Synthesis of Cycloartan-16ß-ol from 16ß 24R-Epoxy-Cycloartane and Their Cytotoxicity Evaluation Against Human Cancer Cell Lines.

It was found that Argentatins A and B triterpenoids make up approximately 20-30 % of the waste resin produced from the industrial processes to isolate rubber from P. argentatum. We have developed an efficient protocol for synthesizing cycloartane-16ß-ol derivatives by opening the oxepane ring of argentatin B acetate (2) with BF3-OEt2. Although three new cycloartenol derivatives showed high cytotoxicity against PC-3 and HCT-15 cancer cell lines, nevertheless, the best results were obtained for (16ß,24R) -(16,24-epoxy-cycloartan-2(1H)-ylidene) acetate (14), compound with intact oxepane ring. These results indicate that the substituents in the argentatin nucleus and a side chain account for the cytotoxic activity. However, according to the selectivity index (SI), 14 did not show selectivity activity to cancer cell lines over the HaCat noncancerous cell line. The compound 3ß,16ß-Dihydroxy-cycloartan-24-one (5), synthesized by oxepane opening, demonstrated high cytotoxic activity to cancer cell lines and showed a remarkable selectivity to cancer cell lines over the noncancerous ones. These results suggest that 5 could lead to the development of new anticancer compounds.

Pentacoordinated Organotin(IV) Complexes as an Alternative in the Design of Highly Efficient Optoelectronic and Photovoltaic Devices: Synthesis and Photophysical Characterization.

The synthesis of four pentacoordinated organotin(IV) complexes prepared in a one-pot reaction from 2-hydroxy-1-naphthaldehyde, 2-amino-3-hydroxypyridine and organotin oxides is reported. The complexes were characterized by UV-Vis, IR, MS, 1H, 13C and 119Sn NMR techniques. The compound based on 2,2-diphenyl-6-aza-1,3-dioxa-2-stannanaphtho[1,2-h]pyrido[3,2-d]cyclononene revealed the formation of a monomeric complex with a distorted five-coordinated molecular geometry intermediate between the trigonal bipyramidal and square pyramidal. In order to find possible applications in photovoltaic devices, hybrid films of organotin(IV) complexes embedded in poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) with graphene were deposited. The topographic and mechanical properties were examined. The film with the complex integrated into the cyclohexyl substituent has high plastic deformation, with a maximum stress of 1.69 × 107 Pa and a Knoop hardness of 0.061. The lowest values of 1.85 eV for the onset gap and 3.53 eV for the energy gap were obtained for the heterostructure having the complex with the phenyl substituent. Bulk heterojunction devices were fabricated; these devices showed ohmic behavior at low voltages and a space-charge-limited current (SCLC) conduction mechanism at higher voltages. A value of 0.02 A was found for the maximum carried current. The SCLC mechanism suggests hole mobility values of between 2.62 × 10-2 and 3.63 cm2/V.s and concentrations of thermally excited holes between 2.96 × 1018 and 4.38 × 1018 m-3.

Synthesis, biological evaluation, molecular docking studies and In-silico ADMET evaluation of pyrazines of pentacyclic triterpenes.

The semisynthesis of novel derivatives of lupeyl palmitate and 3ß-palmitoyloxy-olean-12-ene by introduction of a pyrazine at C-2 / C-3 and modifications of the relatively unexplored C-30 position of lupeol derivatives was conducted, and their cytotoxic and anti-inflammatory activities were evaluated. The derivatives 7, 10 and 11 significantly inhibited the tumor cell lines U251, K562, HCT-15, MCF-7 and SKLU-1, and compounds 7 and 11 were more active (IC50 25.4 ± 2.0 µM and 7.1 ± 0.4 µM, respectively) than the positive control (etoposide (IC50 31.5 ± 2.2 µM) in the tumor line PC-3. Introduction of the pyrazine at C-2 / C-3 in compounds 1 and 2 or modification at C-30 of compound 1 decreased the anti-inflammatory activity in the TPA-induced mouse ear edema. Following the results of the PASS online evaluation of the potential biological activity of the natural compounds and their derivatives, the inhibition of pNF-κB translocation to the prostate cancer (PC-3) cell nucleus was investigated and the binding mode of compounds 7, 10 and 11 with the human NF-κB receptor was explored by a molecular docking study. These derivatives bound directly or close to the amino acids that form the DNA recognition site. The ADMET physicochemical parameters of the fifteen compounds were further analyzed in silico using Molinspiration calculations indicating the potential of compounds 7, 10 and 11 for further investigation.

Tyrame [N-(3-hydroxy-1:3:5(10)-estratrien-17ß-yl)-4-hydroxy-phenethylamine], antithrombotic aminoestrogen that decreases microvesicle formation.

BACKGROUND: Estrogens that are used as contraceptives or in replacement therapy are associated with an increase in the risk for developing thrombosis, mainly during the first year of treatment and in women with associated risk factors. OBJECTIVE: To synthesize, characterize and identify the anticoagulant, antiplatelet aggregation and microvesicle-reducing effect of the new aminoestrogen Tyrame. MATERIAL AND METHODS: CD1 strain mice were used, which had Tyrame (0, 1 and 2 mg/100 g) subcutaneously administered. At 24 h, a blood sample was obtained to determine whole-blood clotting time, microvesicles concentration and inhibitory effect on platelet aggregation. RESULTS: Blood clotting time increased up to 1.5 times in comparison with the control. Platelet aggregation inhibition had different magnitude depending on the agonist agent employed, and was complete with collagen. Both effects had a dose-dependent relationship. The microvesicles decreased up to six times with respect to the control. CONCLUSIONS: Tyrame reduces platelet aggregation and microvesicle formation, which emphasizes its potential therapeutic utility as an estrogen free of thrombotic effects.

ANTECEDENTES: Los estrógenos empleados como anticonceptivos o en la terapia de sustitución se asocian a un incremento en el riesgo de desarrollar trombosis, principalmente durante el primer año de tratamiento y en mujeres con factores de riesgo asociados. OBJETIVO: Sintetizar, caracterizar e identificar el efecto anticoagulante, antiagregante plaquetario y reductor de las microvesículas del nuevo aminoestrógeno tyrame. MATERIAL Y MÉTODOS: Se emplearon ratones cepa CD1 a los que se les administró por vía subcutánea tyrame (0, 1 y 2 mg/100 g). A las 24 h se tomó una muestra de sangre para determinar el tiempo de coagulación en sangre total, la concentración de microvesículas y el efecto inhibidor de la agregación plaquetaria. RESULTADOS: El tiempo de coagulación en sangre se incrementó hasta 1.5 veces con respecto al control. La inhibición de la agregación plaquetaria tuvo diferente magnitud dependiendo del agente agonista, siendo completa con colágena. Ambos efectos siguieron una relación dependiente de la dosis. Las microvesículas disminuyeron hasta seis veces con respecto al control. CONCLUSIONES: el tyrame disminuye la agregación plaquetaria y la formación de microvesículas, lo que acentúa su posible utilidad terapéutica como un estrógeno sin efectos trombóticos.

Synthesis of flutamide-conjugates.

In this paper, we designed and extended modification basing on the flutamide structure. A series of flutamide-conjugates were obtained with methyl bromoacetate and ethylenediamine. Through the synthesis of two conjugates with 3,5-bis(dodecyloxy)benzoate derivatives, these flutamide conjugates were tested for anticancer activity. Among the compounds tested, the flutamide-conjugates showed good inhibition activity against cancer cell lines U-251, PC-3 and K-562. The conjugates showed a better inhibitory effect than free flutamide and did not show activity against normal COS-7 monkey kidney fibroblast cells. It was also observed that the flutamide conjugates had an inhibitory effect against human colorectal adenocarcinoma HCT-15.

Hopane-type triterpenes from Cnidoscolus spinosus and their bioactivities.

Chemical investigation of the aerial parts of Cnidoscolus spinosus resulted in the isolation of relatively infrequent hopane-type triterpenes, 3ß-acetoxy-hop-22(29)-ene (1), first reported here as natural product, together with 3-oxo-hop-22(29)-ene (2), and 3ß-hydroxy-hop-22(29)-ene (3). ß-Amyrin palmitate and three phytosterols were also characterized. The structures of the compounds were established using spectroscopic methods, and those of 1 and 2 were confirmed by crystallographic analysis. Selected biological activities for the isolated hopane-type triterpenes were tested through a series of assays for determining the cytotoxic, anti-inflammatory, α-glucosidase inhibition and antiparasitic activities. Compounds 1-3 did not show cytotoxic activity, compound 1 displayed an important inhibitory effect in the mouse ear induced inflammation assay, and significantly inhibited the yeast α-glucosidase activity in vitro and in silico. Additionally, compounds 2 and 3 showed marginal activities against Trypanosoma cruzi and Leishmania mexicana. Therefore, the bioactivities of hopane-type triterpenes deserve further investigation, particularly their anti-inflammatory properties.

Antifungal and antioomycete activities and modes of action of isobenzofuranones isolated from the endophytic fungus Hypoxylon anthochroum strain Gseg1.

Hypoxylon species are distributed worldwide and have been isolated from different habitats. The endophyte Hypoxylon anthochroum strain Gseg1 was isolated from healthy leaves of Gliricidia sepium. A chemical study of the culture medium and mycelium organic extracts of the endophytic fungus H. anthochroum Gseg1 led to the isolation of three known isobenzofuranones, 7-hydroxy-4,6-dimethyl-3H-isobenzofuran-1-one, 1, 7-methoxy-4,6-dimethyl-3H-isobenzofuran-1-one, 2, 6-formyl-4-methyl-7-methoxy-3H-isobenzofuran-1-one, 3, and one compound was isolated for the first time as a natural product, 7-methoxy-4-methyl-3H-isobenzofuran-1-one, 4. In addition, the chemical synthesis of 1 and 2, and a derivative, 7-methoxy-6-methyl-3H-isobenzofuran-1-one, 5, was performed. The isobenzofuranones showed antifungal and antioomycete activities. Compounds 1-5 inhibited the growth of Fusarium oxysporum, Alternaria alternata, Pythium aphanidermatum, and Phytophthora capsici, in addition, 1, 2 and 5 interrupted the respiration and caused electrolyte leakage due to cell membrane damage. Compound 2 was the most active, inhibiting the growth of the four microorganisms, affecting the respiration and increasing the relative conductivity due to electrolyte leakage. Compounds 1-4 also induce morphological changes in the plant pathogens' mycelia and hyphae. These compounds could be useful for the control of plant pathogenic fungi and oomycetes of agricultural relevance.

Structural Elucidation of Malonylcommunol and 6ß-Hydroxy-trans-communic Acid, Two Undescribed Diterpenes from Salvia cinnabarina. First Examples of Labdane Diterpenoids from a Mexican Salvia Species.

The aerial parts of Salvia cinnabarina afforded two undescribed labdane diterpenoids 1 and 2 (malonylcommunol and 6ß-hydroxy-trans-communic acid) along with two known labdane diterpenoids, trans-communic acid (3) and trans-communol (4). Additionally, seven known metabolites were also isolated; two isopimarane diterpenoids 5 and 6, two sesquiterpenoids identified as ß-eudesmol (7) and cryptomeridiol (8), and three aromatic compounds identified as phthalic acid (9), a mixture of tyrosol fatty acid esters (10) and the flavone salvigenine (11). While compounds compounds 1-3 showed significant inhibition of yeast α-glucosidase, compounds 2, 3 and 7 had no anti-inflammatory activity in the edema model induced by TPA. This paper is not only the first report on a wild population of Salvia cinnabarina, but also of the presence of labdane-type diterpenoids in a Mexican Salvia sp.

The effect of chiral N-substituents with methyl or trifluoromethyl groups on the catalytic performance of mono- and bifunctional thioureas.

We evaluated thiourea organocatalysts that incorporate a chiral group which includes a trifluoromethyl moiety and contrasted their performance with non-fluorinated analogs. The comparison between such systems allows the direct study of the NH acidity of a thiourea bonded to an aliphatic substituent. In principle, -CF3 systems feature an enhanced hydrogen bond (HB) donor capacity that is undoubtedly beneficial for HB-catalysis applied to the Baylis-Hillman reaction. We found that the thiourea substituted on both nitrogens with this group accelerates this reaction like Schreiner's thiourea. On the other hand, we observed a different behavior in reactions promoted by bifunctional catalysts (thiourea-primary amine). In the Michael addition of isobutyraldehyde to methyl benzylidenepyruvate, the -CF3 containing catalysts were better than the -CH3 systems, whereas the conjugate addition to N-phenylmaleimide showed the opposite behavior. Theoretical calculations of the transition states indicated that the phenylethyl group in fluorinated and non-fluorinated compounds have different kinds of interactions with the electrophile. These interactions are responsible for a different arrangement of the electrophile and thereby the selectivity of the catalyst. Therefore, it cannot be generalized that in all cases NH acidity correlates with the performance of the catalyst, particularly, with aliphatic substituents that unlike the aromatic ones possess groups that are outside the plane of the thiourea.

Transient Porosity in Densely Packed Crystalline Carbazole-(p-Diethynylphenylene)-Carbazole Rotors: CO2 and Acetone Sorption Properties.

We report for the first time the high sorption properties of a molecular rotor with no permanent voids or channels in its crystal structure. Such crystalline phase originates from THF, DCM, or the irreversible desolvation of entrapped benzene molecules. From these, the benzene in its solvate form acts as rotation stopper, as supported by dynamic characterization using solid-state 2H NMR experiments. In the solvent-free form, the diffusion of small quantities of iodine vapors caused a significant change in the intramolecular rotation, increasing the known activation energy to rotation from 8.5 to 10.6 kcal mol-1. Notably, those results paved the way for the discovery of the high CO2 uptake (201.6 cm3 g-1 at 196 K, under 1 atm) and acetone (5 wt %), a sorption property that was attributed to both, the restriction of the molecular rotation at low temperatures and the flexibility of the molecular axle made of conjugated p-(ethynylphenylene), surrounded by carbazole.

neo-Clerodane Diterpenoids and Other Constituents of Salvia filipes.

A series of neo-clerodane-type diterpenoids were isolated from the aerial parts of Salvia filipes, including the new compounds 4-epi-polystachyne A (1), salvifilines A (3), C (7), and D (8), and salvifiline B, which was isolated as the 15-O-methyl derivatives 4/5. In addition, the five known diterpenoids (2, 9-12), together with ursolic, oleanolic, and betulinic acids, and the flavone eupatorin were also isolated. The structures were determined by analysis of their spectroscopic data, mainly 1D and 2D NMR. The structure of salvifiline D was confirmed by X-ray analysis. The cytotoxic activities of the diterpenoids were evaluated, but all were inactive against a panel of six human cancer cell lines.

Antidiarrheal Thymol Derivatives from Ageratina glabrata. Structure and Absolute Configuration of 10-Benzoyloxy-8,9-epoxy-6-hydroxythymol Isobutyrate.

Chemical investigation of the leaves from Ageratina glabrata yielded four new thymol derivatives, namely: 10-benzoyloxy-8,9-dehydro-6-hydroxythymol isobutyrate (4), 10-benzoyloxy-8,9-dehydrothymol (5), 10-benzoyloxythymol (6) and 10-benzoyloxy-6,8-dihydroxy-9-isobutyryl-oxythymol (7). In addition, (8S)-10-benzoyloxy-8,9-epoxy-6-hydroxythymol isobutyrate (1), together with other two already known thymol derivatives identified as 10-benzoyloxy-8,9-epoxy-6-methoxythymol isobutyrate (2) and 10-benzoyloxy-8,9-epoxythymol isobutyrate (3) were also obtained. In this paper, we report the structures and complete assignments of the ¹H and (13)C-NMR data of compounds 1-7, and the absolute configuration for compound 1, unambiguously established by single crystal X-ray diffraction, and evaluation of the Flack parameter. The in vitro antiprotozoal assay showed that compound 1 and its derivative 1a were the most potent antiamoebic and antigiardial compounds. Both compounds showed selectivity and good antiamoebic activity comparable to emetine and metronidazole, respectively, two antiprotozoal drugs used as positive controls. In relation to anti-propulsive effect, compound 1 and 1a showed inhibitory activity, with activities comparable to quercetin and compound 9, two natural antipropulsive compounds used as positive controls. These data suggest that compound 1 may play an important role in antidiarrheal properties of Ageratina glabrata.

Retro-Curcuminoids as Mimics of Dehydrozingerone and Curcumin: Synthesis, NMR, X-ray, and Cytotoxic Activity.

Curcumin and its derivatives have been extensively studied for their remarkable medicinal properties, and their chemical synthesis has been an important step in the optimization of well-controlled laboratory production. A family of new compounds that mimic the structure of curcumin and curcuminoids, here named retro-curcuminoids (7-14), was synthesized and characterized using 1D ¹H- and 13C-NMR, IR, and mass spectrometry; the X-ray structure of 7, 8, 9, 10, 12, 13, and 14 are reported here for the first time. The main structural feature of these compounds is the reverse linkage of the two aromatic moieties, where the acid chloride moiety is linked to the phenolic group while preserving α, ß-unsaturated ketone functionality. The cytotoxic screening of 7, 8, 9, and 10 at 50 and 10 µg/mL was carried out with human cancer cell lines K562, MCF-7, and SKLU-1. Lipid peroxidation on rat brain was also tested for compounds 7 and 10. Compounds 7, 8, and 10 showed relevant cytotoxic activity against these cancer cell lines, and 10 showed a protective effect against lipid peroxidation. The molecular resemblance to curcuminoids and analogs with ortho substituents suggests a potential source of useful bioactive compounds.

Acremoxanthone E, a novel member of heterodimeric polyketides with a bicyclo[3.2.2]nonene ring, produced by Acremonium camptosporum W. GAMS (Clavicipitaceae) endophytic fungus.

Bioactivity-directed fractionation of the organic mycelium extract of the endophytic fungus Acremonium camptosporum W. Gams (Clavicipitaceae), isolated from the leaves of Bursera simaruba (Burseraceae), led to the isolation of six major heterodimeric polyketides, including one not previously characterized acremoxanthone derivative. In addition, the already known acremoxanthone C, acremonidins A and B, and acremoxanthones A and B were obtained. The structure of the new compound was established by extensive NMR studies, including DEPT, COSY, NOESY, HSQC, and HMBC methods. The trivial name proposed for this compound is acremoxanthone E. In addition, the structure of acremoxanthone C was unequivocally established for the first time, through X-ray crystal-structure analysis. The anti-oomycete activities of the pure compounds were tested against four economically important phytopathogenic oomycetes. Inhibitory concentration for 50% diameter growth reduction, IC50 , values for the four phytopathogens ranged from 6 to 38 µM. Also, in parallel, the cytotoxic activities against six cancer cell lines were evaluated showing IC50 values similar to those of cisplatin. To the best of our knowledge, this is the first report on three different groups of heterodimeric polyketides, linked by a bicyclo[3.2.2]nonene, such as xanthoquinodins, acremonidins, and acremoxanthones, which are isolated from an endophytic fungus. In addition, a common biosynthetic origin could be proposed.

High Fluorescent Porphyrin-PAMAM-Fluorene Dendrimers.

Two new classes of dendrimers bearing 8 and 32 fluorene donor groups have been synthesized. The first and second generations of these porphyrin-PAMAM-fluorene dendrimers were characterized by 1H-NMR, 13C-NMR, FTIR, UV-vis spectroscopy, elemental analyses and MALDI-TOF mass spectrometry. The UV-vis spectra showed that the individual properties of donor and acceptor moieties were preserved, indicating that the new dendrimers could be used as photosynthetic antennae. Furthermore, for fluorescent spectroscopy, these dendrimers showed good energy transfer.

Anthraquinones from Vismia mexicana.

Vismia mexicana (Clusiaceae) is a small tropical tree found from Mexico to Honduras. The CH2Cl2/MeOH extract from the leaves has been reported to have inhibitory properties against reverse transcriptase of human immunodeficiency virus type 1 (HIV-1 RT). In order to characterize some of its chemical constituents, the EtOAc-soluble fraction of this extract was subjected to column chromatography. A new natural product was isolated and designated vismiaquinone D [1-hydroxy-6-methoxy-7,8-(3',3'-dimethyl-pyrano) anthraquinone]. In addition, vismiaquinone was obtained. The structures of vismiaquinone and vismiaquinone D were determined by 1H and 13C NMR spectroscopy, unambiguous assignments were achieved with DEPT, HSQC, and HMBC experiments, and corroborated by X-ray diffraction studies. The isolated anthraquinones were tested against HIV-1 RT. However, none showed relevant activity, suggesting that other compounds in this extract may be responsible for its HIV-1 RT inhibitory properties.

(tert-But-yl)(2-hy-droxy-eth-yl)ammonium chloride.

In the cation of the title mol-ecular salt, C6H16NO(+)·Cl(-), the N-C-C-O torsion angle is 176.5 (2)°. In the crystal, the cations and chloride ions are linked by N-H⋯O and O-H⋯O hydrogen bonds, generating a two-dimensional network parallel to (100).

4-Methyl-N-(4-methyl-phenyl-sulfon-yl)-N-[4-(4-methyl-phen-yl)-1,3-thia-zol-2-yl]benzene-sulfonamide.

There are two independent mol-ecules in the asymmetric unit of the title compound, C24H22N2O4S3. In each, the sulfonamide N atoms reveal nearly a trigonal-planar geometry with two S atoms of the O=S=O groups and one C atom of the thia-zole ring; the angles around the N atoms are between 117.00 (13) and 123.86 (9)°. The methyl-phenyl-sulfonyl groups are in anti conformations, forming dihedral angles of 78.00 (7)/72.53 (5) and 77.09 (6)/71.50 (7)° with the trigonal S-N-S planes in the two mol-ecules. The thia-zole groups are rotated around the C-N bonds and are almost perpendicular to the S-N-S plane [dihedral angles of 78.00 (7)/72.53 (5) and 77.09 (6)/71.50 (7)°]. In the crystal, pairs of C-H⋯O inter-actions, with the O atoms of the sulfonamide groups as acceptors, link each of the independent mol-ecules into inversion dimers.

Di-chlorido-(4,4'-di-tert-butyl-2,2'-bi-pyridine-κ(2) N,N')palladium(II) dimethyl sulfoxide monosolvate monohydrate.

The title compound, [PdCl2(C18H24N2)]·(CH3)2SO·H2O, the Pd(II) ion is in a distorted square-planar geometry. The Pd-N bond distances are 2.022 (2) and 2.027 (2) Å, the Pd-Cl bond distances are 2.2880 (7) and 2.2833 (7) Å, and the ligand bite angle is 80.07 (9)°. The dimethyl sulfoxide and water mol-ecules form linear chains along [100] by O-H⋯O and O-H⋯S hydrogen bonds, generating eight- and 12-membered rings. C-H⋯Cl inter-actions link the chains, forming a three-dimensional arrangement. In addition, the 4,4-di-tert-butyl-2,2'-bi-pyridine ligand exhibits π-π stacking inter-actions [centroid-centroid distances = 3.8741 (15) and 3.8353 (15) Å]. The DMSO solvent is disordered and was refined with an occupancy ratio of 0.866 (3):0.134 (3).

(2,2'-Bi-pyridine-κ(2) N,N')di-chloridopalladium(II) 1,4-dioxane hemisolvate.

The asymmetric unit of the title compound, [PdCl2(C10H8N2)]·0.5C4H8O2, consists of one Pd(II) complex mol-ecule and a half-mol-ecule of 1,4-dioxane, the complete mol-ecule being generated by inversion symmetry. The Pd(II) atom has an almost square-planar coordination formed by the 2,2'-bi-pyridine ligand and two chloride ligands. Two intra-molecular C-H⋯Cl hydrogen bonds occur. In the crystal, the Pd(II) complex and 1,4-dioxane mol-ecules are connected by C-H⋯O hydrogen bonds, forming a layer parallel to (10-1). Within the layer, weak π-π inter-actions [centroid-centroid distance = 3.817 (4) Å] are observed between the pyridine rings.