Lancifodilactone F: a novel nortriterpenoid possessing a unique skeleton from Schisandra lancifolia and its anti-HIV activity

[structures: see text] Lancifodilactone F (1), possessing an unprecedented rearranged pentanortriterpenoid backbone derived from cycloartane, was isolated from the leaves and stems of Schisandra lancifolia (Rehd. et Wils) A. C. Smith. Its structure was established by comprehensive NMR and MS spectroscopic analysis, coupled with single-crystal X-ray experiment. Compound 1 exerted minimal cytotoxicity against C8166 cells (CC50 > 200 microg/mL) and showed anti-HIV activity with EC50 = 20.69 +/- 3.31 microg/mL and a selectivity index > 6.62.     

Anthecularin: a novel sesquiterpene lactone from Anthemis auriculata with antiprotozoal activity

Anthecularin (1), a minor sesquiterpene lactone with a novel ring system was isolated from Greek Anthemis auriculata (Asteraceae). Its structure was elucidated by means of NMR, HRMS, and X-ray crystallography. Anthecularin showed antitrypanosomal (IC50=10.1 microg/mL) and antiplasmodial activity (IC50=23.3 microg/mL) and inhibited two key enzymes of the plasmodial type II fatty acid biosynthesis pathway, PfFabI and PfFabG (IC50 values=14 and 28.3 microg/mL, respectively). A probable biogenesis of 1 is also proposed and discussed.     

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.     

Antiacetylcholinesterase and antioxidant ent-Kaurene diterpenoid, melissoidesin from Isodon wightii (Bentham) H. Hara

The ent kaurene diterpenoid, melissoidesin was isolated from the acetone extract of the leaves of Isodon wightii and the structure was designated as 3beta, 11beta, 15beta-trihydroxy-6alpha-acetoxy-ent-kaur-16-ene based on spectral data and previous reports. Melissoidesin isolated from the acetone extract of leaves showed potent antiacetylcholinesterase activity and the IC(50) value was observed as 215 microg mL(-1). DPPH (1, 1-diphenyl-2-picrylhydrazyl) free radical scavenging activity of melissoidesin was significant and the IC(50) value was 138 microg mL(-1). The significant reducing property of the melissoidesin was stronger in high concentration. IC(50) value of melissoidesin on hydroxyl radicals and metal chelation was observed as 99 and 143 microg mL(-1), respectively. The 50% inhibitory concentration of melissoidesin on lipid peroxidation was calculated as 133 microg mL(-1). These findings indicate that ent kaurene diterpenoid, melissoidesin was promising antiacetylcholinesterase and antioxidant which can be used as food and drug preparations.     

Antimicrobial activity of globulol isolated from the fruits of Eucalyptus globulus Labill

An antimicrobial sesquiterpene was separated by bioassay-guided isolation from the petroleum ether fraction of the ethanol crude extract of Eucalyptus globulus Labill (Myrtaceae) fruits, and was identified as globulol by physicochemical properties and spectroscopic analysis. Mycelial growth method revealed that the median effective inhibitory concentration (IC50) values of globulol on Alternaria solani, Fusarium oxysporum f.sp. niverum, F. graminearum, Rhizoctonia solani and Venturia pirina were 47.1 microg mL(-1), 114.3 microg mL(-1), 53.4 microg mL(-1), 56.9 microg mL(-1), 32.1 microg mL(-1) and 21.8 microg mL(-1), respectively. MTT-colorimetric assay revealed that IC50 values of globulol on Xanthomonas vesicatoria and Bacillus subtilis were 158.0 microg mL(-1) and 737.2 microg mL(-1), respectively. The results indicated that globulol could be a main antimicrobial compound in the ethanol crude extract of E. globulus fruits.     

Alkaloids from some amaryllidaceae species and their cholinesterase activity

Alkaloid extracts of four Amaryllidaceae species were studied with respect to their acetylcholinesterase and butyrylcholinesterase inhibitory activity and alkaloid patterns. Twenty-one alkaloids were determined by GC/MS, and seventeen of them identified from their mass spectra and retention times. The GC/MS analysis of the alkaloid extract of Nerine filamentosa is the first phytochemical investigation of this species. Promising erythrocytic acetylcholinesterase inhibitory activity was demonstrated by the alkaloid extracts of Narcissus poeticus var recurvus, Nerine filifolia and N. filamentosa (IC(50,HuAChE) = 6.0 +/- 0.1 microg/mL; IC(50,HuAChE) = 18.5 +/- 0.8 microg/mL, IC(50,HuAChE) = 21.6 +/- 1.1 microg/mL). The most potent inhibitory activity against serum butyrylcholinesterase was shown by extracts of Sternbergia lutea and Nerinefilamentosa (IC(50,HuBuChE) = 3.7 +/- 0.1 microg/mL; IC(50.HuBuChE) = 13.0 +/- 0.7 microg/mL).     

Coriatone and corianlactone, two novel sesquiterpenes from Coriaria nepalensis

Both coriatone (1). a novel highly oxygenated picrotoxane-type sesquiterpene, and corianlactone (2). with an unprecedented sesquiterpene basic skeleton, named coriane, were isolated from Coriaria nepalensis Wall. The structures of 1 and 2 were determined by analysis of their two-dimensional NMR data, and the structure of 2 was confirmed by X-ray analysis. Compounds 1 and 2 showed no remarkable inhibitory activity toward K(562) cells. They are cytotoxic with IC(50) > 50 microg/mL (cis-platinim: IC(50) = 0.49 microg/mL).     

Maoecrystal V, cytotoxic diterpenoid with a novel C19 skeleton from Isodon eriocalyx (Dunn.) hara

Maoecrystal V (1), a novel C(19) diterpenoid possessing a unique 6,7-seco-6-nor-15(8-->9)-abeo-5,8-epoxy-ent-kaurane skeleton, was isolated from the leaves of a Chinese medicinal herb, Isodon eriocalyx. Its structure was determined by comprehensive NMR and MS spectroscopic analysis and confirmed by single-crystal X-ray diffraction study. Compound 1 showed remarkable inhibitory activity toward HeLa cells with IC(50) = 0.02 microg/mL (cis-platin: IC(50) = 0.99 microg/mL).     

Analysis of Amaryllidaceae alkaloids from Chlidanthus fragrans by GC-MS and their cholinesterase activity

The underivatized alkaloid mixture extracted from the bulbs of Chlidanthus fragrans Herb. was investigated by capillary GC/MS for the first time. Fifteen known Amaryllidaceae alkaloids of five structure types were identified. The main alkaloids were tazzetine (9, tazettine-type), chlidanthine (2, galanthamine-type), belladine (8, belladine-type) and lycorine (12, lycorine-type). The alkaloid extract from the bulbs showed promising human blood acetylcholinesterase (IC50 = 20.1 +/- 2.9 microg/mL) and human plasma butyrylcholinesterase (IC50 = 136.8 +/- 6.9 microg/mL) inhibitory activity.     

Head-column field-amplified sample stacking in capillary electrophoresis for the determination of cimetidine, famotidine, nizatidine, and ranitidine-HCl in plasma.

In this study, low concentrations of histamine2-receptor (H2-)antagonists were effected across a water plug, with separation taking place in a binary buffer comprising ethylene glycol and NaH2PO4 (pH 5.0), and detection at 214 nm. Liquid-liquid extraction with ethyl acetate- isopropanol is shown to provide extracts that are sufficiently clean. The calibration curves were linear over a concentration range of 0.1-2.00 microg/mL cimetidine, 0.2-5.0 microg/mL ranitidine-HCl, 0.3-5.0 microg/mL nizatidine, and 0.1-3.0 microg/mL famotidine. Mean recoveries were > 82%, while the intra- and interday relative standard deviations (RSDs) and relative errors (REs) were all < 13%. The method is sensitive with a detection limit of 3 ng/mL cimetidine, 30 ng/mL ranitidine HCl, 50 ng/mL nizatidine and 10 ng/mL famotidine (S/N = 3, electric-driven injection 90 s). This newly developed capillary electrophoresis (CE) method was applied for the determination of analytes extracted from plasma taken from a volunteer dosing a cimetidine, ranitidine, and nizatidine tablet simultaneously. These three H2-antagonists can be detected in real samples by this method, excluding the low dosing of famotidine tablet.     

Composition of three essential oils, and their mammalian cell toxicity and antimycobacterial activity against drug resistant-tuberculosis and nontuberculous mycobacteria strains

Tuberculosis (TB) is the most ancient epidemic disease in the world and a serious opportunistic disease in HIV/AIDS patients. The increase in multidrug resistant Mycobacterium tuberculosis (MDR-TB, XDR-TB) demands the search for novel antimycobacterial drugs. Essential oils (EOs) have been widely used in medicine and some EOs and their major components have been shown to be active against M. tuberculosis. The aim of this work was to evaluate the antimycobacterial and cell toxicity activities of three EOs derived from Salvia aratocensis, Turnera diffusa and Lippia americana, aromatics plants collected in Colombia. The EOs were isolated by hydrodistillation and analyzed by GC/MS techniques. The EOs were tested against 15 Mycobacterium spp using a colorimetric macrodilution method and against mammalian Vero and THP-1 cells by MTT. The activity was expressed as minimal concentration in microg/mL that inhibits growth, and the concentration that is cytotoxic for 50 or 90% of the cells (CC50 and CC90). The major components were epi-alpha-cadinol (20.1%) and 1,10-di-epi-cubenol (14.2%) for Salvia aratocensis; drima-7,9(11)-diene (22.9%) and viridiflorene (6.6%) for Turnera diffusa; and germacrene D (15.4%) and trans-beta- caryophyllene (11.3%) for Lippia americana. The most active EO was obtained from S. aratocensis, with MIC values below 125 microg mL(-1) for M. tuberculosis Beijing genotype strains, and 200 to 500 microg mL(-1) for nontuberculous mycobacterial strains. The EOs were either partially or non toxic to Vero and THP-1 mammalian cells with CC50 values from 30 to > 100 microg mL(-1), and a CC90 > 100 microg mL(-1). The EOs obtained from the three aromatic Colombian plants are an important source of potential compounds against TB. Future studies using the major EO components are recommended.     

Synthesis of novel L-N-MCd4T as a potent anti-HIV agent

L-N-MCd4T (1) has been synthesized as a potent anti-HIV agent starting from (R)-epichlorohydrin using tandem alkylation, chemoselective reduction of ester in the presence of lactone functional group, RCM reaction and Mitsunobu reaction as key steps and was found to be a very potent anti-HIV-1 (EC50 = 6.76 microg mL(-1)) agent without cytotoxicity up to 100 microg mL(-1), indicating that the anti-HIV-1 activity found is similar to that of ddI (EC50 = 4.95 microg mL(-1)), which is used clinically for the treatment of AIDS patients.     

Structure activity relationship studies on antileishmanial steroidal alkaloids from Sarcococca hookeriana

The search for antileishmanial constituents from the medicinal plant Sarcococca hookeriana (Buxaceae) of Nepalese origin has resulted in the isolation of 17 (1-17) active steroidal alkaloids. Compounds 1, 2, and 10 were subjected to derivatization and five chemically derived derivatives (1a, 2a, 10a, 10b, 10c) were also obtained. All these natural compounds and derivatives were found to have potent to mild antileishmanial properties. The IC(50) values were found to be in the range of 0.20-61.44 microg mL(-1) (IC(50) value of standard drug amphotericin B = 0.12 microg mL(-1)). The structure activity relationship indicated that the varieties of functionalities present in ring A of the steroidal alkaloids were found to play a characteristic role to increase the antileishmanial activity.     

Anti-babesial compounds from Curcuma xanthorrhiza

Anti-babesial ingredients, (12R)- and (12S)-12,13-dihydro-12,13-dihydroxyxanthorrhizols, were isolated from Curcuma xanthorrhiza. The structures were established by the extensive NMR techniques. The assignments of (1)H NMR data of (12R)-12,13-dihydro-12,13-dihydroxyxanthorrhizol was revised, and (12S)-12,13-dihydro-12,13-dihydroxyxanthorrhizol was isolated as a pure form for the first time. The IC(50) of the active compounds were compared with that of commercial drug, diminazene aceturate (Ganaseg). IC(50) values of Ganaseg, (12R)-, and (12S)-12,13-dihydro-12,13-dihydroxyxanthorrhizols were 0.6 microg mL(-1), 8.3 microg mL(-1) and 11.6 microg mL(-1), respectively.     

Cytotoxic lignans from the stems of Styrax camporum (Styracaceae)

An ethanolic extract from the stems of Styrax camporum Pohl (Styracaceae), a plant traditionally used for gastrointestinal diseases, was fractionated and subjected to flash chromatography and afforded two benzofuran lignans, egonol and homoegonol, and one furofuran lignan, (+/-)syringaresinol, which were identified by spectral data interpretation. Their cytotoxic activities against Hep-2 (larynx epidermoid carcinoma), HeLa (human cervix carcinoma) and C6 (rat glioma) cell lines were evaluated using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) assay at several concentrations for 24h. Activities could be observed for egonol against C6 (IC50 = 3.2 microg/mL) and Hep-2 (IC50 = 3.6 microg/mL) cell lines, and for homoegonol against C6 (IC50 = 4.9 microg/mL) and HeLa (IC50 = 5.3 microg/mL) cells.     

In vitro antitumor activity of triterpenes from Ceriops tagal

The embryo of Ceriops tagal was extracted with 95% ethanol at room temperature, and four triterpenes (1-4) were separated from this extract. For the first time these triterpenes were the separated from this plant. Compounds (1-4) were tested in vitro for antitumor activity against three cell lines (human liver cancer cell (H-7402), human B-lymphoblastoid cell (Raji), and human cervical carcinoma cell (Hela)). Compounds 1 and 3 were effective to inhibit cell proliferation and growth of H-7402 and Hela, the IC(50) of them on H-7402 were 14.42 microg mL(-1) and 9.97 microg mL(-1), and the IC(50) of them on Hela were 11.84 microg mL(-1) and 11.32 microg mL(-1). All compounds 1-4 were not effective to inhibit cell proliferation and growth of Raji. The effects of compound 4 on inhibiting proliferation and growth of these three cancer cells was also not obvious.     

Free radical scavenging activity-guided isolation of a diterpenoid from Plectranthus punuctatus

Free radical scavenging activity-guided investigation of the acetone extract of Plectranthus punuctatus (L'Her) (Lamiaceae) resulted in the isolation of a novel diterpenoid 3,11,12,14,19-pentahydroxy-5,8,11,13-abietatraen-7-pyran[4,6]-16-dione whose structure was elucidated based on spectral evidence. The isolated compound showed a significant antioxidant activity in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and deoxyribose degradation assays with IC50 values of 9.65 microg/mL and 5.25 microg/mL, respectively.     

Development of a novel method based on liquid chromatography-evaporative light scattering detection for the direct determination of streptomycin and dihydrostreptomycin in raw materials, pharmaceutical formulations, culture media and plasma

A novel method for the non-derivatization liquid chromatographic determination of streptomycin (STR) and dihydrostreptomycin (DHSTR) was developed and validated based on evaporative light scattering detection (ELSD). Utilizing a ThermoHypersil BetaBasic C18 analytical column, evaporation temperature of 50 degrees C and pressure of nebulizing gas (nitrogen) of 3.5 bar, the optimized mobile phase was 1.25 mL L(-1) TFA aqueous solution, in an isocratic mode at a rate of 1.0 mL min(-1). STR was eluted at 5.6 min and DHSTR at 7.8 min with a resolution of 4.4. Linear calibration curves were obtained from 2 to 120 microg mL(-1) (r > 0.9990) for STR and 2-75 microg mL(-1) (r > 0.9994) for DHSTR, with a LOD equal to 0.7 and 0.5 microg mL(-1), respectively. The developed method was applied for the assay of STR and DHSTR (sulfate) in pharmaceutical raw materials and formulations, while the simultaneous direct determination of sulfate was feasible (tR = 2.5 min, LOD = 1.4 microg mL(-1), double logarithmic calibration curve in the range of 4-50 microg mL(-1), r > 0.9998). Modified isocratic mobile phase (H2O-ACN, 90:10, v/v, containing 1.25 mL L(-1) TFA), was used for the determination of streptomycin B impurity in STR sulfate raw material and a gradient mobile phase (H2O-ACN containing TFA) was used for the determination of DHSTR in the presence of penicillinG procaine. The developed method was also applied for the assay of commercial formulations (STR powder and DHSTR injection solution and suspension) (%recovery 98-102, %RSD < 1.3, n = 3 x 3), for the determination of STR in bacteria culture medium (%recovery 99.6, %RSD = 0.8, n = 3 x 3), and for the determination of DHSTR in human plasma (2.0-23.0 microg mL(-1)) after solid phase extraction using carboxylate cartridges (%recovery 98.4-101.8, %RSD = 3.2, n = 3 x 3).     

Anthraquinones, Cdc25B phosphatase inhibitors, isolated from the roots of Polygonum multiflorum Thunb

Three anthraquinones, Cdc25B phosphatase inhibitors, were isolated from the methanolic extract of the roots of Polygonum multiflorum Thunb. (Polygonaceae). Anthraquinones, physcion (1), emodin (2), and questin (3), inhibited the enzymatic activity of Cdc25B phosphatase with IC(50) values of 62.5, 30, and 34 microg mL(-1), respectively. Emodin (2) and questin (3) strongly inhibited the growth of human colon cancer cells, SW620 with GI(50) values of 6.1 and 0.9 microg mL(-1), respectively. Commercially available anthraquinones, chrysophanol (4), and rhein (5) also inhibited Cdc25B phosphatase with IC(50) values of 10.7 and 22.1 microg mL(-1), respectively.     

A simple HPLC method for the quantification of mizoribine in human serum: pharmacokinetic applications

A simple high-performance liquid chromatographic (HPLC) method was developed and validated for the quantification of mizoribine in human serum. After the addition of 70% perchloric acid and 3-methylxanthine (50 microg/mL, internal standard) to human serum, the samples were mixed and centrifuged at 12,000 rpm (1432 g) for 10 min. The supernatant was injected onto a C(18) column eluted with a mobile phase of 20 mm Na2HPO4 and methanol (93:7, v/v, pH 3) containing 0.04% octanesulfonic acid and detected utilizing an ultraviolet detector at 275 nm. The linear calibration curve was obtained in the concentration range of 0.1-4.0 microg/mL and the lower limit of quantification was 0.1 microg/mL. This method was validated with selectivity, linearity, precision and accuracy. In addition, the method was successfully applied to estimate the pharmacokinetic parameters of mizoribine in Korean subjects following an oral administration of 100 mg mizoribine (two Bredinine 50 mg tablets). The maximum serum concentration (C(max)) of 2.30 +/- 0.83 microg/mL was reached 2.27 +/- 0.66 h after an oral dose. The mean AUC(0-12 h) and the elimination half-life (t(1/2)) were 13.2 +/- 4.79 microg h/mL and 3.10 +/- 0.74 h, respectively.