Método preparativo para la obtención de ácido ursólico a partir de Clinopodium revolutum / Preparative method to obtain ursolic acid from Clinopodium revolutum / Método preparativo para a obtenção do ácido ursólico a partir de Clinopodium revolutum

Resumen En este trabajo se propuso un método para obtener ácido ursólico de manera fácil, rápida y económica teniendo como materia prima la planta medicinal Clinopodium revolutum endémica del Perú, conocida y comercializada con el nombre de flor de arena o té indio. La técnica de recristalización selectiva que se empleó resultó ser eficiente debido a que se obtuvieron cristales de AU sin la necesidad de métodos cromatográficos de purificación ni el uso de solventes tóxicos. La pureza determinada por HPLC es mayor a 95%. Así, la flor de arena se convierte en una importante biofuente de este compuesto.

Abstract A method to obtain ursolic acid (UA) in an easy, fast, and economical way was proposed, having as raw material the medicinal plant Clinopodium revolutum from Peru. This plant is known and marketed as flor de arena or té indio. The selective recrystallization technique used was efficient since UA crystals were obtained without the need for chromatographic purification methods or the use of toxic solvents. The purity determined by HPLC is greater than 95%. Thus, the flor de arena becomes an important biosource of this compound.

Resumo Este trabalho apresenta um método para a obtenção de ácido ursólico de forma fácil, rápida e barata tendo como matéria prima a planta medicinal Clinopodium revolutum endêmica do Perú, conhecida e comercializada pelo nome de flor de arena ou té indio. A técnica seletiva de recristalização resultou ser eficiente, devido os cristais da AU foram obtidos sem a necessidade de métodos cromatográficos de purificação nem a utilização de solventes tóxicos. A pureza determinada pela HPLC é superior a 95%. Assim, a flor de arena torna-se uma biofonte importante deste composto.

Improvement in Ovarian Tissue Quality with Supplementation of Antifreeze Protein during Warming of Vitrified Mouse Ovarian Tissue

Ice easily recrystallizes during warming after vitrification, and antifreeze protein (AFP) can inhibit the re-crystallization. However, no study has evaluated the effect of AFP treatment only thereon during warming. This study sought to compare AFP treatment protocols: a conventional protocol with AFP treatment during vitrification and first-step warming and a new protocol with AFP treatment during the first-step warming only. According to the protocols, 10 mg/mL of LeIBP (a type of AFP) was used. Five-week-old B6D2F1 mouse ovaries were randomly divided into a vitrified-warmed control and two experimental groups, one treated with the conventional AFP treatment protocol (LeIBP-all) and the other with the new AFP treatment protocol (LeIBP-w). For evaluation, ratios of ovarian follicle integrity, apoptosis, and DNA double-strand (DDS) damage/repairing were analyzed. The LeIBP-treated groups showed significantly higher intact follicle ratios than the control, and the results were similar between the LeIBP-treated groups. Apoptotic follicle ratios were significantly lower in both LeIBP-treated groups than the control, and the results were not significantly different between the LeIBP-treated groups. With regard to DDS damage/repairing follicle ratio, significantly lower ratios were recorded in both LeIBP-treated groups, compared to the control, and the results were similar between the LeIBP-treated groups. This study demonstrated that both protocols with LeIBP had a beneficial effect on maintaining follicle integrity and preventing follicle apoptosis and DDS damage. Moreover, the new protocol showed similar results to the conventional protocol. This new protocol could optimize the mouse ovary vitrification-warming procedure using AFP, while minimizing the treatment steps.

Limit growth of ice crystals under different temperature oscillations levels in nile Tilapia

Abstract The degenerative effect of temperature fluctuations during storage time is a critical condition that needs to be quantitatively characterized in products where drip losses are appreciable. In this work, real storage conditions were reproduced using freezers modified to cause 3 levels of temperature fluctuation (± 0, ± 3, ± 5; ± 7) during storage of Tilapia (Oreochromis sp), at temperature of -18 °C. The fast frozen tilapia muscle (freezing cabinet) was chosen to quantify the growth of ice crystals according to temperature fluctuations. The identification of crystals in the optical microscope as well as histological treatments and measurements using specific software has shown that the growth of ice crystals in the first days of storage follows an asymptote, whose final value is conditioned only by the level of temperature fluctuations regardless of initial diameter, which begins storage. It has also been found that the growth of crystals formed during rapid freezing rapidly develops according to temperature fluctuations to which the product has been subjected. This work also identified statistically significant differences in the equivalent diameter of crystals formed at the four proposed levels of temperature fluctuation with significance level of p < 0.05.

Preparation and Characterization of Betulinic Acid Nanoparticles / 中国药房

OBJECTIVE:To prepare the betulinic acid nanoparticles,and characterize them. METHODS:Using ethanol as sol-vent and water as anti-solvent,anti-solvent recrystallization method was used to prepare betulinic acid nanoparticles. Using particle size as indicator,single factor test and orthogonal test were adopted to optimize the mass concentration of betulinic acid solution, anti-solvent-solvent volume ratio,anti-solvent drip rate,reaction temperature and stirring speed in formulation technology of betulin-ic acid nanoparticles,and verification test was conducted. The betulinic acid nanoparticles were characterized by scanning electron microscopy,laser particle size analyzer,Fourier infrared spectrometer and mass spectrum analyzer. RESULTS:The optimal technol-ogy was as follow as betulinic acid solution mass concentration of 3 mg/mL,anti-solvent-solvent volume ratio of 1:1,anti-solvent drip rate of 8 mL/min,reaction temperature of 20 ℃ and stirring speed of 900 r/min. The average size of prepared betulinic acid nanosuspension was(156.0±8.6)nm(n=3)and the particle size was(235.0±12.2)nm(n=3)after freeze-drying,with nearly spherical appearance,uniform size and regular form. Compared with raw material of betulinic acid,the chemical structure of pre-pared betulinic acid nanoparticles did not change,and there were no significant changes in molecular weight and mass ratio. CON-CLUSIONS:Betulinic acid nanoparticles are successfully prepared.

Study on the Chemical Constituents of Rabdosia rubescens / 中国药房

OBJECTIVE:To study the chemical constituents of Rabdosia rubescens. METHODS:The chemical constituents of R. rubescens were isolated and purified by silica gel,MCI GEL-CHP 20P,Sephadex LH-20 column and recrystallization,and their structure was identified on the base of spectral analysis and physicochemical properties. RESULTS:8 compounds were isolated in R. rubescens and identified as 24ζ-methyl-5α-lanosta-25-ketone(1),maoyecrystal F(2),rosthorin A(3),β-sitosterol(4),daucosterol (5),heptacosanoic acid (6),oridonin (7) and ponicidin (8). CONCLUSIONS:Compound 1 is isolated from R. genera for the first time and compound 3,6 are isolated from this plant for the first time. The research lays a certain foundation for the quality evaluation of R.rubescens.

Antifreeze proteins enable plants to survive in freezing conditions.

Overwintering plants secrete antifreeze proteins (AFPs) to provide freezing tolerance. These proteins bind to and inhibit the growth of ice crystals that are formed in the apoplast during subzero temperatures. Antifreeze activity has been detected in more than 60 plants and AFPs have been purified from 15 of these, including gymnosperms, dicots and monocots. Biochemical characterization of plant antifreeze activity, as determined by the high ice recrystallization inhibition (IRI) activities and low thermal hysteresis (TH) of AFPs, showed that their main function is inhibition of ice crystal growth rather than the lowering of freezing temperatures. However, recent studies showed that antifreeze activity with higher TH also exists in plants. Calcium and hormones like ethylene and jasmonic acid have been shown to regulate plant antifreeze activity. Recent studies have shown that plant AFPs bind to both prism planes and basal planes of ice crystals by means of two flat ice binding sites. Plant AFPs have been postulated to evolve from the OsLRR-PSR gene nearly 36 million years ago. In this review, we present the current scenario of plant AFP research in order to understand the possible potential of plant AFPs in generation of freezing-tolerant crops.

Representation and in vitro transdermal characteristics of glycyrrhizic acid nanoparticles prepared by antisolvent recrystallization method / 中草药

Objective: To prepare glycyrrhizic acid nanoparticles (GAN) using ethanol as solvent and ethyl acetate as the antisolvent, and to investigate the osmosis of GAN as carrier of dermal administration. Methods: Using scanning electron microscope (SEM), laser particle size analyzer, Fourier transform-infrared spectroscopy (FT-IR), and release rate analysis, the untreated glycyrrhizic acid (GA) and GA powder were characterized; In vitro cutaneous permeation experiments were carried out on modified Franz diffusion cells, using excised mouse skin. The concentration of diammonium glycyrrhizinate in the receptor compartments and skin were determined by HPLC. Results: The GAN was spherical, the average particle size was 220 nm, and the dissolution rate of nanosized glycyrrhizinate was improved obviously. The transdermal rate of nanosized glycyrrhizinate was better than the original glycyrrhizin, and the 12 h unit accumulation transmissibility of GAN and GA was 78.51 and 9.792 μg/cm2, respectively. Conclusion: After preparing, the particle size becomes smaller, the chemical structure does not change significantly, and both of dissolution rate and in vitro transdermal performance have been improved. The GAN has the potential application values in the development of pharmaceutical industry.

Effect of Recrystallization on the Pharmaceutical Properties of Valsartan for Improved Therapeutic Efficacy.

Valsartan (VAL) is a potent, highly selective and orally active antihypertensive drug and is poorly soluble in aqueous fluids, especially in gastric fluids, and its absorption is thus dissolution rate limited. In the present research work an attempt has been made to improve the aqueous solubility of VAL by the recrystallization of VAL from a variety of different organic solvents, and evaluating the recrystallized VAL products for its physicochemical characteristics and in-vitro dissolution properties. The water solubility of methanol (MET), ethanol (ETH), isopropanol (ISP) and acetonitrile (AN) recrystallized products of VAL is significantly higher when compared to untreated VAL. Physicochemical characterization techniques like scanning electron microscopy, differential scanning calorimetry, powder X-RD reveal the change in crystallinity of VAL with recrystallized products and hence the increase in the solubility and superior dissolution properties when compared to the untreated VAL.

De novo DESIGN AND SYNTHESIS OF AN ICE-BINDING, DENDRIMERIC, POLYPEPTIDE BASED ON INSECT ANTIFREEZE PROTEINS / SÍNTESIS Y DISEÑO De novo DE UN POLIPÉPTIDO DENDRÍMERO CON UNIÓN AL HIELO BASADO EN LAS PROTEINAS ANTICONGELANTES DE INSECTOS / Síntes e desenhoo de novo de um polipetídeos dendrímero com uniâo ao gelo baseado nas proteínas anticongelantes de insetos

A new strategy is presented for the design and synthesis of peptides that exhibit ice-binding and antifreeze activity. A pennant-type dendrimer polypeptide scaffoíd combining an a-helical backbone with four short (β-strand branches was synthesized in solid phase using Fmoc chemistry in a divergent approach. The 51-residue dendrimer was characterized by reverse phase high performance liquid chromatography, mass spectrometry and circular dichroism. Each (β-strand branch contained three overlapping TXT amino acid repeats, an ice-binding motif found in the ice-binding face of the spruce budworm (Choristoneura fumiferana) and beetle (Tenebrio molitor) antifreeze proteins. Ice crystals in the presence of the polypeptide monomer displayed fiat, hexagonal plate morphology, similar to that produced by weakly active antifreeze proteins. An oxidized dimeric form of the dendrimer polypeptide also produced fiat hexagonal ice crystals and was capable of inhibiting ice crystal growth upon temperature reduction, a phenomenon termed thermal hysteresis, a defining property of antifreeze proteins. Linkage of the pennant-type dendrimer to a tri-functional cascade-type polypeptide produced a trimeric macromolecule that gave flat hexagonal ice crystals with higher thermal hysteresis activity than the dimer or monomer and an ice crystal burst pattern similar to that produced by samples containing insect antifreeze proteins. This macromolecule was also capable of inhibiting ice recrystallization.

Una nueva estrategia se presenta para el diseño y síntesis de péptidos que se unen al hielo y evidencian actividad anticongelante. Un polipéptido dendrímero del tipo banderín, que combina en su estructura un núcleo a-hélice con cuatro ramificaciones cortas de hojas β, se sintetizó en fase sólida utilizando la química Fmoc con una estrategia divergente. El dendrímero de 51 residuos se caracterizó por cromatografía líquida de alta resolución, espectrometría de masas y dicroís-mo circular. Cada ramifcación de hoja β contiene tres repeticiones de los motivos de aminoácidos TxT sobrelapados, un motivo de unión al hielo presente en la cara de unión de las proteínas anticongelantes del gusano de brotes de abeto (Choristoneura fumiferana) y en el escarabajo (Tenebrio molitor). Los cristales de hielo en presencia del polipéptido monomérico presentan una morfología hexagonal plana, similar a la producida por las proteínas anticongelantes con una débil actividad. Un dímero oxidado del polipéptido también produce cristales de hielo hexagonales planos que fueron capaces de inhibir el crecimiento de los cristales de hielo a medida que se disminuía la temperatura, un fenómeno conocido como histéresis térmica, esto es, una propiedad que define las proteínas anticongelantes. La vinculación del dendrímero tipo banderín a un polipéptido tipo cascada trifuncional produjo una macro-molécula trimérica que generó cristales de hielo hexagonales planos con una mayor actividad de histéresis térmica que los dímeros y los monómeros y un patrón de estallido del cristal de hielo muy similar al producido por las muestras que contienen proteínas anticongelantes de insectos. Estas moléculas además fueron capaces de inhibir la recristianización del hielo.

Uma nova estratégia é apresentada para o desenho e síntese de peptídeos que se unem ao gelo e apresentam atividade anticongelante. Um polipeptídeo dendrímero do tipo pennant que combina em sua estrutura um núcleo a-hélice com quatro ramifcacoes curtas de folhas β foi sintetizado em fase sólida utilizando a química Fmoc com uma estratégia divergente. O dendrímero de 51 resíduos foi caracterizado por cromatografa líquida de alta resolução, espectrometria de massas e dicroísmo circular. Cada ramifcacao de folha (β contém três repeticoes dos motivos de aminoácidos TxT sobrepostos, um motivo de união ao gelo presente na cara de união das proteínas anticongelantes do verme de Choristoneura fumiferana e no escaravelho (Tenebrio molitor). Os cristais de gelo, em presença do polipeptídeo monomérico, apresentam urna morfologia hexagonal plana, similar à produzida pelas proteínas anticongelantes com uma atividade fraca. Um dímero oxidado do polipeptídeo também produz cristais de gelo hexagonais planos e fo-ram capazes de inibir o crescimento dos cristais de gelo à medida que a temperatura diminuia, um fenômeno conhecido como histerese térmica una propriedade que def ne as proteínas anticongelantes. A vinculação do dendrímero tipo pen-nant a um polipeptídeo tipo cascata tri-funcional produziu uma macromolécula trimérica que gerou cristais de gelo hexa-gonais planos com uma maior atividade de histerese térmica que os dímeros e os monómeros e um padrão de estouro do cristal de gelo muito similar ao produzi-do pelas amostras que contêm proteínas anticongelantes de insetos. Estas moléculas, aliás, foram capazes de inibir a recristalização do gelo.

Gram-scale isolation of isobrucein B and neosergeolide from Picrolemma sprucei Hook. f. / Isolamento de isobruceina B e neosergeolida de Picrolemma sprucei Hook. f. em escala-grama

Quassinoids neosergeolide and isobrucein B, obtained from Picrolemma sprucei, have proven in vitro antitumor, antimalarial, anthelminthic, cytotoxic, insecticide and leishmanicidal activities. There is interest in the in vivo pharmacological study of these natural compounds and their semi-synthetic derivatives, however, the quantities obtained in previous extraction processes have been shown to be a limiting factor for continuation of these studies. Herein, we describe a method for obtaining grams of these quassinoids whose purification relies only on recrystallization.

Os quassinóides neosergeolida e isobruceína B, obtidos de Picrolemma sprucei, possuem atividades antitumoral, antimalárica, anti-helmíntica, citotóxica, inseticida e anti-leishmania comprovadas em estudos in vitro. Há interesse no estudo farmacológico in vivo dessas substâncias naturais e de seus derivados semi-sintéticos, porém a quantidade obtida nos processos de extração tem se mostrado um fator limitante à continuação desses estudos. No presente trabalho, descrevemos um método para obtenção de gramas desses quassinóides cuja purificação depende apenas de cristalização fracionada.