The uses of natural compounds, such as essential oils (EOs), are limited due to their instability to light, oxygen and temperature, factors that affect their application. Therefore, improving ...stability becomes necessary. The objective of this study was to prepare inclusion complexes of
essential oil (LCEO) with β-cyclodextrin (β-CD) using physical mixing (PM), kneading (KN) and co-precipitation (CP) methods and to evaluate the efficiency of the complexes and their physicochemical properties using ATR-FTIR, FT-Raman, DSC and TG. The study also assessed cytotoxicity against human colorectal and cervical cancer cells and antifungal activity against
and
. The complexation efficiency results presented significant evidence of LCEO:β-CD inclusion complex formation, with KN (83%) and CP (73%) being the best methods used in this study. All tested LCEO:β-CD inclusion complexes exhibited toxicity to HT-29 cells. Although the cytotoxic effect was less pronounced in HeLa tumor cells, LCEO-KN was more active against Hela than non-tumor cells. LCEO-KN and LCEO-CP inclusion complexes were efficient against both toxigenic fungi,
and
. Therefore, the molecular inclusion of LCEO into β-CD was successful, as well as the preliminary biological results, evidencing that the β-CD inclusion process may be a viable alternative to facilitate and increase future applications of this EO as therapeutic medication, food additive and natural antifungal agent.
USE OF COMPLEXING AGENTS FOR INCREASED TARGETED PRODUCTION OF CYCLODEXTRINS BY COMMERCIAL ENZYME TORUZYME®. Cyclodextrins (CDs) are cyclic oligosaccharides, products of the intramolecular ...transglycosylation reaction promoted by the enzyme cyclomaltodextrin glucanotransferase (CGTase). The most commonly produced CDs are a-CD, b-CD and g-CD, composed of 6, 7 and 8 glucose molecules, respectively. They form non-covalent inclusion complexes with several molecules, increasing their stability and/or solubility. Due to the importance of CDs and the various industrial applications, this work aimed to use the commercial enzyme Toruzyme® to obtain CDs and direct its production to a-CD or b-CD through the use of ethanol and complexing agents in the reaction medium. The reaction medium added with ethanol and cyclohexanecarboxylic acid directed the production to b-CD, reaching 47.09 mg mL-1 of this molecule. The production medium containing ethanol and stearic acid proved to be more advantageous for the production of a-CD and, after 48 h of reaction, the production of a-CD reached 19.57 mg mL-1, a value six times greater than that of amount of b-CD produced. With this study it was possible to prove that with the use of ethanol and complexing agents in the reaction medium it is possible to direct the production of a certain CD and, thus, make different CGTases economically viable for industrial use.
This research evaluated the chemical composition of
Ocimum basilicum
and
Syzygium aromaticum
and to characterize their complex with β-cyclodextrin (β-CD) using physical mixing, kneading, and ...co-precipitation methods. Gas chromatography coupled to a mass spectrometer showed that methyl-chavicol and eugenol were, respectively, the major compounds from
O. basilicum
and
S. aromaticum
. By the use different vibrational spectroscopic methods (ATR-FTIR and FT-Raman) and thermal analysis (DSC and TGA), it was possible to strongly suggest the formation of EO-β-CD complex. The antioxidant activity was evident in
S. aromaticum
EO due to the presence of the eugenol compound in the complexes. The antioxidant stability was evaluated at different temperatures, in which OE had its antioxidant activity reduced drastically while the complexes had a reduction of 6–13% of its activity. The antimicrobial activity was observed for EO and its complexes of
S. aromaticum
against yeasts of the genus Candida, in which there was a reduction of the concentration of the MIC and CFM for the complexes formed by the co-precipitation methodology. The antitumor activity against HT-29 and HeLa cells was observed in both EOs, in contrast, the cytotoxicity of EOs was also increased. The complex formed from OE
S. aromaticum
showed the best antitumor activity against HT-29 cells (IC 50 = 12.5 µg/mL) with a better selectivity index (IS = 12.32). It is concluded that the techniques used were suitable for the confirmation of the complexes with β-CD, and that the complexation contributed with the stability and action of the essential oils evaluated, allowing their use in the various industrial sectors, such as pharmaceutical and food industry.
Graphic abstract
Curdlan is a linear polysaccharide considered a dietary fiber and with gelation properties. This study evaluated the structure, morphology and the physicochemical and technological properties of ...curdlan produced by Agrobacterium sp. IFO 13140 recovered by pre-gelation and precipitation methods. Commercial curdlan submitted or otherwise to the pre-gelation process was also evaluated. The data obtained from structural analysis revealed a similarity between the curdlan produced by Agrobacterium sp. IFO 13140 (recovered by both methods) and the commercial curdlans. The results showed that the curdlans evaluated differed significantly in terms of dispersibility and gelation, and only the pre-gelled ones had significant potential for food application, because this method influence on the size of the particles and in the presence of NaCl. In terms of technological properties, the curdlan produced by Agrobacterium sp. IFO 13140 (pre-gelation method) had a greater water and oil holding capacity (64% and 98% greater, respectively) and a greater thickening capacity than the pre-gelled commercial curdlan. The pre-gelled commercial curdlan displayed a greater gelling capacity at 95°C than the others. When applied to food, only the pre-gelled curdlans improved the texture parameters of yogurts and reduced syneresis. The curdlan gels, which are rigid and stable in structure, demonstrated potential for improving the texture of food products, with potential industrial use.
Nystatin (Nys) is a fungicidal drug commonly prescribed for candidiasis disease in several administration routes. However, Nys is a class IV drug, according to the Biopharmaceutical Classification ...System, that possesses limited bioavailability and is used for local activity.
This study developed and characterized nystatin:β-cyclodextrin (Nys:βCD) inclusion complexes and evaluated their activity against
spp.
Complexes were characterized by physicochemical techniques and drug dissolution profiles. The susceptibility of
and
was assessed using the broth microdilution method. The applicability of Nys:βCD inclusion complex was evaluated by incorporating it into a temporary soft material for denture stomatitis treatment.
Nys was better complexed in a 1:1 molar ratio by freeze-drying and spray-drying methods. The inclusion complexes show bi-exponential release, an initial burst release followed by a sustained manner, presenting higher dissolution efficiency than raw Nys. The 1:1 freeze-drying Nys:βCD complex presents antifungal activity against all evaluated
strains, showing the maintenance of the drug effectiveness. The inclusion complex incorporated into a tissue conditioner material for denture stomatitis treatment effectively inhibited more than 90% of C. albicans biofilm growth during 7 and 14 days, in a half dose compared to raw Nys.
This work represents a significant contribution to treating a wide variety of diseases caused by the
species, optimizing the drug bioavailability and compliance to the treatment due to improved drug solubility, dissolution, and sustained delivery.
Curdlan production by Agrobacterium sp. IFO13140 immobilized on loofa sponge, alginate and loofa sponge with alginate was investigated. There was no statistically-significant difference in curdlan ...production when the microorganism was immobilized in different matrices. The loofa sponge was chosen because of its practical application and economy and because it provides a high stability through its continued use. The best conditions for immobilization on loofa sponge were 50 mg of cell, 200 rpm and 72 h of incubation, which provided a curdlan production 1.50-times higher than that obtained by free cells. The higher volumetric productivity was achieved by immobilized cells (0.09 g/L/h) at 150 rpm. The operating stability was evaluated, and until the fourth cycle, immobilized cells retained 87.40% of the production of the first cycle. The immobilized cells remained active after 300 days of storage at 4 °C. The results of this study demonstrate success in immobilizing cells for curdlan biosynthesis, making the process potentially suitable for industrial scale-up. Additional studies may show a possible contribution to the reduction of operating costs.
•Complexation of the essential oil C. matinii (EOP) with β –CD;.•ATR-FTIR, FT-Raman, DSC and TGA methods suggested the formation of the EO-β-CD complex;.•Complexation efficiency by co-precipitation ...and kneading methods of 77.68% and 47.74%, respectively;.•Bioactivity of the complexes, as antifungal and antitumor activity superior to pure EO;.•EOP + β –CD stability against pure EO degradation for 14 days;.
An essential oil complex (EOP) of Cymbopogon martinii with β-cyclodextrin (β-CD) was evaluated as a strategy to stabilize the essential oil of Palmarosa and increase its bioactivity. The complexation methods used were co-precipitation and kneading, and, for comparison, physical mixing was carried out. To confirm the molecular inclusion, techniques were combined for the characterization of the inclusion complex, such as Fourier Transformer Raman Spectroscopy (FT-Raman), Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR), Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA), which suggested the formation of the EOP-β-CD complex with complexation efficiency through the co-precipitation and kneading methods of 77.68% and 47.74%, respectively. Stability of the free and complexed EOP in relation to major compounds (linalool, geraniol, geranyl acetate and caryophyllene) during 14 days of storage was analyzed through Headspace Gas Chromatography coupled with Mass Spectrometry. Geraniol showed stability over the period of evaluation and increased availability when complexed by the Co-precipitation and kneading complex. Furthermore, the antifungal and antitumor activity of the EOP-β-CD complex was evaluated, showing reduced mycelial growth against Aspergillus flavus and Fusarium verticillioides strains compared to the free EOP (percentage of inhibition to toxigenic fungi A. flavus EOP-KM: 29.41%; EOP-CP and EOP-PM: 24.37 and 14.28%, respectively, and, the free EOP with 11.76%). In addition, an interesting activity against tumor cells (HeLa and HT-29) was observed against the tested complexes, which emphasizes the importance of the biotechnological use of β-CD for the stability of natural compounds.
Fish bones are a natural calcium phosphate (CaP) sources used in biomaterials production for bone regeneration. CaP scaffolds can be enriched with other substances with biological activity to improve ...bone repair. This study aimed to evaluate the physicochemical properties and bone regeneration potential of biphasic calcium phosphate (BCP) scaffolds impregnated with free curcumin (BCP-CL) or complexed with β-cyclodextrin (BCP-CD) compared to BCP scaffolds. Rietveld's refinement showed that BCP is composed of 57.2% of HAp and 42.8% of β-TCP and the molar ratio of Ca/P corresponds to 1.59. The scaffolds presented porosity (macro and microporosity) of 57.21%. Apatite formation occurred on the BCP, BCP-CL, and BCP-CD surface, in vitro, in SBF. Micro-Raman technique showed a reduction in the dissolution rate of β-TCP in the curcumin-impregnated scaffolds over time, and in vivo studies on critical-size defects, in rat calvaria, had no additional regenerative effect of BCP-CL and BCP-CD scaffolds, compared to BCP scaffolds. Despite this, the study showed that curcumin impregnation in BCP scaffolds prolongs the release of the β-TCP phase, the BCP- phase with the higher osteoinductive potential, representing an advantage in tissue engineering.
A repetitive batch process was employed followed by membrane ultrafiltration system to produce low-cost cyclodextrins (CDs) using commercial enzymes Toruzyme® cyclomaltodextrin glucanotransferase ...(CGTase) and its kinetic parameters were determined. The ultrafiltration system enabled the removalof inhibitory products from the reaction medium, allowing the enzyme to be recovered for reuse. A 10 kDa membrane was used to separate the different CDs produced by the CGTase. The substrates evaluated were maltodextrin, corn starch and cassava starch at 5, 10 and 15% (w/V), in the presence and absence of 10% (V/V) ethanol. After reaction for 132 h, 10% (w/V) cassava starch in the presence of ethanol provided the best results with 32.1 mg/mL of β-CD. Maximum production occurred after 72 h of reaction, with a yield of 87.4% of β-CD and an α-CD, β-CD and γ-CD production ratio of 1:1:0.08 g, respectively. When eight repetitive batches of 72 h followed by ultrafiltration and crystallization of β-CD were performed, 2.1 g of precipitate was obtained with a purity of 67.6% β-CD. The supernatant from the crystallization process was lyophilized and resulted in 35.3% α-CD. The developed model can be used industrially for the production of low cost CDs from easily obtained raw material.
The alkalophilic
Bacillus sphaericus strain 41 was isolated from soybean-soil culture, using a highly alkaline pH medium containing 1% Na
2CO
3. The cyclodextrin glycosyltransferase (CGTase) from ...this microorganism was purified up to 315-fold with a yield of 31%, by biospecific affinity-column chromatography using Sepharose 6B gel and β-cyclodextrin (β-CD) as the ligand. The molecular weight of the purified enzyme was estimated to be 59
kDa by SDS-PAGE. In addition to the cyclization, the CGTase showed disproportionation and coupling activities. For cyclization activity, the optimal pH was 6.0 and the temperature was 65
°C. The enzyme showed pH stability in the range of 6.0–7.0. Thermal deactivation was noticeable above 70
°C, and the enzyme was highly stable below 65
°C. The activation and deactivation energy for the production of β-CD were 9.4
kcal/mol and 28.0
kcal/mol, respectively. The influence of substrate concentration on the initial rate of CD production was studied, and the kinetic parameters were determined. The
K
m
was 0.0008
mol/L and
V
max
was 0.0631
mol of β-CD/(L
h), using maltodextrin as substrate. The CGTase was strongly inhibited by the products, and produced a level of CDs reaching 22
g/L with a β-CD ratio of 54%. This enzyme produced α-, β- and γ-CD in the ratio of 0.40:1:0.45.
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