Fraction Of Latex Research Articles

LATEX AGGLOMERATION AND COAGULATION IN LATICIFERS OF LIVE TARAXACUM KOK-SAGHYZ (RUBBER DANDELION) ROOTS

ABSTRACT The commercialization of Taraxacum kok-saghyz (rubber dandelion) as an alternative rubber crop requires fundamental knowledge of latex, an aqueous suspension of rubber particles, and rubber yield and quality. Rubber particles are formed in the root laticifers from Golgi bodies via the vesicular trafficking system in the cytosol and are then translocated into the vacuoles for storage. However, when freshly harvested roots are processed to extract the latex, much of the latex has already coagulated into solid rubber, reducing the commercial viability of latex extraction from this species. The process of in vivo loss of the latex fraction was investigated histologically, by transmission electron microscopy, in roots of plants grown in soil or hydroponically. In both root types, some rubber particles agglomerated in the cytosol as a precursor to coagulation. Other rubber particles agglomerated and then coagulated after rubber particles were translocated into vacuoles, and also after the cell internal cytoplasmic structure degraded. Uniquely large rubber particles were formed in the vacuoles of hydroponically grown plants by particle coalescence, but were not found in soil-grown roots. Eventually, some root laticifers of both root types filled with solid rubber. The instability of the aqueous latex phase postontogeny through rubber particle agglomeration, coalescence, and coagulation suggests that commercial processes likely would involve root drying to convert residual latex into solid rubber followed by aqueous- or solvent-based extraction.

Stratified and gradient films by evaporation-induced stratification of bimodal latexes. Potential of confocal and scanning electron microscopy for compositional depth profiling

In the field of bimodal latex film's formation, finding methods to quantify particle concentration profiles within the film thickness is a challenge. Herein the advantages and limitations of confocal fluorescence microscopy (CFM) and scanning electron microscopy (SEM) are presented. Films are prepared from a bimodal fluorescent acrylic mixture of large non-deformable particles and small deformable particles having high Péclet numbers. A fixed volume fraction of large particles (ΦL) in the dispersion is used with increasing volume fractions of small particles latex (ΦS). At low ΦS, a surface stratification of large particles occurs with thicknesses up to several micrometers, allowing detection by both CFM and SEM. Small particles form a stratified surface layer above a threshold ΦS value. Its thickness of less than 500 nm is evidenced only by SEM due to the resolution limit of the confocal scan. SEM is also able to reveal concentration gradients of large particles below the “small-on-top” stratified layer.

Strength and Durability of Recycled Concrete Strengthened with Steel Fibers and Styrene Butadiene Rubber Latex

Demolition of any structure is costly, and simultaneously there is non-accessibility of land or disposal sites in nearby areas. Recycling such demolished concrete material and converting it into an appropriate size of aggregates can be further used for the following construction cycle. Prior exploration showed utilization of Steel Fibers (SF) and Styrene Butadiene Rubber (SBR) latex in Recycled Concrete (RC) independently for various strength and durability improvements. This experimental work cast RC as M25 & M40 grade to satisfy reinforced concrete and rigid concrete pavement concrete demand. Total 132 cubes, 198 cylinders, and 198 beams of Normal Concrete (NC), RC, and RC reinforced by SF with SBR latex cast and termed as Polymer Modified Steel Fiber Reinforced Recycled Concrete (PMSFRRC). The objective was to evaluate the properties due to SF and SBR latex blending and obtaining the optimum dosages of SF and SBR latex. A strength and durability study was carried out to find out cube compressive strength, indirect tensile strength, flexural strength, chloride attack, and sulfate attack. The concrete was modified with the SBR latex dosage range of 2.5% –7.5% by cement weight. SF was added as 0.5% – 1.5% by concrete mix volume at the average length of 25 mm and 0.5 mm in diameter. Experimental findings of PMSFRRC for grade M25 with SF 1% volume fraction of concrete and SBR latex 5% of cement weight improve NC in indirect tensile strength by 9.93% and 8.58%, flexural strength by 10.01% and 8.99% at 28 and 91 days, respectively. Similarly, there was an enhancement in indirect tensile strength by 13.18 % and 11.11 % and flexural strength by 12.88 % and 10.78 % at 28 and 91 days, respectively, for PMSFRRC of grade M40 compared to NC. Durability analysis shows that a combined dosage of SF 1.5% volume of concrete mix and SBR latex 7.5% of cement weight seemed to be excellent concrete additives for good resistance to acid and sulfate attack for both mixtures. The results exhibited improved hardened properties of modified concrete due to the combined addition of SF and SBR latex, improved cracking resistance, flexure resistance, and reduced acid and sulfate attack rate into the specimens. The study also demonstrated an effective way of preparing sustainable concrete with SF and SBR latex to improve strength and durability.

Lysozymes from natural rubber latex (Hevea brasiliensis): Assay development and recovery using ammonium sulphate and surfactant precipitations

To date, the C-serum and the bottom fraction of natural rubber latex (NRL) are still generally being considered as waste. However, they are rich sources of lysozyme, which is a bacteriolytic enzyme that has huge potential for biotechnological exploitations. So far, there are no reports on lysozyme recovery for the valorisation of NRL by-products. Therefore, this study aimed to (1) develop and validate a lysozyme assay based on the lysoplate method using the cloudy NRL sample and Micrococcus lysodeikticus cells and (2) recover lysozyme from the NRL fractions using ammonium sulphate ([NH4]2SO4) precipitation (direct and fractional modes) and the novel sodium di-(2-ethylhexyl) sulfosuccinate (AOT) surfactant precipitation. The assay developed in this study was high in both accuracy (97.54%) and precision (13.61% relative standard deviation). The detection and quantification limits, as well as the linearity range of the assay were 0.13 U/mL, 0.04 U/mL and 0-10,445.40 U/mL, respectively. As for the lysozyme recovery from the C-serum of NRL, the performance of the AOT precipitation via negative mode (activity recovery [AR] = 67.29%; purification factor [PF] = 2.42) was comparable (p > 0.05) to that of (NH4)2SO4 precipitation (direct mode: AR = 88.44%, PF = 2.18; fractional mode: AR = 95.44%, PF = 3.05). Meanwhile, for the lysozyme recovery from the bottom fraction of NRL, the AOT precipitation (AR = 71.94%; PF = 1.73) was shown to be superior than (NH4)2SO4 precipitation (direct mode: AR = 25.68%, PF = 3.23; fractional mode: AR = 27.88%, PF = 12.87). Hence, considering its effectiveness, simplicity, rapidity, as well as its great potential to be integrated with rubber product manufacturing, the AOT precipitation is an attractive alternative recovery method for lysozyme recovery from NRL. The findings described herein are significant for the development of a downstream processing scheme for lysozyme recovery from NRL.

Natural latex serum: characterization and biocompatibility assessment using Galleria mellonella as an alternative in vivo model

Natural latex serum (NLS) is one of the natural rubber latex fractions from Hevea brasiliensis tree, which is formed by centrifuged serum and is composed of proteins, acids, nucleotides, salts and carbohydrates. The proteins present in NLS have demonstrated several interesting biological properties, including angiogenic, healing, osteogenic, anti-inflammatory, antimicrobial, in addition to inducing neovascularization, bone formation and osseointegration. Thus, we proposed to characterize NLS by physicochemical techniques and to investigate the biocompatibility by toxicological assays and safety test in Galleria mellonella. Infrared spectrum showed vibrational bands characteristic of amide I, II and III that are linked to the protein content, which was confirmed by the High Performance Liquid Chromatography profile and by the Electrophoresis analysis. This material did not exhibit hemolytic (rate <0.5%) and cytotoxic effects (viability >70%) and was able to enhance the proliferation of fibroblasts (>600%) after 3 days. The pronounced proliferative effect observed in fibroblast cells can be explained by the presence of the fibroblast growth factor (FGF) like protein revealed by the Western blot test. Moreover, NLS did not provoke toxic effects (survival ∼ 80%) on the G. mellonella model, indicating that it is a biocompatible and safe material.

Combined Protein and Alkaloid Research of Chelidonium majus Latex Reveals CmMLP1 Accompanied by Alkaloids with Cytotoxic Potential to Human Cervical Carcinoma Cells.

Chelidonium majus L. is a latex-bearing plant used in traditional folk medicine to treat human papillomavirus (HPV)-caused warts, papillae, and condylomas. Its latex and extracts are rich in many low-molecular compounds and proteins, but there is little or no information on their potential interaction. We describe the isolation and identification of a novel major latex protein (CmMLP1) composed of 147 amino acids and present a model of its structure containing a conserved hydrophobic cavity with high affinity to berberine, 8-hydroxycheleritrine, and dihydroberberine. CmMLP1 and the accompanying three alkaloids were present in the eluted chromatographic fractions of latex. They decreased in vitro viability of human cervical cancer cells (HPV-negative and HPV-positive). We combined, for the first time, research on macromolecular and low-molecular-weight compounds of latex-bearing plants in contrast to other studies that investigated proteins and alkaloids separately. The observed interaction between latex protein and alkaloids may influence our knowledge on plant defense. The proposed toolbox may help in further understanding of plant disease resistance and in pharmacological research.

Potential enzyme inhibitory properties of extracts and fractions from fruit latex of Ficus carica-based on inhibition of α-amylase and α-glucosidase

Ficus L. is one of the widespread genera of the Moraceae family. We aimed to evaluate the inhibiting effect on digestive enzymes linked to diabetes, the antioxidant activity and the phytochemical composition of active extract/fraction of fruit latex of Ficus carica L. subsp. carica (All.) Schinz Et Thel. The inhibition effect of extracts and fractions tested with α-amylase and α-glucosidase methods and the antioxidant effect investigated with ABTS·+ and FRAP tests. The qualitative determination of compounds within the active extract/fraction was carried out by LC–MS/MS. In a result, the highest α-amylase and α-glucosidase activity found in F2 fraction of fruit latex (IC50 = 195.205 ± 0.015 µg/mL and 6.920 ± 0.026 µg/mL, respectively). Moreover, the highest total phenolic (26.816 ± 0.007 mgGAE/gextract) and total flavonoid content (8.615 ± 0.009 mgCA /gextract) was found in S1extract and this extract showed the highest antioxidant activity on FRAP (at a concentration of 1 mg/mL equivalent to 179.802 ± 2.201 mmol Fe2+) and ABTS+· (at a concentration of 1 mg/mL equivalent to 0.296 ± 0.055 µM Trolox) tests. Besides that, a preliminary examination of the mass spectrums of active F2 fraction and S1 extract revealed the presence of one xanthone, one organic acid derivative, one chromone derivative, one fatty acid and one phenolic acid. It is the first report on α-amylase, α-glucosidase and antioxidant activities, and phytochemical analysis of fruit latex of F. carica subsp. carica and these studies could contribute to the advanced pharmacological activity studies of this species.

Effects of natural rubber latex fraction to glycidyl methacrylate on grafting polymerization and its application as Th4+ and UO2 2+ ions bio adsorbent

Natural rubber (NR) latex was modified by in situ gamma radiation-induced grafting copolymerization of glycidyl methacrylate (GMA). NR latex to GMA emulsion ratio of 100:0, 50:50, 40:60, 30:70 and 20:80 have been investigated at the absorbed dose of 150kGy. The grafted GMA natural rubber-based follow the subsequent chemical modification to anchor phosphate group by open up the epoxy ring. The modified NR was characterized by Fourier transform infrared. Demonstration of modified NR on Th4+ and UO2 2+ ions adsorption in 25ml of 10ppm standard solution gave 95% and 28% percentage removal respectively.

Antimicrobial Evaluation of Latex and TLC Fractions from the Leaves of Aloe adigratana Reynolds.

Background The highest prevalence and emergence of microbial infections coupled with the threat of antimicrobial resistance constitute a global concern, which entails searching for novel antimicrobial agents. Medicinal plants are among the major sources of medicines for novel drug discovery. Aloe adigratana is one of the endemic Aloe species in Ethiopia where the leaf latex of the plant is traditionally used for the treatment of various pathogenic conditions such as wound, dandruff, malaria, and diabetes. In spite of such claims, there was no scientific study done so far. The aim of the current study was, therefore, to evaluate the antimicrobial effect of leaf latex of A. adigratana and its thin layer chromatography (TLC) fractions. Methods Thin layer chromatography (TLC) separation was employed for isolation of bioactive compounds. Agar well diffusion and microdilution assay method were used to evaluate the antimicrobial actions of the leaf latex and TLC fractions against six bacterial strains and four Candida species of reference and clinical isolate microbial strains. Results Three major fractions, AA01, AA02, and AA03, were identified by TLC. Among the tested microbial strains, the reference strain of Staphylococcus aureus ATCC 29213 (MIC = 0.06 mg/mL) and clinical Candida krusei 242/18 (MIC = 0.14 mg/mL) exhibited higher susceptibility towards AA02, while reference strains of Klebsiella pneumoniae ATCC 700603 (MIC = 0.19 mg/mL) revealed the highest susceptibility towards AA01. The leaf latex displayed the highest activity against Staphylococcus aureus ATCC 29213 and clinical Candida krusei 242/18 with a MIC value of 0.19 mg/mL. Conclusion The leaf latex and TLC fractions were found to be active against the tested bacterial and Candida species. Therefore, this finding supports the traditional claim of Aloe adigratana and the need for characterization of the TLC fractions to provide as lead compounds for further comprehensive antibacterial and antifungal activities.

Hancornia speciosa serum fraction latex stimulates the angiogenesis and extracellular matrix remodeling processes.

The Hancornia speciosa latex reveals angiogenic, osteogenic, and anti-inflammatory properties, which present its potential for developing of wound healing drugs; however, the latex compounds responsible for angiogenesis remain unknown. One strategy to screen these active compounds is evaluation of latex fractions. This study aimed to obtain different fractions of latex and evaluate its angiogenic activity separately using the chick chorioallantoic membrane (CAM) assay. The serum (SE) fraction was responsible for angiogenesis, which was subject to biochemical characterization and computational simulations in order to understand the contribution of H. speciosa latex in wound healing process. Our results revealed weak antioxidant potential and absence of antimicrobial activity in the SE fraction. Phytochemical analysis identified chlorogenic acids (CGA) as the main compound of SE fraction. CGA bioactivity predictions identify different molecules associated with extracellular matrix (ECM) remodeling, such as metalloproteinases, which also are overexpressed in our CAM assay experiment. Docking simulations revealed the interactions between CGA and matrix metalloproteinase 2. In conclusion, SE latex fraction stimulates angiogenesis and may influence ECM remodeling. These properties may contribute to the wound healing process, and also confirm the widespread use of this plant.

The wound healing action of a cream latex formulation of Jatropha gaumeri Greenm. in a pre-clinical model.

Background and Aim:Jatropha gaumeri Greenm. is commonly used to treat mouth blisters and skin rashes, its latex has analgesic and anti-inflammatory activity on buccal ulcer. This study aimed to demonstrate the wound healing activity of a cream formulation of Jatropha gaumeri Greenm. latex in a murine model, provide a histological assessment of its scarring effects, and identify the family of phytochemicals involved in these effects.Materials and Methods:Latex was obtained from the cut stalk leaves and young stems of J. gaumeri and stored in sterile tubes with protection from light. Chloroform, ethyl acetate, and aqueous fractions of the latex were obtained. Fifty male Balb/c mice aged 10-12 weeks were divided into10 groups of five mice: Group 1 corresponded to healthy mice with wounds; Group 2 corresponded to mice with wounds and treated with A-Derma®; and from Group 3 to group 10 corresponded to mice treated with a different latex fraction. A circular skin wound of about 1 cm was made on the paravertebral region of each mouse under anesthetized and aseptic conditions. The wounds were topically treated every 24 h with the respective extracts for 22 days, after which skin tissue specimens were obtained and stained with hematoxylin-eosin and Masson’s trichrome. The efficiency of healing was measured by quantifying the tensile strength of the scars. The phytochemicals in the latex were elucidated using thin chromatography.Results:The aqueous latex fraction produced the best wound healing activity and was superior to the positive control. Reepithelialization at the histological level resulted in tissue that resembled healthy skin in terms of the appearance of collagen, the regeneration of hair follicles, and cellularity of the dermis, which showed organized epithelialization. A wound healing efficacy of 97% was observed, and it seems that alkaloids were the phytochemicals mostly likely responsible for these effects.Conclusion:J. gaumeri latex exhibited wound healing activity, possibly mediated by phytochemicals such as alkaloids in the aqueous fraction.

Ficus Carica L. Latex: Possible Chemo-Preventive, Apoptotic Activity and Safety Assessment.

Hepatocellular carcinoma is the third cause of cancer-related mortality with the low 5-year survival in which more than 50 percent of patients have recurrent cancer within 2 years of treatment. The present study investigated the cytotoxicity and lethal dose of Ficus carica L. (Figure) latex and phytochemical composition of effective fraction. Figure latex was collected in summer and 4 fractions of Figure latex were prepared. The cytotoxic effect of each fraction was studied and the most effective fraction was selected for apoptosis assay, acute toxicity study, and phytochemical analysis using column chromatography. The isolated compounds were identified by 1H-NMR, 13C-NMR, and mass spectroscopy. Chloroform fraction was the most effective fraction with the IC50 value of 0.219 and 0.748 mg/mL for HepG2 and NIH cell lines, respectively. Presence of cells in early apoptotic phase was documented by flow cytometry assay. Single dose administration of 2g/kg of fraction did not cause any death. Phytochemical analyses confirmed presence of lupeol acetate and lupeol palmitate in chloroform fraction. The present study revealed that the chloroform fraction is not only 3.4 times more toxic in HepG2 cell line but also has low in-vivo toxicity which could be considered as a good candidate for a chemo-preventive agent.

Evaluation of antitumor and cytotoxic activity in vitro of latex Vasconcellea quercifolia A. St.-Hil. (Caricaceae)

The high cancer rate that affects the population nowadays and the adverse effects of treatments make it important to search for new drugs obtained by researching the biodiversity potential of each country. Vasconcellea quercifolia A. St.-Hil. is a species of the family Caricaceae, native to Brazil with high latex production. Other species of the same family have already proven to have antitumour activity. Thus, this study evaluated the effect of the aqueous fraction of the latex extracted from the green twigs and fruits of V. quercifolia on the viability of squamous neoplastic lines of human uterine cervix (SiHa), breast adenocarcinoma (MCF-7), and non-tumour immortalized human keratinocytes (HaCat). Cells were cultured in Dulbecco's modified Eagle's medium (DMEM) with 10% foetal bovine serum (FBS) maintained at 5% CO2 and 37 °C, and were treated with different concentrations of the aqueous fraction of latex (0 to 310 μg mL−1). Results showed that the treatment induced an inhibition of 91.6% and 50.8% in the viability of SiHa and MCF-7 cells, respectively, with an IC 50 of 18.98 μg mL−1 for the SiHa strain and 48.82 μg mL−1 for the MCF-7 lineage. In the non-tumour lineage (HaCat), the treatment induced an inhibitory effect of approximately 50% at concentrations above 22 μg mL−1. Despite these findings, this study emphasizes the relevance of additional studies involving V. quercifolia latex as a potential therapeutic alternative against the tumours evaluated. It is worth noting that this study is the first related to cytotoxic and antitumour activities in vitro using latex from this species.

Colloidal properties of epoxidized natural rubber latex prepared via membrane separation technology

To date, epoxidized natural rubber (ENR) latex is still far from being commercially available for the production of dipped latex goods although the process was reported in 1922. Therefore, the objective of this work is to establish an understanding on the colloidal properties of ENR latex and relate them to coagulation and film formation. To do so, ENR latex was first prepared from low ammonia preserved natural rubber (LATZ) latex and then concentrated (C-ENR) using a patented process via membrane separation technology. NMR was used to determine the epoxidation level and ring opening in the ENR latex. The LATZ latex and both epoxidized latexes (ENR and C-ENR) were characterized for their particle size distribution, morphology, zeta potential and rheological properties. NMR analysis revealed an epoxidation level of 26% with < 2% ring opening. Particle size analysis showed C-ENR latex to have a narrow size distribution with no flocculation upon sonication. Zeta potential analysis as a function of pH showed a lower isoelectric point for C-ENR latex compared to LATZ latex. Zeta potential was also low for C-ENR latex compared to LATZ latex above pH 5 indicating an outward shift in the shear plane of the latex particle due to adsorption of the nonionic surfactant. Rheology of the latexes was studied using steady-state and oscillatory measurements. Elastic overshoot was observed for C-ENR latex at volume fraction (ϕ) of 0.490–0.584 indicating strong particle–particle interaction. The calculated maximum packing fraction (ϕp) of C-ENR latex was 0.721 compared to the ϕp of 0.815 for LATZ latex. The lower ϕp was attributed to the adsorbed nonionic surfactant layer on C-ENR latex particles. Oscillatory measurements showed that C-ENR latex behaved as dominantly elastic material from ϕ of 0.4975–0.584. At ϕ of 0.497 (= 48.5 wt%), the adsorbed polymer layers start to interact with each other. At this ϕ, the calculated adsorbed nonionic surfactant layer thickness (Δ) was 35 nm. As the latex concentration was increased, the latex became more elastic due to the interpenetration and compression of the surfactant layers. At the highest latex ϕ of 0.584 (= 57.6 wt%), tan δ was 0.3 resulting in an Δ of 20 nm. This thick layer of adsorbed surfactant hinders the coagulation of particles by salt during dipping thereby prohibiting the film formation process required to make the latex dipped products.

Morphological, molecular evolution an in vitro digestibility of filamentous granules of banana starch during fruit development.

The development of starch granules of a banana cultivar (morado variety - Musa AAA subgroup Red dacca) from filamentous shape to semi-spherical and finally to oval shape, was studied. The purity of the extracted starch changed from 83.5% (6 weeks) to 95.4% (16 weeks). Impurities were ascribed to cellulosic and latex fractions responsible for the integrity of the pristine fruit. The amylose content was stabilized at about 29.6% after the 12th week. The thermal analysis showed that the gelatinization enthalpy increased from 5.0 to 11.2 J/g from the 6th to the 12th week, indicating an increased degree of internal molecular organization. The analysis of chain-length distribution and gel permeation chromatography, showing that the content of long chains (B1, B2, and B3+) increased with the development of the starch granule. Also, XRD analysis indicated that C- type X-ray diffraction pattern from early to later phases of development, although the relative crystallinity content increased from 19.3 to 23.5% after 16 weeks of development. FTIR revealed the formation of more ordered structures with the development time. In vitro digestion tests showed that the resistant starch fraction increased from 37.5% for week 6 to 55.5% for week 16.

Latex from Tabernaemontana catharinensis (A. DC)—Apocynaceae: An alternative for the sustainable production of biologically active compounds

Lattices from the plant species Tabernaemontana catharinensis have been traditionally used as an antidote for snakebites, for the relief of toothaches, as a vermifuge for the elimination of warts, and as an anti-inflammatory compound. It is accepted that the antidote activity is the result of the proteolytic fraction of the water-soluble latex of the plant. Thus, the present study aimed to assess the proteolytic activity of T. catharinensis latex. The insoluble material from the latex of T. catharinensis was removed by centrifugation. The resulting water-soluble fraction of the latex was subjected to colorimetric and spectroscopic analysis. It was also assayed for proteolytic activity using azocasein as a substrate. The water-soluble fraction of the latex consisted mainly of carbohydrates, proteins, and amino acids. The soluble fraction exhibited strong proteolytic activity compared to trypsin. The latex was subjected to extraction with hexane to obtain a fraction rich in n-alkanes that was analysed by gas chromatography-mass spectrometry (MS) followed by acid-based alkaloid extraction, resulting in two alkaloidal extracts whose compounds were identified by off-line electrospray ionisation (+)-MS/MS analysis. The results suggest that latex from T. catharinensis is a rich source of sugars, amino acids, n-alkanes, alkaloids, and proteins.

Comparison of Different Latex Fractions of Carica Papaya L., and Novozyme 435® in the Methanolysis of Canola Oil

Se investigó la actividad de las fracciones crudas (P3) y libres de proteasas (CPL-p) del látex de Carica papaya en la lipólisis y metanólisis del aceite de canola. Las fracciones P3 y CPL-p fueron extraídas de frutos de C. papaya colectados en el departamento del Atlántico (Colombia), obteniéndose rendimientos de extracción del 26,89±0,26 y 4,85±0,04 g/100 g de látex fresco, respectivamente. La actividad lipasa de CPL-p, determinada mediante titulación de ácidos grasos fue 58,4% mayor con respecto a P3. Ambas fracciones fueron evaluadas como catalizadores en la producción de ésteres metílicos de ácidos grasos (EMAG. Como catalizador de referencia se usó la lipasa B de Candida antarctica (Novozyme 435®). Las reacciones se llevaron a cabo en un bioreactor tipo batch durante 48 h, a 200 rpm y 50 ºC. Las condiciones de reacción con P3 y CPL-p fueron: 6g de aceite, 20 %p/p de n-hexano, 15 %p/p del catalizador y relación molar metanol/aceite de 3:1. Los porcentajes de conversión obtendios fueron: P3 = 31,55±1,01 %, CPL-p = 38,48±0,76 % y Novozyme-435 = 62,96±0,63 %. Estos resultados demuestran el potencial de CPL-p en la hidrólisis de aceites de interés en la industria de los alimentos. Sin embargo, bajo las condiciones experimentales usadas en el presente estudio, su aplicación en la producción de EMAG fue limitada. Se concluye que el látex del fruto de C. papaya, de los árboles que se cultivan en la región del Caribe colombiano, es un subproducto agroindustrial con un alto potencial en la bioconversión de lípidos.

Chemical constituents of apolar fractions from fruit latex of twelve Clusia species (Clusiaceae)

The apolar fractions components of fruit latex of twelve species of Clusia belonging to four different taxonomic sections were examined by GC-MS. The latex of Clusia is characterised by large amounts of sesquiterpene hydrocarbons as major constituents like germacrene D: C. paralicola (44.28 %), C. criuva subsp. criuva (29.03 %); β-caryophyllene: C. fluminensis (35.61 %), C. lanceolata (36.39 %), C. hilariana (58.10 %); α-trans-bergamontene: C. spirictus-sanctensis (36.30 %); α-bulnesene: C. weddelliana (25.61 %); bicyclogermacrene: C. panapanari (25.93 %) and trans-β-farnesene: C. nemorosa (24.63 %), while C. grandiflora is composed of 42.16 % monoterpene hydrocarbons. Verbenone (31.91 %) was the major component. In contrast, C. rosea, C. grandiflora, C. lanceolata and C. criuva subsp. parviflora are rich in 3-methylcyclohexanone (19.56 %), hexadecanol (22.72 %), p-anisaldehyde (23.39 %) and octadecanol (26.81 %), respectively. This study suggests considerable chemical variation among the non-polar fractions of fruit latex of the twelve Clusia species.

Subcellular proteome profiles of different latex fractions revealed washed solutions from rubber particles contain crucial enzymes for natural rubber biosynthesis

Rubber particle (RP) is a specific organelle for natural rubber biosynthesis (NRB) and storage in rubber tree Hevea brasiliensis. NRB is processed by RP membrane-localized proteins, which were traditionally purified by repeated washing. However, we noticed many proteins in the discarded washing solutions (WS) from RP. Here, we compared the proteome profiles of WS, C-serum (CS) and RP by 2-DE, and identified 233 abundant proteins from WS by mass spectrometry. Many spots on 2-DE gels were identified as different protein species. We further performed shotgun analysis of CS, WS and RP and identified 1837, 1799 and 1020 unique proteins, respectively. Together with 2-DE, we finally identified 1825 proteins from WS, 246 were WS-specific. These WS-specific proteins were annotated in Gene Ontology, indicating most abundant pathways are organic substance metabolic process, protein degradation, primary metabolic process, and energy metabolism. Protein-protein interaction analysis revealed these WS-specific proteins are mainly involved in ribosomal metabolism, proteasome system, vacuolar protein sorting and endocytosis. Label free and Western blotting revealed many WS-specific proteins and protein complexes are crucial for NRB initiation. These findings not only deepen our understanding of WS proteome, but also provide new evidences on the roles of RP membrane proteins in NRB. SignificanceNatural rubber is stored in rubber particle from the rubber tree. Rubber particles were traditionally purified by repeated washing, but many proteins were identified from the washing solutions (WS). We obtained the first visualization proteome profiles with 1825 proteins from WS, including 246 WS-specific ones. These WS proteins contain almost all enzymes for polyisoprene initiation and may play important roles in rubber biosynthesis.

Bone repair of critical-sized defects in Wistar rats treated with autogenic, allogenic or xenogenic bone grafts alone or in combination with natural latex fraction F1

Bone grafts are used in the medical-surgical field for anatomical and functional reconstruction of lost bone areas, aiding the bone repair process by osteogenesis, osteinduction and osteoconduction. New materials such as F1 (fraction 1) protein extracted from the rubber tree Hevea brasiliensis have been investigated and currently present important properties for tissue repair, and are associated with neoangiogenesis, promoting cell adhesion and extracellular matrix formation. The main objective of this study was to investigate the association of F1 protein to different bone grafts in the repair of critical bone defects in the calvaria of Wistar rats. A total of 112 Wistar rats were divided as follows: autograft (AuG), allograft (AlG), xenograft (XeG), autograft/F1 (AuG–F1), allograft/F1 (AlG–F1), xenograft/F1 (XeG–F1), F1 (F1), control (CTL), with a waiting period of 4 and 6 weeks (w). The stereological AuG, AlG, AuG–F1 and AlG–F1 results had greater bone neoformation (p < 0.05). For immunohistochemistry, the angiogenic and osteogenic factors were higher for AuG–F1 and AlG–F1. TRAP-positive cells were higher in XeG–F1 and AlG (37 ± 9.53, 13.3 ± 4.16) (4 w) and XeG, AlG–F1 and XeG–F1 (20.33 ± 7.37; 15.25 ± 6.02, 19.33 ± 3.21) (6 w). For zymography, F1 showed increased gelatinolytic activity of MMP-2 and -9. It was concluded that the bone graft associated or not with F1 increases the angiogenic and osteogenic, biochemical and stereological factors.