Self-Organizing Maps as a New Tool for Classification of Plants at Lower Hierarchical Levels

A chemotaxonomic analysis is described of a database containing various types of compounds from the Heliantheae tribe (Asteraceae) using Self-Organizing Maps (SOM). The numbers of occurrences of 9 chemical classes in different taxa of the tribe were used as variables. The study shows that SOM applied to chemical data can contribute to differentiate genera, subtribes, and groups of subtribes (subtribe branches), as well as to tribal and subtribal classifications of Heliantheae, exhibiting a high hit percentage comparable to that of an expert performance, and in agreement with the previous tribe classification proposed by Stuessy.

Nestmate recognition in a stingless bee: does the similarity of chemical cues determine guard acceptance?

The ability to discriminate nestmates from non-nestmates is critical to the maintenance of the integrity of social insect colonies. Guard workers compare the chemical cues of an incoming individual with their internal template to determine whether the entrant belongs to their colony. In contrast to honeybees, Apis mellifera, stingless bees have singly mated queens and, therefore, are expected to have a higher chemical homogeneity in their colonies. We tested whether aggressive behaviour of Frieseomelitta varia guards towards nestmate and non-nestmate foragers reflects chemical similarities and dissimilarities, respectively, of cuticular hydrocarbon profiles. We also introduced individuals of Lestrimelitta limao, an obligatory robber species, to test the ability of guards to react effectively to intruders from other taxa. We verified that foraging nestmates were almost invariably accepted, while heterospecific and conspecific non-nestmates were rejected at relatively high rates. However, non-nestmate individuals with higher chemical profile similarity were likely to be accepted by guards. We conclude that guards compare the chemical cuticular blend of incoming individuals and make acceptance decisions according to the similarity of the compounds between the colonies. (c) 2007 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

Chemical Signals in the Stingless Bee, Frieseomelitta varia, Indicate Caste, Gender, Age, and Reproductive Status

Chemical compounds on the cuticle are a rich source of information used during interactions among social insects. Despite the multitude of studies on these substances and their function in ants, wasps, and honeybees, little is known about this subject in stingless bees (Hymenoptera: Apidae, Meliponini). We studied the chemical composition of the cuticle of the stingless bee, Frieseomelitta varia, by gas chromatography-mass spectrometry (GC-MS), to investigate potential chemical variation among castes, gender, age, and reproductive status. We found differences in the cuticular hydrocarbon composition among workers, males, and queens, recording both qualitative and quantitative differences among individuals of different ages and gender. The cuticle of physogastric queens presented a chemical profile that was distinct from all other groups in the analysis, with high relative abundances of alkenes and alkadienes with 27, 29, and 31 carbon atoms. We discuss the possibility that these compounds signal a queen`s presence to the colony, thereby initiating all vital worker-queen interactions.

THE ROLE OF COLLOIDAL SILICON DIOXIDE IN THE ENHANCEMENT OF THE DRYING OF HERBAL PREPARATIONS IN SUSPENDED STATE

Recently, some research groups have been developing studies aiming to apply spouted beds of inert particles for production of dried herbal extracts. However, mainly due to their complex composition, several problems arise during the spouted bed drying of herbal extracts such as bed instability, product accumulation, particle agglomeration, and bed collapse. The addition of drying carriers, like colloidal silicon dioxide, to the extractive solution can minimize these unwanted effects. The aim of this work was to study the influence of the addition of colloidal silicon dioxide on enhancement of the performance of the drying of hydroalcoholic extract of Bauhinia forficata Link on a spouted bed of inert particles. The physical properties of the herbal extract and of its mixture with colloidal silicon dioxide at several concentrations (20% to 80% related to solids content) were quantified by determination of the surface tension, rheological properties, density, pH, and contact angles with the inert surfaces. Drying performance was evaluated through determination of the elutriation ratio, product recovery ratio, and product accumulation. The product was characterized through determination of the thermal degradation of bioactive compounds and product moisture content. The results indicated that the rheological properties of the extracts and their preparations, the contact angle with inert material, and the work of adhesion play important roles in the spouted bed drying of herbal extracts. Higher concentration of the drying carrier significantly improved the spouted bed drying performance.

Azaphilones from the Endophyte Chaetomium globosum

Six new azaphilones, 5`-epichaetoviridin A (7), 4`-epichaetoviridin F (9), 12 beta-hydroxychaetoviridin C (10), and chaetoviridins G-I (11-13), and six known azaphilones, chaetoviridins A E (1-5) and 4`-epichaetoviridin A (8), were isolated from the endophytic fungus Chaetomium globosum cultivated in PDB medium for 21 days. The structure elucidation and the assignment of the relative configurations of the new natural products were based on detailed NMR and MS spectroscopic analyses. The structure of compound 1 was confirmed by single-crystal X-ray diffraction analysis. were determined using Mosher`s method. The antibiotic activity of the elegans infection model. The absolute configurations of compounds 4, 7, 8, and 12 compounds was evaluated using an in vivo Caenorhabditis elegans infection model.

Quercetin in lyotropic liquid crystalline formulations: Physical, chemical and functional stability

The purpose of this study was to develop a lyotropic liquid crystalline formulation using the emulsifier vitamin E TPGS and evaluate its behavior after incorporation of a flavonoid, quercetin. The physical (macro and microscopic), chemical (determination of quercetin content by the HPLC method) and functional (determination of quercetin antioxidant activity by DPPH center dot assay) stability of the lamellar liquid crystalline formulation containing flavonoid was evaluated when stored at 4+/-2 degrees C; 30+/-2 degrees C/70+/-5% RH (relative humidity) and 40+/-2 degrees C/70+/-5% RH during 12 months. The lamellar liquid crystalline structure of the formulation was maintained during the experiment, however chemical and functional stability results showed a great influence of the storage period in all conditions tested. A significant decrease in quercetin content (approximately 40%) was detected during the first month of storage and a similar significant loss in antioxidant activity was detected after 6 months. The remaining flavonoid content was unchanged during the final 6 months of the experimental period. The results suggest possible interactions between quercetin and the liquid crystalline formulation, which could inhibit or reduce the quercetin activity incorporated in the system. In conclusion, the present study demonstrated that incorporation of quercetin (1%) did not affect the liquid crystalline structure composed of vitamin E TPGS/IPM/PG-H2O (1:1) at 63.75/21.25/15 (w/w/w). Nevertheless, of the total quercetin incorporated in the system only 60% was free to act as an antioxidant.

Comparison of the chemical composition of the essential oil and the water soluble oil of Baccharis dracunculifolia DC. (Asteraceae)

This study aimed to evaluate the chemical composition of Baccharis dracunculifolia essential oil and the water soluble oil obtained by steam distillation that were analyzed by GC and GUMS. in the first hour of distillation, B. dracunculifolia aerial parts yielded 0.08% oil and in the second hour, 0.27%. The oil recovered from the distillate water yielded 0.18 g/L in the first hour and 0.44 g/L in the second hour of distillation. The main volatile compounds identified in the distillate water were aromatic compounds and sesquiterpene alcohols.

Effect of the Maillard reaction on properties of casein and casein films

The use of biodegradable natural polymers has increased due to the over-solid packaging waste. In this study, a chemical modification of the casein molecule was performed by Maillard reaction, and the modified polymer was evaluated by polyacrylamide gel electrophoresis (PAGE), thermogravimetry/derivative thermogravimetry (TG/DTG), FT-IR, and (1)H-NMR spectroscopy. Subsequently, films based on the modified casein were obtained and characterized by mechanical analysis, water vapor transmission, and erosion behavior. The PAGE results suggested an increase of molecular mass of the modified polymer, and FT-IR spectroscopy data indicated inclusion of C-OH groups into this molecule. The TG/DTG curves of modified casein presented a different thermal decomposition profile compared to the individual compounds. Mechanical tests showed that the chemical modification of the casein molecules provided higher elongation rates (45.5%) to the films, suggesting higher plasticity, than the original molecules (13.4%). The modified casein films presented higher permeability (0.505 +/- A 0.006 mu g/h mm(3)) than the original polymer (0.387 +/- A 0.006 mu g/h mm(3)) films at 90% relative humidity (RH). In pH 1.2, modified casein films presented higher erosion rates (32.690 +/- A 0.692%) than casein films (19.910 +/- A 2.083%) after 8 h, suggesting an increased sensibility for erosion of the modified casein films in acid environment. In water (pH 7.0), the films erosion profiles were similar. Those findings indicate that the modification of molecule by Maillard reaction provided films more plastic, hydrophilic, and sensitive to erosion in acid environment, suggesting that a new polymer with changed properties was founded.

Validation of a gas chromatographic method to quantify sesquiterpenes in copaiba oils

Copaifera species (Leguminoseae) are popularly known as ""copaiba"" or ""copaiva"". The oleoresins obtained from the trunk of these species have been extensively used in folk medicine and are commercialized in Brazil as crude oil and in several pharmaceutical and cosmetic products. This work reports a complete validated method for the quantification of beta-caryophyllene, alpha-copaene, and alpha-humulene in distinct copaiba oleoresins available commercially. Thus, essential oil samples (100 mu L) were dissolved in 20 mL of hexanes containing internal standard (1,2,4,5-tetramethylbenzene, 3.0 mM) in a 25 mL glass flask. A 1 mu L aliquot was injected into the GC-FID system. A fused-silica capillary column HP-5, coated with 5% phenylmethylsiloxane was used for this study. The developed method gave a good detection response with linearity in the range of 0.10-18.74 mM. Limits of detection and quantitation variety ranged between 0.003 and 0.091 mM. beta-Caryophyllene, alpha-copaene, and alpha-humulene were recovered in a range from 74.71% to 88.31%, displaying RSD lower than 10% and relative errors between -11.69% and -25.30%. Therefore, this method could be considered as an analytical tool for the quality control of different Copaifera oil samples and its products in both cosmetic and pharmaceutical companies. (C) 2010 Elsevier B.V. All rights reserved.

Development of a Phytopharmaceutical Intermediate Product via Spray Drying

The influence of concentration and incorporation time of different drying excipients on the processing yields and physical properties of Eugenia dysenterica DC spray-dried extracts were investigated following a factorial design. Under the established conditions, the process yield ranged from 57.55 to 89.14%, and in most experiments, the recovered products presented suitable flowability and compressibility, as demonstrated by the Hausner factor, Carr index, and angle of repose. Additionally, in a general way, the parameters related to the dried products` flowability varied over a range acceptable for pharmaceutical purposes. An analysis of variance (ANOVA) proved that both factors and some of their interactions significantly affected most of the investigated responses at different levels. Mannitol proved to be an interesting alternative as an excipient for the drying of herbal extracts, even at low concentrations such as 12.5%. Furthermore, these results imply that the best condition to obtain dry extracts of E. dysenterica with high performance and adequate pharmacotechnical properties involves the lowest concentration and the highest incorporation time of mannitol.

Spray Drying of Extracts from Red Yeast Fermentation Broth

Red yeast rice is a pigmented material that is traditionally used in Asia as a food colorant. In addition to food applications, red yeast rice is known in traditional Chinese medicine for its therapeutic actions. The aim of this work was to study the quality interactions during spray drying of extracts from the Monascus ruber van Tiegham fermentation broth. The quality indicators used for the dry powder properties were the levels of monacolin K, ratio of red to yellow pigments, as well as their antioxidant activity. The experiments followed a Box-Behnken design to study the effects of the adjuvant/drug ratio, adjuvant incorporation time, and oulet drying temperature on the pharmacotechnical, chemical, and biological properties of the dry extract. The influences of these factors on the characteristics of the dry powder were evaluated by the bulk density, tapped density, Carr index, Hausner factor, residual moisture content, water activity, antioxidant activity, monacolin K, yellow-to-red pigment ratio, and antioxidant activity. The analysis of variance (ANOVA) on experimental data revealed that an increase in drying temperature significantly increased the dry powder yield and caused an improvement in powder flow properties, which may be related to lower moisture contents. The drying temperature did not affect the monacolin K content in dry powder but showed a complex influence on its antioxidant activity. The increase in drying adjuvant-to-drug ratio affected the yield and also indicated a protective effect on the monacolin K content. The duration of drying adjuvant incorporation had little or negligible effect on powder properties. The dry extracts of red yeast rice showed adequate properties and the process proposed herein can be used to prepare nutraceutical products.

Characterization and stability study of a water-in-oil microemulsion incorporating quercetin

Background: The effectiveness of a water/oil (w/o) microemulsion containing quercetin against ultraviolet B radiation (UVB) induced damage was recently demonstrated by our group. However, during the development of new pharmaceutical products, the evaluation of percutaneous absorption and in vivo effectiveness should be accompanied by evaluation of stability parameters as an integral part of the process. Objective: The aim was to investigate the stability of the final microemulsion formulation considering the temperature ranges of storage and application. Methods: The physical, chemical, and functional stability of this formulation under different conditions of storage during 12 months and the photostability of quercetin incorporated into this system over UVB exposure for 7 days were evaluated. Results: Although the results indicated a notable physical stability of the w/o microemulsions during the experimental period under all employed conditions, in both, the chemical and functional studies, a significant loss of quercetin content and antioxidant activity was found after 6 months of storage at 30 degrees C/70% relative humidity and after 2 months at 40 degrees C/70% relative humidity. The photostability study results demonstrated that the incorporation of quercetin into the w/o microemulsion maintained the previously demonstrated photostability of this flavonoid under forced exposure to UVB irradiation. Conclusion: Thus, this work demonstrates that special storage conditions (at 4 +/- 2 degrees C) are necessary to maintain the functionality of the w/o microemulsion containing quercetin and mainly emphasizes the importance of studying physical, chemical, and functional parameters at the same time during stability evaluation of active principles.

Stabilization of Endophytic Fungus Cercospora kikuchii Lipase by Spray Drying in the Presence of Maltodextrin and beta-Cyclodextrin

In this study the effects of spray-drying conditions on the retention of enzyme activity of lipase produced by the endophytic fungus Cercospora kikuchii have been investigated. Drying runs were carried out in a bench-top spray dryer with a concurrent flow regime. The influence of the variables inlet temperature of drying gas, Tgi (86.4 to 153.6 degrees C); mass flow rate of the enzymatic extract fed to the dryer, Ws (2.63 to 9.36g/min); and concentration of the drying adjuvant added to the extract, ADJ (1.95 to 12.05%), on the spray-drying performance and on product quality was evaluated through experimental planning and regression analysis. The use of maltodextrin, as a stabilizing agent, slightly improved the retention of enzyme activity compared to -cyclodextrin. Statistical optimization of the experimental results allowed the determination of the processing conditions that maximized the retention of the enzymatic activity (RAE), namely, concentration of drying adjuvants of 12.05%, inlet temperature of the drying gas of 153.6 degrees C, and flow rate of the enzymatic extract fed to the dryer of 9.36g/min for the both drying adjuvants investigated.

A stabilized demethoxyviridin derivative inhibits PI3 kinase

The viridins like demethoxyviridin (Dmv) and wortmannin (Wm) are nanomolar inhibitors of the PI3 kinases, a family of enzymes that play key roles in a host of regulatory processes. Central to the use of these compounds to investigate the role of PI3 kinase in biological systems, or as scaffolds for drug development, are the interrelated issues of stability, chemical reactivity, and bioactivity as inhibitors of PI3 kinase. We found that Dmv was an even more potent inhibitor of PI3 kinase than Wm. However, Dmv was notably less stable than Wm in PBS, with a half-life of 26 min versus Wm`s half-life of 3470 min. Dmv, like Wm, disappeared in culture media with a half-life of less than 1 min. To overcome Dmv`s instability, it was esterified at the C1 position, and then reacted with glycine at the C20 position. The resulting Dmv derivative, termed SA-DmvC20-Gly had a half-life of 218 min in PBS and 64 min in culture media. SA-DmvC20-Gly underwent an exchange reaction at the C20 position with N-acetyl lysine in a manner similar to a WmC20 derivative, WmC20-Proline. SA-DmvC20-Gly inhibited PI3 kinase with an IC(50) of 44 nM, compared to Wm`s IC(50) of 12 nM. These results indicate that the stability of Dmv can be manipulated by reactions at the C1 and C20 positions, while substantially maintaining its ability to inhibit PI3 kinase. Our results indicate it may be possible to obtain stabilized Dmv derivatives for use as PI3 kinase inhibitors in biological systems. (C) 2009 Elsevier Ltd. All rights reserved.