Jener David G. Santos

Aqueous extraction of pectin from sisal waste

In this work, sisal waste was used as a source of pectin. Sisal is known worldwide as a source of hard fibres, and Brazil is the largest producer of sisal, producing more than 246,000 tonnes. However, the process of removing the fibres of the sisal leaf generates 95% waste. This study investigated the effect of the liquid/solid ratio (%), time (min), and temperature (°C) on the yield of the pectin obtained from sisal waste by attractive environmentally friendly process. A statistical Box-Behnken design was applied to determine the important effects and interactions of these independent variables on the yield of pectin, the dependent variable. Significant models were obtained. The yield of the extracted pectin ranged from 4.61 to 19.2%. The conditions that produced the highest yield (19.2%) were a temperature of 85 °C, extraction time of 60 min and a liquid/solid ratio of 2%.

Antimicrobial activity of Agave sisalana

This study was carried out to evaluate the antimicrobial activity of extracts of the leaves and leaf waste discarded in the process of obtaining the hard fibers of Agave sisalana. The antimicrobial activity was determined by the paper disk diffusion method using Gram-positive and Gram-negative bacteria (nonresistant and resistant to antibiotics) and a fungus. The hydroalcoholic extract obtained from leaves and from sisal waste showed significant inhibition of Candida albicans, on the other hand, it was inactive against three strains of Staphylococcus aureus, two strains of Escherichia coli, a strain of Micrococcus luteus, Bacillus cereus, Pseudomonas aeruginosa and Salmonella choleraesuis. The methanol extract of leaves showed weaker reduction in the inhibitory action of C. albicans when compared with the above extracts, and it was also inert against the other microorganisms tested.

In vitro ovicidal and larvicidal activity of Agave sisalana Perr. (sisal) on gastrointestinal nematodes of goats.

This study describes the in vitro anthelmintic activity of aqueous extracts (AE), ethyl acetate extracts (EE), flavonoid fractions (FF) and saponin fractions (SF) obtained from sisal waste (Agave sisalana) against gastrointestinal nematodes of goats. The activity of these extracts was evaluated by performing inhibition of egg hatch (EHA) and larval migration (LMI) assays. The EC(50) results of the EHA corresponded to 4.7, 0.1 and 0.05 mg/mL for EE, EA and FF, respectively. The SF fraction showed no ovicidal activity. The percent efficacies that were observed for the LMI were 50.3, 33.2 and 64.1% for the AE, EE and SF, respectively. The FF fraction did not show activity against the larvae. The analysis of the FF fraction indicates the presence of a homoisoflavonoid. This report suggests that the A. sisalana has activity in vitro against gastrointestinal nematodes of goats. This effect is likely related to the presence of homoisoflavonoid and saponin compounds, which have different actions for specific stages of nematode development.

In vivo anthelmintic activity of an aqueous extract from sisal waste (Agave sisalana Perr.) against gastrointestinal nematodes in goats.

The resistance of gastrointestinal nematodes (GINs) of small ruminants to anthelmintics has required the investigation of new alternatives. The aim of the present study was to evaluate the in vivo anthelmintic activity of an aqueous extract from sisal waste (Agave sisalana) (AESW) against GINs in goats and to observe the animals for toxic effects. Thirty animals that were naturally infected with GINs were distributed into three groups: group I, was treated with daily doses of AESW (1.7 g/kg) for eight days; Group II, the positive control, was treated with a single dose of levamisole phosphate (6.3mg/kg); and group III, the negative control, was left untreated. Faecal eggs counts (FECs), coprocultures and post-mortem worm counts were performed to assess the efficacy of the treatments. Clinical and laboratory analyses were performed to evaluate any toxic effects associated with the treatment. In the goats in groups I and II, a significant reduction (p<0.05) of the number of eggs and infective larvae (L(3)) was observed. The maximum reductions of the FECs were 50.3% and 93.6% for groups I and II, respectively, whereas the percent reductions of the total number of L(3) larvae were 80% (group I) and 85.6% (group II). There was no difference between groups I and III with respect to worm burden, and the percent reductions were 28.8% and 63.4% for Oesophagostomum columbianum and Trichostrongylus colubriformis, respectively. No reduction was detected for the Haemonchus contortus. The positive control group demonstrated a 74% reduction of the parasites that were recovered from the digestive tract. There were no changes in clinical and haematological parameters. The levels of serum urea and creatinine were higher in group I, but remained within the normal range. At necropsy, pale mucous membranes, abomasitis and enteritis were associated with parasitism. In addition, a histological analysis of the liver and kidney did not reveal any changes suggestive of toxicity. A chemical analysis of the AESW demonstrated the presence of saponins, which after acid-hydrolyses reaction, gave the sapogenins hecogenin and tigogenin. The AESW had a low efficacy for the parasitic stages and was moderately effective against eggs and free-living stages. Furthermore, the treatment was not toxic to the goats.

Chemicals from Agave sisalana Biomass: Isolation and Identification

Agave sisalana (sisal) is known worldwide as a source of hard fibers, and Brazil is the largest producer of sisal. Nonetheless, the process of removing the fibers of the sisal leaf generates 95% waste. In this study, we applied chemical sequential steps (hydrothermal extraction, precipitation, liquid-liquid extraction, crystallization, SiO2 and Sephadex LH 20 column chromatography) to obtain pectin, mannitol, succinic acid, kaempferol and a mixture of saponins as raw chemicals from sisal biomass. The structural identification of these compounds was performed though spectrometric methods, such as Infrared (IR), Ultraviolet (UV), Mass spectrometry (MS) and Nuclear magnetic resonance (NMR). All the sisal chemicals found in this work are used by both the chemical and pharmaceutical industries as excipients or active principles in products.

Extraction optimization and antinociceptive activity of (1→3)-β-d-glucan from Rhodotorulamucilaginosa.

β-d-glucans are polymers of d-glucose monomers found in the cell walls of many bacteria, plants, fungi and yeasts. A variety of β-d-glucans differing in structures have been isolated from various sources and their biological activity to be regulated by various structural factors, such as the primary structure, molecular weight, solubility, and conformation. This study investigated the effect of extraction time and temperature on the yield of β-d-glucan produced by Rhodotorulamucilaginosa. A statistical Doehlert design was applied to determine the important effects and interactions of these independent variables on the yield of β-d-glucan, the dependent variable. Significant models were obtained. The best yield was of 25% obtained after 128min of extraction in a temperature of 72°C. The polysaccharides were characterized as (1⟶3)-β-d-glucan by methods spectroscopic (FT-IR, (1)HNMR and (13)CNMR). In addition, the antinociceptive effect was evaluated using different experimental tests (acetic acid-induced writhing test, formalin test and tail immersion test). The (1⟶3)-β-d-glucan showed a potent peripheral antinociceptive effect, possibly by the inhibition of inflammatory mediators.

Saponin-rich fraction from Agave sisalana: effect against malignant astrocytic cells and its chemical characterisation by ESI-MS/MS

Abstract Astrocytic tumour cells derived from human (GL-15) and rat (C6) gliomas, as well as non-tumoural astrocytic cells, were exposed to the saponin-rich fraction (SF) from Agave sisalana waste and the cytotoxic effects were evaluated. Cytotoxicity assays revealed a reduction of cell viability that was more intensive in glioma than in non-tumoural cells. The SF induced morphological changes in C6 cells. They were characterised by cytoplasmic vacuole formation associated with increase in the formation of acidic lysosomes. The SF was subjected to purification on Sephadex LH-20, which characterised three probable steroidal saponins (sisalins) by electrospray ionisation mass spectrometry multistage (ESI-MSn). Sisalins from sisal may be responsible for the cytotoxicity, which involves cytoplasmatic vacuole formation and selective action for glioma cells.

Betulinic acid from Zizyphus Joazeiro bark using focused microwave-assisted extraction and response surface methodology

Background: The effect of the extraction time (min) and temperature (°C) on the yield of betulinic acid (BA) from Zizyphus joazeiro barks using focused microwave-assisted extraction was investigated. Materials and Methods: The ethyl acetate was used as extractor solvent because it was shown to provide a betulinic acid-clean extract. A full two-level statistical factorial design was applied to determine the important effects and interactions of these independent variables upon the yield of BA. Results: The conditions that produced the highest yield of BA were at temperature of 70°C and an extraction time of 15 min (3.33 mg per gram of plant). Conclusion: The BA has drawn attention due to its use as a raw material in the synthesis of active compounds against the Human Immunodeficiency Virus (HIV). Abbreviation used: BA: Betulinic acid; FMAE: Focused microwave assisted extraction; HPLC: High-performance liquid chromatography; RSD: Relative standard deviations.

The extraction and characterisation of a polysaccharide from Moniliophthora perniciosa CCMB 0257

Abstract The alpha-D-glucans are worldwide acknowledged as powerful immune system stimulants found in several sources; however, the fungal-derived sources appear to respond with higher activity. The present study has investigated polysaccharide production in Moniliophthora perniciosa. The dry biomass was subjected to thermal treatment in alkaline solution after fermentation. The biopolymers dissolved in this solution were precipitated after three volumes of absolute ethanol were added to the supernatant. The pure polysaccharide MPS1 was obtained through molecular exclusion chromatography using the Sephacryl S-200 column. The HPLC-RI analysis showed that MPS1 was a glucose homopolysaccharide. Nuclear magnetic resonance (NMR) spectra indicated the α-form as the anomeric carbon configuration in glucose residue. The structure of the polysaccharide was further confirmed as (1→4)-α-D-glucan through the chemical shift of C4. The molecular weight of MPS1 was 31.0 kDa.