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The Rubiaceae family, comprising 550 species in the Philippines, is a significant source of bioactive components with ethnopharmacological uses. This study assessed the total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity of six Rubiaceae species, collected in Ilocos Norte, Philippines: Guettardella microphylla (Bartl. ex DC.) Merr., Timonius ternifolius (Bartl. ex DC.) Fern.-Vill., Kanapia monstrosa (A. Rich.) Arriola & Alejandro, Pyrostria triflora Arriola, Calaramo & Alejandro, Pyrostria subsessilifolia (Merr.) Arriola & Alejandro, and Psychotria luzoniensis (Cham. & Schltdl.) Fern.-Vill. Identification of the plant species was done using morphological characterization. The TFC results ranged between 1.86-3.81 mg quercetin equivalent/g dry weight (GAE/g DW), while TPC indicated 5.47-17.17 mg gallic acid equivalent/g dry weight (QE/g DW). G. microphylla showed the highest TFC (3.81±0.20 mg QE/g DW) while P. triflora exhibited the highest TPC (17.17±0.83 mg GAE/g DW). Antioxidant profiling showed P. luzoniensis exhibiting the highest activity in the NOS, ABTS, DPPH, and FRAP assays. G. microphylla showed the highest hydrogen peroxide scavenging activity, while T. ternifolius demonstrated the highest hydroxyl radical scavenging activity. Findings suggest that the crude methanolic extracts of the Rubiaceae species have relatively high TPC and TFC values and exhibit promising antioxidant capacities. [ABSTRACT FROM AUTHOR]

The majority of multi-cellular terrestrial life is found in tropical forests and is either an invertebrate or a plant: for decades ecologists have sought to understand why. As global change erodes the list of extant species on our planet quantifying what species remain, along with their origins and ecology, contributes to our ability to preserve ecosystem functioning and resilience. Here we study three feeding guilds of caterpillars (Lepidoptera) and seek to understand the drivers of their diet breadth across four diverse tropical plant genera in Papua New Guinea. Host specificity is central to biodiversity estimates and the resilience of ecological networks. Specifically, we calculate distance-based host specificity in relation to plant phylogenetic relationships alongside chemical and mechanical traits of leaves. In terms of chemical defenses, we focus on the major polyphenol groups, a compound class shared across many plant species. We refine our data exploration using food webs and ordinations to pick out specific traits of relevance to insect host specificity. Our results showed that the degree of specialization for caterpillars took the following order: phylogenetic>polyphenol>mechanical, such that insect specificity was explained best by host phylogeny and polyphenol chemistry in our study system. Leaf mining insects had higher host specificity than those feeding externally. Of the traits studied hexahydroxydiphenoyl derivatives, galloyl derivatives, trichome density, quinic acid derivatives, myricetins and successional index explained the most variation in overall insect community structure. Our findings build on earlier studies of New Guinean rainforest communities and add a mechanistic explanation to previous findings that host genera are functional islands for insect herbivores. Further, we demonstrate that different plant genera combine different defensive traits that appear to drive associated insect diversity. Our approach integrates trait data and phylogeny to explore dimensions of specialization and we welcome metabolomic studies that will provide more detailed explanations for insect-herbivore host use. Finally, chemical diversity is directly linked to organismal diversity and by studying a range of insect herbivore guilds we make a connection between feeding ecology and specialization that will help to predict species interactions and, potentially, the persistence of ecological networks. [ABSTRACT FROM AUTHOR]

The Rubiaceae family, comprising 550 species in the Philippines, is a significant source of bioactive components with ethnopharmacological uses. This study assessed the total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity of six Rubiaceae species, collected in Ilocos Norte, Philippines: Guettardella microphylla (Bartl. ex DC.) Merr., Timonius ternifolius (Bartl. ex DC.) Fern.-Vill., Kanapia monstrosa (A. Rich.) Arriola & Alejandro, Pyrostria triflora Arriola, Calaramo & Alejandro, Pyrostria subsessilifolia (Merr.) Arriola & Alejandro, and Psychotria luzoniensis (Cham. & Schltdl.) Fern.-Vill. Identification of the plant species was done using morphological characterization. The TFC results ranged between 1.86-3.81 mg quercetin equivalent/g dry weight (GAE/g DW), while TPC indicated 5.47-17.17 mg gallic acid equivalent/g dry weight (QE/g DW). G. microphylla showed the highest TFC (3.81±0.20 mg QE/g DW) while P. triflora exhibited the highest TPC (17.17±0.83 mg GAE/g DW). Antioxidant profiling showed P. luzoniensis exhibiting the highest activity in the NOS, ABTS, DPPH, and FRAP assays. G. microphylla showed the highest hydrogen peroxide scavenging activity, while T. ternifolius demonstrated the highest hydroxyl radical scavenging activity. Findings suggest that the crude methanolic extracts of the Rubiaceae species have relatively high TPC and TFC values and exhibit promising antioxidant capacities.

Phytochemical study of Psychotria schlechtendaliana (Rubiaceae) aerial parts resulted in the isolation of alkaloids 4 N oxide harmane (1) and strictosidinic acid (2), and the terpenoids sitosterol, estigmasterol, α-amyrin, β-amyrin and betulinic acid. The crude extract (CE), its fractions (hexane FH, chloroform FC, ethyl acetate FEA, hydromethanolic FHM, alkaloidal chloroform FCOH, alkaloidal aqueous FAq) and majority alkaloid (1) were investigated for their antiproliferative potential against nine human tumor cells lines and one non-tumoral human cell line (HaCat). CE, FH and FEA fractions exhibited strong growth inhibition for ovary cells (OVCAR-3, GI50 = 5.89; 1.36 and 6.59 μg mL-1, respectively) and FC, FH and FAq fractions showed potent activity on the growth of leukemia cell lines (K562, GI50 = 1.92; 7.23 and 8.81 μg mL-1, respectively). Compound 1 exhibited selective antiproliferative activity to breast cancer (MCF-7, GI50 = 32.7 μg mL-1) and was non-toxic to HaCat cells. To evaluate the anti-inflammatory effect, models of ear edema induced by croton oil and the enzyme myeloperoxidase (MPO) were used. FH and FC fractions exhibited anti-inflammatory effect and reduce ear edema compared to the control group. These fractions showed results superior to those exhibited by indomethacin (75.1%), FH (97.5%) and FC (95.5%) fractions.

The majority of multi-cellular terrestrial life is found in tropical forests and is either an invertebrate or a plant: for decades ecologists have sought to understand why. As global change erodes the list of extant species on our planet quantifying what species remain, along with their origins and ecology, contributes to our ability to preserve ecosystem functioning and resilience. Here we study three feeding guilds of caterpillars (Lepidoptera) and seek to understand the drivers of their diet breadth across four diverse tropical plant genera in Papua New Guinea. Host specificity is central to biodiversity estimates and the resilience of ecological networks. Specifically, we calculate distance-based host specificity in relation to plant phylogenetic relationships alongside chemical and mechanical traits of leaves. In terms of chemical defenses, we focus on the major polyphenol groups, a compound class shared across many plant species. We refine our data exploration using food webs and ordinations to pick out specific traits of relevance to insect host specificity. Our results showed that the degree of specialization for caterpillars took the following order: phylogenetic>polyphenol>mechanical, such that insect specificity was explained best by host phylogeny and polyphenol chemistry in our study system. Leaf mining insects had higher host specificity than those feeding externally. Of the traits studied hexahydroxydiphenoyl derivatives, galloyl derivatives, trichome density, quinic acid derivatives, myricetins and successional index explained the most variation in overall insect community structure. Our findings build on earlier studies of New Guinean rainforest communities and add a mechanistic explanation to previous findings that host genera are functional islands for insect herbivores. Further, we demonstrate that different plant genera combine different defensive traits that appear to drive associated insect diversity. Our approach integrates trait data and phylogeny to explore dimensions of specialization and we welcome metabolomic studies that will provide more detailed explanations for insect-herbivore host use. Finally, chemical diversity is directly linked to organismal diversity and by studying a range of insect herbivore guilds we make a connection between feeding ecology and specialization that will help to predict species interactions and, potentially, the persistence of ecological networks.

Under natural conditions plants are generally subjected to complex scenarios of combined or sequential environmental stresses. Among the various components of plant biochemistry modulated by abiotic variables, a pivotal role is played by antioxidant systems, including specialized metabolites and their interaction with central pathways. To help address this knowledge gap, a comparative analysis of metabolic changes in leaf tissues of the alkaloid accumulating plant Psychotria brachyceras Müll Arg. under individual, sequential, and combined stress conditions was carried out. Osmotic and heat stresses were evaluated. Protective systems (accumulation of the major antioxidant alkaloid brachycerine, proline, carotenoids, total soluble protein, and activity of the enzymes ascorbate peroxidase and superoxide dismutase) were measured in conjunction with stress indicators (total chlorophyll, ChA/ChB ratio, lipid peroxidation, H2O2 content and electrolyte leakage). Metabolic responses had a complex profile in sequential and combined stresses compared to single ones, being also modified over time. Different stress application schemes affected alkaloid accumulation in distinct ways, exhibiting similar profile to proline and carotenoids, constituting a complementary triad of antioxidants. These complementary non-enzymatic antioxidant systems appeared to be essential for mitigating stress damage and re-establishing cellular homeostasis. The data herein provides clues that may aid the development of a key component framework of stress responses and their appropriate balance to modulate tolerance and yield of target specialized metabolites. [ABSTRACT FROM AUTHOR]

The natural history and morphology of two sympatric species of Rubiaceae-feeding metalmark butterflies, Mesosemia m. machaera and Mesosemia philocles jeziela, are described and illustrated using both light and scanning electron microscopy. These species use the same Rubiaceae host plant species and have similar life cycles. Single eggs are laid on old leaves, caterpillars are solitary, and pupation occurs off the host plant. Differences occur during ontogeny with caterpillars using different host plant parts, M. m. machaera feeds on the abaxial leaf surface and M. philocles jeziela on the new leaves and adaxial surface. There is also variation in the number of instars, size and number of setae and details in larval and pupal color patterns. Caterpillars are non-myrmecophilous and have defense-related tentacle nectary organs (TNOs), the functionality of this organ in pupae is recorded for the first time. These results show that although similar, subtle differences exist in the Mesosemia life cycles. [ABSTRACT FROM AUTHOR]

Background and aims – The genus Carapichea (Rubiaceae), recently resurrected and separated from Psychotria, currently includes 24 Neotropical species and is morphologically heterogeneous. A revision of the genus in the Guianas is presented here, as part of the authors’ work on the Rubiaceae treatment in the Flora of the Guianas series.Material and methods – This paper is based on a study of herbarium specimens from BBS, BM, BR, BRB, CAY, INPA, K, P, P-JJR, and U; type specimens from other herbaria were consulted online. Some of the species were also studied in the field by the authors. Normal practices of herbarium taxonomy have been applied.Results – Three species previously included in Carapichea (C. altsonii, C. nivea, and C. sandwithiana) show aberrant characters for the genus and are transferred to Notopleura; new combinations are published for the former two (N. altsonii and N. nivea). Eight species of Carapichea, one of them still imperfectly known, are recorded from the Guianas; a ninth species, C. araguariensis, is included in this revision as it is expected to occur in the region. New combinations are published for two species: Carapichea galbaoensis and C. squamelligera, based on Psychotria galbaoensis and P. squamelligera, respectively; the former species was previously included in synonymy of C. guianensis, which is here redefined in a narrower sense. The delimitation of C. ligularis is expanded to include C. pacimonica as a synonym. The first records of C. adinantha in French Guiana – and the Guiana Shield – are documented. The taxonomy of the two remaining species, C. tillettii and C. urniformis, is left unchanged. For every species a complete description is presented, as well as data on distribution, ecology, phenology, local names (when known), and a list of collections studied.

Review of specimens of Psychotria L. (i.e., Psychotria s. str., Psychotria subg. Psychotria) from Madagascar has revealed some species new to science. Here we describe and provide Red List conservation status assessments for 10 new species of Malagasy Psychotria: P. anosiana C. M. Taylor and P. apomurioides C. M. Taylor are found in humid forest in southeastern Madagascar; P. kuhliana C. M. Taylor, P. luteofructa C. M. Taylor, P. ranomafanensis C. M. Taylor, and P. razakamalalae C. M. Taylor are found in humid forest in central-eastern Madagascar; P. littoralis C. M. Taylor is found in subhumid, littoral and sublittoral forest in northeastern Madagascar; P. malcomberiana C. M. Taylor is found in subhumid, semi-deciduous forest in northern Madagascar; P. parvihama C. M. Taylor is found in wet forest in the Masoala Peninsula of northeastern Madagascar; and P. rakotovaoi C. M. Taylor is found in humid forest in northern and northeastern Madagascar, sometimes at relatively high elevations. Three of these species are assessed as Near Threatened, one as Vulnerable, five as Endangered, and one as Critically Endangered. résumé. L'examen des échantillons d'herbier appartenant au genre Psychotria L. (c'est à dire le genre Psychotria au sens stricte, Psychotria subg. Psychotria) provenant de Madagascar a permis de découvrir plusieurs nouvelles espèces pour la Science. Dans ce présent manuscrit, nous décrivons et fournissons des évaluations préliminaires du statut de conservation selon les critères de la Liste Rouge de l'UICN des 10 espèces de Psychotria de Madagascar: P. anosiana C. M. Taylor et P. apomurioides C. M. Taylor se trouvent dans la forêt humide du sud-est de l'ile, P. kuhliana C. M. Taylor, P. luteofructa C. M. Taylor, P. ranomafanensis C. M. Taylor et P. razakamalalae C. M. Taylor dans la forêt humide du centre-est, P. littoralis C. M. Taylor dans les forêts littorales et forêts sublittorales subhumides du nord-est, P. malcomberiana C. M. Taylor dans la forêt subhumide et semi-décidue du Nord, P. parvihama C. M. Taylor dans la forêt perhumide de la presqu'île Masoala dans le Nord-Est, et P. rakotovaoi C. M. Taylor dans la forêt humide du nord et du nordest. Parmi ces 10 nouvelles espèces, trois sont considerées comme presque menacées (NT), une espèce comme Vulnérable (VU), cinq autres comme "En danger" (EN), et une dernière comme En danger Critique d'extinction (CR). [ABSTRACT FROM AUTHOR]

Psychotria carthagenensis (Rubiaceae), popularly known as "erva-de-rato", is known as poisonous, and its leaves are used as a constituent of "ayahuasca". An anatomical study of its leaves was carried out to define parameters to support its taxonomy and quality control of ethnodrugs. Transverse and paradermic sections of petioles and leaf blades were made following the usual techniques of botanical anatomy. All semi-permanent laminas were then analyzed and photographed by light microscopy. Leaf blades were also studied with the support of the scanning electron microscope. Psychotria carthagenensis has hypostomatic epidermis, 1-2-stratified, in cross section, with three types of stomata (paracytic, anisocytic and anomocytic), and predominantly straight anticlinal cell walls, in frontal view, and glandular-peltate trichomes on both surfaces, the cuticle is smooth and thickened. The leaf edges are acute, mesophyll dorsiventral with the palisade parenchyma 1-seriate, and spongy parenchyma 4-seriate. The midrib is flat-convex with 4 bundles; petiole is semicircular with lateral projections with 9 vascular bundles. Midrib and petiole have collateral vascular system. Anisocytic and anomocytic stomata, glandular-peltate trichomes, petiole with the central bundle invaginate at the end, the syntopism of epicuticular waxes are distinctive parameters for P. carthagenensis, which support the standardization of its leaves used as medicines, in addition to contributing to the systematic of the Psychotria genus. [ABSTRACT FROM AUTHOR]

Background and aims - The genus Carapichea (Rubiaceae), recently resurrected and separated from Psychotria, currently includes 24 Neotropical species and is morphologically heterogeneous. A revision of the genus in the Guianas is presented here, as part of the authors' work on the Rubiaceae treatment in the Flora of the Guianas series. Material and methods - This paper is based on a study of herbarium specimens from BBS, BM, BR, BRB, CAY, INPA, K, P, P-JJR, and U; type specimens from other herbaria were consulted online. Some of the species were also studied in the field by the authors. Normal practices of herbarium taxonomy have been applied. Results - Three species previously included in Carapichea (C. altsonii, C. nivea, and C. sandwithiana) show aberrant characters for the genus and are transferred to Notopleura; new combinations are published for the former two (N. altsonii and N. nivea). Eight species of Carapichea, one of them still imperfectly known, are recorded from the Guianas; a ninth species, C. araguariensis, is included in this revision as it is expected to occur in the region. New combinations are published for two species: Carapichea galbaoensis and C. squamelligera, based on Psychotria galbaoensis and P. squamelligera, respectively; the former species was previously included in synonymy of C. guianensis, which is here redefined in a narrower sense. The delimitation of C. ligularis is expanded to include C. pacimonica as a synonym. The first records of C. adinantha in French Guiana - and the Guiana Shield - are documented. The taxonomy of the two remaining species, C. tillettii and C. urniformis, is left unchanged. For every species a complete description is presented, as well as data on distribution, ecology, phenology, local names (when known), and a list of collections studied. [ABSTRACT FROM AUTHOR]

Nomenclatural and taxonomic analyses clarify the identities, correct names, and typifications for four previously-described species of Palicourea. A nomenclatural study shows that P. carruthersii is the overlooked oldest name for plants from Central and South America currently called P. microbotrys, and a taxonomic study finds that P. furcata is the oldest name for plants from Central and South America currently called P. longiinvolucrata. The name Psychotria japurensis was inadvertently published twice in the same work, for two different species; this situation has a previously overlooked published resolution, as clarified here: one of Müller's species is correctly called Palicourea iodotricha and the other is P. japurensis. Four new species of Palicourea have been discovered through recent botanical exploration and are described here. Palicourea geminata, from Amazonian Ecuador, is distinctive in its subcapitate inflorescences borne on paired axillary short shoots, well-developed bracts, and white corollas. Palicourea monsalveae, from coastal western Colombia, is distinctive in its glabrous leaves and stems, robust stipules and leaves, and robust and subcapitate inflorescences. Palicourea wilburiana, from the Andes of Ecuador, is distinctive in its sericeous pubescence, relatively large stipules, and subcapitate inflorescences with well-developed bracts. Palicourea woytkowskii, from the Andes of northern Peru, is distinctive in its densely pilosulous leaves and stems and subcapitate inflorescences with well-developed, bright pink bracts. [ABSTRACT FROM AUTHOR]

The function of the reciprocal position of anthers and stigmas of the floral morphs in distylous flowers is to promote cross-pollination between morphs (legitimate pollination). Deviations from reciprocity can negatively affect the rates of legitimate pollen deposition, but other floral traits or the pollination environment might contribute to the function of distyly. In populations of four species of Palicourea and Psychotria , we quantified reciprocity using adaptive inaccuracy and measured the stigmatic lobe length to estimate how these traits influenced legitimate pollen deposition. We described the functional groups of pollinators and compared legitimate pollen flow between morphs in populations visited by different groups. Variations in reciprocity and stigmatic lobe length correlated with the rates of legitimate pollen depositions, with more reciprocal stigmas and longer stigmatic lobes presenting proportionally more legitimate pollen. Populations most frequently visited by bees or with generalized pollination displayed asymmetries in pollen flow between morphs, but with higher legitimate pollination in the S-morph. In contrast, L- and S-flowers showed similar legitimate pollen deposition in the population predominantly visited by hummingbirds. Our results suggest that reciprocity affects the function of distyly; however, floral traits such as stigmatic lobe length and the pollination environment can also influence the rates of legitimate pollen. [ABSTRACT FROM AUTHOR]

Recent exploration on the northern Cordillera Mountain Range of Ilocos Norte, Philippines, resulted in the rediscovery of Psychotria palimlimensis Sohmer & A.P. Davis. This is an endemic Psychotria species first collected by Ramos in 1918 and identified as P. subalpina. However, the diagnosis of Sohmer and A.P. Davis in 2007 proposed it as a new species based on herbarium materials, and no further recollection was made to date since its last collection in 1953. Therefore, an amended taxonomic description of P. palimlimensis is proposed with color photographs, additional records on the distribution and morphological comparison with its allied species. The current conservation status is also provided. [ABSTRACT FROM AUTHOR]

The genus Chassalia (Gentianales: Rubiaceae-Palicoureeae) in Borneo is revised based on a morphological survey of herbarium specimens using classical taxonomic methods. The tribal placement and probable paraphyly of Chassalia as currently delimited is reviewed. Previously, four described species of Chassalia were known from Borneo, with only one endemic species, Chassalia psychotriformis I.M.Turner nom. nov. (≡ Cephaelis psychotrioides Valeton). A key is given to the 18 species of the genus recognised from Borneo in this study. In total, 14 new species are described, all of them endemic to Borneo. These are: Chassalia atropurpurea T.Y.Yu sp. nov., Chassalia beamanii T.Y.Yu sp. nov., Chassalia calamus T.Y.Yu sp. nov., Chassalia chewii T.Y.Yu sp. nov., Chassalia involucrata T.Y.Yu sp. nov., Chassalia kinabaluensis T.Y.Yu sp. nov., Chassalia lancifolia T.Y.Yu sp. nov., Chassalia lancifolioides T.Y.Yu sp. nov., Chassalia longipes T.Y.Yu sp. nov., Chassalia macrocarpa T.Y.Yu sp. nov., Chassalia muluensis T.Y.Yu sp. nov., Chassalia muscicola T.Y.Yu sp. nov., Chassalia northiana T.Y.Yu sp. nov. and Chassalia ramosa T.Y.Yu sp. nov. Circumscriptions and discussions are given for all Bornean species recognised. A morphological glossary for Asian species of Chassalia is provided. Three separate species groups are recognised, the Chassalia curviflora and C. javanica groups, represented by a single species each in Borneo, and a new informal group, the ‘Involucrate group’, which is proposed and circumscribed to encompass the majority (16) of the Bornean species. Proposals for further work on Asian Chassalia are given.

The objective of this study was to assess the potential antioxidant, antimicrobial, and toxicological properties of crude extracts and fractions obtained from the leaves and stem of Psychotria fractistipula L.B. Sm., Klein & Delprete. The content of phenolic compounds varied significantly between samples (783.70–78.22 GAE mg/g), with the highest concentrations being in the ethyl acetate fraction of the leaves and stem (679.39 and 783.70 GAE mg/g, respectively). The latter yielded also the best IC50 of the DPPH radical, which amounted to 9.48 and 4.75 µg/mL, respectively; whereas other samples ranged up to 156.64 µg/mL. Similarly, phosphomolybdenum activity varied between 90.17% and 16.00%, with the ethyl acetate fractions of the leaves and stem corresponding to 90.17% and 87.37%, respectively. Antimicrobial activity was elevated in the leaves crude extract (Staphylococcus aureus, 62.5 µg/mL), leaves ethyl acetate fraction (S. aureus, 31.25 µg/mL; Enterococcus faecalis, 62.4 µg/mL), and the stem ethyl acetate fraction (S. aureus, 31.25 µg/mL; Pseudomonas aeruginosa, 62.5 µg/mL). Hemolytic activity was high in the chloroform fractions of the leaves (1000 µg/mL) and stem (500 µg/mL). Larvicidal activity against Aedes aegypti was observed in the hexane fraction of the stem (LC50, 297.44 µg/mL). The ethyl acetate fractions of the stem and leaves were toxic to Artemia salina, with LC50 values of 277.91 and 933.89 µg/mL, respectively. These results indicate that P. fractistipula may constitute an unexplored source of natural antioxidants and antimicrobials with low toxicity [ABSTRACT FROM AUTHOR]

RESUMO (A família Rubiaceae no Parque Nacional de Boa Nova, Estado da Bahia, Brasil). Rubiaceae ocupa o quarto lugar em diversidade de espécies entre as Angiospermas. É uma família cosmopolita, concentrada principalmente nas regiões tropicais e subtropicais, com cerca de 13.765 espécies, distribuídas em 611 gêneros. No Brasil, Rubiaceae apresenta 1.406 espécies, distribuídas em 126 gêneros. O Parque Nacional de Boa Nova (PNBN) está situado na região nordeste do Planalto da Conquista, Estado da Bahia e possui áreas de Mata Atlântica e Caatinga, além da transição representada por Floresta Estacional Semideciual. O objetivo do presente trabalho foi realizar um levantamento das espécies de Rubiaceae ocorrentes no PNBN. Foram realizadas expedições de coleta entre 2012 e 2017, além de consulta a herbários. A família está representada por 29 gêneros e 60 espécies, das quais quatro espécies são prováveis novas espécies. A forma de vida mais representativa foi arbustiva (60,6%), seguida por herbácea (27,9%), trepadeira ou liana (4,9%), epifítica (3,3%) e arbórea (3,2%). Os caracteres importantes na identificação foram hábito, morfologia das estípulas, tipo de arranjo da inflorescência, prefloração, morfologia do estigma, número de óvulos e tipo de fruto. Considerando os resultados obtidos, pode-se concluir que o PNBN possui um número elevado de espécies de Rubiaceae, destacando o estudo como uma importante área para a conservação de espécies vegetais.

Psychotria fractistipula L.B.Sm, R.M. Klein & Delprete (Rubiaceae) is found in the existing Atlantic Forest in the South of Brazil, in the Paraná and Santa Catarina States. The members of Rubiaceae are characterized chemically by the presence of alkaloids, some pharmacological properties of which include antifungal, antibacterial, analgesic, antioxidant, antimutagenic, and antiviral activities. In this study, we report the results of anatomical, morphological, and histochemical analyses of the leaves and stems of the Rubiaceae family member, P. fractistipula. The anatomical analysis involved of light microscopy and scanning electron microscopy. Morpho-anatomical and histochemical characterization were made using standard methodology. The isolated compounds were identified by Nuclear Magnetic Resonance spectroscopic analysis. The following structures are highlighted as the distinctive features of the species: presence of petiolate leaves and a petiole base, leaf blade with smooth cuticle on both surfaces, paracytic stomata, and, dorsiventral mesophyll and presence of trichomes on the leaves and stems. Phytosteroids, identified as β-sitosterol and campesterol, were observed in the hexane fraction of the stem. Future studies should focus on the isolation of other fractions of interest and their characterization through specific biological and cytotoxicity assays.

The genus Mapouria is synonymous with Psychotria, and based on Mapouria guianensis. The identity of M. guianensis, the correct name for P. mapourioides, and the identities of several other neotropical Psychotria names studied here have been unclear. The name M. guianensis corresponds to the plants currently treated as P. ernestii, and P. pedunculosa is an older name for P. mapourioides. The distinctions among the commonly confused species P. guianensis, P. carthagenensis, P. cupularis, and P. pedunculosa are clarified here, and typifications and identities are determined for several other names associated with these species. [ABSTRACT FROM AUTHOR]

Phytochemical investigation of the stem bark extract of Psychotria djumaensis led to the isolation of ten known pentacyclic triterpenoids among which one lupane-, three oleanane-, and six ursanetypes. The structures of the isolated compounds were established by means of spectroscopic methods and by comparison with previously reported data. The isolated compounds were tested against five strains of bacteria, and the cytotoxicity against the human cervix carcinoma KB-3-1 cell was evaluated. The isolates exhibited weak antibacterial activity against the five strains. The cytotoxic activity exhibited by 3ß,19a-dihydroxyurs-12-en-28-oic acid (5) (IC50 5.9 µM) was about three times more significant than that of the reference [(+) griseofulvin, IC50 17-21 µM]. [ABSTRACT FROM AUTHOR]

Premise: Interactions between fungal endophytes and their host plants present useful systems for identifying important factors affecting assembly of host‐associated microbiomes. Here we investigated the role of secondary chemistry in mediating host affinity of asymptomatic foliar endophytic fungi using Psychotria spp. and Theobroma cacao (cacao) as hosts. Methods: First, we surveyed endophytic communities in Psychotria species in a natural common garden using culture‐based methods. Then we compared differences in endophytic community composition with differences in foliar secondary chemistry in the same host species, determined by liquid chromatography–tandem mass spectrometry. Finally, we tested how inoculation with live and heat‐killed endophytes affected the cacao chemical profile. Results: Despite sharing a common environment and source pool for endophyte spores, different Psychotria host species harbored strikingly different endophytic communities that reflected intrinsic differences in their leaf chemical profiles. In T. cacao, inoculation with live and heat‐killed endophytes produced distinct cacao chemical profiles not found in uninoculated plants or pure fungal cultures, suggesting that endophytes, like pathogens, induce changes in secondary chemical profiles of their host plant. Conclusions: Collectively our results suggest at least two potential processes: (1) Plant secondary chemistry influences assembly and composition of fungal endophytic communities, and (2) host colonization by endophytes subsequently induces changes in the host chemical landscape. We propose a series of testable predictions based on the possibility that reciprocal chemical interactions are a general property of plant–endophyte interactions. [ABSTRACT FROM AUTHOR]

The genus Chassalia in Asia is reviewed. In total 23 species are accepted, including one new combination and a validation of a combination proposed earlier. Some 17 names in Chassalia relevant to the Asia‐Pacific region are excluded from the genus, and recognised in genera such as Psychotria, Eumachia and Geophila. Names in Cephaelis for the region are also reviewed. One new combination and two new names are proposed in Psychotria. Synonyms and types are given for all names treated, including 29 lectotypifications. [ABSTRACT FROM AUTHOR]

To understand how tropical plants have adapted to acid soils, we analyzed the transcriptome of seedlings of Psychotria rubra, a typical species found on acid soils. Using RNA-seq, we identified 22,798 genes, including several encoding proteins of the Al3+-activated malate transporter (ALMT) and multidrug and toxic compound extrusion (MATE) families. Molecular phylogenetic analysis of ALMTs and MATEs revealed the grouping of those from P. rubra, which may be useful to select targets for elucidating the molecular basis of P. rubra adaptation to acid soils in the future. The transcriptome datasets obtained in this study would help us to further understand the physiological and ecological aspects of soil adaptation of Psychotria species.

Palicourea Aubl. (Rubiaceae) comprises a large group of Neotropical species, many of which were previously classified in Psychotria L. subg. Heteropsychotria Steyerm. Ongoing study of those species here clarifies the identity of Palicourea pilosa (Ruiz & Pav.) Borhidi, Palicourea hazenii (Standl.) Borhidi, and several similar species, and classifies them all in Palicourea subg. Montanae C. M. Taylor sect. Montanae ser. 4 subser. f. Twenty-five species found from southern Central America through western South America are studied here. The circumscription of Palicourea pilosa is narrowed, four new nomenclatural combinations are made in Palicourea, and 10 new species and one new subspecies are described. [ABSTRACT FROM AUTHOR]

Wallace's Riverine Barrier hypothesis is one of the earliest biogeographic explanations for Amazon speciation, but it has rarely been tested in plants. In this study, we used three woody Amazonian plant species to evaluate Wallace's Hypothesis using tools of landscape genomics. We generated unlinked single‐nucleotide polymorphism (SNP) data from the nuclear genomes of 234 individuals (78 for each plant species) across 13 sampling sites along the Rio Branco, Brazil, for Amphirrhox longifolia (8,075 SNPs), Psychotria lupulina (9,501 SNPs) and Passiflora spinosa (14,536 SNPs). Although significantly different migration rates were estimated between species, the population structure data do not support the hypothesis that the Rio Branco—an allopatric barrier for primates and birds—is a significant genetic barrier for Amphirrhox longifolia, Passiflora spinosa or Psychotria lupulina. Overall, we demonstrated that medium‐sized rivers in the Amazon Basin, such as the Rio Branco, are permeable barriers to gene flow for animal‐dispersed and animal‐pollinated plant species. [ABSTRACT FROM AUTHOR]

For 185 years, the genus Eumachia (Rubiaceae) was considered to include one species from Tonga. Since 2015, 94 more names have been added to it, expanding Eumachia into a pantropical genus of shrubby plants, most of whose members were originally described in Psychotria. Four Psychotria species from Southeast Asia that were identified as potentially belonging in Margaritopsis (now a synonym of Eumachia) have not yet had combinations made in Eumachia. They are considered here, and new combinations are made for Psychotria extensa Miq., P. montana Blume and P. rostrata Blume. The fourth name, Psychotria expansa Blume, is considered a synonym. The identities of Chassalia sangiana Miq. and Psychotria rhodocarpa Teijsm. & Binn. are also discussed. Lectotypes are designated for several names. [ABSTRACT FROM AUTHOR]

The plant Psychotria kirkii hosts an obligatory bacterial symbiont, Candidatus Burkholderia kirkii, in nodules on their leaves. Recently, a glucosylated derivative of (+)‐streptol, (+)‐streptol glucoside, was isolated from the nodulated leaves and was found to possess a plant growth inhibitory activity. To establish a structure–activity relationship study, a convergent strategy was developed to obtain several pseudosugars from a single synthetic precursor. Furthermore, the glucosylation of streptol was investigated in detail and conditions affording specifically the α or β glucosidic anomer were identified. Although (+)‐streptol was the most active compound, its concentration in P. kirkii plant leaves extract was approximately ten‐fold lower than that of (+)‐streptol glucoside. These results provide compelling evidence that the glucosylation of (+)‐streptol protects the plant host against the growth inhibitory effect of the compound, which might constitute a molecular cornerstone for this successful plant‐bacteria symbiosis. Protective glucosylation: A convergent synthetic route was developed to obtain the novel growth plant inhibitor, streptol glucoside, recently isolated from P. kirkii plant leaves extract. The biological activity investigation of the natural product and its derivatives suggests that the glucose of streptol glucoside protects the plant against the potent growth inhibitor streptol. [ABSTRACT FROM AUTHOR]

Background and aims: The bacterial leaf nodule symbiosis is a close interaction between endophytes and their plant hosts, mainly within the coffee family. The interaction between Rubiaceae species and Burkholderia bacteria is unique due to its obligate nature, high specificity, and predominantly vertical transmission of the endophytes to the next generation of host plants. This vertical transmission is intriguing since it is the basis for the uniqueness of the symbiosis. However, unequivocal evidence of the location of the endophytes in the seeds is lacking. The aim of this paper is therefore to demonstrate the presence of the host specific endophyte in the seeds of Psychotria punctata and confirm its precise location. In addition, the suggested location of the endophyte in other parts of the host plant is investigated. Methods: To identify and locate the endophyte in Psychotria punctata, a two-level approach was adopted using both a molecular screening method and fluorescent in situ hybridisation microscopy. Key results: The endophytes, molecularly identified as Candidatus Burkholderia kirkii, were detected in the leaves, vegetative and flower buds, anthers, gynoecium, embryos, and young twigs. In addition, they were in situ localised in leaves, flowers and shoot apical meristems, and, for the first time, in between the cotyledons of the embryos. Conclusions: Both independent techniques detected the host specific endophyte in close proximity to the shoot apical meristem of the embryo, which confirms for the first time the exact location of the endophytes in the seeds. This study provides reliable proof that the endophytes are maintained throughout the growth and development of the host plant and are transmitted vertically to the offspring. [ABSTRACT FROM AUTHOR]

Ixora L. is a pantropical genus of 500 or more woody species. A review of Neotropical Ixora found two species described in other genera that belong to this genus, clarified the identity of another name, and discovered some plants new to science. Faramea mattogrossensis Standl. is here reclassified as I. mattogrossensis (Standl.) C. M. Taylor, and the replacement name I. standleyana C. M. Taylor is published for Psychotria decora Standl. The identity and circumscription of I. rufa Müll. Arg. are clarified and this name is epitypified. Newly described here are I. andina C.M. Taylor, I. froelichiana C. M. Taylor, I. guillenii C. M. Taylor, I. moskovitsiana C. M. Taylor, I. rudasiana C. M. Taylor, I. rudgeoides C. M. Taylor, I. schunkeana C. M. Taylor, I. smithiana C. M. Taylor, and I. vasquezii C. M. Taylor. The types of I. spruceana Müll. Arg. and I. francavillana Müll. Arg. are not separable taxonomically, and this first name is synonymized under the second. [ABSTRACT FROM AUTHOR]

Between 1815 and 1818, Count Nikolai Romanzoff funded an expedition of the Russian brig Rurik. Besides their primary goal to discover the Northeast Passage, their aim was to collect scientific specimens, for which the botanist Adelbert von Chamisso and the entomologist Johann Friedrich von Eschscholtz were commissioned. On the Hawaiian Islands, they collected two unknown endemic species that Chamisso and Diederich Franz Leonhard von Schlechtendal later described as Coffea kaduana and C. mariniana, both now assigned to the large and complex genus Psychotria (Rubiaceae, Psychotrieae). The private herbarium of Chamisso is now preserved at the Komarov Botanical Institute, St. Petersburg (LE). In the late 1930s, their type collections of Psychotria kaduana and P. mariniana were sent out on loan for study, but got lost in transit during the aftermath of the Second World War. No extant original material was found during a subsequent revision of Hawaiian Psychotria and both species were consequently neotypified. These neotypes are superseded by the here-reported rediscovery of original material in the herbarium of Stephan Ladislaus Endlicher preserved at the Natural History Museum, Vienna (W) and these specimens are here designated as lectotypes. As both are rather fragmentary, the former neotypes are additionally designated as epitypes. In addition, some peculiarities and details of the expedition and its collections are noted. [ABSTRACT FROM AUTHOR]

Recent study of the flora of eastern Brazil finds some new species of Palicourea Aubl. that are related to species currently classified in Psychotria L. subg. Heteropsychotria Steyerm. and found in Atlantic Forest vegetation. Two new species are described here in Palicourea pending transfer of their relatives to this genus: Palicourea alagoana C. M. Taylor from Alagoas and Palicourea amorimii C. M. Taylor & J. G. Jardim from Bahia. Another new species, Palicourea atlantica C. M. Taylor & J. G. Jardim, from Bahia is related to two previously described species that have been classified in Psychotria since 1881. Psychotria jambosioides Schltdl. is transferred to Palicourea here, as Palicourea jambosioides (Schltdl.) C. M. Taylor, and Psychotria schlechtendaliana Müll. Arg. is treated here under its type-bearing name Palicourea divaricata Schltdl. These last three species are separated in a new section, Palicourea sect. Jambosioides (Müll. Arg.) C. M. Taylor. Resumo.: Estudo recente sobre a flora do leste do Brasil revelou algumas espécies novas de Palicourea Aubl. relacionadas a espécies atualmente classificadas em Psychotria L. subg. Heteropsychotria Steyerm. Duas espécies novas descritas em Palicourea dependiam de serem transferidas seus parentes deste gênero: são elas Palicourea alagoana C. M. Taylor e Palicourea amorimii C. M. Taylor & J. G. Jardim. Uma outra nova espécie, Palicourea atlantica C. M. Taylor & J. G. Jardim da Mata Atlântica da Bahia, é relacionada a duas espécies classificadas em Psychotria desde 1881. Psychotria jambosioides Schltldl. é aqui transferida para Palicourea jambosioides (Schltdl.) C. M. Taylor e Psychotria schlechtendaliana Müll. Arg. é tratada com seu primeiro nome Palicourea divaricata Schltdl. As três últimas espécies separam-se numa nova seção, Palicourea sect. Jambosioides (Müll. Arg.) C. M. Taylor. [ABSTRACT FROM AUTHOR]

Sympatric plant species that flower at the same time in highly seasonal environments are subject to competitive interference. Many species of the genus Psychotria (Rubiaceae) are sympatric and have an aggregated flowering period, which may have a strong influence on interactions among these species and their pollinators. We assessed the strategies of sympatric species of Psychotria to segregate or share pollinators, and the consequences for intra- and interspecific pollen flow. We sampled pollinators and analyzed flowering phenology, floral tube length, pollinator tongue length and floral nectar production of three sympatric species of Psychotria in the understory of a tropical forest in Brazil. We also marked flowers with fluorescent powder to monitor the flow of pollen. The studied species of Psychotria exhibited a short synchronous flowering period, with the sharing of pollinators and interspecific pollen exchange. The prevalence of shared or unshared pollinators and of intra- or interspecific pollen exchange varied among the studied species. Variation in floral tube length and nectar was not enough to hamper the sharing of most pollinators and pollen flow between Psychotria nitidula and P. hoffmannseggiana. Non-shared pollinators were more common in flowers of P. prunifolia, probably due to its longer floral tube, which can impede the access of shared pollinators. The higher offer of floral nectar by P. prunifolia makes this species more attractive to a greater number of flower visitors. Pollinator sharing seems to have no negative effect on intraspecific pollen flow and on the reproductive success of the studied synchronopatric species of Psychotria. [ABSTRACT FROM AUTHOR]

Ayahuasca is a psychoactive brew traditionally used in shamanistic and vegetalistic rituals and has recently received lot of attention due to potential cognitive benefits. Ayahuasca effects are caused by the synergistic interaction of β-carbolines (harmine, harmaline and tetrahydroarmine) contained in Banisteriopsis caapi stalks combined with the N,N-dimethyltryptamine (DMT) from Psychotria viridis leaves, a potent agonist to serotonin (5-HT) receptors. The present study approaches the effects of chronic and acute exposure to two Ayahuasca concentrations (0.1 and 0.5 ml/L) on the cognitive ability to discriminate objects in a one-trial learning task in zebrafish. Based on the combination of concentrations and exposure regimens, we divided adult zebrafish in five treatment groups: acute 0.1 and 0.5 ml/L, chronic 0.1 and 0.5 ml/L, and control 0.0 (n = 20 for each group). Then we tested them in a memory task of object discrimination. Acute Ayahuasca exposed groups performed similarly to the control group, however chronically treated fish (13 days) presented both impaired discriminative performance and locomotor alterations. Overall, these results indicate that Ayahuasca is a potent psychoactive drug that, in chronic exposure, negatively affects mnemonic parameters in zebrafish. In single exposure it does not affects cognitive performance, but the higher concentration (0.5) affected locomotion. Moreover, we reinforce the importance of the zebrafish for behavioral pharmacological studies of drug screening, in special to psychedelic drug research. [ABSTRACT FROM AUTHOR]

Abstract. The newly circumscribed group Palicourea Aubl. sect. Egenses C. M. Taylor includes 13 species found in South America in the Amazon and Orinoco basins, the Guayana Highlands, northwestern Venezuela, and the central Andes, often on nutrient-poor (oligotrophic) soils, and is diagnosed by features of its leaves, inflorescences, and fruits. Its species are separated mainly by details of stipules, inflorescence arrangement, bracts, and flower and fruit size, as outlined in a key, and have different ranges and some unusual morphological features as detailed for each. Newly published here are the combination P. moyobambana (Standl.) C. M. Taylor, the new species P. articulata C. M. Taylor from southeastern Colombia and P. flagellifera C. M. Taylor from Amazonian Colombia, and the new subspecies P. egensis subsp. zuliana C. M. Taylor from northwestern Venezuela. [ABSTRACT FROM AUTHOR]

Psychotria L. subg. Heteropsychotria Steyerm. (Rubiaceae) has been shown by morphological and molecular analyses to be polyphyletic. Most of its species, including its type, belong to Palicourea Aubl. Some of its species have previously been transferred to Palicourea, and several more are studied and transferred here. The species studied here are classified in a newly circumscribed group that includes the type of Palicourea sect. Bracteiflorae Borhidi and so takes that name but differs in circumscription from it. This new circumscription of Palicourea sect. Bracteiflorae includes 51 species of shrubs and small trees found in wet vegetation from southern Mexico and the Antilles to Brazil and Bolivia, and is diagnosed by a combination of stipule, inflorescence, and fruit characters. Its center of diversity is now in the Andean region. Twelve previously described species are newly transferred to Palicourea here, and analysis here clarifies the identity and circumscription of several of these. The 23 species newly described here are documented from Colombia, Ecuador, and Peru. The replacement name Palicourea palenquensis C. M. Taylor is published for the species originally described as Cephaelis gentryi Dwyer. The newly described section Palicourea sect. Egenses C. M. Taylor includes the species of Palicourea sect. Bracteiflorae sensu Borhidi that are excluded from the present circumscription of that section. [ABSTRACT FROM AUTHOR]

Objective: Various traditional systems of medicine enlightened the importance of Psychotria rubra (Lour.) Poir to have a great medicinal value. The present study was carried out to provide a scientific basis of the identification and the authenticity of Psychotria rubra (Lour.) Poir with the help of pharmacognostic parameters, which is not done before. Methods: Roots, stems, and leaves of P. rubra were collected for Pharmacognostic studies involving macros, microscopic evaluation, histochemistry and physicochemical parameters analysis like Ash value, Moisture content, Fluorescence analysis and Thin Layer Chromatography et al. Results: Transverse section of root was found like stone cells, calcium oxalate crystal and vessels in circular shape. Transverse section of stem showed the presence of lenticels and stone cell bands. Transverse section of leaf vein revealed the presence of shaft type of porosity. Powder microscopy revealed the presence of cork cells, stone cells, crystals and resin, fibers, needle crystal beam, thread tracheid and scalariform tracheid. Phytochemical investigation was found like alkaloids, flavones, carbohydrates, saponins, tannins and volatile oils. Results obtained in physicochemical parameters like Total ash value, acid insoluble ash and moisture content were 9.77%, 0.68% and 1.28%, respectively. The leaching degree of P. rubra was higher in ethanol(75%, v/v) and methanol solutions than that in chloroform, petroleum ether, and tetrachloromethane solutions. Thin Layer Chromatography (TLC) of the extract revealed 4 spots with the Rf values 0.47, 0.46, 0.46, 0.47 with the solvent system of chloroform: methanol: water: formic acid(7:3:1:0.1). Conclusion: The observations confirmed that P. rubra has an obvious Pharmacognostic characteristics, which will be useful towards providing a reliable basis for identification, purity, quality and classification of the plant. [ABSTRACT FROM AUTHOR]

The prominent but complex genus Psychotria (Rubiaceae: Psychotrieae) is one of the largest genera of flowering plants and its generic circumscription has been controversial for a long time. Recent DNA-phylogenetic studies in combination with a re-evaluation of morphological characters have led to a disintegration process that peaked in the segregation of hundreds of species into various genera within the new sister tribe Palicoureeae. These studies have also shown that species of Psychotria subg. Heteropsychotria are nested within Palicourea, which was traditionally separated by showing an ornithophilous (vs. entomophilous) pollination syndrome. In order to render the genera Palicourea and Psychotria monophyletic groups, all species of subg. Heteropsychotria have to be transferred to Palicourea and various authors and publications have provided some of the necessary combinations. In the course of ongoing research on biotic interactions and chemodiversity of the latter genus, the need for a comprehensive and modern compilation of species of Palicourea in its new circumscription became apparent. As first step towards such a synopsis, the entomophilous Mexican and Central American species (the traditional concept of Psychotria subg. Heteropsychotria) are covered here. These are enumerated and synonyms as well as an annotated list of type specimens are given. In addition, the new combination Palicourea croceovenosa (Dwyer) A.C. Berger is provided and a number of lectotypifications are made. [ABSTRACT FROM AUTHOR]

Distyly is usually rare or not observed in species thriving on oceanic islands. The rarity of this breeding system is probably because of the difficulty of colonization for distylous plants and the paucity of pollinators on oceanic islands. However, the endemic and endangered tree Psychotria homalosperma has maintained its distylous nature in the oceanic Bonin Islands, Japan. To understand how the distylous breeding system of P. homalosperma has been maintained on these islands and to characterize the reproduction systems, we studied the pollination and reproductive biology of this species. Specifically, we observed current flower visitors and estimated their effects on plant reproduction. We also examined the floral traits and floral volatiles of P. homalosperma to infer its original pollinators, because plant-pollinator relationships in the Bonin Islands have recently been disrupted by anthropological activities. Finally, we examined the fruit set and pollen tube growth in the stigmas under hand and open pollination. Although original pollinators were presumed to be moths with long proboscises, the introduced honeybee, Apis mellifera, was the most common flower visitor. The honeybee carried pollen grains only unidirectionally, from the short- to long-styled morphs, because it could not reach the hidden stigmas of the short-styled flowers, and long-styled flowers set fruits 1.7-38 times more than short-styled ones. This case study indicates that the instability of pollinator fauna can cause distylous species to be rare on oceanic islands. [ABSTRACT FROM AUTHOR]