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At least 19 recordsLinked to original sources

Morphological and ultrastructural diversity of orbicules in relation to evolutionary tendencies in apocynaceae s.L.

Minute granules of sporopollenin, called orbicules, can be observed on the innermost tangential and/or radial walls of secretory tapetum cells. Orbicules were investigated in 62 species (50 genera) of Apocynaceae s.l. using light microscopy, scanning electron microscopy and transmission electron microscopy. Orbicules were found in 43 species (34 genera) distributed amongst the subfamilies Rauvolfioideae, Apocynoideae, Periplocoideae, and in the genus Riocreuxia (Asclepiadoideae). Absence of orbicules is apparent in Secamonoideae and Asclepiadoideae (except Riocreuxia). The orbicule types described are based on observed morphological and ultrastructural variation. Of the six orbicule types previously described, Type I and Type II orbicules are lacking. In the majority of species, Type III orbicules were recorded in addition to Types IV, V and VI. In this study we suggest that embedded Type VI orbicules are more derived. A correlation between orbicule typology and evolutionary tendencies in Apocynaceae s.l. palynology was found. A trend was observed from the presence of Type III orbicules in the majority of species belonging to the basal group of genera characterized by colporate to porate single pollen grains, or 3-6-porate tetrads, towards the more derived embedded Type VI orbicules in the more advanced Periplocoideae genera with multiporate tetrads or pollinia. Orbicule data have proven not to be useful for evaluating tribal delimitation within the Apocynaceae s.l. contrary to the Rubiaceae and Loganiaceae s.l.

Apocynaceae↗

The complete chloroplast genome of Heterostemma pingtaoi (Apocynaceae).

Heterostemma pingtaoi, a species endemic to Hainan Island, China, was discovered and formally described in the family Apocynaceae in 2010. However, genetic and evolutionary information on the genus Heterostemma remains poorly understood. Here, we report the complete chloroplast (cp) genome sequence of H. pingtaoi. The genome displays the typical quadripartite structure characteristic of dicotyledonous plant cp genomes, with a total length of 162,681 bp and a GC content of 38.25%. The cp genome encodes 131 genes, including 84 protein-coding genes, 8 rRNA genes, and 39 tRNA genes. Phylogenetic analysis based on the complete cp genome sequences confirmed that the genus Heterostemma forms a monophyletic group at the base of tribe Ceropegieae (Apocynaceae), with 100% bootstrap support. This study provides essential genomic resources for future taxonomic and evolutionary studies of Heterostemma species.

Apocynaceae↗

Screening of antimicrobial activity of some plants belonging to the Apocynaceae and Loganiaceae.

A review is given of the literature on the antimicrobial activity of various indole alkaloids. The data are briefly discussed. A screening was performed of a series of plants belonging to the indole alkaloid rich plant families Apocynaceae and Loganiaceae, 25 materials representing 14 Apocynaceae species and 54 materials representing 41 Strychnos species were investigated. No activity against the yeast or the fungus, used as test organisms was found. A number of extracts showed activity against the gram-positive test organisms, 4 species showed activity against gram-negative bacteria.

Alkaloids↗

Is there a justification for differential a priori weighting in coding sequences? A case study from rbcL and Apocynaceae s.l.

Functional constraints are often assumed to influence the performance of nucleotide characters in phylogenetic analysis: First and second codon positions and sites of structural importance are considered to show less homoplasy. We investigate the performance of rbcL characters with differential functional constraints in a cladistic analysis of the plant family Apocynaceae s.l. (Sennblad and Bremer, in prep.). Performance is measured as rescaled consistency indices (rc). We show there is no significant difference in performance between parsimony-informative sites constrained by function in the enzyme, and sites that are not. Furthermore, the substitutions in third-codon position performed significantly better than those in first and second. The variation of rc within the different classes was high, however. Consequently, there is no support for routinely applied a priori differential weighting, neither of codon positions, nor of different functional classes from the present analysis of rbcL data in the Apocynaceae s.l.

Asteraceae↗

Moth pollination of Metaplexis japonica (Apocynaceae): pollinaria transfer on the tip of the proboscis.

Asclepiad pollinaria (including pollen masses) attach to diverse body parts of flower visitors in many ways. In this paper, we observed nocturnal moths (Lepidoptera: Pyralidae and Noctuidae) transporting the pollinaria of the Japanese species Metaplexis japonica (Thunb.) Makino (Apocynaceae: Asclepiadoideae) on the tip of the proboscis. Flowers of this species may induce nectar-feeding moths to pull out the proboscis along a guide rail (anther slit), thus clipping the pollinaria onto the tip of the proboscis and transferring the pollinaria to the next flower. The transfer of pollinaria on the unique vector of a moth proboscis tip is an interesting pollination mechanism among previously reported entomophiles.

Animals↗

Philibertain g I, the most basic cysteine endopeptidase purified from the latex of Philibertia gilliesii Hook. et Arn. (Apocynaceae).

A new papain-like cysteine peptidase isolated from latex of Philibertia gilliesii Hook. et Arn., Apocynaceae (formerly Asclepiadaceae) has been purified and characterized. The enzyme, named philibertain g I, is the most basic component present in latex extracts and was purified by acetone fractionation followed by cation exchange chromatography (SP-Sepharose HR) using FPLC system. Homogeneity was confirmed by SDS-PAGE and mass spectroscopy (MS). Molecular mass of the enzyme was 23,530 Da (MALDI-TOF MS), its isoelectric point was >10.25, and maximum proteolytic activity (casein) was achieved at pH 7-8. The new protease was inhibited by E-64 a cysteine peptidases inhibitor. Km was 0.15 mM, using PFLNA as substrate. The N-terminal sequence of philibertain g I (LPASVDWRKEGAVLPIRHQGQCG) was compared with those of twenty plant proteases. Philibertain g I showed the higher degree of identity (73%) with caricain, one of the Carica papaya endopepetidases.

Amino Acid Sequence↗

Molecular phylogeny of Vincetoxicum (Apocynaceae-Asclepiadoideae) based on the nucleotide sequences of cpDNA and nrDNA.

Molecular phylogenetic analyses of Vincetoxicum and Tylophora (Apocynaceae-Asclepiadoideae) were conducted based on the nucleotide sequences of cpDNA (two intergenic spacers of trnL (UAA)-trnF (GAA) and psbA-trnH and three introns, i.e., atpF, trnG (UCC) and trnL (UAA)), and nrDNA (ITS and ETS regions). Our phylogenetic analysis revealed two monophyletic groups; one consisted of seven taxa of Tylophora and Vincetoxicum inamoenum, Vincetoxicum magnificum and Vincetoxicum macrophyllum (Clade I) and the other consisted of 17 accessions of Vincetoxicum (Clade II). The monophyly of the genus Vincetoxicum was not supported. Although many nucleotide substitutions were observed in Clade I, the genetic differentiation within Clade II was small. Low genetic diversification but considerable morphological divergence suggests that the species in Clade II had undergone rapid diversification. Although most species in Clade I have tiny flowers, those in Clade II have larger and more nectariferous ones. Thus, we hypothesized that the rapid morphological radiation in Clade II may have been due to the gaining of floral characters such as large flowers and large amounts of nectar corresponding to diverse pollinators.

Adaptation, Biological↗

Wax plants disentangled: a phylogeny of Hoya (Marsdenieae, Apocynaceae) inferred from nuclear and chloroplast DNA sequences.

Hoya (Marsdenieae, Apocynaceae) includes at least 200 species distributed from India to the Pacific Islands. We here infer major species groups in the genus based on combined sequences from the chloroplast atpB-rbcL spacer, the trnL region, and nuclear ribosomal DNA ITS region for 42 taxa of Hoya and close relatives. To assess levels of ITS polymorphism, ITS sequences for a third of the accessions were obtained by cloning. Most ITS clones grouped by species, indicating that speciation in Hoya usually predates ITS duplication. One ITS sequence of H. carnosa, however, grouped with a sequence of the morphologically similar H. pubicalyx, pointing to recent hybridization or the persistence of paralogous copies through a speciation event. The topology resulting from the combined chloroplast and nuclear data recovers some morphology-based sections, such as Acanthostemma and Eriostemma, as well as a well-supported Australian/New Guinean clade. The combined data also suggest that morphological adaptations for ant-symbiosis evolved at least three times within Hoya.

Apocynaceae↗

Classification of apocynaceae s.l. according to a new approach combining Linnaean and phylogenetic taxonomy.

A new approach to a nomenclatural system, including elements from both Linnaean and phylogenetic nomenclature, is proposed. It is compatible with the existing Linnaean system, including "standard names" corresponding to principal and secondary ranks, and uses a variant of the definitions from the Phylocode system. A new infrafamilial classification, using this nomenclatural approach, of the Apocynaceae s.l. (i.e., including the Asclepiadaceae) based mainly on analyses of rbcL and ndhF data is discussed. Twenty-one tribes and four rankless taxa are defined.

Apocynaceae↗

Generic delimitations in tuberous Periplocoideae (Apocynaceae) from Africa and Madagascar.

BACKGROUND AND AIMS: The number of genera included in Apocynaceae subfamily Periplocoideae is a matter of debate. DNA sequences are used here as an independent dataset to clarify generic relationships and classification of the tuberous periplocoid genera and to address the question of the phylogenetic interpretation of pollinia formation in Schlechterella. METHODS: Representatives of nearly all African and Malagasy genera of Periplocoideae possessing root tubers were analysed using ITS and plastid DNA sequence characters. RESULTS: Sequence data from non-coding molecular markers (ITS of nrDNA and the trnT-L and trnL-F spacers as well as the trnL intron of plastid DNA) give support for a broad taxonomic concept of Raphionacme including Pentagonanthus. Together with Schlechterella, which is sister to Raphionacme, all Raphionacme-like taxa form a derived monophyletic group of somewhat diverse species. Sister to the Schlechterella/Raphionacme clade is a clade comprising Stomatostemma and the not truly tuberous vine Mondia. In the combined analysis, sister to these two clades combined is a clade formed by Petopentia natalensis and Periploca. CONCLUSIONS: The recent inclusion of the monotypic South African Petopentia in the monotypic Malagasy endemic Ischnolepis is to be rejected. The Malagasy Camptocarpus is sister to the remainder of Periplocoideae in the ITS and combined analyses, and a Malagasy origin for the subfamily is discussed.

Africa↗

Evaluation of the antimicrobial property of the stem bark of Picralima nitida (Apocynaceae).

The basic fraction (BF) of the methanol extract of the stem bark of Picralima nitida (family Apocynaceae) exhibited significant antimicrobial activity against a wide range of Gram-positive bacteria and fungi, but limited activity against Gram-negative bacteria. The BF had a similar minimum inhibitory concentration (MIC) for S. aureus to the control drug ampicillin, and lower MIC values against A. flavus and A. niger than those of tiaconazole. Values of the minimum bactericidal concentration (MBC) of the BF against microorganisms tested were generally much higher than those for the control drugs ampicillin and gentamicin. The results suggest that some constituents of the stem bark could be isolated and developed into effective antimicrobial agents.

Alkaloids↗

Chemical constituents of Echites hirsuta (Apocynaceae).

A phytochemical investigation of an ethanolic extract of the whole plant of Echites hirsuta (Apocynaceae) resulted in the isolation and identification of the flavonoids naringenin, aromadendrin (dihydrokaempferol), and kaempferol; the coumarin fraxetin; the triterpene ursolic acid; and the sterol glycoside sitosteryl glucoside.

Chromatography, Gel↗

Tabernaemontana L. (Apocynaceae): a review of its taxonomy, phytochemistry, ethnobotany and pharmacology.

The taxonomy, phytochemistry, ethnobotany, and pharmacology of the genus Tabernaemontana L. (Apocynaceae) is reviewed. The genus is currently being revised taxonomically; most of the segregate genera are being reunited with it and the number of species that will ultimately be recognized will probably be about 100. All the names encountered in the chemical and ethnobotanical literature have been evaluated as far as possible, and a list is presented of the recognized species and their synonyms. The biogenesis and classification of the indole alkaloids found in Tabernaemontana species is set out and some problems in the determination of their stereochemistry are discussed. To facilitate access to the information, three lists have been compiled: the alkaloids in alphabetical order; the alkaloids in order of increasing molecular weight; and the alkaloids grouped according to their biogenetic classification, together with the species and plant part(s) in which they are known to occur. Biogenetic and chemotaxonomic aspects are briefly considered. A table of the non-alkaloidal constituents is also included. The ethnobotany of individual Tabernaemontana species is outlined and an overall assessment made. Likewise, information on the pharmacology of crude extracts and individual alkaloids from Tabernaemontana species has been assembled and appraised.

Alkaloids↗

Ethnobotany of Apocynaceae species in Kenya.

The study of Apocynaceae species used in traditional medicine reveals that 25 species in 16 genera are of ethnobotanical interest. Nineteen species are medicinal, sixteen of which fall under the subfamily Plumerioideae which usually has indole alkaloids. The most common category of diseases treated is skin and ectoparasitic diseases followed by abdominal diseases, diseases of the head, female conditions and venereal diseases. The root is the most commonly used part of the plant and it is possible that the alkaloids play an important role in the medicinal value of the plants. Many species are used for non-medicinal purposes as fruit (Saba comorensis), edible roots (Carissa edulis), poisons (Acokanthera schimperi), fodder (Strophanthus mirabilis), wood (Funtumia africana), birdlime (Tabernaemontana pachysiphon), ornamentals (Adenium obesum), dye (Carissa edulis) and perfume (Wrightia demartiniana).

Animals↗

A preliminary chemotaxonomic review of Kopsia (Apocynaceae).

The present paper is the result of a botanical and chemical study of the Indo-Pacific genus Kopsia (Plumerioideae-Rauvolfieae) Apocynaceae. Some of the species of this genus possess medicinal uses. A survey of the accepted taxa and their synonymy, based on the study of types, is presented. Studies on alkaloids provides chemotaxonomic information. Indeed, in some cases, chemical relationships occur between species belonging to the same botanical group.

Alkaloids↗

Opioid activity of alkaloids extracted from Picralima nitida (fam. Apocynaceae).

Extracts of the seeds of Picralima nitida (fam. Apocynaceae) have been reported to have opioid analgesic activity. In this investigation, isolated tissue bioassays and radioligand binding assays have been used to determine the opioid activity of five alkaloids--akuammidine, akuammine, akuammicine, akuammigine and pseudoakuammigine--extracted from the seeds of P. nitida. Akuammidine showed a preference for mu-opioid binding sites with Ki values of 0.6, 2.4 and 8.6 microM at mu-, delta- and kappa-opioid binding sites, respectively. The agonist actions of akuammidine in the mouse-isolated vas deferens were antagonised by naloxone and the mu-opioid receptor selective antagonist D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2 (CTOP) confirming an action at mu-opioid receptors. In contrast, akuammine also showed highest affinity for mu-opioid binding sites (Ki 0.5 microM) but was an antagonist at mu-opioid receptors with a pK(B) of 5.7 against the selective mu-opioid receptor agonist [D-Ala2,MePhe4,Gly-ol5]enkephalin (DAMGO). Akuammicine has the highest affinity for kappa-opioid binding sites (Ki 0.2 microM) and was a full agonist at kappa-opioid receptors in the guinea pig ileum preparation but a partial kappa-opioid receptor agonist in the vasa deferentia of the mouse and the rabbit. Akuammigine and pseudoakuammigine showed little or no efficacy in the opioid bioassays. None of the alkaloids had significant activity for opioid receptor-like binding sites (ORL1-binding sites) with Ki values >> 10 microM. These data show that some alkaloids extracted from the medicinal plant P. nitida possess varying degrees of agonist and antagonist activity at opioid receptors but possess neither high affinity nor selectivity for mu-, delta- or kappa-opioid receptors or the ORL1-receptor.

Alkaloids↗

Immunostimulating effect of pule (Alstonia scholaris L. R.Br., Apocynaceae) bark extracts.

The immunostimulating effect of "Pule" (Alstonia scholaris (L.) R.Br., Apocynaceae) bark extracts was studied in BALB/c mouse. The extracts were administered orally, once a day for 7 consecutive days. The results showed that at the same doses (50, 100 and 200 mg/kg b.w.) the aqueous extract had higher phagocytic index (1.39-1.79) than the ethanolic extracts (0.81-0.93) in normal mice. The aqueous extract at 50 mg/kg b.w. also enhanced phagocytic activity of immunosuppressed mice significantly (P < 0.01). At 50 and 100 mg/kg b.w. the extract prevents the decrease of immune system induced by prednisone. The aqueous extract at 100 mg/kg b.w. increased lytic activity of peritoneal exudate cells against Escherichia coli significantly (P < 0.05). At the doses of 50 and 100 mg/kg b.w. the aqueous extract had no effect on primary antibody level. The aqueous extract at 50 mg/kg b.w. induced the cellular immune response while at 100 mg/kg b.w. inhibited the delayed type of hypersensitivity reaction.

Adjuvants, Immunologic↗