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La búsqueda de metabolitos secundarios de interés biológico, clínico o farmacéutico, en raíces y semillas de Senna bicapsularis (Caesalpiniaceae), dio como resultado el aislamiento de 1,8-dihidroxi-3-metoxi-6-metil antraquinona (fisción), 1,8-dihidroxi-3-metil antraquinona (crisofanol) y una mezcla de estigmasterol y dehidroestigmasterol.

De la Espeletiopsis santanderensis (Compositae) fueron aislados e identificados cinco derivados de ent-Kaurano a los que se les evaluó su actividad giberélica empleando el bioensayo del endospermo. El compuesto GA3 (ácido giberélico) fue usado como referencia a concentraciones de 5 x 10-5 a 5 x 10-1 ppm. El 16α-17-19-ent-kauranotriol a 200 ppm presentó mayor actividad con relación a los demás compuestos ensayados: 16α-17-ent-kauranodiol, ácido kaur-16-en-19-oico, kaur-16-en-19-al y tetrachirina, con porcentajes de 73.1, 61.9, 35.9 y 10.3, respectivamente.

El estudio fitoquímico de las hojas y flores de Senna bicapsularis dio como resultado el aislamiento de un flavonoide (luteolina), un alcohol (eicosanol) y una mezcla de los esteroles (estigmasterol y dehidroestigmasterol).

En un estudio preliminar para evaluar el potencial citotóxico de los metabolitos de doce plantas colombianas, se analizaro los metabolitos de los géneros Ageratina, Pentacalia, Curatela, Espeletia, Ageratina y Stemmadenia. Los resultados obtenidos muestran que los compuestos jacaranona y acetato de longipilina presentaron el mayor potencial citotóxico a bajas concentraciones, 4 μg/mL.

Isomers 5,7-dihydroxy-3,6,8-trimethoxy-2-phenyl-4H-chromen-4-one (5,7–dihydroxy-3,6,8 trimethoxy flavone) (flavone A) and 3,5-dihydroxy-6,7,8-trimethoxy-2-phenyl-4H-chromen-4-one (3,5-dihydroxy-6,7,8-trimethoxy flavone) (flavone B) have recently demonstrated differential antineoplastic activities against pancreatic cancer in vitro. These studies also indicated that these compounds target highly tumorigenic cells while sparing normal cells. The in vivo antitumor activities of these flavones have not been determined, and detection protocols for these compounds are needed to conduct pre-clinical assays following intravenous dosing. Here, we report methods developed using acetonitrile to extract two flavone isomers and corresponding internal standards, celecoxib and diclofenac, from rat plasma. Separation was achieved using a Shimadzu liquid chromatography system with a C18 column and mobile phase acetonitrile/water (60:40 and 70:30 for flavones A and B, respectively) containing 0.2% acetic acid and 0.05% triethylamine at a flow rate of 0.4 mL/min and detection at 245 nm. Calibration curves ranging from 250 to 2500 ng/mL and 2500 to 100,000 ng/mL for both flavones were linear (r2 ≥ 0.99) with the lower limits of quantification being 250 ng/mL. Recovery of concentrations 250, 1000, 2500, 5000, and 100,000 ng/mL ranged from 87 to 116% and 84 to 103% (n = 3) for flavone A and B, respectively. Stability of both flavones after a freezing/thawing cycle yielded a mean peak ratio ≥0.92 when compared to freshly extracted samples. Intravenous administration of a 20 mg/kg dose in rats yielded half-lives of 83.68 ± 56.61 and 107.45 ± 53.31 min with clearance values of 12.99 ± 13.78 and 80.79 ± 35.06 mL/min/kg for flavones A and B, respectively.

Flavones, found in nature as secondary plant metabolites, have shown efficacy as anti-cancer agents. We have examined the binding of two flavones, 5,7-dihydroxy-3,6,8-trimethoxy-2-phenyl-4H-chromen-4-one (5,7-dihydroxy-3,6,8-trimethoxy flavone; FlavA) and 3,5-dihydroxy-6,7,8-trimethoxy-2-phenyl-4H-chromen-4-one (3,5-dihydroxy-6,7,8-trimethoxy flavone; FlavB), to phiX174 RF DNA using restriction enzyme activity assays employing the restriction enzymes Alw44, AvaII, BssHII, DraI, MluI, NarI, NciI, NruI, PstI, and XhoI. These enzymes possess differing target and flanking sequences allowing for observation of sequence specificity analysis. Using restriction enzymes that cleave once with a mixture of supercoiled and relaxed DNA substrates provides for observation of topological effects on binding. FlavA and FlavB show differing sequence specificities in their respective binding to phiX. For example, with relaxed DNA, FlavA shows inhibition of cleavage with DraI (reaction site 5′TTTAAA) but not BssHII (5′GCGCGC) while FlavB shows the opposite results. Evidence for tolological specificity is also observed, Molecular modeling and conformational analysis of the flavones suggests that the phenyl ring of FlavB is coplanar with the flavonoid ring while the phenyl ring of FlavA is at an angle relative to the flavonoid ring. This may account for aspects of the observed sequence and topological specificities in the effects on restriction enzyme activity. © 2013 Wiley Periodicals, Inc. Biopolymers 99: 530–537, 2013.

Objetivo Determinar las concentraciones de aluminio en suero de pacientes con terapia de reemplazo renal crónico con hemodiálisis y las concentraciones en agua de redes de distribución y diálisis en dos unidades renales en Bogotá. Material y Métodos Estudio descriptivo en 63 pacientes en hemodiálisis y 20 individuos sanos. Las concentraciones de aluminio se determinaron por espectrofotometría de absorción atómica horno de grafito con corrección de lámpara de deuterio. Resultados El promedio de las concentraciones de aluminio en suero de los pacientes fue de 26,5 µg/L (11,2 a 49,2 µg/L, DE=8,03), en individuos sanos de 8,05 µg/L (menor al Límite de Detección a 17,2 µg/L, DE=4,31), en agua de diálisis fue menor a 2 µg/L y en agua de las redes de distribución menor a 200 µg/L. Conclusiones Las concentraciones de aluminio en el agua de la red de distribución y diálisis estudiadas se encontraron por debajo de los valores establecidos internacionalmente indicando un adecuado tratamiento de las mismas. Igualmente las concentraciones de aluminio pre-HD y post-HD observadas en los pacientes se encontraron por debajo de las reportadas en la literatura. El consumo de hidróxido de aluminio aumenta significativamente la concentración de aluminio en suero. Variables como edad, género, estado civil y situación laboral no son factores de riesgo que alteren significativamente las concentraciones de aluminio en suero.

Apoptosis can be triggered in two different ways, through the intrinsic or the extrinsic pathway. The intrinsic pathway is mediated by the mitochondria via the release of cytochrome C while the extrinsic pathway is prompted by death receptor signals and bypasses the mitochondria. These two pathways are closely related to cell proliferation and survival signaling cascades, which thereby constitute possible targets for cancer therapy. In previous studies we introduced two plant derived isomeric flavonoids, flavone A and flavone B which induce apoptosis in highly tumorigenic cancer cells of the breast, colon, pancreas, and the prostate. Flavone A displayed potent cytotoxic activity against more differentiated carcinomas of the colon (CaCo-2) and the pancreas (Panc28), whereas flavone B cytotoxic action is observed on poorly differentiated carcinomas of the colon (HCT 116) and pancreas (MIA PaCa). Apoptosis is induced by flavone A in better differentiated colon cancer CaCo-2 and pancreatic cancer Panc 28 cells via the intrinsic pathway by the inhibition of the activated forms of extracellular signal-regulated kinase (ERK) and pS6, and subsequent loss of phosphorylation of Bcl-2 associated death promoter (BAD) protein, while apoptosis is triggered by flavone B in poorly differentiated colon cancer HCT 116 and MIA PaCa pancreatic cancer cells through the extrinsic pathway with the concomitant upregulation of the phosphorylated forms of ERK and c-JUN at serine 73. These changes in protein levels ultimately lead to activation of apoptosis, without the involvement of AKT. Incluye bibliografia

Foi demonstrada a ação antifúngica do extrato clorofórmico e de duas substâncias isoladas da superfície foliar de Pentacalia ledifolia (H.B.K.) Cuatr. e P. corymbosa (Benth) Cuatr. frente aos fungos fitopatógenos Fusarium oxysporum e Botrytis cinerea, cultivados em BDA (batata-dextrose-ágar). Destes extratos foram isolados, além de cumarinas já identificadas em estudos anteriores, dois derivados quinóides: (1-hidroxi-4-oxo-2,5-ciclohexadienil) acetato de metila ou jacaranona e (1-hidroxi-4-oxo-2,5-ciclohexadienil) acetato de etila ou metiljacaranona. Para o (1-hidroxi-4-oxo-2,5-ciclohexadienil) acetato de etila foi calculado CI50 de 650 μg/mL para os dois tipos de fungos e o (1-hidroxi-4-oxo-2,5-ciclohexadienil) acetato de metila teve um CI50 de 660 μg/mL. Quinols identified in the surface waxes of Pentacalia ledifolia (H.B.K.) Cuatr and P. corymbosa (Benth) Cuatr. leaves, possess antifungal activity against Fusarium oxysporum and Botrytis cinerea, cultured on PDA (potato-dextrose-agar) medium. These extracts were prepared by dipping fresh leaves in chloroform for 5 min, and afforded ethyl-(1-hydroxy-4-oxocyclohexa-2,5-dien-1-yl) acetate and methyl-(1-hydroxy-4-oxocyclohexa-2,5-dien-1-yl) acetate, the major surface compounds.

Bursera graveolens (Burseraceae), known in Colombia as "sasafrás", is useful for its medicinal properties and is rich in secondary metabolites. In our research, we carried out antimicrobial tests of several fractions and ethanolic extracts from aerial parts against Bacillus subtilis and Staphylococcus aureus, that showed growth inhibitory activity when applied at 250 mg/mL for extracts and 150 mg/mL for fractions. We carried out an antiinflamatory assay also, that showed 71% of inhibition by extracts (81% of Indomethacin) and 70% of inhibition by fractions (78% of Indomethacin). Phytochemical investigation of the bark of Bursera graveolens (Burseraceae) yielded three tetracyclic triterpene acids that have oxygenation in C-3, carboxylic acid in C-21 and unsaturation in C-24 and have been identified as 3-oxotirucalla-8,24-dien-21-oic acid (b-elemonic acid), 3a-hydroxytirucalla-8,24-dien-21-oic acid (a-elemolic acid) and 3a-hydroxytirucalla-7,24-dien-21-oic acid. The isolated compounds were identified using spectroscopic methods including one and two-dimensional Nuclear Magnetic Resonance (COSY, HMQC, HMBC, NOESY) experiments and comparison with published data. This is the first report of the isolated compounds in Bursera graveolens and they have a very important chemotaxonomic significance within the Burseraceae family and related families from the order Rutales.

From the seeds of Tabernaemontana cymosa ( = T. psychotrifolia) 17 indole alkaloids and six lignan glucosides were isolated, besides triacylglycerols, 9,12-octadecadienoic acid, lupeol, (+)-lyoniresinol, obtusifoliol, sweroside and a glucoside of 3- O -methylgallic acid. 9-(β- d -Glucopyranosyloxy)-tetrahydroalstonine, (+)-5,5′- dimethoxy -9-O- (β- d -glucopyranosyl)lariciresinol , (−)-2α-O- (β- d -glucopyranosyl)-lyoniresinol and 3-O-(β- d -glucopyranosyl )-5-O- methylgallic acid are described for the first time. Structural determination is based on spectroscopic studies and/or on comparison with authentic compounds. Some of the isolated substances exhibited significant antifungal and/or cytotoxic effects.

Over 4000 flavonoids have been identified so far and among these, many are known to have antitumor activities. The basis of the relationships between chemical structures, type and position of substituent groups and the effects these compounds exert specifically on cancer cells are not completely elucidated. Here we report the differential cytotoxic effects of two flavone isomers on human cancer cells from breast (MCF7, SK-BR-3), colon (Caco-2, HCT116), pancreas (MIA PaCa, Panc 28), and prostate (PC3, LNCaP) that vary in differentiation status and tumorigenic potential. These flavones are derived from plants of the family Asteraceae, genera Gnaphalium and Achyrocline reputed to have anti-cancer properties. Our studies indicate that 5,7-dihydroxy-3,6,8-trimethoxy-2-phenyl-4H-chromen-4-one (5,7-dihydroxy-3,6,8-trimethoxy flavone) displays potent activity against more differentiated carcinomas of the colon (Caco-2), and pancreas (Panc28), whereas 3,5-dihydroxy-6,7,8-trimethoxy-2-phenyl-4H-chromen-4-one (3,5-dihydroxy-6,7,8-trimethoxy flavone) cytototoxic action is observed on poorly differentiated carcinomas of the colon (HCT116), pancreas (Mia PaCa), and breast (SK-BR3). Both flavones induced cell death (>50%) as proven by MTT cell viability assay in these cancer cell lines, all of which are regarded as highly tumorigenic. At the concentrations studied (5–80 µM), neither flavone demonstrated activity against the less tumorigenic cell lines, breast cancer MCF-7 cells, androgen-responsive LNCaP human prostate cancer line, and androgen-unresponsive PC3 prostate cancer cells. 5,7-dihydroxy-3,6,8-trimethoxy-2-phenyl-4H-chromen-4-one (5,7-dihydroxy-3,6,8-trimethoxy flavone) displays activity against more differentiated carcinomas of the colon and pancreas, but minimal cytotoxicity on poorly differentiated carcinomas of these organs. On the contrary, 3,5-dihydroxy-6,7,8-trimethoxy-2-phenyl-4H-chromen-4-one (3,5-dihydroxy-6,7,8-trimethoxy flavone) is highly cytotoxic to poorly differentiated carcinomas of the colon, pancreas, and breast with minimal activity against more differentiated carcinomas of the same organs. These differential effects suggest activation of distinct apoptotic pathways. In conclusion, the specific chemical properties of these two flavone isomers dictate mechanistic properties which may be relevant when evaluating biological responses to flavones.

From the leaves of Conyza trihecatactis we have isolated the labdane-type diterpenes and diterpene xylosides ent-sclareol, ent-3β-hydroxymanool, ent-manool 13-O-β- d -xylopyranoside and ent-sclareol 13-O-β- d -xylopyranoside. Structure elucidation was achieved by spectroscopic methods.

Determining aluminium concentrations in the serum of patients undergoing chronic renal replacement therapy with haemodialysis and concentration in distribution network water and dialysis in two renal units in Bogotá.This was a descriptive study of 63 haemodialysed patients and 20 healthy subjects. Aluminium concentration was determined in water and serum using graphite furnace atomic absorption spectrometry with deuterium lamp background corrector.Average aluminium concentration was 26.5 µg/L in patients (ranging from 11.2 to 49.2 µg/L; 8.03 standard deviation) and 8.05 µg/L in healthy individuals (ranging from undetectable to 17.2 µg/L; 4.31 standard deviation). Aluminium concentration in dialysis water and distribution network water was below 2 µg/L and 200 µg/L, respectively.Aluminium concentration in water and serum in this study was below international standard values, thereby indicating appropriate treatment. Additionally, aluminium concentration in pre-HD and post-HD sera was below that reported previously. Aluminium hydroxide uptake increases aluminium concentration in serum. Personal situation regarding age, gender, civil and work status were not risk factors determining aluminium concentrations in serum.

13- epi -Cyclosclareol, a novel labdane-type diterpene with a cyclopropane ring has been isolated from Gnaphalium pellitum as well as from Gnaphalium graveolens . Structure elucidation was achieved by spectroscopic methods. The known diterpenes (−)-16-kauren-19-oic acid, (−)-11β-acetoxy-16-kauren-19-oic acid, 13- epi -sclareol and a mixture of sitosterol and stigmasterol were also isolated.

De Espeletia killipi Cuart. foi isolado uma sesquiterpenlactona identificada como acetato de longipilina que mostrou atividade citotóxica. A citotoxidade foi avaliada em células normais obtidas de sangue periférico, tiróide, testículo e epitélio da boca. Células da medula óssea de pacientes com leucemia crônica mielóide, linfoma de Hodking (do Instituto Nacional de Câncer de Bogotá, Colômbia) e células K562 também foram avaliadas. A citotoxidade foi determinada através do teste MTT (3-(4,5-dimethyldiazol-2-yl)-2,5 diphenyl Tetrazolium Bromid). Os ensaios mostraram que a substância não é tóxica para células normais mas a 3 mg/mL apresentou significante atividade em células tumorais e linhagem K562. Conseqüentemente, lavando-se em conta essa significante ação, novas investigações podem ser consideradas plausíveis. The compound responsible for the citotoxic effect was identified as longipilin acetate, a sesquiterpenelactone isolated from Espeletia killipi Cuatr. Citotoxicity was assessed by using normal cells obtained from peripheral blood, thyroid, testicle and mouth epithelium. Bone marrow cells from patients with chronic myeloid leukemia, Hodking lymphoma (from Cancer National Institute, Bogotá Colombia) and the cell line K562 were also assayed. Citotoxicity was determined by the MTT cell viability test (3-(4,5-dimethyldiazol-2-yl)-2,5 diphenyl Tetrazolium Bromid]. The assays revealed that the substance is risk-free on normal cells but at 3 mg/mL has significant activity on tumor cells and K562 cell line. Consequently, taken into account this significant action, new research approaches can be foreseen.

O extrato etanólico e as frações de Espeletia killipii (espécie endêmica da vegetação dos páramos do altiplano Cundiboyacense); mostraram atividade citotóxica significativa in vitro nas linhagens celulares tumorais humanas de câncer de mama MCF-7, CSC-1170, CSC-1595, CSC-3322, CSC-3325 e na linhagem Hep-2 de laringe. A fração CH2Cl2 e suas sub-frações foram ativas contra as linhagens celulares cancerígenas de mama na concentração de 50 µg/mL, obtendo-se percentagens de viabilidade entre 13 e 20%. O principio ativo ainda não identificado foi obtido por ensaios bioguiados sucessivos e apresentou valores de Concentração Citotóxica media (CC50) menores que 1 µg/mL para as linhagens celulares colombianas CSC-1170, CSC-1595, CSC-3322 e CSC-3325; CC50 = 1 µg/mL contra MDA MB 435 e NCl-H23; contra MCF-7 uma CC50 = 2 µg/mL e uma CC50 superior a 16 µg/mL contra PC-3 e U-251. It was found that the ethanol extracts and fractions of Espeletia killipii (an endemic species of the páramo vegetation of the Cundiboyacense plateau) exhibited cytotoxic activity against several human tumor cell lines. Thus, the extracts and fractions exhibited significant cytotoxic activity against both the human tumor cell lines of breast cancer MCF-7, CSC-1170, CSC-1595, CSC-3322, CSC-3325 and the Hep-2 cell lines of laryns. The CH2Cl2 fraction and its sub-fractions were active against the breast lines at concentration of 50 µg/mL, with a viability percentage between 13 and 20%. The active principle, not identified yet, was obtained by successive bio-directed assays. It showed activity against the Colombian cell lines CSC-1170, CSC-1595, CSC-3322 and CSC-3325 at a half Cytotoxic Concentration (CC50) less than 1 µg/mL, against MDA MB-435 and NCI-H23 at CC50= 1 µg/mL against MCF-7 at CC50= 2 µg/mL, and against PC-3 and U-251 at CC50 greater than 16 µg/mL.

The title compound, C26H42O9·1.5H2O, was extracted from the leaves and flowers of Ageratina vacciniaefolia, a Colombian native plant, which is called `chilca' by locals. The mol­ecule consists a kauranol group connected to a glucopyranosyl group by an O-atom bridge adjacent to a β-type anomeric center. In the crystal structure, inter­molecular O—H⋯O hydrogen bonds link mol­ecules to form a three-dimensional network. One solvent water mol­ecule lies on a crystallographic twofold axis, while another is disordered over three sites with equal occupancies.

From leaves and flowers of Ageratina vacciniaefolia [1-7] we have isolated several compounds: a flavonoid, a diterpene [8] and a new compound identified as b-D-glucopyranosil ester of (-)17-(bglucopiranosyloxyl)- 16-hydroxy-kauran-19-oic acid (see the formula).[...]

From leaves and flowers of Ageratina vacciniaefolia we have isolated several compounds: a flavonoid, a diterpene and a new compound identified as (-)-b-D-18–glucopiranosyl-9,15-dihydroxy kaurenoate (see the formula).[...]

The aerial parts of G. gracile afforded three methoxylated flavones: 5,7-dihydroxy-3,8-dimethoxy-flavone; 5,7-dihydroxy-3-methoxyflavone, 3-methoxyquercetin, as well as quercetin. The structures of the compounds were determined by spectroscopic methods and by comparison with authentic samples.

A methanolic extract from the stem bark of the Colombian Bowdichia virgiloides yielded alkaloids of the ormosanine- and homoormosanine-type. Among them are the new natural products homopiptanthine and homo-18-epiormosanine, the latter exhibiting strong cytotoxic activity.

Antineoplastic activity has been previously shown for two isomeric flavones, 5,7-dihydroxy-3,6,8-trimethoxy flavone (flavone A) and 3,5-dihydroxy-6,7,8-trimethoxy flavone (flavone B), against colon cancer cell lines (Thomas et al. in PLoS ONE 7:e39806, 5). Here, we present modified methods for the extraction and quantification of flavones A and B in rat colon tissue after intravenous dosing via high performance liquid chromatography, from the originally described procedure for extraction and quantification in rat plasma (Whitted et al. in J Chromatogr B Analyt Technol Biomed Life Sci 1001:150–155, 7). Modifications included tissue homogenization (1 g tissue: 2 mL water), filtration of the supernatant with a PVDF membrane, and the use of only one calibration curve to determine the concentration of each flavone in colon tissue. Good separation was achieved and representative equations were linear with r 2 ≥ 0.99 for both flavones. Precision and accuracy for flavone A ranged from 0.88–24.03 and 109–116%. Precision and accuracy for flavone B ranged from 1.62–33.56 and 98–113%. Concentrations of 1639 ± 601 ng/g flavone A and 5975 ± 2480 ng/g of flavone B were detected in rat colon tissue 6 h post dosing. Modifications to the extraction methods for flavone A and flavone B from rat colon tissue had good separation, precision, and accuracy.

5,7-Dihydroxy-3,6,8-trimethoxyflavone was isolated from the flowers of Gnaphalium elegans . The structure elucidation is based mainly on proton resonance studies using Eu(fod) 3 shift reagent.