscus arboreus Cav. (Malvaceae), a Mexican plant used in traditional medicine for the treatment of hypertension and other illnesses. Also, we determined the vasorelaxant activity of these extracts by ex vivo rat thoracic aorta assay. Organic extracts of stems and leaves were prepared by a comprehensive maceration process. The vasorelaxant activity was determined by measuring the relaxant capability of the extract to decrease a contraction induced by noradrenaline (0.1 μM). The hexane extract induced a significant vasorelaxant effect in a concentration- and endothelium-dependent manner. Secondary metabolites, such as polyunsaturated fatty acids, terpenes and one flavonoid, were annotated by liquid chromatography/quadrupole time-of-flight mass spectrometry (LC/QTOF-MS) in positive ion mode. This exploratory study allowed us to identify bioactive secondary metabolites from Malvaviscus arboreus, as well as identify potentially-new vasorelaxant molecules and scaffolds for drug discovery.     

Origins of non-linear and dissimilar relationships between epidermal UV absorbance and UV absorbance of extracted phenolics in leaves of grapevine and barley

A recent review of climate patterns in Southern Germany has suggested significant increases in ultraviolet (UV) radiation due to decreases in cloud coverage and in cloud frequency which compound the effects of stratospheric ozone depletion. Whether such UV radiation increases result in UV damage of higher plant leaves depends partly on the capacity of UV-absorbing hydroxycinnamic acids and flavonoids located in the plant epidermis to screen out UV radiation. Epidermal UV screening is most often assessed from UV absorbance of whole-leaf extracts but in the present work, this method is critically examined. In grapevine (Vitis vinifera L.), hydroxycinnamic acid as well as mono-hydroxylated and ortho-dihydroxylated flavonoid concentrations increased in parallel with fluorometrically detected adaxial epidermal UV absorbance but only the latter class of flavonoids was associated with epidermal UV absorbance in barley (Hordeum vulgare L). For both species, curvilinear relationships between epidermal and total phenolic UV absorbance were established: initial slopes of the curves differed markedly between species. Modelling suggested that curvilinearity arises from UV-transparent epidermal areas located between vacuoles which are particularly UV-absorbing due to high levels of phenolics. The species-dependent differences were related to allocation of high amounts of phenolics in the mesophyll and abaxial epidermis in barley but not in grapevine. Both factors, optical heterogeneity and variable distribution of phenolics, severely restrict the use of phenolic absorbance to estimate true epidermal screening.     

Les relations entre les prairies du Triseto-Polygonion et les mégaphorbiaies de l''Adenostylion: l''analyse flavonique d''espèces communes aux deux groupements

Relationships between two plant communities in the south-western Alps, high-altitude manured meadows (Triseto-Polygonion) and lower tall grass prairies (Adenostylion) have been examined by means of the flavonoid analysis of specimens belonging to six species common to those two associations. The species, collected at eight stations of the Ligurian Alps and the Ubaye valley, are: Trollius europaeus (Ranunculaceae), Chaerophyllum aureum (Umbellifereae), Silene cucubalus (Caryophyllaceae), Polygonum bistorta) (Polygonaceae), Alchemilla vulgaris (Rosaceae) and Centaurea montana (Compositae). In every species, factorial analysis of correspondence was applied to the distribution of flavonoid glycosides. This led to the partition of the populations into two groups according to the two sectors (Ligurian Alphs Ubaye valley) of the collection area. Secondly, populations of two species, Alchemilla vulgaris and Centaurea montana, exhibited further correlation of their flavonoid pattern with their phytosociological origin.