Sesquiterpene lactones from Mikania micrantha and Mikania cordifolia and their cytotoxic and anti-inflammatory evaluation.

The guaianolide 8-epi-mikanokryptin (1) and the melampolide 11Hß-11,13-dihydromicrantholide (2) along with known sesquiterpene lactones (3-13) and other constituents were isolated from the aerial parts of different populations of Mikania micrantha and Mikania cordifolia collected in several states of Mexico. The relative and absolute configurations of 1 were determined by X-ray diffraction and CD analysis, respectively. Considering the (1)H and (13)C NMR chemical shift similarities and the H-H coupling constant values, a [(1)D(14), (15)D5] conformation was established for micrantholides (2, 8-13). We tested nearly all the sesquiterpene lactones for antiproliferative activity in human cancer cell lines, and they exhibited moderate activity. Additionally, in a mouse ear model of edema induced by TPA, the anti-inflammatory activities were marginal.

Dependence of DNA-protein cross-linking via guanine oxidation upon local DNA sequence as studied by restriction endonuclease inhibition.

Oxidative damage plays a causative role in many diseases, and DNA-protein cross-linking is one important consequence of such damage. It is known that GG and GGG sites are particularly prone to one-electron oxidation, and here we examined how the local DNA sequence influences the formation of DNA-protein cross-links induced by guanine oxidation. Oxidative DNA-protein cross-linking was induced between DNA and histone protein via the flash quench technique, a photochemical method that selectively oxidizes the guanine base in double-stranded DNA. An assay based on restriction enzyme cleavage was developed to detect the cross-linking in plasmid DNA. Following oxidation of pBR322 DNA by flash quench, several restriction enzymes (PpuMI, BamHI, EcoRI) were then used to probe the plasmid surface for the expected damage at guanine sites. These three endonucleases were strongly inhibited by DNA-protein cross-linking, whereas the AT-recognizing enzyme AseI was unaffected in its cleavage. These experiments also reveal the susceptibility of different guanine sites toward oxidative cross-linking. The percent inhibition observed for the endonucleases, and their pBR322 cleavage sites, decreased in the order: PpuMI (5'-GGGTCCT-3' and 5'-AGGACCC-3') > BamHI (5'-GGATCC-3') > EcoRI (5'-GAATTC-3'), a trend consistent with the observed and predicted tendencies for guanine to undergo one-electron oxidation: 5'-GGG-3' > 5'-GG-3' > 5'-GA-3'. Thus, it appears that in mixed DNA sequences the guanine sites most vulnerable to oxidative cross-linking are those that are easiest to oxidize. These results further indicate that equilibration of the electron hole in the plasmid DNA occurs on a time scale faster than that of cross-linking.

ANÁLISIS DEL PERFIL DE COMPUESTOS VOLÁTILES DEL MANGO (Mangifera indica L. Var. Tommy Atkins) TRATADO POR MÉTODOS COMBINADOS / VOLATILE COMPOUNDS PROFILE ANALYSIS OF MANGO (Mangifera indica L. Var. Tommy Atkins) TREATED BY COMBINED METHODS / ANÁLISE DOS COMPOSTOS VOLÁTEIS DAMANGA (Mangifera indica L. Var. Tommy Atkins) TRATADA POR MÉTODOS COMBINADOS

Se evaluó el perfil de compuestos volátiles del mango (Mangifera indica L. Var. Tommy Atkins) al ser tratado con la combinación de los métodos de deshidratación osmótica con o sin pulso de vacío (DOPV y DO) y con secado por aire caliente o con vacío (SAC y VAC). El tiempo utilizado en la cinética del proceso de DO fue de 42 horas y la DOPV de 30 horas; en los procesos de secado, el SAC se realizó durante 24 horas y el VAC requirió 40 horas. En el perfil de compuestos volátiles del mango fresco analizado por cromatografía de gases acoplada a detector de espectrometría de masas (GC-MS) se encontraron compuestos tipo mono y sesquiterpénico, además de ácidos y ésteres grasos. El germacreno D (20,49%) fue el compuesto terpénico de mayor abundancia encontrado en el análisis realizado. La cantidad de compuestos volátiles en la fruta procesada fue afectada por la aplicación de DOPV y VAC; sin embargo estas pérdidas fueron menores que en las muestras secadas sin pretratamiento osmótico. En el análisis sensorial realizado, las frutas tratadas con DOPV y DO presentaron una menor intensidad calificada en el olor en comparación con la muestra no pretratada.

The aromatic profile of mango (Mangifera indica L. Var. Tommy Atkins) after be treated with the combination of osmotic dehydration methods with or without vacuum pulse (DOPV and DO) and with hot air or vacuum drying (SAC and VAC) was evaluated. The time spent on the kinetics of the DO process was 42 hours and for DOPV was 30 hours, in drying processes, the SAC was held for 24 hours and the VAC for 40 hours. In the profile of volatile compounds of fresh mango analyzed by gas chromatography coupled with mass spectrometry detector (GC-MS), compounds founded were mono and sesquiterpenes type, besides fatty acids and esters. The germacrene D (20.49%) was the terpene compound most abundant found in the analysis. The amount of volatile compounds in processed fruit was affected by the application of DOPV and VAC, but these losses were lower than in the dried samples without osmotic pretreatment. In the sensory analysis performed, the treated fruit by DO and DOPV showed less qualified odor intensity compared with the sample not pretreated.

Neste trabalho, foram analisadas as mudanças no perfil químico e sensorial dos compostos aromáticos da manga (Mangifera indica L. Var. Tommy Atkins) tratada pela combinação dos métodos de desidratação osmótica com ou sem pulso de vácuo (DOPV e DO) e secagem com ar quente ou com vácuo (SAC e VAC). O tempo utilizado na cinética do processos de DO e de DOPV foi de 42 horas e 30 horas, respectivamente; nos processos de secagem, o SAC foi realizado durante 24 horas e o VAC durante 40 horas. No perfil dos compostos voláteis da manga fresca analizada por cromatografia gasosa acoplada a espetrometria de massa (GC-MS) foram encontrados compostos do tipo mono e sesquiterpenos juntamente com ácidos e ésteres gordos. O composto terpénico presente em maior abundância foi o germacreno D (20.49%). A quantidade de compostos voláteis presentes nas frutas processadas foi afectada pela aplicação dos métodos DOPV e VAC, no entanto, estas perdas foram menores do que as ocorridas nas amostras secas sem pré-tratamento osmótico. Na análise sensorial realizada, as frutas tratadas com os métodos DOPV e DO apresentaram um aroma qualificado como sendo menos intenso do que o aroma das frutas que não receberam pré-tratamento osmótico.

Redetermination of 2,4,6-tricyclo-hexyl-1,3,5-trioxane.

The title compound, C(21)H(36)O(3), was obtained by treatment of cyclo-hexa-necarbaldehyde with catalytic toluene-4-sulfonic acid monohydrate. This redetermination results in a crystal structure with significantly higher precision than the original determination [Diana & Ganis (1963 ▶). Atti Accad. Naz. Lincei, 35, 80-88]. The asymmetric unit contains one sixth of the mol-ecule, the formula unit being generated by crystallographic 3m symmetry. In the mol-ecule, the trioxane and cyclo-hexane rings are in chair conformations. In the crystal structure, mol-ecules are linked by weak C-H⋯O hydrogen bonds along the [001] direction.