Biologically active constituents of Aglaia erythrosperma

From the fruits and leaves of Aglaia erythrosperma (Meliaceae), 10 chemical constituents were isolated and identified, i.e. the dammarane triterpenoids cabraleadiol (1), cabraleahydroxylactone (2), ethyl eichlerianoate (3), eichlerialactone (4), aglinin A (5), cabralealactone (6), the aglaialactone 5,6-desmethylenedioxy-5-methoxy-aglalactone (7), the flavagline 4'-demethoxy-3',4'-methylenedioxy-methyl rocaglate (8) and two coumarins: scoparone and scopoletin. Flavagline 8 exhibited antimalarial activity with an IC(50) value of 7.30 μg mL(-1) and was strongly cytotoxic against small cell lung cancer (NCI-H187), epidermoid carcinoma (KB) and breast cancer (BC) cell lines, with IC(50) values of 2.17, 2.10 and 0.11 μg mL(-1), respectively. Aglinin A (5) displayed moderate cytotoxicity against all the three cancer cell lines, whereas ethyl eichlerianoate (3), cabralealactone (6) and the aglaialactone 7 were exclusively cytotoxic to NCI-H187 cell line. Cabraleahydroxylactone (2) showed antiviral activity against herpes simplex virus type-1 with an IC(50) value of 3.20 μg mL(-1), in comparison with the standard acyclovir (IC(50)?= 1.90 μg mL(-1)). When tested for antimycobacterial activity against Mycobacterium tuberculosis H(37)Ra, compounds 1-4 and 6-8 displayed minimum inhibitory concentration in the range of 25-50 μg mL(-1).     

Anti-HIV-1 and cytotoxicity of the alkaloids of Erythrina abyssinica Lam. growing in Sudan

Erythrina abyssinica Lam. is an important medicinal plant growing in Sudan; its seeds were investigated for the first time for their alkaloidal constituents and biological activity. The in vitro cytotoxicity of the crude alkaloidal fraction (CAF) against the cell lines HeLa, Hep-G2, HEP-2, HCT116, MCF-7 and HFB4 showed promising activity, with IC?? values of 13.8, 10.1, 8.16, 13.9, 11.4 and 12.2?μg?mL?1, respectively. Doxorubicin (positive control) showed in vitro cytotoxic activity with IC?? values 3.64, 4.57, 4.89, 3.74, 2.97 and 3.96?μg?mL?1, respectively. Bioassay-guided fractionation and isolation of the CAF led to the isolation of five Erythrina alkaloids, identified as erythraline, erysodine, erysotrine, 8-oxoerythraline and 11-methoxyerysodine. These were evaluated for their in vitro cytotoxic activity against Hep-G2 which resulted in IC?? values 17.60, 11.80, 15.80, 3.89 and 11.40?μg?mL?1, respectively. Furthermore, in vitro cytotoxic activity against HEP-2 was evaluated, which resulted in IC?? values 15.90, 19.90, 21.60, 18.50 and 11.50?μg?mL?1, respectively. The CAF caused a reduction in the viability of mock-infected MT-4 cells with a CC?? of 53?μM and a 50% protection of MT-4 cells against HIV-1 induced cytopathogeneticy with a EC?? of >53?μM, compared with EFV as a positive control, which had a CC?? of 45?μM and an EC?? of 0.003?μM. We concluded that the isolated alkaloids were responsible for the carcinogenic actions of the plant extract previously reported in the literature.     

Synthesis and anti-HIV activity of new homo acyclic nucleosides, 1-(pent-4-enyl)quinoxalin-2-ones and 2-(pent-4-enyloxy)quinoxalines

A series of acyclonucleosides 6,7-disubstituted 1-(pent-4-enyl)quinoxalin-2-one derivatives and the O-analogs were synthesized by a one-step condensation of the corresponding quinoxaline bases with 5-bromo-1-pentene.The acyclonucleosides prepared were assayed against HIV-1 and HIV-2 in MT-4 cells. 6,7-Dimethyl-2-(pent-4-enyloxy)quinoxaline showed inhibition of HIV-1 with EC₅₀ value of 0.22 ± 0.08 μg/ml and a therapeutic index of 13. This means that it was cytotoxic to MT-4 cells at CC₅₀ of 2.6 ± 0.1 μg/ml. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1243–1250, August, 2007.     

Thiophene derivatives with antileishmanial activity isolated from aerial parts of Porophyllum ruderale (Jacq.) Cass

Porophyllum ruderale (Jacq.) Cass. is a plant native to Brazil and in the northwest region of the state of Paraná, Brazil, aerial parts of P. ruderale have been used popularly in the treatment of lesions caused by Leishmania sp.. In this study the antileishmanial and cytotoxic activities of the crude extract, fractions, and isolated compounds from aerial parts of P. ruderale was evaluated. The dichloromethane extract was submitted to chromatography to yield compounds active against Leishmania amazonensis. Their structures were established by comparison of their spectroscopic data with literature values. The activities of crude extract against promastigote and axenic amastigote forms of L. amazonensis (IC(50)) were 60.3 and 77.7 μg/mL, respectively. Its cytotoxic activity against macrophage cells (CC(50)) was 500 μg/mL. The thiophene derivatives isolated were: 5-methyl-2,2':5',2"-terthiophene (compound A) and 5'-methyl-[5-(4-acetoxy-1-butynyl)]-2,2'-bithiophene (compound B). The activity of compound A against promastigote and axenic amastigote forms were 7.7 and 19.0 μg/mL and of compound B were 21.3 and 28.7 μg/mL, respectively. The activity of the isolated compounds against promastigote and axenic amastigote forms was better than that of the crude extract and more selective against protozoa than for macrophage cells.     

Chemical and biological analyses of the essential oils and main constituents of Piper species

The essential oils obtained from leaves of Piper duckei and Piper demeraranum by hydrodistillation were analyzed by gas chromatography-mass spectrometry. The main constituents found in P. demeraranum oil were limonene (19.3%) and β-elemene (33.1%) and in P. duckei oil the major components found were germacrene D (14.7%) and trans-caryophyllene (27.1%). P. demeraranum and P. duckei oils exhibited biological activity, with IC(50) values between 15 to 76 μg mL(-1) against two Leishmania species, P. duckei oil being the most active. The cytotoxicity of the essential oils on mice peritoneal macrophage cells was insignificant, compared with the toxicity of pentamidine. The main mono- and sesquiterpene, limonene (IC(50) = 278 μM) and caryophyllene (IC(50) = 96 μM), were tested against the strains of Leishmania amazonensis, and the IC(50) values of these compounds were lower than those found for the essential oils of the Piper species. The HET-CAM test was used to evaluate the irritation potential of these oils as topical products, showing that these oils can be used as auxiliary medication in cases of cutaneous leishmaniasis, with less side effects and lower costs.     

稀土、钨酸、1,3-二苯基-4-吡唑甲醛缩异烟肼三元配合物的合成、表征及抗癌活性的研究

通过回流冷凝法和低温固相法制备了5种稀土、钨酸、1,3-二苯基-4-吡唑甲醛缩异烟肼三元配合物,并通过元素分析,摩尔电导,IR,UV,TG-DTA,TC-ICP,XPS等对其结构和化学组成进行表征,确定其化学组成Na[RE(HL)(WO4)2]·6H2O(HL:1,3-二苯基-4-吡唑甲醛缩异烟肼).采用MTT比色法研究了配合物对K562肿瘤细胞的细胞毒性,结果表明:三元配合物的IC50在25μg/mL左右,并进行了形态学观察.流式细胞术结果表明:配合物对癌细胞最佳凋亡浓度为12.5μg/mL,细胞被配合物阻滞在S期,抑制了细胞的有丝分裂过程.     

Direct hapten-linked competitive inhibition enzyme-linked immunosorbent assay (CIELISA) for the detection of O-pinacolyl methylphosphonic acid

Immunoassay detection of O-pinacolyl methylphosphonic acid (PMPA) employing direct coating of N-2-aminoethyl-O-pinacolyl methylphosphonate (hapten B) on microtiter plates is reported. Coating was achieved by covalently linking hapten B to a glutaraldehyde (GA) polymer network directly bound to the polystyrene (PS) surface of a standard 96-well microtiter plate. 4-(2-(O-Pinacolylmethylphosphoryl amino)ethyl amino)-4-oxobutanoic acid (hapten A)-ovalbumin (OVA) conjugate served as the coating antigen for comparison with direct hapten B-coated plates in the CIELISA format. The developed assay employing direct hapten B coated plates demonstrated enhanced sensitivity with the IC(50) value for PMPA being 0.027 μg mL(-1). The assay could detect PMPA even at the concentration of 0.006 μg mL(-1). The mean recovery of standard PMPA (spiked in water) was found to be 83.7%.     

Synthesis and In Vitro Anti-HIV Activity of Some New Schiff Base Ligands Derived from 5-Amino-4-phenyl-4H-1,2,4-triazole-3-thiol and Their Metal Complexes

New Schiff base ligands (6–9) derived from 5-amino-4-phenyl-4H-1,2,4-triazole-3-thiol 1 and substituted benzaldehydes (2–5) as well as their metal complexes with Cu(II), Fe(II), Au(III), and Mn(II) (12–17) have been synthesized. A new benzothiazole derivative (11) was prepared from coupling of 7 with N-(benzothiazol-2-yl)-2-chloroacetamide 10. Their spectral properties were investigated. The newly designed and synthesized Schiff base ligands and the metal complexes were assayed for anti-HIV-1 and HIV-2 activity by examination of their inhibition of HIV-induced cytopathogenicity in MT-4 cells. Compounds 11 and 16 were found to be the most active inhibitors in cell culture (EC₅₀ = 12.2 μg/mL (SI = 4) and > 2.11 μg/mL (SI = > 1), respectively) against HIV-1, whereas 11 showed inhibition against HIV-2 of EC₅₀ > 10.2 μg/mL with SI = 9, which provided a good lead for further optimization.     

Cytotoxic cardenolide and sterols from Calotropis gigantea

The dichloromethane extract from the leaves of Calotropis gigantea Linn. was strongly cytotoxic against non-small cell lung carcinoma (A549), colon carcinoma (HCT 116) and hepatocellular carcinoma (Hep G2), and non toxic to Chinese hamster ovary (AA8). The extract afforded uscharin (1), 3,5,8-trihydroxy-24-methylcholest-6,22-diene (2), a mixture of (24R)-3beta-hydroxy-24-ethylcholest-5-en-7-one (3a) and 6beta-hydroxy-24-ethylcholest-4,22-dien-3-one (3b), and another mixture of (24R)-24-ethylcholest-4-en-3-one (4a) and (24S)-24-ethylcholest-4,22-dien-3-one (4b). Cardenolide 1 exhibited extreme toxicity to A549, HCT 116 and Hep G2 with IC50 values of 0.003 microg/mL, 0.013 microg/mL, and 0.018 microg/mL, respectively, while sample 3 exhibited an IC50 of 1.35 microg/mL, 4.46 microg/mL, and 3.83 microg/mL, respectively.     

Phenolic glucosides and chromane analogs from the insect fungus Conoideocrella krungchingensis BCC53666

Six new compounds, named conoideoglucosides A − C and conoideochromanes A − C, together with eight known compounds, including eutypinic acid, 2,2-dimethyl-2H-1-chromene-6-carboxylic acid, (−)-luteoskyrin, (−)-4a-oxyluteoskyrin, chrysophanol, islandicin, catenarin, and (22E)-5α,8α-epidioxyergosta-6,22-dien-3β-ol were isolated from the insect fungus Conoideocrella krungchingensis BCC53666. (−)-Luteoskyrin exhibited a broad range of antimicrobial activity such as antimalarial (IC₅₀ 0.51 μg/mL), antitubercular (MIC 6.25 μg/mL), antibacterial (both Gram positive; MIC 0.39–1.56 μg/mL and Gram negative; MIC 3.13–12.50 μg/mL), and antifungal (against various plant pathogens; MIC 3.13–50.00 μg/mL) activities, while (−)-4a-oxyluteoskyrin and catenarin showed weaker antibacterial activity. Moreover, eutypinic acid, (−)-luteoskyrin, (−)-4a-oxyluteoskyrin, and catenarin showed cytotoxicity against NCI-H187 cells with IC₅₀ in a range of 0.16–17.99 μg/mL, while eutypinic acid and catenarin had no cytotoxicity against non-cancerous (Vero) cells at maximum tested concentration (50 μg/mL). The complete NMR spectral data and biological activity of the known (−)-4a-oxyluteoskyrin was also reported for the first time.     

HPLC analysis of supercritical carbon dioxide and compressed propane extracts from Piper amalago L. with antileishmanial activity

Piper amalago L. leaves were extracted with supercritical carbon dioxide and compressed propane under different conditions, and with chloroform by the conventional maceration method. These methods were compared for the pyrrolidine alkaloid content. Supercritical carbon dioxide (SFE-CO?) at 313 K and 12.55 MPa showed the highest selectivity for the main compound (600.53 mg/g of extract). A gradient high-performance liquid chromatography (HPLC) method was developed and validated to quantify the alkaloid N-[7-(3',4'-methylenedioxyphenyl)-2(Z),4(Z)-heptadienoyl]pyrrolidine in the extracts. The HPLC method showed linearity, precision and accuracy, allowing the quantitative analysis of the alkaloid in all the samples. All the extracts were tested against the promastigote and intracellular amastigote forms of Leishmania amazonensis. The antileishmanial activity was evaluated in terms of inhibitory concentration for 50% of protozoa (IC??). The cytotoxicity was also evaluated against J774A1 macrophages, and the cytotoxic concentrations for 50% of macrophages were obtained (CC??). The SFE-CO? (313 K; 12.55 MPa) extract showed the highest antileishmanial activity with the following IC?? values of 16 and 7 μg/mL against the promastigotes and intracellular amastigotes forms, respectively. The extract showed low cytotoxicity with a CC?? value of 93 μg/mL.     

Synthesis of heparin oligosaccharides and their interaction with eosinophil-derived neurotoxin

A convenient route for the synthesis of heparin oligosaccharides involving regioselective protection of D-glucosamine and a concise preparation of rare L-ido sugars from diacetone α-D-glucose is described. Stereoselective coupling of a D-glucosamine-derived trichloroacetimidate with a 1,6-anhydro-β-L-idopyranosyl 4-alcohol gave the desired α-linked disaccharide, which was used as repeating unit for dual chain elongation and termination. Stepwise assembly from the reducing to the non-reducing end with a D-glucosamine-derived monosaccharide as starting unit furnished the oligosaccharide skeletons having different chain lengths. A series of functional group transformations afforded the expected heparin oligosaccharides with 3, 5 and 7 sugar units. Interaction of these oligosaccharides with eosinophil-derived neurotoxin (EDN), a cationic ribonuclease and a mediator produced by human eosinophils, was further investigated. The results revealed that at 5 μg mL(-1), the heptasaccharide has sufficiently strong interference to block EDN binding to Beas-2B cells. The tri- and pentasaccharides have moderate inhibitory properties at 50 μg mL(-1) concentration, but no inhibition has been observed at 10 μg mL(-1). The IC(50) values of the tri-, penta- and heptasaccharides are 69.4, 47.2 and 0.225 μg mL(-1), respectively.     

Photoprotecting action and phytochemical analysis of a multiple radical scavenger lipophilic fraction obtained from the leaf of the seagrass Thalassia testudinum

The apolar fraction F1 of Thalassia testudinum was chemically characterized by gas chromatography-mass spectrometry, which led to the identification of 43 metabolites, all of them reported for the first time in the genus Thalassia. More than 80% of the F1 composition was constituted by aromatic metabolites including the major components 1,1-bis(p-tolyl)ethane (6.0%), 4,4'-diisopropylbiphenyl (4.8%) and a 1,1-bis(p-tolyl)ethane isomer (4.7%). This lipophilic fraction was assayed for its antioxidant effects and skin protective action. In vitro assays showed that F1 strongly scavenged DPPH* (IC(50) 312.0 ± 8.0 μg mL(-1)), hydroxyl (IC(50) 23.8 ± 0.5 μg mL(-1)) and peroxyl radical (IC(50) 6.6 ± 0.3 μg mL(-1) ), as well as superoxide anion (IC(50) 50.0 ± 0.7 μg mL(-1)). Also, F1 markedly inhibited the spontaneous lipid peroxidation (LPO) in brain homogenates (IC(50) 93.0 ± 6.0 μg mL(-1)) and the LPS-stimulated nitrite generation on RAW624.7 macrophages (58.6 ± 3.2%, 400 μg mL(-1)). In agreement with these findings, its topical application at 250 and 500 μg cm(-2) strikingly reduced skin damage on mice exposed to acute UVB radiation by 45% and 70%, respectively and significantly attenuated the LPO developed following the first 48 h after acute exposure to UVB irradiation, as manifested by the decreased malondialdehide level and by the increased of reduced gluthatione content. Our results suggest that F1 may contribute to skin repair by attenuating oxidative stress due to its antioxidant activity.     

Composition and antioxidant activity of essential oil of pimento (Pimenta dioica (L) Merr.) from Jamaica

The composition and antioxidant activity of the essential oil obtained through hydrodistillation of pimento berry [Pimenta dioica (L.) Merr] samples, namely P1 and P2, sourced from Jamaica, were studied. The chemical composition was analysed by GC and GC-MS methods. The antioxidant activities of the oils were evaluated in terms of their free-radical-scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) radical cation and superoxide anion (?[image omitted]). Total phenolic content, total reducing power and metal-chelating capacity of the oils were also estimated. Forty-five constituents were identified. The major compound identified was eugenol (74.71%, 73.35%), followed by methyl eugenol (4.08%, 9.54%) and caryophyllene (4.90%, 3.30%). The antioxidant assays showed that the oils possess very high radical scavenging activities (DPPH IC(50) 4.82 ± 0.08, 5.14 ± 0.11 μg mL(-1), ABTS IC(50) 2.27 ± 0.16, 2.94 ± 0.03 μg mL(-1), superoxide IC(50) 17.78 ± 1.31, 20.65 ± 0.82 μg mL(-1)). The metal chelating capacities (IC(50) 83.62 ± 2.10, 101.77 ± 1.01 μg mL(-1)) and reducing power were also very high. The results show that the essential oils possess significant antioxidant activity which is comparable to that of pure eugenol. Therefore the oil can be utilised as a natural antioxidant which gives good flavour as well as health benefits.     

Antimicrobial metabolites from the endophytic fungus Pichia guilliermondii isolated from Paris polyphylla var. yunnanensis

Three steroids and one nordammarane triterpenoid were isolated for the first time from the endophytic fungus Pichia guilliermondii Ppf9 derived from the medicinal plant Paris polyphylla var. yunnanensis. By means of physicochemical and spectrometric analysis, they were identified as ergosta-5,7,22-trienol (1), 5α,8α-epidioxyergosta-6,22-dien-3β-ol (2), ergosta-7,22-dien-3β,5α,6β-triol (3), and helvolic acid (4). Both micro-dilution-colorimetric and spore germination assays were employed to evaluate their antimicrobial activity. Among them, helvolic acid (4) exhibited the strongest antibacterial activity against all test bacteria, with MIC values ranging from 1.56 μg/mL to 50 μg/mL, and IC(50) values from 0.98 μg/mL to 33.19 μg/mL. It also showed strong inhibitory activity on the spore germination of Magnaporthe oryzae with an IC(50) value of 7.20 μg/mL. Among the three steroids, 5α,8α-epidioxyergosta-6,22-dien-3β-ol (2) exhibited relatively strong antimicrobial activity. The results suggest that the endophytic fungus Pichia guillermondii Ppf9 could be a candidate for producing helvolic acid, and the metabolites from this fungus could be potentially developed as antimicrobial agents in the future.     

Synthesis of Hydroxylated Sterols(Ⅱ)--Synthesis of 24-Methylenecholest-4-en-3β,6α-diol

In our study on the soft coral,Alcyonium patagonicum,a new hydroxylated sterol,24-methylenecholest-4-en-3β,6α-diol(1) exhibiting a potent activity to murine leukemia cells(IC50=1 μg/mL) has been isolated[1] and synthesized[2,3].As a part of our studies on the relationship between the chemical structure and the biological activity of the hydroxylated sterols,the synthesis of 24-methylenecholest-4-en-3β,6α-diol(2) is reported here.     

Sterostreins A-E, new terpenoids from cultures of the Basidiomycete Stereum ostrea BCC 22955

Sterostreins A-E (1, 2, 3a/3b, 4, and 5), five novel terpenoids, were isolated from cultures of the mushroom fungus Stereum ostrea BCC 22955. Sterostrein A (1) exhibited antimalarial activity (IC(50) 2.3 μg/mL) and cytotoxicity (IC(50) 5.3-38 μg/mL).     

Evaluation of the effects of Mitragyna speciosa alkaloid extract on cytochrome P450 enzymes using a high throughput assay

The extract from Mitragyna speciosa has been widely used as an opium substitute, mainly due to its morphine-like pharmacological effects. This study investigated the effects of M. speciosa alkaloid extract (MSE) on human recombinant cytochrome P450 (CYP) enzyme activities using a modified Crespi method. As compared with the liquid chromatography-mass spectrometry method, this method has shown to be a fast and cost-effective way to perform CYP inhibition studies. The results indicated that MSE has the most potent inhibitory effect on CYP3A4 and CYP2D6, with apparent half-maximal inhibitory concentration (IC(50)) values of 0.78 μg/mL and 0.636 μg/mL, respectively. In addition, moderate inhibition was observed for CYP1A2, with an IC(50) of 39 μg/mL, and weak inhibition was detected for CYP2C19. The IC(50) of CYP2C19 could not be determined, however, because inhibition was <50%. Competitive inhibition was found for the MSE-treated CYP2D6 inhibition assay, whereas non-competitive inhibition was shown in inhibition assays using CYP3A4, CYP1A2 and CYP2C19. Quinidine (CYP2D6), ketoconazole (CYP3A4), tranylcypromine (CYP2C19) and furafylline (CYP1A2) were ACCESSused as positive controls throughout the experiments. This study shows that MSE may contribute to an herb-drug interaction if administered concomitantly with drugs that are substrates for CYP3A4, CYP2D6 and CYP1A2.     

Chemical composition and bioactivity of Citrus medica L. cv. Diamante essential oil obtained by hydrodistillation, cold-pressing and supercritical carbon dioxide extraction

The chemical composition of the essential oil of Citrus medica L. cv. Diamante peel obtained by hydrodistillation, cold-pressing and supercritical carbon dioxide extraction techniques was determined by GC/MS analysis. Forty-six components were fully characterised. Limonene and γ-terpinene were the major components of the oils obtained by hydrodistillation (HD) and cold-pressing (CP), while citropten was the major constituent in the oil obtained by supercritical carbon dioxide extraction (SFE). Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities were evaluated. The essential oil obtained by hydrodistillation exerted the highest inhibitory activity against BChE (IC?? value of 154.6 μg mL?1) and AChE (IC?? value of 171.3 μg mL?1. Interestingly, the oil obtained by cold-pressing exhibited a selective inhibitory activity against AChE. The essential oils have also been evaluated for the inhibition of NO production in LPS induced RAW 264.7 macrophages. The oil obtained by hydrodistillation exerted a significant inhibition of NO production with an IC?? value of 17 μg mL?1 (IC?? of positive control 53 μg mL?1).