In vitro assessment of antiprotozoal and antimicrobial activities of fractions and isolated compounds from Pallenis hierochuntica.

The antiprotozoal and antimicrobial properties of the extract and fractions of the whole plant of Pallenis hierochuntica were investigated against a panel of pathogenic organisms. Fractionation of the methanol extract of the whole plant of Pallenis hierochuntica using reverse-phase chromatography gave 28 fractions and led to the isolation of 2 new bisabolone hydroperoxides, 6,10 ß,11-trihydroxy-bisabol-2-ene-1-one (1a), 6,10 α,11-trihydroxy-bisabol-2-ene-1-one (1b) and also 6,10 ß-dihydroxy-bisabol-2,11-diene-1-one (2). They were characterised by extensive spectrometric analysis. Anti-infective investigations of the fractions revealed that 22 to 26 possessed significant antimalarial activity against the D6 and W2 strains of Plasmodium falciparum with IC50 = 7.62 - 9.91 µg/mL and 5.49 - 6.08 µg/mL, respectively, and SI>6.0 on average. Fractions 7, 16 to 24 exhibited good activity against Leishmania donovani promastigotes (IC50 = 6.71 - 18.77 µg/mL). Fractions 25 to 28 were active against T. brucei trypomastigotes, 25 being the most potent (IC50 = 4.13 µg/mL). Only 11 to 13 were active against Aspergillus fumigatus (IC50 = 13.406 µg/mL). 1a and 2 were not promising against the organisms tested. 1a and 1b were characterised for the first time.

Biochemical investigation of the upstream anti-sickling mechanisms of soursop (Annona muricata): 15-acetyl guanacone as an inhibitor of deoxyhaemoglobin polymerisation.

Current sickle cell disease (SCD) therapies are limited and inefficient. The ethnomedicinal values of Annona muricata in the treatment of SCD, leading to this present research. Leaves and fruits of Annona muricata were processed using solvent extraction and partitioning; aqueous, chloroform and ethyl acetate fractions. In vitro (anti-oxidant and anti-sickling), in silico, quantitative (amino acids) and kinetic simulation experiments were done. 15-acetyl guanacone, was used, in silico against 2,3-bisphosphoglycerate (2, 3-BPG) mutase and deoxyhaemoglobin. The ethyl acetate and chloroform fractions better NO● scavengers, iron-chelators and ferric reducing. In vitro unsickling (UT50) had ethyl acetate = 5 h and methanol = 7 h. Chloroform fraction had EC50 1.00 mg/mL (EC50 = 546 mg/mL) to 10.00 mg/mL (EC50 = 99 mg/mL). EC50 and IC50 of ethyl acetate fraction had steady-decrease. At higher concentration, chloroform fraction had higher Bmax (1.48 × 1021 U/mL) and higher Kd (3.66 × 1019 mg/mL), whereas, at a lower concentration, the ethyl acetate fraction demonstrated higher Bmax (7.23 × 1012 U/mL) and lower Kd (2.12 × 1011 mg/mL); The relative affinity (BP) of chloroform fraction increased progressively with concentration. The amino acid profile revealed rich concentrations glycine, valine, leucine, lysine, phenylalanine, histidine, arginine, and tryptophan. From the in silico experiments, 15-acetyl guanacone specifically targeted the A and B chains, with greater affinity for the beta subunit. This suggested that 15-acetyl guanacone might be able to prevent the polymerisation of deoxyHbSS, induce an allosteric conformational change that increases the oxygen affinity, and decrease the cellular 2, 3-BPG concentration.Communicated by Ramaswamy H. Sarma.

Crystal structure, Hirshfeld surface analysis and electrostatic potential study of naturally occurring cassane-type diterpenoid Pulcherrimin C monohydrate at 100†K.

The title cassane-type diterpenoid known as pulcherrimin C, C34H36O8·H2O, systematic name 5,6-bis-(benzo-yloxy)-4a-hy-droxy-4,7,11b-trimethyl-1,2,3,4,4a,5,6,6a,7,11,11a,11b-dodeca-hydro-phenanthro[3,2-b]furan-4-carb-oxy-lic acid monohydrate, was isolated as a monohydrate from the medicinally important plant Caesalpinia pulcherrima, found in the tropical regions of south and south-east Asia. The mol-ecule is composed of three trans-fused six-membered rings having chair, chair and half-chair conformations, and a five-membered planar furan ring. In the crystal, O-H⋯O hydrogen bonds link mol-ecules into chains parallel to the b axis. Weak C-H⋯π inter-actions are also observed. Hirshfeld surface analysis indicates that the contribution of O⋯H inter-actions towards the total generated Hirshfeld surface is 21.5%.

Berberis orthobotrys - A promising herbal anti-tumorigenic candidate for the treatment of pediatric alveolar rhabdomyosarcoma.

ETHNOPHARMACOLOGICAL RELEVANCE: Berberis orthobotrys (BORM) is a medical plant with a long history in traditional usage for the treatment of wounds, cancer, gastrointestinal malady and several other diseases. Our previous studies identified the endemic Pakistani plant Berberis orthobotrys Bien. ex Aitch. as promising source for the treatment of breast cancer and osteosarcoma. AIM OF THE STUDY: The present study was aimed to evaluate the anti-cancer properties of 26 plant derived extracts and compounds including the methanolic root extract of Berberis orthobotrys (BORM) on pediatric alveolar rhabdomyosarcoma (RMA), which is known to develop drug resistance, metastatic invasion and potential tumor progression. MATERIALS AND METHODS: The main anti-tumor activity of BORM was verified by focusing on morphological, cell structural and metabolic alterations via metabolic profiling, cell viability measurements, flow cytometry, western blotting and diverse microscopy-based methods using the human RMA cell line Rh30. RESULTS: Exposure of 25 µg/ml BORM exerts an influence on the cell stability, the degradation of oncosomes as well as the shutdown of the metabolic activity of RMA cells, primarily by downregulation of the energy metabolism. Therefore glycyl-aspartic acid and N-acetyl serine decreased moderately, and uracil increased intracellularly. On healthy, non-transformed muscle cells BORM revealed very low metabolic alterations and nearly no cytotoxic impact. Furthermore, BORM is also capable to reduce Rh30 cell migration (~50%) and proliferation (induced G2/M cycle arrest) as well as to initiate apoptosis confirmed by reduced Bcl-2, Bax and PCNA expression and induced PARP-1 cleavage. CONCLUSIONS: The study provides the first evidence, that BORM treatment is effective against RMA cells with low side effects on healthy cells.

Crystal structure and Hirshfeld surface analysis of the naturally occurring cassane-type diterpenoid, 6ß-cinnamoyl-7ß-hy-droxy-vouacapen-5α-ol.

The title compound, C29H36O5, a cassane-type diterpenoid {systematic name: (4aR,5R,6R,6aS,7R,11aS,11bR)-4a,6-dihy-droxy-4,4,7,11b-tetra-methyl-1,2,3,4,4a,5,6,6a,7,11,11a,11b-dodeca-hydro-phenanthro[3,2-b]furan-5-yl 3-phenyl-prop-2-enoate}, was isolated from a medicinally important plant, Caesalpinia pulcherrima (Fabaceae). In the mol-ecule, three cyclo-hexane rings are trans-fused and adopt chair, chair and half-chair conformations. In the crystal, mol-ecules are linked via O-H⋯O hydrogen bonds, forming a tape structure along the b-axis direction. The tapes are further linked into a double-tape structure through C-H⋯π inter-actions. The Hirshfeld surface analysis indicates that the contributions to the crystal packing are H⋯H (65.5%), C⋯H (18.7%), O⋯H (14.5%) and C⋯O (0.3%).

Crystal structure and Hirshfeld surface analysis of pulcherrin J.

The title compound, C29H36O4 [systematic name (4aR,5R,6aS,7R,11aS,11bR)-4a-hydroxy-4,4,7,11b-tetramethyl-1,2,3,4,4a,5,6,6a,7,11,11a,11b-dodecahydrophen-anthro[3,2-b]furan-5-yl cinnamate], a natural diterpene known as pulcherrin J, was isolated from stem barks of medicinally important Caesalpinia pulcherrima (L.). The crystal structure of pulcherrin J shows it to be composed of a central core of three trans-fused cyclo-hexane rings and a near planar five-membered furan ring, along with an axially oriented cinnamate moiety and an -hydroxy substituent attached at positions 4a and 5 of the steroid ring system, respectively. The absolute structure was established with the use of Cu Kα radiation. In the crystal, mol-ecules are linked by O-H⋯O hydrogen bonds to generate [100] C(8) chains. Hirshfeld surface analysis indicates that the most significant contacts in packing are H⋯H (67.5%), followed by C⋯H (19.6%) and H⋯O (12.9%).

Cytotoxic, Anti-inflammatory, and Leishmanicidal Activities of Diterpenes Isolated from the Roots of Caesalpinia pulcherrima.

A phytochemical investigation on the chloroform extract of Caesalpinia pulcherrima roots led to the isolation of ten known furanocassane diterpenoids, vouacapen-5α-ol (1), 8,9,11,14-didehydrovouacapen-5α-ol (2), 6ß-cinnamoyl-7ß-hydroxyvouacapen-5α-ol (3), pulcherrin A (4), pulcherrin B (5), pulcherrin J (6), pulcherrimin A (7), pulcherrimin B (8), pulcherrimin C (9), and pulcherrimin E (10). Chemical transformation of 3 and 7 gave compounds 6ß-hydroxyisovouacapenol C (11), 6ß-cinnamoyl-7ß-acetoxyvouacapen-5α-ol (12), and pulcherrimin D (13). Cytotoxicity of compounds 1-13 was evaluated against three cancer cell lines (MCF-7, HeLa, and PC-3). Anti-inflammatory potential of the compounds was evaluated via the oxidative burst assay using a luminol-amplified chemiluminescence technique. Leishmanicidal activity was tested against promastigotes of Leishmania major in vitro. Compounds 3, 4, 8, 9, and 10 were found active against all three cancer cell lines with IC50s ranging from 7.02 ± 0.31 to 36.49 ± 1.39 µM. Compounds 8 and 13 exhibited a potent inhibitory effect on reactive oxygen species generated from human whole blood phagocytes (IC50 = 15.30 ± 1.10 µM and 8.00 ± 0.80 µM, respectively). Compounds 3, 9, and 13 showed significant activity against promastigotes of L. major (IC50 = 65.30 ± 3.20, 58.70 ± 2.80, and 55.90 ± 2.40 µM, respectively).

Crystal structure of (3S*,4S*,4aS*,5R*,6R*,6aS*,7R*,11aS*,11bR*)-5,6-bis(benzo-yloxy)-3,4a-dihy-droxy-4,7,11b-trimethyl-1,2,3,4,4a,5,6,6a,7,11,11a,11b-dodeca-hydro-phenanthro[3,2-b]furan-4-carb-oxy-lic acid methanol monosolvate.

The title compound, C34H36O9·CH3OH, is a diterpenoid isolated from the roots of Caesalpinia pulcherrima (L.) Swartz. The three trans-fused six-membered rings are in chair, chair and half-chair conformations. The mean plane of this fused-ring system makes dihedral angles of 67.95 (15) and 83.72 (14)° with the two phenyl rings of the benzo-yloxy groups. An intra-molecular C-H⋯O hydrogen bond is observed. In the crystal, mol-ecules are linked via O-H⋯O hydrogen bonds, forming an infinite chain along the b-axis direction.

Evaluation of three medicinal plant extracts against Plasmodium falciparum and selected microganisms.

BACKGROUND: A great revival of scientific interests in drug discovery has been witnessed in recent years from medicinal plants for health maintenance. The aim of this work was to investigate three Nigerian medicinal plants collected in Nigeria for their in vitro antiplasmodial and antimicrobial activities. MATERIALS AND METHODS: Extracts obtained from parts of Persea americana, Jatropha podagrica and Picralima nitida and their fractions were evaluated for in vitro antiprotozoal and antimicrobial activity. RESULT: The methanol extract of P. nitida demonstrated activity against chloroquine-sensitive and chloroquine-resistant P. falciparum clones with IC50 values of 6.3 and 6.0 µg/mL, respectively. Methanol and chloroform extracts of P. americana seed showed antifungal activity against Cryptococcus neoformans IC50 less than 8 and 8.211 µg/mL respectively. Finally, the petroleum ether extract of P. americana had activity against methicillin-resistant Staphylococcus aureus (MRSA) with an IC50 value of 8.7 µg/mL. CONCLUSION: The study revealed the antibacterial and antiplasmodial activities of the plants extracts at the tested concentrations.

Evaluation of the antioxidant activity of root extract of pepper fruit (Dennetia tripetala), and it's potential for the inhibition of lipid peroxidation.

BACKGROUND: The antioxidant properties of ethanolic root extract of pepper fruit (Donnetia tripetala), and its effect on lipid peroxidation of some fresh beef tissues during frozen storage were investigated. MATERIALS AND METHODS: The antioxidant parameters were assessed using standard methods, while malondialdehyde levels of different fresh beef tissue sections treated with the extract prior to freezing, were estimated in a colorimetric reaction with thiobarbituric acid. RESULTS: The H2O2-scavenging ability of the extract was similar to that of ascorbic acid, with a maximum scavenging power of 55.61 ±4.98%, and an IC50 value of 86µg/ml. The extract exhibited a concentration-dependent ferric ion-reducing power, although this was significantly lower relative to that of the ascorbic acid (p < 0.05). The total phenolic content was 212.5 ± 0.002 mg/g, while the nitric oxide-scavenging ability was 64.33 ± 0.2% after 150 min. The capacity of the extract to inhibit lipid peroxidation in frozen heart muscle slices was significantly higher than that of vitamin C (p < 0 .05), but comparable to vitamins C and E in frozen testes and kidney slices. CONCLUSION: These results suggest that the root extract of D. tripetala is rich in antioxidants which can be applied to meat preservation during refrigerated storage.

Isolation of antileishmanial, antimalarial and antimicrobial metabolites from Jatropha multifida.

OBJECTIVE: To investigate the antileishmanial, antimicrobial and antimalarial activities of the pure metabolites from Jatropha multifida used in African ethnomedicine. METHODS: The methanolic stem bark extract of Jatropha multifida used in Nigerian folk medicine as remedy against bacterial infections was subjected to column chromatography and HPLC analyses to obtain three known metabolites, microcyclic lathyrane diterpenoids (1-3). Structures were confirmed by comparison of 1D and 2D spectral data with literature. RESULTS: The three compounds exhibited inhibition of antileishmanial, antimalarial and antimicrobial actions against the tested organisms with compouds 2 and 3 active against Cryptococcus neoformans at IC50 of 8.2 and 8.7 µg/mL, respectively. CONCLUSIONS: The research lends support to the ethnomedicinal use of the plant in combating microbial infections, leishmaniasis and malarial infections.

Pro-apoptotic and anti-adhesive effects of four African plant extracts on the breast cancer cell line MCF-7.

BACKGROUND: Jatropha curcas (JCP1), Pyrenacantha staudtii (PS), Picralima nitida (ZI) and Jatropha gossypifolia (JCP2) are plants used in the African folklore for the treatment of various cancers. METHODS: This study investigated the in vitro anticancer effects of the ethanol extracts against human epithelial MCF-7 breast cancer cells in a dose-dependent manner (1-50 µg/ml) by using cell cycle analysis, viability assay, annexin V/PI staining, TUNEL method and expression determination of apoptotic and adhesion relevant proteins. Adhesion processes were monitored by detachment via flow cytometry, ß1-integrin expression and formation of the actin cytoskeleton. RESULTS: The three extracts, termed PS, JCP1 and JCP2 at a concentration of 10 µg/ml induced cell death in MCF-7 breast cancer cells verified by high amounts of PI-positive cells in the cell cycle analysis, Annexin V/PI staining and DNA fragmentation measurements. In parallel cell detachment was accompanied by decreased ß1- integrin expression and phosphorylation of the focal adhesion kinase at Tyr397. ZI extract was the exception by the increasing ß1-integrin expression and strengthening the cortical actin cytoskeleton. However, all four plant extracts mediated strong anti-cancer properties with IC50 values between 23-38 µg/ml. CONCLUSION: PS, JCP1 and JCP2 were found to be very active against MCF-7 cells by inducing anoikis and therefore possessing vast potential as medicinal drugs especially in estrogen receptor positive breast cancer treatment. ZI mediated their anti-cancer action by different signaling mechanisms which should be analyzed in future studies. Our results further supported the idea that medicinal plants can be promising sources of putative anticancer agents.

Anticancer activity of five forest crops used in African folklore: antiproliferative and pro-apoptotic effects.

Acalypha wilkesiana, Caesalpinia bonduc, Jatropha multifida, Momordica charantia and Picralima nitida used in African folklore for treating cancer were investigated. All extracts except J. multifida resulted in no significant alteration in cell cycle distribution and apoptosis in MCF-7 and BT-20. The J. multifilda (JMR-Ch) caused cell cycle arrest at G1 checkpoint and apoptosis in MCF-7. Slight changes in the integrin expression of MCF-7 after treatment with 1 and 10 µg/mL of JMR-Ch were observed. Fluorescence-activated confocal microscopy shows changes in cell morphology and ß1 integrin localisation within MCF-7 cells after exposure to 10 and 25 µg/mL of JMR-Ch. JMR-Ch (1 µg/mL) treatment resulted in time-dependent decrease in cell acidification and respiration in MCF-7 cells and a time-dependent decrease in BT-20 cell respiration, while in MCF-10A, there was an enhancement of acidification. These results revealed the probable application of JMR-Ch in cancer therapy.

Medicinal uses, phytochemistry and pharmacology of Picralima nitida (Apocynaceae) in tropical diseases: a review.

Picralima nitida Durand and Hook, (fam. Apocynaceae) is a West African plant with varied applications in African folk medicine. Various parts of the plant have been employed ethnomedicinally as remedy for fever, hypertension, jaundice, dysmenorrheal, gastrointestinal disorders and malaria. In order to reveal its full pharmacological and therapeutic potentials, the present review focuses on the current medicinal uses, phytochemistry, pharmacological and toxicological activities of this species. Literature survey on scientific journals, books as well as electronic sources have shown the isolation of alkaloids, tannins, polyphenols and steroids from different parts of the plant, pharmacological studies revealed that the extract or isolated compounds from this species posses analgesic, anti-inflammatory, hypoglyceamic, hypotensive, antiplasmodial, antimicrobial, antiulcer and antitumorigenic activities. Results from various scientific investigations to date have revealed the potential of the extract from the plant or isolated compounds for use in the treatment and prevention of various kinds of human diseases. However, further studies on the extracts and pure compounds from this species is required to completely assess its phytochemical, pharmacological and toxicological profile as well as the mechanism of action behind these pharmacological activities exhibited by the compounds isolated from this species.

Novel anticancer alkene lactone from Persea americana.

CONTEXT: Persea americana Mill (Lauraceae) root bark is used in ethnomedicine for a variety of diseases including cancer. OBJECTIVE: To isolate and characterize the chemical constituent in P. americana, and also to determine the anticancer property of a new alkene lactone from the root bark of P. americana. MATERIALS AND METHODS: The MCF-7 cells were treated with different concentrations of the pure compound for 48 h. The percentage of cells in the various phases, online monitoring of metabolic changes and integrin receptor expression determined by flow cytometry. RESULTS: One novel alkene lactone (4-hydroxy-5-methylene-3-undecyclidenedihydrofuran-2 (3H)-one) (1) was isolated and characterized using 1D-NMR, 2D-NMR, infrared, UV and MS. At a concentration of 10 µg/mL, significant reduction of proliferation of MCF-7 was induced while MCF-12 A cell was significantly stimulated by 10 µg/mL. The IC50 value for MCF-7 cells is 20.48 µg/mL. Lower concentration of 1 harbor no significant effect on either MCF-7 or MCF-12A. The apoptotic rates of MCF-7 cells were increased significantly. At the final concentration 10 µg/mL, up to 80% of all breast cancer cells were dead. On the non-tumorigenic cell line MCF-12A, the same concentrations (1 and 10 µg/mL) of compound 1 caused significant enhanced apoptotic rates. A total of 1 µg/mL of 1 caused a decrease of α4-, α6-, ß1- and ß3-integrin expression. CONCLUSIONS: The compound caused a stimulatory effect on non-tumorigenic MCF-12A cells with respect to cell adhesion while tumorigenic MCF-7 cells detached continuously. This is the first report on the anticancer effects of this class of compound.

A novel anticancer diterpenoid from Jatropha gossypifolia.

Jatropha gossypifolia root bark is used in ethnomedicine for bacterial infections and cancer of the lungs. Phytochemical investigation resulted in the isolation and characterization of a potent anticancer and novel lathyrane diterpenoid compound, abiodone, with an unusual methylene group. The structure of this novel compound was established by 1D, and 2D NMR spectroscopic experiments a nd confirmed by X-ray analysis.

Smooth muscle relaxant evaluation of Jatropha curcas Linn (Euphorbiaceae) and isolation of triterpenes.

Jatropha curcas is a herbal preparation used in the tropics for the treatment of threatened abortion and related problems associated with pregnancy. The Stem bark of Jatropha curcas is used ethno medicinally in Nigeria especially in the eastern part of the country for the treatment of infertility and spontaneous abortion (miscarriage). The present study was undertaken in order to validate the folkloric claim, using scientific experimental procedures and bioassay guided fractionation. The crude powdered sample was subjected to phytochemical screening testing for the presence of alkaloids, tannins, saponins and carbohydrates. Chromatographic analysis (TLC and VLC) were carried out using various solvent systems. The effect of methanolic extracts on rat uterine contractions was studied in vitro, in 40ml organ baths containing physiological salt solution of De Jalon maintained at 370C, aerated with 95% O2 and 5% CO2 with an isometric transducer connected an UgoBasile recorder under a resting tension of 750mg. The result of the phytochemical screening revealed the presence of glycosides, tannins, saponins and alkaloids. The extract abolished significantly the spontaneous contraction of the uterus and reduced acetylcholine induced uterine contractions at a dose of 50mg/ml. The tocolytic effects indicate the presence of active principle(s) which would explain the ethno medicinal use of the stem bark of Jatropha curcas to treat spontaneous abortion.

Oxytocic effects of the aqueous leaf extract of Costus lucanusianus - family Costaceae on isolated non-pregnant rat uterus.

Costus lucanusianus J. Braun (Costaceae) is a climbing herb, found mainly in the Niger Delta region of Nigeria. This plant is locally used in situations of pains, inflammation, dysmenorrhoea and in pyrexia. The purpose of this study was to investigate this claim with view to validating scientifically the ethno-medicinal usage. The aqueous extract was subjected to pharmacological testing in vitro on a piece of isolated rat uterus previously pretreated with 1 mg/kg stilbestrol for 24 h. The dose response curves of oxytocin and that of the extract were first obtained. The effects of antagonists like atropine (1 mg) and salbutamol (2 microg) on the dose response curve of the extract were also investigated. Possible synergy was investigated via co-administration of the extract and oxytocin. Finally the proximate analysis of the extract was investigated. The aqueous extract of C. lucanusianus and oxytocin both produced a dose dependent contraction of the uterus. An effect of 0.63+/-0.06 g force of uterine contraction produced by 12.5 mg of the extract was increased to 1.37+/-0.09 g when 200 mg of the extract was administered. Oxytocin at 0.16 i.u was observed to produce a similar force of contraction with 200 mg of the aqueous extract. Synergy was established as co administration of the extract at 200 mg and oxytocin at 0.08 i.u, produced higher contractile effect, significantly higher (p<0.05) than when either the extract (200mg) or oxytocin (0.08 i.u) was administered alone. Both atropine and salbutamol significantly (p<0.0001) inhibited the contractile effect produced by the extract. The inhibitory effect showed by atropine on the contractile effect of the extract seems to suggest the involvement of muscarinic receptors. The proximate analysis carried out in this study is used to establish the identity of the crude drug sample. A moisture content of 10.047 % was obtained. The total ash is a measure of the non-volatile inorganic constituents remaining after ashing. The values of 3.42 % were obtained.

Evaluation of tocolytic activity of ethanol extract of the stem bark of Ficus capensis Thunb. (Moraceae).

Ficus capensis, a wild fig tree is used in herbal medicines to treat pregnancy related ailment and most especially as a remedy for threatened abortion. The purpose of this study was to investigate this claim with view to validating scientifically the ethno-medicinal usage. The ethanolic extract obtained by maceration technique was subjected to pharmacological testing in vitro on a piece of isolated rat uterus previously pretreated with stilbestrol, suspended in De Jalon at 37 degrees C. Concentrations used were 40 mg/mL and 80 mg/mL. The higher concentration (80 mg/mL) significantly (p < 0.05) exerted smooth muscle relaxant activity on the uterus (a reduction of oxytocin, ergometrin and acetylcholine induced contractions as well as an increase of the EC50 was observed for all the agonists tested in the presence of the extract). Evaluation of the data also indicated that the effect of the 40 mg/mL concentration was statistically insignificant, although a lowering of the dose response curve was observed for oxytocin, acetylcholine and ergometrin. Its relaxant activity at 80 mg/mL was 40 and 50% of the inhibitory effects produced by salbutamol (0.002 microg/mL) and atropine (0.02 microg/mL) on oxytocin and acetylcholine induced contractions, respectively. The results indicate the presence of active principles in the bark extract of Ficus capensis which may be responsible for some of the applications in traditional medicines as an anti-abortifacient and as a remedy against threatened abortion.

Isolation and characterization of xanthine oxidase inhibitory constituents of Pyrenacantha staudtii.

Six compounds have been isolated from the leaves of Pyrenacantha staudtii, two of which are new compounds. The new compounds have been characterized as kaempherol 3-O-beta-rhamnopyranosyl (1-->6)-beta-D-glucopyranoside (1) and 4-beta-glucopyranosyl-(2-furyl)-5-methy-1,2-glucopyranoside phenylmethanone (2). The known compounds are 3-pyridinecarboxylic acid (3), beta-sitosterol (4), sitosterol 3-O-beta-glucopyranoside (5) and taraxerol (6). Their structures were determined by spectroscopic and chemical evidences. The two new compounds together with 3-pyridinecarboxylic acid showed significant in vitro xanthine oxidase inhibitory activity. To the best of our knowledge, this is the first report of these compounds from this plant.