Plant Gums Research Articles

GC/MS Characterization of Beeswax, Protein, Gum, Resin, and Oil in Romano-Egyptian Paintings

This article presents results from a binding media survey of 61 Romano-Egyptian paintings. Most of the paintings (51) are the better-known funerary mummy portraits created using either encaustic or tempera paint medium. Samples from all the paintings (on wooden panels or linen shrouds) were analyzed with gas chromatography/mass spectrometry (GC/MS) to identify waxes, fatty acids, resins, oils, and proteins in one sample. Analytical protocols that utilized three separate derivatization techniques were developed. The first analysis identified free fatty acids, waxes, and fatty acid soaps, the second characterized oils and plant resins, and the third identified proteins. The identification of plant gums required a separate sample. Results showed that fatty acids in beeswax were present as lead soaps and dicarboxylic fatty acids in some samples was consistent with an oxidized oil. The tempera portraits were found to contain predominantly animal glue, revising the belief that egg was the primary binder used for ancient paintings. Degraded egg coatings were found on several portraits, as well as consolidation treatments using paraffin wax and animal glue. The unknown restoration history of the portraits caused uncertainty during interpretation of the findings and made the identification of ancient paint binders problematic. Also, deterioration of the wooden support, residues from mummification, biodegradation, beeswax alteration, metal soap formation, and environmental conditions before and after burial further complicated the analysis. The inherent problems encountered while characterizing ancient organic media in funerary portraits were addressed. The fourteen museums that participated in this study are members of APPEAR (Ancient Panel Paintings: Examination, Analysis, and Research), an international collaborative initiative at the J. Paul Getty Museum whose aim is to expand our understanding of ancient panel paintings through the examination of the materials and techniques used for their manufacture.

Multifaceted activities of plant gum synthesised platinum nanoparticles: catalytic, peroxidase, PCR enhancing and antioxidant activities.

A single pot, green method for platinum nanoparticles (Pt NP) production was devised with gum ghatti (Anogeissus latifolia). Analytical tools: ultraviolet-visible (UV-vis), dynamic light scattering, zeta potential, transmission electron microscope, X-ray diffraction (XRD), and Fourier transform infrared spectroscopy were employed. Wide continuous UV-vis absorption and black solution colouration proved Pt NP formation. Face-centred cubic crystalline structure of NP was evidenced from XRD. NPs formed were nearly spherical with a mean particle size of 3 nm. NP demonstrated a myriad of properties including catalytic, peroxidase, polymerase chain reaction (PCR) enhancing and antioxidant activities. Catalytic action of NP was probed via NaBH4 reduction of arsenazo-III dye. NP displayed considerable peroxidase activity via catalysis of 3, 3', 5, 5'-tetramethylbenzidine oxidation by H2O2. NP showed exceptional stability towards varying pH (3-11), temperature (25-100°C), salt concentration (0-100 mM) and storage time duration (0-12 months). In comparison with horse radish peroxidase, its applicability as an artificial peroxidase is advantageous. NP caused a two-fold enhancement in PCR yield at 0.4 nM. Also showed significant 1', 1' diphenyl picryl-hydrazyle scavenging (80.1%) at 15 µg/mL. Author envisages that the biogenic Pt NP can be used in a range of biological and environmental applications.

Bioactivity and Heavy Metal Removal Using Plant Gum Mediated Green Synthesized Silver Nanoparticles

In this study, silver nanoparticles was synthesized by a simple and ecofriendly method using plant gums of Araucaria heterophylla, Azadirachta indica and Prosopis chilensis. The biosynthesised silver nanoparticles were characterized by UV–visible spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive spectroscopy, Dynamic light scattering etc. Silver nanoparticles were tested for its antibacterial activity against Escherichia coli and Streptococcus sp. and anticancer activity against human breast cancer cell line (MCF 7) and also utilized for chromium removal. The particles were found to have antibacterial activity.

Making glue from seeds and gums: Working with plant-based polymers to introduce students to plant biochemistry.

Plants and plant products are key to the survival of life on earth. Despite this fact, the significance of plant biochemistry is often underrepresented in science curricula. We designed an innovative laboratory activity to engage students in learning about the biochemical properties of natural polymers produced by plants. The focus of the hands-on activity is on mucilages and gums, which contain complex polysaccharides that have applications in industry. The 1.5-h activity is organized into three laboratory exercises. It begins with a demonstration of the water absorption property of seed coat mucilage upon hydration of seeds from psyllium, a plant that is grown commercially for mucilage production. The second exercise involves microscopy of a variety of plant seeds stained with ruthenium red dye to visualize pectin polysaccharides of the seed mucilage. Students learn about phenotypic variation among plant species and how the seed coat mucilage is beneficial to keep seeds hydrated during germination. The third exercise highlights an industrial application of plant gums as adhesives. The students prepare edible glue made with gum arabic, a type of plant polymer from the dried exudate of the Acacia plant. This three-part activity has been implemented in conjunction with a Girls Researching Our World (GROW) summer workshop for sixth to eighth graders over a 4-year period. It may be adapted as a laboratory activity for students of all ages, for example, to enhance biochemistry education for high-school students or undergraduate non-majors. © 2019 International Union of Biochemistry and Molecular Biology, 47(4):468-475, 2019.

Physicochemical, Spectroscopic and Rheological Characterization of Anacardium occidentale gum Exudates

Anacardium occidentale gum exudate was analyzed for physicochemical, spectroscopic and rheological characteristics. Physicochemical analysis revealed that the gum is mildly acidic, ionic, extremely rich in carbohydrate and calcium. GCMS spectrum revealed the presence of some carboxylic acids, ketone and alkanes. The FTIR spectrum of the gum closely resembled those of other polysaccharides. Scanning electron micrograph revealed the presence of pores containing particles with irregular shapes. The average value of intrinsic viscosity of the gum was 3.28 dL/g, which compared favourably with those obtained for some plant gums. From the Huggins, Kraemer and Power law models, it was deduced that there is absence of molecular association and that the conformation of the gum is more rod like. Viscosity of the studied gum was found to be greatly influenced by the presence of urea, K+, Ca2+ and Al2+. Anarcadium occidentale gum exhibited a non-Newtonian property with characteristics dilatant and shears thickening properties.

Azurite in medieval illuminated manuscripts: a reflection-FTIR study concerning the characterization of binding media

In illuminated manuscripts, a reliable identification of oxyanion pigments such as azurite by rFTIR is simple, as several combination and overtone bands are strongly enhanced compared to transmission mode. However, the characterization of the used binding media is rather difficult, as the analysis of four medieval manuscripts from the late thirteenth to the fifteenth century (e.g. Cod. slav. 8 in the collection of the Austrian National Library), as well as the earliest known map of Vienna (Albertinischer Plan from 1421, Wien Museum) showed. According to the literature, mainly glair (egg white) and plant gums were applied as binding media for azurite. Moreover, both were used in many cases also as “varnishes” in order to improve optical and mechanical properties of the paint layer. In order to assess the possibilities and to distinguish between proteinaceous and carbohydrate binders, mock-ups with azurite were prepared on parchment support with various quantities of binders. Additionally, some of the specimen were varnished using the binders mentioned above. Furthermore, mock-ups on aluminium foil were prepared to evaluate the influence of the support on the reflection spectra. The results showed that the binding medium content in the mock-ups usually was too low for a reliable determination by rFTIR (except the ones with the highest contents), whereas it was possible to characterize the varnish materials. Only an insignificant influence of the support on the spectra from the mock-ups was observed. However, the spectra obtained from three manuscripts suggested a certain influence of the parchment support, which indicates thinner paint layers.

The use of strawberry and arabic gum blend as an inhibitor for the corrosion of aluminium in an acidic medium

The manuscripts entails the use of plant gum blends prepared with gum Arabic and strawberry gum, to inhibit the corrosion of aluminum immersed in concentrated sulfuric acid solution. The miscibility tests of the blended gums (Arabic and strawberry) were carried out using Ostwald viscometer. Following the ratio of gum Arabic to strawberry gum, the ratio 0.2:0.8 has the highest relative viscosity and thus more viscous than all the other blends prepared in this work, and due to its viscosity strength the 0.2:0.8 ratio was used. In addition, the inhibitive and adsorption properties of Arabic and strawberry gums were studied using gravimetric method. The results obtained indicated that the blend of Arabic and strawberry gums are effective in the corrosion inhibition of aluminum in H2SO4 solutions. The adsorption of the inhibitor on the aluminium surface is spontaneous and supports the Langmuir adsorption model, the data was also subjected to other isotherms and thermodynamic models.

Antimicrobial activities of green synthesized gums-stabilized nanoparticles loaded with flavonoids

Herein, we report green synthesized nanoparticles based on stabilization by plant gums, loaded with citrus fruits flavonoids Hesperidin (HDN) and Naringin (NRG) as novel antimicrobial agents against brain-eating amoebae and multi-drug resistant bacteria. Nanoparticles were thoroughly characterized by using zetasizer, zeta potential, atomic force microscopy, ultravoilet-visible and Fourier transform-infrared spectroscopic techniques. The size of these spherical nanoparticles was found to be in the range of 100–225 nm. The antiamoebic effects of these green synthesized Silver and Gold nanoparticles loaded with HDN and NRG were tested against Acanthamoeba castellanii and Naegleria fowleri, while antibacterial effects were evaluated against methicillin-resistant Staphylococcus aureus (MRSA) and neuropathogenic Escherichia coli K1. Amoebicidal assays revealed that HDN loaded Silver nanoparticles stabilized by gum acacia (GA-AgNPs-HDN) quantitatively abolished amoeba viability by 100%, while NRG loaded Gold nanoparticles stabilized by gum tragacanth (GT-AuNPs-NRG) significantly reduced the viability of A. castellanii and N. fowleri at 50 µg per mL. Furthermore, these nanoparticles inhibited the encystation and excystation by more than 85%, as well as GA-AgNPs-HDN only completely obliterated amoeba-mediated host cells cytopathogenicity. Whereas, GA-AgNPs-HDN exhibited significant bactericidal effects against MRSA and E. coli K1 and reduced bacterial-mediated host cells cytotoxicity. Notably, when tested against human cells, these nanoparticles showed minimal (23%) cytotoxicity at even higher concentration of 100 µg per mL as compared to 50 µg per mL used for antimicrobial assays. Hence, these novel nanoparticles formulations hold potential as therapeutic agents against infections caused by brain-eating amoebae, as well as multi-drug resistant bacteria, and recommend a step forward in drug development.

The chemistry of pastels: Investigation of the organic materials in a drawing by Umberto Boccioni

Abstract Although many prominent artists have experimented with pastels, this technique has been the subject of very limited scientific research. The first known recipes of pastels date back to the 16th century, but only during the 18th century did the pastel technique become more common. Identifying and characterising the organic constituents in pastels materials is challenging given that they are present in extremely low concentrations and could be produced using many organic substances, whose chemical composition alters during ageing. The chemical-physical behaviour of organic media in artworks is often crucial in causing the degradation problems, which need to be addressed by conservation. We evaluated the applicability of an analytical approach based on chromatography and mass spectrometry to investigate the composition of the pastels used by Umberto Boccioni in a drawing dated 1908 and conserved at the Museo del Novecento in Milan (Italy). The investigation of the formulation of artists’ pastels used in the first decade of the 20th century is particularly important in order to improve the knowledge of this technique. The analysis highlighted the presence of proteins and plant gums in the artwork samples, with differences in the composition for the different samples.

Effects of Baneh (Pistacia atlantica) Gum on Human Breast Cancer Cell Line (MCF-7) and Its Interaction with Anticancer Drug Doxorubicin.

Pistacia atlantica is one of the species of Anacardiaceae that grows in the wild in different regions of Iran. Traditionally, anacardiaceae family has antibacterial, fungicidal, and cytotoxic properties. Therefore, the present study was designed to investigate the possible cytotoxic and anti-proliferative properties of Baneh gum. Cytotoxicity of the plant gum was determined using MTT assay on MCF-7 human breast cancer cells. The cellular makers of apoptosis (caspase3 and P53) and cell proliferation (Cyclin-D1) were evaluated by western blotting. Doxorubicin was used as anticancer control drug in combination treatment. The result showed that Baneh gum (100 µg/mL) significantly induced cell damage, activated caspase3, and increased P53 protein level. In addition, Cyclin-D1 was significantly decreased in gum-incubated cells. Furthermore, combination treatment of cells with Baneh gum (25 µg/mL) and doxorubicin (200 nM) produced a significant cytotoxic effect as compared to each drug alone. In conclusion, Baneh gum (100 µg/mL) has a potential pro-apoptotic/anti-proliferative property against human breast cancer cells and its combination with doxorubicin in low doses may induce cell death effectively and be a potent modality to treat this type of cancer.

Manufacture and Characteristics of Oil-Modified Refined Lacquer for Wood Coatings

Oriental lacquer, a natural and renewable polymeric coating, comes from the sap produced by lacquer trees. For practical applications, oriental lacquer must be refined to reduce its water content and enhance its quality. In this study, drying oils were blended with oriental lacquer during a refining process to produce oil-modified refined lacquer (OMRL). Rhus succedanea lacquer, composed of 54.1% urushiols, 34.3% water, 7.2% plant gum, and 4.4% nitrogenous compounds, and drying oils, including tung oil (TO), linseed oil (LO), and dehydrated castor oil (DCO), were used as materials in this study. The effect of type and amount (0%, 10%, and 20% by wt %) of drying oils added to lacquer on lacquer properties were evaluated. Results show that the drying oils acted as a diluent, which reduced the viscosity, and enhanced workability, shortened touch-free drying time and accelerated the hardened drying of the OMRL. The results also indicated that the hardness, mass retention, Tg, tensile strength, abrasion resistance, and lightfastness of OMRL films decreased as more drying oils were blended with lacquer. Conversely, the bending resistance, elongation at break, impact resistance increased. Gloss was greatly improved through the blending of more drying oils with lacquer. In conclusion, the LO-modified refined lacquer (RL) had the highest film gloss and the DCO-modified RL had the shortest drying time for coating. Otherwise, the film properties were similar among the three types of drying oils.

Impact of the Basil and Balangu gums on physicochemical properties of part baked frozen Barbari bread

Part baking of bread and frozen storage as the new methods have attracted a lot of attention due to an increase in shelf life and the availability of fresh bread at any time. Replacing traditional additives with natural gums such as plant gum for producing bread with long shelf life is considered as a major technological challenge in bakery industry. The present study aimed to evaluate the effects of 0, 0.3%, and 0.5% concentrations of plant gums including Basil and Balangu, compared to guar gum at 0.4% on the physicochemical properties such as specific volume, extensibility, hardness, and color parameter, as well as sensory properties of part baked frozen bread. The results indicated adding gums to bread decreased in hardness and increased in specific volume, extensibility, color parameter and sensory properties. Based on the comparison between plant gums and guar, Basil and Balangu could improve volume, porosity, and sensory score more than guar against the guar which was more effective on moisture content and firmness of Barbari bread. The best results were obtained in the interaction between Basil and Balangu gums on 0.5% concentration.

Elucidating the composition and the state of conservation of nitrocellulose-based animation cells by means of non-invasive and micro-destructive techniques

Abstract This paper presents the first study on Rodovetri, animation cels produced between the 1950s and the 1970s for the Italian television and conserved at the Museum of Industry and Labour “Musil” (Italy). Although these cels are considered as works of art and witnesses of Italian animation design, they have never been studied before. The study of one of the most endangered cel groups of the Musil collection is presented here. The main aims were to investigate the composition of these animation cels, to identify the materials used for painting the characters, and to assess the state of conservation of the cels. The results, which were obtained by means of a multi-analytical non-invasive and micro-destructive approach, underline the composition of the plastic substrate as nitrocellulose, while the painted layers – which contain a variety of pigments and dyes – were found to be bound with a mixture of plant gum and animal glue. This study also provides information on their state of conservation, in particular in relation to the de-nitration of plastic sheets. Important issues on the preventive conservation are also raised.

Discrimination of Acacia gums by MALDI-TOF MS: applications to micro-samples from works of art

This paper reports the discrimination of Acacia gums from the two most widely used and commercially significant species, A. senegal and A. seyal, using an innovative strategy based on matrix assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) after enzymatic digestion of the polysaccharide component. MALDI-TOF MS/MS experiments were carried out to determine the composition of the most intense ions of A. seyal gum and elucidate its mass fingerprint. The analytical method was applied to the analysis of gums from 12 other Acacia species and an attempt was made to find specific oligosaccharides that could be used to discriminate among them. Statistical analysis was performed to further explore the capability to differentiate these species. The implementation of a library of MALDI mass profiles of plant gums, with an initial focus on Acacia gums, represents the first MS-based attempt to facilitate reliable, species-level identification of these materials in unknown samples. The technique was successfully applied to the analysis of micro-samples from art objects of different types, with regard to geographical origin and date, including artefacts from ancient Egypt and a 20th century painting by Georges Braque, in the collections of The Metropolitan Museum of Art, New York, and the Art Institute of Chicago. Results demonstrated the possibility to detect Acacia gums from different species even in complex and aged micro-samples, providing important insights into the materials and condition of the objects. This research shows the potential to open new avenues of art historical and technical investigation into the specific plant sources, trade, and selection of materials by artists.

Colourants made from aphids and ivy gum

The purpose of this study was to determine whether workable flesh-toned paints can be made from colourants from aphid insects and ivy gum using medieval gum and scale insect recipes. The processes of extracting pigment from the lesser-known ivy, wormwood and the giant willow aphids were explored, whilst paint binder and colourant was obtained from ivy plant gum. This work follows on experiences applying past practices derived from painters’ to illuminators’ technical manuals using similar processes once used for making colourants from historical scale insects, such as kermes and cochineal. The experimental reconstructions created by using selected locally sourced aphid insects and ivy gum, indicate that an aphid-stain and dye-based colourant which was fixed to calcium carbonate can form a successful paint source.

Disclosing the composition of historical commercial felt-tip pens used in art by integrated vibrational spectroscopy and pyrolysis-gas chromatography/mass spectrometry

In this work the formulation of 20 Johann Faber felt-tip pens commercialized in the 1960s and belonging to and used by the architect and designer Lina Bo Bardi have been investigated by an integrated analytical methodology. Minimally destructive vibrational spectroscopic methods permitted a qualitative interpretation of constituents which could be corroborated and ulteriorly supplemented by more destructive chromatographic techniques. This combined approach constitutes an effective collaboration for an in-depth study chronicling the chemical characterization of the first era of commercially viable felt-tip pen inks by providing for the identification of dyes and separation of their mixtures (triarylmethanes, xanthenes, indigoids, azo dyes, azines), binders (plant gums) and additives (diethylene glycol, phenols/antioxidant, diisoctyl phthalate/plasticizer). The comparison between the early and more recent commercial felt-tip pens has allowed to differentiate dyes, pigments and binders, which may provide a useful reference for future studies on the chemical characterization of historical samples.

Tree gum stabilised selenium nanoparticles: characterisation and antioxidant activity.

Selenium nanoparticles (Se NPs) were synthesised using sodium borohydride as a reductant and gum kondagogu as a stabiliser. Plant gum serves as a renewable, non-toxic, non-immunogenic, biopolymer based feedstock. Role of gum on synthesis and mean particle size was studied using ultraviolet-visible spectroscopy and dynamic light scattering. NP generation was visualised with orange red colouration and NPs exhibited a surface plasmon resonance peak at 250 nm. Formed NPs were amorphous, polydisperse and spherical. NPs showed a bimodal distribution, size varied from 44.4 to 200 nm and mean particle size was 105.6 nm. NP solution exhibited a zeta potential of -39.9 mV, confirming the superior stability. In comparison to ionic Se, the gum capped Se NPs exhibited superior 1, 1-diphenyl-2-picrylhydrazyle and 2, 2-azinobis-(3-ethylbenzthinzoline-6-sulphonic acid) radial scavenging activities of 73.2 and 92.2%, respectively, at 25 µg/ml. Antibacterial potential of NPs was checked with well diffusion assay. NPs exhibited growth inhibition activity against Gram-positive bacteria only. Bacillus subtilis and Micrococcus luteus showed respective inhibition zones of 6.3 and 8.6 mm at 12 µg. Thus, the present study demonstrates the applicability of tree gum stabilised Se NPs as a potent antioxidant nutrition supplement at a much lower dose, in comparison with ionic Se.

Chemical composition, total phenolic content, antioxidant and antinutritional characterisation of exudate gums

Abstract Present study was conducted to determine the chemical composition, antioxidant potential and antinutritional factors in some plant gums that have been commercially used as additives in different food formulations. For this purpose, exudate gums were chosen which included commercially used acacia and karaya gum. The properties were compared with an underutilised gum exuded from apricot tree, called apricot gum. Monosaccharide composition and linkages in gum polysaccharides were studied using Electron spray ionization-mass spectrometry coupled with time-of-flight analyser (ESI-MS-TOF). The assay involves ionization of gum polysaccharides by passing their organic solution into electric field and converting them into a mist of charged droplets that are further analysed and detected using Time-of-flight mass spectrometry. Relative array of peaks elucidated the presence of glucosyl, galactosyl and a small proportion of uronic acid units in all gums. Spectral fragmentation distribution was bimodal with polydispersity values greater than or equal to two (Mw/Mn ≥ 2). In all the antioxidant assays, methanol and ethanol were separately used for extraction. Total phenolic content, ferrous ion chelating ability and reducing power of the gums varied from 0.44 to 1.25 mg GAE/g, 11.80–60.42% and 0.12–0.23 AAE/g, respectively. The DPPH radical scavenging ability (12.03–27.23%) and bile acid binding activity (40.98–46.60%) of the gums was also high. Presence of tannins (0.20–0.73 TAE/g), phytic acid (0.03–0.60 mg/g) and haemagglutinins (0.006–0.11 HU/mg protein) was observed at a very small concentration. On the other hand, the antinutritional factors like terpenoids, saponins and alkaloids were found completely absent.

MORINGA OLEIFERA AS A PHARMACEUTICAL EXCIPIENT

Plant gums and mucilages are being used due to their abundance in nature, safety and economy. Additives play an important role in pharmaceutical preparations like tablet, lotions, suspensions, syrups and ointments. Recent trends towards the use of the natural and nontoxic products which demand the replacement of synthetic excipients with natural ones. Moringaoleifera gum has good mucoadhesive polymer, disintegrating agent and binder. Moringa Oleiferagum show that it has high potential for industrial application especially in the food, textile and pharmaceutical industries.

Painting the Palace of Apries I: ancient binding media and coatings of the reliefs from the Palace of Apries, Lower Egypt

This study gives an account of the organic components (binders and coatings) found in the polychromy of some fragmented architectural reliefs from the Palace of Apries in Memphis, Egypt (26th Dynasty, ca. 589-568 BCE). A column capital and five relief fragments from the collections of the Ny Carlsberg Glyptotek in Copenhagen were chosen for examination, selected because of their well-preserved polychromy. Samples from the fragments were first investigated using Fourier transform infrared (FTIR) spectroscopy to screen for the presence of organic materials and to identify the chemical family to which these materials belong (proteinaceous, polysaccharides or lipid). Only the samples showing the potential presence of organic binder residues were further investigated using gas chromatography with mass spectrometry detection (GC–MS) targeting the analysis towards the detection and identification of compounds belonging to the chemical families identified by FTIR. The detection of polysaccharides in the paint layers on the capital and on two of the fragments indicates the use of plant gums as binding media. The interpretation of the sugar profiles was not straightforward so botanical classification was only possible for one fragment where the results of analysis seem to point to gum arabic. The sample from the same fragment was found to contain animal glue and a second protein material (possibly egg). While the presence of animal glue is probably ascribable to the binder used for the ground layer, the second protein indicates that either the paint layer was bound in a mixture of different binding materials or that the paint layer, bound in a plant gum, was then coated with a proteinaceous material. The surface of two of the investigated samples was partially covered by translucent waxy materials that were identified as a synthetic wax (applied during old conservation treatments) and as beeswax, respectively. It is possible that the beeswax is of ancient origin, selectively applied on yellow areas in order to create a certain glossiness or highlight specific elements.