In vitro toxicity, antiplatelet and acetylcholinesterase inhibition of Buddleja thyrsoides Lam. leaves

Alzheimer's disease (AD) is a neurodegenerative disorder resulting in impaired memory and behaviour of remarkable socio-economic impact. A decrease in cholinergic activity is a key event in the biochemical of AD. Buddleja thyrsoides is a plant widely distributed in Southern parts of South America. In Brazilian traditional medicine, the infusion of its leaves and flowers is used for the treatment of bronchitis and cough. Crude ethanolic (70%) extract and fractions (dichloromethane, ethyl acetate and n-butanolic) were investigated regarding their toxicities in?vitro and antiplatelet action. The enzyme acetylcholinesterase inhibition was evaluated to study the crude extract. The crude extract and fractions were evaluated by means of Brine Shrimp Lethality test and they showed low activities with LC(50) values 1698, 2818, 2187 and 3672?μg?mL(-1) for dichloromethane, ethyl acetate, n-butanolic fractions and crude extract, respectively. Buddleja thyrsoides presented great antiplatelet action. The IC(50) values obtained for crude extract and dichloromethane, ethyl acetate and n-butanolic fractions were 361.29, 354.23, 368.75 and 344.30, respectively, while the IC(50) for the standard AAS was 257.01?μg?mL(-1). The crude extract showed an inhibition of 22.8% of the acetylcholinesterase enzyme in 24?h.     

Antioxidant activity and cytotoxicity study of the flavonol glycosides from Bauhinia galpinii

The antioxidant activity of the crude extract and solvent fractions obtained from the leaves of Bauhinia galpinii was evaluated in terms of capacity to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals. The crude extract and the more polar solvent fractions (ethyl acetate and butanol) showed considerable antioxidant activity. The antioxidant potential of the extracts, expressed as EC50, ranged between 28.85 +/- 1.28 microg mL(-1)and 118.16 +/- 6.41 microg mL(-1). L-Ascorbic acid was used as a standard (EC50 = 19.79 +/- 0.14 microM). Bioassay guided fractionation of the two active solvent fractions led to the isolation of three flavonoid glycosides, identified as: quercetin-3-O-galactopyranoside (1), myricetin-3-O-galactopyranoside (2), and 2'-O-rhamnosylvitexin (3). These compounds are reported for the first time from this species. The structures of the compounds were determined on the basis of spectral studies (1H NMR, 13C NMR and MS). Their antioxidant potential was evaluated using a DPPH spectrophotometric assay. Compound 2 had higher and 3 had lower antioxidant activity than L-ascorbic acid. No cytotoxic effects were displayed by compounds 1 and 3, but compound 2 was cytotoxic to Vero cells (LC50 = 74.68 microg mL(-1)) and bovine dermis cells (LC50 = 30.69 microg mL(-1)).     

Antioxidant and anticancer activity of fresh corm extract from Romulea tempskyana (Iridaceae)

The antioxidant and anticancer properties of a medicinal plant, Romulea tempskyana (R. tempskyana) (Iridaceae) were investigated. The fresh corm water extract of R. tempskyana significantly increased cell viability against H(2)O(2) cytotoxicity(.) The extract also showed high inhibition of the lipid peroxidation activity (78.20%), reducing power (IC(50) 64.99?μg?mL(-1)) activity and hydroxyl (IC(50) 38.66?μg?mL(-1)), superoxide (IC(50) 25.99?μg?ml(-1)) and DPPH (IC(50) 19.88?μg?mL(-1)) radical scavenging activity. On the other hand, treatment of the cells with higher extract concentration showed the anticancer activity inducing cytotoxicity. The extract significantly affected Hepatoma G2 and H1299 cell proliferation (IC(50); 103.79 and 88.15?μg?mL(-1)). The amount of MDA (2-fold and 2.5-fold) and activities of several cellular antioxidant enzymes, including Se-GSPx (30%, 15%), non-Se-GSH-Px (11%, 16%) and GST (17%, 23%) increased in Hepatoma G2 and H1299 cells treated with IC(50) concentrations of extract, respectively. These findings suggest that R. tempskyana extract exhibits antioxidant and carcinogenesis-reducing potential.     

α-(2-苯并噻唑氧基)烃基膦酸酯的合成性质和生物活性

为探索α-芳(杂 环)磷酸衍生物的生物活性,寻求含磷农药的新母体,合成了十六个未见文献报道的α-(苯并噻唑-2-氧代)烃基膦酸衍生物,所有化合物的结构均IR,HNMR, 元素分析等确证,并对生物活性进行了初步的研究.     

Larvicidal activity of some secondary lichen metabolites against the mosquito Culiseta longiareolata Macquart (Diptera: Culicidae)

The larvicidal activity of some lichen metabolites, (+)-usnic acid, atranorin, 3-hydroxyphysodic acid and gyrophoric acid, against the second and third instar larvae of the mosquito Culiseta longiareolata were studied. All metabolites caused high larvicidal activities. When metabolites were compared on the basis of their LC(50) values, the order of increasing toxicity was as follows: gyrophoric acid (0.41?ppm)?>?(+)-usnic acid (0.48?ppm)?>?atranorin (0.52?ppm)?>?3-hydroxyphysodic acid (0.97?ppm). However, when LC(90) values were compared, the order of toxicity was (+)-usnic acid (1.54?ppm)?>?gyrophoric acid (1.93?ppm)?>?3-hydroxyphysodic acid (4.33?ppm)?>?atranorin (5.63?ppm). In conclusion, our results found that lichen secondary metabolites may have a promising role as potential larvicides.     

β'-芳氨基ａ,β-不饱和酮及其盐酸盐与苯肼的反应

本文通过β'-芳氨基ａ,β-不饱和酮及其盐酸盐与苯肼反应的研究,进一步扩大了β-芳氨基酮在有机合成上的应用范围,并为了-β-芳氨乙基-2-吡唑啉化合物和1,2,8-三氮双环[3,3,0]辛烷找到了切实可行的合成方法,具有原料易得、操作简便、易于纯化等特点.     

The Antimicrobial Activity,Mosquito Larvicidal Activity,Antioxidant Property and Tyrosinase Inhibition of Piper Betle

The essential oil and methanolic and aqueous extracts of Piper betle L. were assayed for their antimicrobial activity, mosquito larvicidal activity, antioxidant property and mushroom tyrosinase inhibition. The methanolic and aquaous extracts showed strong activity against the yeasts: C. albicans, and M. pachydermatis. The crude essential oil exhibited a broad‐spectrum strong antimicrobial activity against all test organisms. The strongest activity was observed against C. albicans, followed by S. aureus and M. pachydermatis. The chemical composition of the essential oil and its fractions was analyzed by GC/MS analysis. Eugenol (36.2%), chavibetol acetate (16.9%), 4‐allylphenyl acetate (9.4%) and 4‐allylphenol (7.2%) were the main components, comprising 69.7% of the oil. The fractionation of the essential oil gave two fractions. Fraction I was rich in eugenol (71.3%) and fraction II in eugenol (46.4%), chavibetol acetate (19.4%) and 4‐allylphenyl acetate (11.8%). The essential oil exhibited the mosquito larvicidal activity with 2 h and 24 h LD₅₀ value of 86 and 48 ppm, respectively. The methanolic extract of P. betle showed larvicidal activity with 2 h and 24 h LD₅₀ value of 153 and 125 ppm, respectively, whereas the aqueous extract showed slight active. The individual antioxidant assays such as DPPH scavenging activity, chelating effect of ferrous ions and reducing power have been used. P. betle showed remarkable antioxidant activity in DPPH and reducing power assays. The activity observed can be attributed to the presence of the phenolic compounds. The essential oil exhibited concentration‐dependent inhibition of mushroom tyrosinase, giving an IC₅₀ value of 126 ppm. The fraction I showed a strong inhibition of tyrosinase activity, giving an IC₅₀ value of 115 ppm. The presence of 4‐allylphenolic components in the essential oil may play an important role in the inhibition of tyrosinase. In conclusion, the results presented here show that Piper betle essential oil could be considered as a natural antimicrobial, mosquito larvicidal, antioxidant and tyrosinase inhibition source.     

Phytopathogenic fungal inhibitors from celery seeds

Extract of celery (Apium graveolens L.) seeds was investigated against phytopathogenic fungi. The light petroleum extract showed promising inhibition activities in the tests against Rhizoctonia solani and Fusarium oxysporum f. sp. vasinfecum. Chromatographic separation of the extract gave 19 fractions, one of which, QCZ-4, possessed significant inhibitory rates of 64.6%, 88.4% and 54.7% at a concentration of 100 ppm against R. solani, F. oxysporium f. sp. vasinfecum and Alternaria alternata, respectively. Major components in the active fraction were identified by GC-MS as p-(2-aminoethyl)phenol (39.7%), 3-(3,4-dimethybenzoyl) propionic acid (32.6%) and p-heptylphenol (26.9%).     

Brine shrimp cytotoxicity of Caesalpinia pulcherrima aerial parts, antimicrobial activity and characterisation of isolated active fractions

Caesalpinia pulcherrima Swartz. is an ornamental plant, shrub or a small tree belonging to the family Caesalpiniaceae. The plant has been used for the treatment of inflammatory disorders, skin diseases and so on. In this study, the cytotoxicity of the methanol extract of the aerial parts of C. pulcherrima was tested using an Artemia salina (brine shrimp) bioassay. Further, the methanol extract was fractionated by silica gel column chromatography using a solvent gradient of hexane:ethyl acetate:methanol in different ratios and 56 fractions were collected. On the basis of thin layer chromatography profiles, 13 major fractions were obtained, which were tested for antimicrobial activity against 14 microorganisms using the agar disc diffusion method and also tested for their minimal inhibitory concentration and minimal bactericidal concentration values. In terms of cytotoxicity, the extract caused 26% mortality of brine shrimp larvae after 24?h at a concentration of 1000?μg?mL(-1). Fractions 3, 9 and 10 showed significant antimicrobial activities. Phytochemical analysis of these three fractions led to the identification of 11 compounds, and their structures were established by means of gas chromatography-mass spectroscopy techniques. These findings suggest that these bioactive compounds may be useful as potential antimicrobials. Further investigation is needed to establish the mode of action of these bioactive compounds.     

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.     

Ethanolic extract of Rubia peregrina L. (Rubiaceae) inhibits haloperidol-induced catalepsy and reserpine-induced orofacial dyskinesia

In the traditional Sardinian system of medicine, Rubia peregrina L. (Rubiaceae) is reported as an aphrodisiac herb. Since the aphrodisiacs may also have antioxidant and dopaminergic activities, the aim of this study was to study the effect of ethanolic extract of aerial parts of R. peregrina for the scavenging of free DPPH radicals and the inhibition of haloperidol-induced catalepsy in mice and reserpine-induced orofacial dyskinesia in rats. The extract exhibited significant antioxidant activity in a free radical DPPH assay with IC(50)?=?55.6?μg?mL(-1), which was very close to IC(50) of ascorbic acid. The extract of R. peregrina (100 and 200?mg?kg(-1) intraperitoneally, i.p.) significantly inhibited haloperidol (1?mg?kg(-1) i.p.) - induced catalepsy in mice (p?相似文献   

Tetracyclic triterpenoids from the leaves of Azadirachta indica and their insecticidal activities

A new tetranortriterpenoid, meliatetraolenone [24,25,26,27-tetranor-apotirucalla-(apoeupha)-6alpha-O-methyl, 7alpha-senecioyl(7-deacetyl)-11alpha,12alpha,21,23-tetrahydroxy-21,23-epoxy-2,14,20(22)-trien-1,16-dione] (1) was isolated from the methanolic extract of fresh leaves of Azadirachta indica along with the known compound odoratone (3) which was hitherto unreported from this source. Their structures have been elucidated by spectral studies including 2D NMR. The insecticidal activities of 1 as well as those of odoratone (3) are reported. 1 and odoratone both showed mortality on fourth instar larvae of mosquitoes (Anopheles stephensi) with LC(50) values of 16 and 154 ppm, respectively.     

Antiproliferative activity of Luehea candicans Mart. et Zucc. (Tiliaceae)

Luehea candicans Mart. et Zucc. (Tiliaceae) is known as 'a?oita-cavalo' and is one of the most important medicinal plants found in the Brazilian cerrado. The crude methanolic extracts of the branches and leaves and their fractions were evaluated using the following cancer cell lines: MCF-7 (breast), NCI-ADR (breast expressing the multidrug resistance phenotype), NCI-460 (lung), UACC-62 (melanoma), 786-0 (kidney), OVCAR (ovarian), PCO-3 (prostate), HT-29 (colon) and K-562 (leukaemia). The crude methanolic extracts from the branches (B) and leaves (L) were able to inhibit the growth of the K-562 and 786-0 cell lines in a dose-dependent manner, with GI(50) values of 8.1 and 5.4 μg mL(-1), respectively. The hexane (L1), chloroform (L2) and methanol (L4) fractions derived from extract L showed a high selectivity and pronounced cytostatic activity against 786-0 (GI(50) ~ 40 μg mL(-1)). A significant amount of lupeol was isolated from fraction L2. The chloroform (B2) and methanol (B3) fractions derived from extract (B) exhibited less selectivity, showing the highest cytostatic activity against K-562, NCI-ADR, OVCAR, MCF-7 and NCI-460 cells, with GI(50) values between 27 and 40 μg mL(-1). Lupeol, betulin, a mixture of steroids, (-)-epicatechin, vitexin and liriodendrin were isolated from these active fractions.     

Enantioselective diene Cyclization/Hydrosilylation catalyzed by optically active palladium bisoxazoline and pyridine-oxazoline complexes

A 1:1 mixture of (N-N)Pd(Me)Cl ?N-N = (S,S)-4,4'-dibenzyl-4,5,4', 5'-tetrahydro-2,2'-bisoxazoline (S,S-4a) and NaBAr(4) ?Ar = 3, 5-C(6)H(3)(CF(3))(2) (5 mol %) catalyzed the asymmetric cyclization/hydrosilylation of dimethyl diallylmalonate (2) and triethylsilane at -30 degrees C for 48 h to form an 8.1:1 mixture of the silylated carbocycle (S,S)-trans-1, 1-dicarbomethoxy-4-methyl-3-?(triethylsilyl)methylcyclop ent ane (S, S-3) (95% de, 72% ee) and dimethyl 3,4-dimethylcyclopentane-1, 1-dicarboxylate (S,S-6) in 64% combined yield. In comparison, a 1:1 mixture of the palladium pyridine-oxazoline complex (N-N)Pd(Me)Cl ?N-N = (R)-(+)-4-isopropyl-2-(2-pyridinyl)-2-oxazoline (R-5b) and NaBAr(4) (5 mol %) catalyzed the asymmetric cyclization/hydrosilylation of 2 and triethylsilane at -32 degrees C for 24 h to form carbocycle S,S-3 in 82% yield (>95% de, 87% ee) as the exclusive product. Asymmetric diene cyclization catalyzed by complex R-5b was compatible with a range of functional groups and produced carbocycles with up to 91% ee. The procedure also tolerated substitution at a terminal olefinic position and at the allylic position of the diene.     

Chemical composition analysis of the essential oil of Melissa officinalis L. from Kurdistan, Iran by HS/SPME method and calculation of the biophysicochemical coefficients of the components

The volatile constituents of the essential oil of wild Melissa officinalis L. obtained from the Kurdistan province of Iran were extracted by headspace/solid-phase micro-extraction and were analysed by gas chromatography and gas chromatography/mass spectrometry. Of a total of 14 compounds in the oil, 12 (85.7%) were identified. The main components were as follows: (E)-citral (37.2%), neral (23.9%) and citronellal (20.3%). Some physicochemical properties, such as the logarithm of calculated octanol-water partitioning coefficients (log?K (ow))(,) total biodegradation (TB (d) in mol?h(-1) and g?h(-1)), water solubility (S (w), mg?L(-1) at 25°C) and median lethal concentration 50 (LC(50)), were calculated for compounds 1-14 from M. officinalis L.     

Bioguided isolation of pentacyclic triterpenes from the leaves of Alstonia scholaris (Linn.) R. Br. growing in Egypt

Ethanolic and aqueous extracts of the leaves and flowers of Alstonia scholaris were evaluated for their antioxidant activity by investigating their effect on blood glutathione levels in alloxan-induced diabetic rats. The ethanolic extract of the leaves was the most active; therefore, its cytotoxicity against HepG2 cells was also tested. Promising GI?? values of 1.96, 4.34 and 4.65?μg?mL?1 were observed for the extract, its chloroform and ethyl acetate fractions, respectively. The chloroform active subfraction I (GI???=?2.97?μg?mL?1) yielded betulin (1), betulinic acid (2) and ursolic acid (3) upon purification. Compounds 1-3 were identified using spectroscopic techniques and by comparison with reported data. GLC of unsaponifiable and saponifiable fractions of the hexane extract revealed β-sitosterol (7.37%) and n-tetracosane (54.4%) to be the major sterol and hydrocarbon components, respectively. Linoleic acid (48.89%) was the predominant fatty acid.     

Three diterpenoids (excoecarins V1-V3) and a flavanone glycoside from the fresh stem of Excoecaria agallocha

Three new diterpenoids, excoecarins V1-V3 (1-3) and a new flavanone glycoside (7) were isolated from the fresh stem of Excoecaria agallocha L. Their structures were elucidated as: 2alpha,3alpha,18-trihydroxy-3beta,20-epoxybeyer-15-ene (1), ent-2,3-secokaur-16-en-2,3-dioic acid (2), ent-3,4-seco-16alpha-hydroxyatis-4(19)-en-3-oic acid (3), and 3,5,7,3',5'-pentahydroxy-2R,3R-flavanonol 3-O-alpha-L-rhamnopyranoside (7) on the basis of spectroscopic data, chemical evidence, and/or X-ray analysis.     

Phytochemical study and cytotoxicity evaluation of Colchicum stevenii Kunth (Colchicaceae): a Jordanian meadow saffron

Isolation, characterization, and biological evaluation of active components of Colchicum stevenii Kunth (Colchicaceae) are described. Colchicum stevenii is an unexplored Jordanian specie with toxic reputation. Directed by brine shrimp lethality test (BST), methanolic extraction, liquid-liquid partition, preparative TLC, and semi-preparative HPLC, it resulted in the isolation of six cytotoxic compounds. The compounds, reported for the first time from this specie, are: (-)-colchicine (1), 2-demethyl-(-)-colchicine (2), (-)-cornigerine (3), beta-lumicolchicine (4), (-)-isoandrocymbine (5) and (-)-O-methylandrocymbine (6). A new, in-house developed, acidic-based reverse-phase gradient semi-preparative HPLC method for the separation of colchisides is presented here. Structural elucidation was based on spectroscopic techniques principally; 1H-NMR and low resolution EIMS. Based on BST results, reported as LC50 values in microg mL(-1) (ppm) with 95% confidence intervals, (-)-colchicine (2.5 ppm) and (-)-cornigerine (2.7 ppm) were the most potent.     

Studies on the potential antioxidant properties of Senecio stabianus Lacaita (Asteraceae) and its inhibitory activity against carbohydrate-hydrolysing enzymes

This study showed for the first time the antioxidant and hypoglycaemic properties of the methanol, n-hexane and ethyl acetate extracts from Senecio stabianus Lacaita, a plant that belongs to the Asteraceae family. The antioxidant activities were carried out using two different in vitro assays, namely 2,2-diphenyl-1-picrylhydrazyl (DPPH) test and 2,2'-azinobis(3-ethylbenzthiazoline-6-sulphonate) (ABTS) test. The ethyl acetate extract showed the highest activity with inhibitory concentration 50% (IC(50)) values of 35.5 and 32.7?μg?mL(-1) on DPPH test and ABTS test, respectively. This activity may be related to a good total phenol and flavonoid content. All extracts were also tested for their potential inhibitory activity of α-amylase and α-glucosidase digestive enzymes. The n-hexane extract exhibited the highest α-amylase inhibition with an IC(50) value of 0.21?mg?mL(-1). Through bioassay-guided fractionation processes seven fractions (A-G) were obtained and tested. Based on the phytochemical analysis, the activity of n-hexane extract may be related to the presence of monoterpenes and sesquiterpenes.     

Cytotoxic and insecticidal activities of derivatives of harmine, a natural insecticidal component isolated from Peganum harmala

In a continuing effort to develop novel β-carbolines endowed with better insecticidal activity, a simple high-yielding method for the synthesis of harmine compounds starting from L-tryptophan has been developed and a series of 1,3-substituted β-carboline derivatives have been synthesized and evaluated for their cytotoxicity against insect cultured Sf9 cell line in vitro and insecticidal activities against 4th instar larvae of mosquitos, Culex pipiens quinquefasciatus and mustard aphid, Lipaphis erysimi. The results demonstrated that 1-phenyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (compound 2) and methyl 1-phenyl-β-carboline-3-carboxylate (compound 13) represented the best potential compounds, with Sf9 cells inhibition rates of 71.55% and 60.21% after 24 h treatment at concentrations of 50-200 mg/L, respectively. Both compounds 2 and 13 also showed strong insecticidal activity towards 4th instar larvae of mosquitos with LC(50) values of 20.82 mg/L and 23.98 mg/L, and their LC(90) values were 88.29 mg/L and 295.13 mg/L, respectively. Furthermore, the LC(50) values of compounds 2 and 13 against mustard aphids were 53.16 mg/L and 68.05 mg/L, and their LC(90) values were 240.10 mg/L and 418.63 mg/L after 48 h treatment. The in vitro cytotoxicity of these compounds was consistent with the insecticidal activity in vivo. The results indicated that the 1- and 3-positions of the β-carboline ring deserve further investigation to develop biorational insecticides based on the natural compound harmine as a lead compound.