Innovation in a Continuous System of Distillation by Steam to Obtain Essential Oil from Persian Lime Juice (Citrus latifolia Tanaka)

The citrus industry is one of the most important economic areas within the global agricultural sector. Persian lime is commonly used to produce lime juice and essential oil, which are usually obtained by batch distillation. The aim of this work was to validate a patented continuous steam distillation process and to both physically and chemically characterize the volatile fractions of essential Persian lime oil. Prior to distillation, lime juice was obtained by pressing the lime fruit. Afterwards, the juice was subjected to a continuous steam distillation process by varying the ratio of distillate flow to feed flow (0.2, 0.4, and 0.6). The distillate oil fractions were characterized by measuring their density, optical rotation, and refractive index. Gas chromatography GC-FID was used to analyze the chemical compositions of the oil fractions. The process of continuous steam distillation presented high oil recovery efficiencies (up to 90%) and lower steam consumption compared to traditional batch process distillation since steam consumption ranged from 32 to 60% for different steam levels. Moreover, a reduction in process time was observed (from 8 to 4 h). The oil fractions obtained via continuous steam distillation differed significantly in their composition from the parent compounds and the fractions.     

Leaves of Citrus aurantifolia exhibit a different sensibility to solar UV-B radiation according to development stage in relation to photosynthetic pigments and UV-B absorbing compounds production

Plants of Citrus aurantifolia grown in a greenhouse without solar UV radiation (UVR) were transferred outdoors to evaluate the effect of solar UV-B radiation (UVBR, 280–315 nm) in prior-developed leaves, constituted by apical bud and those fully expanded before being taken outdoors, and post-developed leaves, formed by those expanded outdoors. Results demonstrated that over a 40 d outdoor period leaf chlorophyll content and distribution pattern were different with and without solar UVBR. Chlorophyll a, chlorophyll b and total chlorophyll contents in both treatments were higher in prior-developed leaves than in post-developed ones. However, highest values were observed in prior-developed leaves under solar UVBR, whereas in post-developed leaves an opposite trend was observed. Carotenoids content in prior-developed leaves was higher with solar UVBR, whereas in post-developed leaves there were no significant differences in both with and without solar UVBR. In addition, prior-developed leaves under solar UVBR accumulated flavonoids, but not anthocyanins. Growth parameters (e.g. DW, DW/FW ratio, LMA, plant height, length and width of foliar lamina) did not show significant differences between plants grown with and without solar UVBR. Thus, our results demonstrated that C. aurantifolia leaves exhibited a different sensibility to solar UVBR according to development stage in relation to photosynthetic pigments and UV-B absorbing compounds production. In addition, the solar UVBR was not necessary as inductor of photosynthetic protection mechanisms in a short-time growth period. On the other hand, our results also demonstrated that solar UVBR acted as an effective feeding deterrent against citrus leafminer.     

Chemical Profiling and Antimicrobial Properties of Honey Bee (Apis mellifera L.) Venom

The incidence of antibiotic resistance in pathogenic bacteria has become an alarming clinical and social problem. Therefore, the demand for alternative antimicrobial compounds has increased. In this study, a chemical profile of honey bee (Apis mellifera L.) venom (HBV) has been determined by HPLC and FTIR-ATR spectroscopy, and tested for antibacterial activity, as well as efficiency with regard to conventional antibiotics. The investigated HBV was of high quality with melittin and total protein contents of 70.10 ± 7.01%, and 84.44 ± 3.12 g/100 g, respectively. The purity of HBV was confirmed by FTIR-ATR spectral profiling, which revealed a unique pattern of absorption bands that are characteristic of its major fractions. In addition, HBV showed a broad spectrum of activity against all three tested biomasses of potentially pathogenic Gram-positive and Gram-negative bacteria with MIC values ranging between 12.5 and 200 µg/mL, and MBC between 12.5 and 400 µg/mL. When compared to conventional antibiotics, HBV (400 µg) showed up to 27.8% efficiency of tetracycline (30 µg), 52.2% erythromycin (15 µg), 21.2% ciprofloxacin (5 µg), and 34.6% of ampicillin-sulbactam (20 µg). The overall results demonstrate the therapeutic potential of the analyzed HBV.     

Colloidal aggregation phenomena: Spatial structuring of TEOS-derived silica aerogels

In this contribution, the homogeneity of silica aerogels made from tetraethyl orthosilicate (TEOS) was studied by means of Fourier transform infrared (FTIR) and 29Si nuclear magnetic resonance (NMR) spectroscopies. FTIR spectra show a slight difference in the asymmetric Si-O-Si stretching vibration frequency in the outer and inner part of the aerogels. According to the 29Si NMR data, a higher relation Q4/Q3 was obtained in the inner parts of the gels compared with their outer parts, proving the difference in the cross linkage of the silica network. The obtained results are interpreted in terms of the specific spatial structuring of the colloidal suspensions due to the presence of gravity.     

Palygorskite organophilic for dermopharmaceutical application

Due to the growing interest of the population in natural treatments, the clays represent a good alternative to the treatment of wounds. Its modification by organophilization happens when the same inorganic cations are exchanged for organic cations of the surfactant used in the process. Thus, the clay has the properties of its surface modified from being hydrophilic to hydrophobic, improving its functionality on the skin. In order to determine changes in surface palygorskite and to assess its healing action, this clay was organophilizated by two cationic surfactants: dimethyl benzyl ammonium chloride alkyl, and cetyl trimethyl ammonium chloride, and characterized by sieve analysis, property flow, test oil adsorption, and the techniques of X-ray fluorescence, X-ray diffraction, infrared Fourier transform, thermogravimetric analysis, scanning calorimetry—differential and histological of cutaneous wounds in rats. The results indicate that the attapulgite has good rheological properties, a high capacity of adsorption of oil, and the presence of clay minerals that reduce inflammation. The analysis by X-ray fluorescence is not observing any change in the crystal structure of palygorskite organophilizated but through infrared spectroscopy Fourier transform, verifying the interaction and incorporation of the clay ammonium salts, as well as thermoanalytical analysis also suggests that the organophilic process reduces the hydrophilic character of palygorskite. The histological analysis showed healing effect after topical application of natural and organophilizated clay in skin wounds in rats. These analyses favor a good prospect of its application in dermopharmaceuticals, because the use of palygorskite provides greater interaction with skin and heals wounds.     

Preparation and X-Ray Structure of 3,4,8-Tris(T-Butyl)- 1,6-Bis(4-Trifluormethylphenyl)-2,5,7,9-Tetraza-3λ3, 4λ5 8λ3-Triphospha [4.3.0]Bicyclonona-1,4,6-Trien (4). Study of the Thermal Stability of 4, and two Other Ci- Clocarbophosphazenes

Abstract

In this work, we expose the synthesis of the new bicyclocarbophosphazene 4, its x-ray crystall structure and the experimental data obtained. The results of the study of thermal stability of 4 and two related compounds are also presented.     

CH, a problem of Rolewicz and bidiscrete systems

We give a construction under CH of a non-metrizable compact Hausdorff space K such that any uncountable ‘nice’ semi-biorthogonal sequence in C(K) must be of a very specific kind. The space K has many nice properties, such as being hereditarily separable, hereditarily Lindelöf and a 2-to-1 continuous preimage of a metric space, and all Radon measures on K are separable. However K is not a Rosenthal compactum.We introduce the notion of a bidiscrete system in a compact space K. These are subsets of K² which determine biorthogonal systems of a special kind in C(K) that we call nice. We note that for every infinite compact Hausdorff space K, the space C(K) has a bidiscrete system and hence a nice biorthogonal system of size d(K), the density of K.     

Synthesis of all low-energy stereoisomers of the tris(pyrrolidinoindoline) alkaloid hodgkinsine and preliminary assessment of their antinociceptive activity

The previously unknown stereoisomers 3, 4, ent-1, and ent-4 of the tris(pyrrolidinoindoline) alkaloids hodgkinsine (1) and hodgkinsine B (2) were prepared by stereocontrolled total synthesis. In each synthesis, a catalyst-controlled intramolecular Heck reaction was the key step in appending a third cis-pyrrolidinoindoline ring to a hexacyclic chimonanthine precursor. Results of the preliminary evaluation of these hodgkinsine stereoisomers in the tail flick and capsaicin pain models are reported.     

Model-free kinetics applied for the removal of CTMA<Superscript>+</Superscript> and TPA<Superscript>+</Superscript> of the nanostructured hybrid AlMCM-41/ZSM-5 material

The nanostructured hybrid AlMCM-41/ZSM-5 composite was synthesized starting from a hydrogel with molar composition SiO₂:0.32Na₂O:0.03Al₂O₃:0.20TPABr:0.16CTMABr:55H₂O. The cetyltrimethylammonium bromide (CTMABr) and tetrapropylammonium bromide (TPABr) were used as templates. The above mentioned material presents morphological properties with specific characteristics, such as the surface area of the composite which is approximately half of the surface area of the conventional MCM-41. Another interesting feature is the formation of walls with the double of the density of the MCM-41 structure, which characterizes the hybrid material, resulting in a high stability material for catalytic application. The aim of this study is obtain optimized structures of the hybrid material and for this purpose variations in the synthesis time were carried out. A comparative analysis was performed including X-ray diffraction, Fourier transform infrared spectroscopy, and Thermogravimetry measurements. The model-free kinetic algorithms were applied in order to determinate conversion and apparent activation energy of the decomposition of the CTMA⁺ and TPA⁺ species from the hybrid AlMCM-41/ZSM-5.