The efficiency of Raphia hookeri adsorbent in indigo carmine dye removal: Economy depth via chemometrics.

The remediation of dye pollutants remains a concern in contemporary water management practices. Hence, the need for efficient and cost-effective techniques for dye removal from wastewater. In this study, the epicarp of Raphia hookeri fruits was treated with orthophosphoric acid for enhanced porosity and efficiency in the uptake of Indigo carmine dye (ICD). Treated Raphia hookeri fruit waste (RHPW) presented morphologically distributed pores as well as high porosity with Branneur-Emmet-Teller (BET) surface area of 945.43 m2/g. RHPW displayed functional groups suitable for adsorption. The maximum ICD uptake was observed at pH 5 while the maximum uptake (qmax) was 20.41 mg/g in the concentration range of 2-10 mg/L. Freundlich isotherm and Pseudo-second order kinetics well-described equilibrium and kinetics data respectively. This indicated a multilayered adsorption. The Dubinin-Radushkecich model energy value was 40.82 kJ/mol, indicating chemical adsorption. The ridge regression, the Lasso and the Elastic net statistical models were used to establish a positive relationship between the various adsorption operational parameters studied. Lasso provided the best result based on the estimated mean squared error. The RHPW-ICD adsorption system was more favorable at room temperature, as the removal efficiency decreased with temperature rise. The findings established Raphia hookeri fruit epicarp as an economical and sustainable precursor for the preparation of potent adsorbent for Indigo carmine dye removal. This can find possible application in wastewater treatment.

Effect of Chemical Treatment and Length of Raffia Fiber (Raphia vinifera) on Mechanical Stiffening of Polyester Composites.

In recent decades, the unique characteristics of natural fibers have promoted their use as reinforcement in polymeric composites. This is verified in several industrial sectors, from packaging to automotive and civil construction. Among the natural fibers, the raffia fiber extracted from the palm tree Raphia vinifera and introduced in the Amazon region a long time ago; started to be considered for the production of polymeric composites only in recent years. For the first time, the effect of raffia fiber length and its alkali treatment on the mechanical properties of a polymer composite was disclosed. Tensile tests were performed in composites with raffia fibers randomly dispersed into terephthalate-based unsaturated polyester resin. The results showed an increase in the Young's moduli, confirmed by ANOVA, for the composite with both untreated and alkali-treated fibers in comparison to the plain polyester, which characterizes a stiffening effect. The composites with alkali treated fibers exhibited similar tensile strength values for all lengths; however, their strengths are lower than those for the untreated condition due to a weak raffia fiber/polyester matrix adhesion. Therefore, this work fills the current knowledge gap on raffia fiber incorporation in polyester matrix and valorizes this abundant Brazilian resource, providing additional information towards the use of raffia fiber in polymer composites.

Steroidal saponins from Raphia vinifera and their cytotoxic activity.

Phytochemical analysis of the fruits of Raphia vinifera led to the isolation of four new steroidal saponins (1-4), along with six known secondary metabolites (6-10). The structures of the isolated compounds were determined based on the analyses of NMR and mass spectrometric data, and chemical degradation reactions. Among the compounds tested, 1 and 4 showed the most promising cytotoxic activity against the drug-sensitive CCRF-CEM leukemia cell lines, with IC50 values of 3.55 µM and 7.14 µM, respectively.

Microwave-assisted urea modified crop residue in Cu2+ scavenging.

Raphia hookeri fruit epicarp (RHFE) was used in a novel adsorbent preparation via a combination of urea modification and microwave irradiation. The prepared adsorbent (URHFE) was characterized physicochemically, spectroscopically and microscopically characterized. URHFE efficiency in Cu2+ scavenging was tested with focus on operational parameters such as pH, dosage, concentration, contact time, ionic strength and temperature. Adsorption data were tested with isotherms and kinetics models. Optimum adsorption occurred at pH of 5.5. The presence of competing ion decreased Cu2+ removal and this varied with competing ion concentration. Cu2+ uptake decreased with increase in temperature. Percentage desorption was found generally low. The Langmuir monolayer adsorption capacity (qmax) was obtained to be 144.93 mg/g, this compared well in effectiveness with other adsorbent previously reported. Dubinin Radushkevich (D-R) isotherm model suggests that adsorption mechanism was chemical in nature. Pseudo second order kinetics best described the adsorption kinetics while multilinear adsorption was observed from the intraparticle diffusion model.

Unraveling the Phylogenomic Relationships of the Most Diverse African Palm Genus Raphia (Calamoideae, Arecaceae).

Palms are conspicuous floristic elements across the tropics. In continental Africa, even though there are less than 70 documented species, they are omnipresent across the tropical landscape. The genus Raphia has 20 accepted species in Africa and one species endemic to the Neotropics. It is the most economically important genus of African palms with most of its species producing food and construction material. Raphia is divided into five sections based on inflorescence morphology. Nevertheless, the taxonomy of Raphia is problematic with no intra-generic phylogenetic study available. We present a phylogenetic study of the genus using a targeted exon capture approach sequencing of 56 individuals representing 18 out of the 21 species. Our results recovered five well supported clades within the genus. Three sections correspond to those based on inflorescence morphology. R. regalis is strongly supported as sister to all other Raphia species and is placed into a newly described section: Erectae. Overall, morphological based identifications agreed well with our phylogenetic analyses, with 12 species recovered as monophyletic based on our sampling. Species delimitation analyses recovered 17 or 23 species depending on the confidence level used. Species delimitation is especially problematic in the Raphiate and Temulentae sections. In addition, our clustering analysis using SNP data suggested that individual clusters matched geographic distribution. The Neotropical species R. taedigera is supported as a distinct species, rejecting the hypothesis of a recent introduction into South America. Our analyses support the hypothesis that the Raphia individuals from Madagascar are potentially a distinct species different from the widely distributed R. farinifera. In conclusion, our results support the infra generic classification of Raphia based on inflorescence morphology, which is shown to be phylogenetically useful. Classification and species delimitation within sections remains problematic even with our phylogenomic approach. Certain widely distributed species could potentially contain cryptic species. More in-depth studies should be undertaken using morphometrics, increased sampling, and more variable markers. Our study provides a robust phylogenomic framework that enables further investigation on the biogeographic history, morphological evolution, and other eco-evolutionary aspects of this charismatic, socially, and economically important palm genus.

Evaluation of vegetation communities, water table, and peat composition as drivers of greenhouse gas emissions in lowland tropical peatlands.

Tropical peatlands are globally important source of greenhouse gases to the atmosphere, but data on carbon fluxes from these ecosystems is limited due to the logistical challenges of measuring gas fluxes in these ecosystems. Proposals to overcome the difficulties of measuring gas carbon fluxes in the tropics include remote sensing (top-down) approaches. However, these require information on the effect of vegetation communities on carbon dioxide (CO2) and methane (CH4) fluxes from the peat surface (bottom-up). Such information will help reducing the uncertainty in current carbon budgets and resolve inconsistencies between the top-down and bottom-up estimates of gas fluxes from tropical peatlands. We investigated temporal and spatial variability of CO2 and CH4 fluxes from tropical peatlands inhabited by two contrasting vegetation communities (i.e., mixed forest and palm swamp) in Panama. In addition, we explored the influence of peat chemistry and nutrient status (i.e., factorial nitrogen (N) and phosphorus (P) addition) on greenhouse gas fluxes from the peat surface. We found that: i) CO2 and CH4 fluxes were not significantly different between the two vegetation communities, but did vary temporally across an annual cycle; ii) precipitation rates and peat temperature were poor predictors of CO2 and CH4 fluxes; iii) nitrogen addition increased CH4 fluxes at the mixed forests when the water table was above the peat surface, but neither nitrogen nor phosphorus affected gas fluxes elsewhere; iv) gas fluxes varied significantly with the water table level, with CO2 flux being 80% greater at low water table, and CH4 fluxes being 81% higher with the water table above the surface. Taken together, our data suggested that water table is the most important control of greenhouse gas emissions from the peat surface in forested lowland tropical peatlands, and that neither the presence of distinct vegetation communities nor the addition of nutrients outweigh such control.

Aphrodisiac property of aqueous and methanolic extracts of Raphia vinifera (Arecaceae) in sexually experienced male rats.

BACKGROUND: Raphia vinifera (Arecaceae) is a medicinal plant commonly used as a sexual enhancer. OBJECTIVE: To investigate the aphrodisiac potential of aqueous extract (AE) and methanolic extract (ME) of R. vinifera in sexually experienced male rats. MATERIALS AND METHODS: Thirty male Wistar rats were randomly distributed into six groups (5 rats per group) and administered for 14 days with distilled water (10 ml/kg), sildenafil citrate (1.44 mg/kg), and AE or ME of R. vinifera (100 or 500 mg/kg). The copulatory activity was tested on days 0, 7, and 14 using receptive females. Further, on day 14, rats were sacrificed and biochemical analyses (testosterone, total protein, and acid phosphatase) were performed. RESULTS: Sildenafil citrate significantly decreased the intromission latency (day 14, p = 0.04) and frequency (days 7 and 14, p = 0.03) but increased the mount frequency (day 14, p = 0.04), compared with control. Remarkably, R. vinifera enhanced the sexual activity by significantly decreasing the intromission latency (AE and ME, 500 mg/kg, day 14, p = 0.04) and increasing the mount frequency (AE and ME, 100 mg/kg, day 7, p = 0.02) compared with control. Moreover, R. vinifera improved plasmatic (AE, 100 mg/kg, p = 0.03; AE, 500 mg/kg, p = 0.001; ME, 100 mg/kg, p = 0.01) and testicular (AE, 100 mg/kg, p = 0.001; AE, 500 mg/kg, p = 0.01; ME, 100 mg/kg, p = 0.001; ME, 500 mg/kg, p = 0.01) testosterone levels as well as plasmatic total proteins concentration (ME, 500 mg/kg, p = 0.04). CONCLUSION: These findings showed that R. vinifera possesses an aphrodisiac property which could further justify its folkloric use in traditional medicine as a sexual enhancer.

Raphia vinifera (Arecaceae; Calamoideae): Misidentified for far too long.

BACKGROUND: The genus Raphia (Arecaceae/Palmae) is the most economically and culturally important genus of African palms. With over 20 recognized species, it is also the most diversified among tropical African palms. However, significant taxonomic confusion still persists in the genus. Raphia vinifera P.Beauv. is one of the first two names described in the genus, but the species has been misidentified and confused for several decades. NEW INFORMATION: We clarify the taxonomic identity of R. vinifera. We retrace the taxonomic history of the name and clarify its morphological identity using the literature and type material. We synonymize the name R. mambillensis with R. vinifera. We provide a new detailed morphological description of R. vinifera based on the study of herbarium material and field data. A distribution map is also provided. Raphia vinifera is still incompletely known, and more research should be undertaken on this species' presence and ecology, especially in West Africa.

Diversity and enzymatic profiles of indigenous yeasts isolated from three types of palm wines produced in Côte d'Ivoire.

AIMS: To investigate the genotypic diversity and enzymatic activity of yeast flora isolated from spontaneous fermenting saps of various palm trees (Borassus aethiopum, Raphia hookeri, Elaeis guineensis) tapped for palm wines. METHODS AND RESULTS: PCR-restriction fragment length polymorphism of ITS-5.8S rDNA combined to 26S rRNA gene and/or the partial ACT1 gene sequencing were applied for yeast characterization, and their enzymatic profiles assessed by using API ZYM kits. Thirteen genera and 23 species were identified, with the highest diversity (14 species) in raffia wine. Saccharomyces cerevisiae was dominant and common to all palm wines. Some potentially pathogenic yeasts were also isolated. The majority of tested strains displayed high amylo-peptidase, phosphatase, ß-glucosidase and α-glucosidase activities and esterase activity. CONCLUSIONS: Diverse yeast species colonized palm wines, among which some were related to a specific type of wine and the majority of them have the ability to digest starch, sugar, protein or lipid. SIGNIFICANCE AND IMPACT OF THE STUDY: This study is a first step in understanding the significance of indigenous yeast flora of palm wines from Côte d'Ivoire. This knowledge is important as a tool for establishing new indigenous yeast collection; which could be used for the product quality improvement and as enzyme sources for biotechnological purposes.

Screening for gum-producing Lactic acid bacteria in Oil palm (Elaeis guineensis) and raphia palm (Raphia regalis) sap from South-West Nigeria.

Lactic acid bacteria have wide applications in food processing. Lactic acid bacteria produced exopolysaccharides (EPS) which could be used as possible replacer for commercial stabilizer and thickeners produced by nonfood grade bacteria. Seventy-two samples of Oil and Raphia palm sap were collected in eighteen locations across South-Western Nigeria and screened for exopolysaccharide production in 6% sucrose agar using streaked plate method. Four hundred EPS-producing bacteria (EPB) isolated were clustered based on morphological characteristics into two broad groups and preliminary screened for EPS-producing capacity. Twenty representative of EPB were selected from the broad groups for tentative identification by API 50CHL and 10 high yielding EPB were selected for large-scale EPS production. Each strain was inoculated into 6% sucrose broth with 3% (v/v) preculture grown overnight in a 1.5 ml flask and incubated at 37°C for 72 hr. The EPSs were purified and freeze-dried prior to quantification of yields. EPS-producing bacteria were identified as Leuconostoc lactis, Lactobacillus fermentum, Lactobacillus delbrueckii ssp. lactis, L. delbrueckii ssp. delbrueckii, Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus crispatus, and Leuconostoc mesenteroides ssp. mesenteroides/dextranicum. EPS yield ranged from 132-810.75 mg/L and EPS-producing potential of lactic acid bacteria (LAB) strains ranged; 36% (132-245 mg/L), 36% (250-460 mg/L), and 28% (461-820 mg/L). L. plantarum had the highest EPS yield of 810.75 mg/L whereas L. crispatus had the least yield 242.5 mg/L. These results suggest that majority of LAB in palm wine saps are gum-producing bacteria. Leuconostoc and Lactobacillus were the most abundant LAB found in this study while L. plantarum could have applications as potential starter cultures for the production of exopolysaccharides (EPS) at industrial level.

Two new species of Raphia (Palmae/Arecaceae) from Cameroon and Gabon.

Raphia (Arecaceae, Calamoideae) is the most diverse genus of African palms with around 20 species. Two new species from Cameroon and Gabon, Raphiagabonica Mogue, Sonké & Couvreur, sp. nov. and Raphiazamiana Mogue, Sonké & Couvreur, sp. nov. are described and illustrated. Their affinities are discussed and the conservation status of each species is assessed. For both species, distribution maps are provided. Raphiagabonica is restricted to two small populations from central Gabon, where it occurs on hillsides on tierra firme soil, and close to small streams. Its preliminary IUCN status is Endangered, being amongst the five most threatened palm species in Africa. Raphiagabonica potentially belongs to the moniliform section. Raphiazamiana is largely distributed from south Cameroon to south Gabon and is very common. It is also a multi-used palm, from which wine, grubs and construction material are extracted and sold. It generally occurs in large stands in a wide range of ecosystems such as swamps, coastal forests on partially inundated sandy soils and inundated savannahs. Its large stature, hard to access habitat (swamps) and abundant presence might have discouraged botanists to collect it until now. Raphiazamiana belongs to the taxonomically complex raphiate section.

Evaluation of the chemical composition of Dacryodes edulis and Raphia hookeri Mann and Wendl exudates used in herbal medicine in south eastern Nigeria.

The phytochemical contents and medicinal values of Dacroydes edulis and Raphia hookeri exudates were investigated. Phytochemical screening of the plant showed that they contain the presence of bioactive compounds comprising saponins (2.08-3.98 mg 100 g(-1)), alkaloids (0.28-0.49 mg 100 g(-1)), tannins (0.47-0.72 mg 100 g(-1)), flavonoids (0.26-0.39 mg 100 g(-1)), and phenolic compounds (0.01-0.05 mg 100 g(-1)). The carbohydrates, lipids and protein content were 77.42-78.90%, 2.02-4.185% and 16.63-18.38% respectively. The exudates are a good source of water soluble vitamins; ascorbic acid (7.04-26.40 mg 100 g(-1)), niacin (3.12-4.00 mg 100 g(-1)), riboflavin (0.14-0.54 mg 100 g(-1)) and thiamine (0.15-0.22 mg 100 g(-1)). Both plants exudates are good sources of minerals such as Ca, Mg, P, Fe, Zn, Cu and Mn while Cr and Co were trace. These results indicate that exudates can be potential sources of feedstock for the pharmaceutical industry.