Pure Active Compounds Research Articles

Medicinal compounds with antiepileptic/anticonvulsant activities

Epilepsy is a serious neural disease that affects around 50 million people all over the world. Although for the majority patients with epilepsy, seizures are well controlled by currently available antiepileptic drugs (AEDs), there are still >30% of patients suffered from medically refractory epilepsy and approximately 30-40% of all epileptic patients affected by numerous side effects and seizure resistance to the current AEDs. Therefore, many researchers try to develop novel approaches to treat epilepsy, for example, to discover new antiepileptic constituents from herbal medicines. Although there are already several reviews on phytotherapy in epilepsy, most of them placed emphasis on the plant crude extracts or their isolated fractions, not pure active compounds derived from herbal medicines. This article aims to review components in herbal medicines that have shown antiepileptic or anticonvulsant properties. We searched online databases and identified articles using the preset searching syntax and inclusion criteria. The active medicinal compounds that have shown anticonvulsant or antiepileptic activity were included and classified according to structural types. We have reviewed herein the active constituents including alkaloids, flavonoids, terpenoids, saponins, and coumarins. The screening models, the seizures-inducing factors and response, the effective dose, the potential mechanisms, as well as the structure-activity relationships in some of these active components have also been discussed. The in vitro and in vivo experimental data reviewed in this paper would supply the basic science evidence for research and development of novel AEDs from medicinal plants.

An open-labeled, randomized, multicenter phase IIa study of gambogic acid injection for advanced malignant tumors

Background Gambogic acid is a pure active compound isolated from the traditional Chinese medicinal plant gamboge (Garcinia morella Desv.). Based on the preliminary results of a phase I study, this phase IIa study compared the efficacy and safety of different dosage schedules of gambogic acid in patients with advanced malignant tumors. Methods Patients with advanced or metastases cancer who had not received any effective routine conventional treatment or who had failed to respond to the existing conventional treatment were randomly assigned to receive either 45 mg/m2 gambogic acid intravenously from Days 1 to 5 of a 2-week cycle (Group A), or 45 mg/m2 every other day for a total of five times during a 2-week cycle (Group B). The primary endpoint was objective response rate (ORR). Results Twenty-one patients assigned to Group A and 26 to Group B were included in the final analysis. The ORRs were 14.3% in Group A and 0% in Group B. It was not possible to analyze the significant difference because one of the values was zero. The disease control rates (DCRs) were 76.2% in Group A and 61.5% in Group B (P=0.0456). The observed adverse reactions were mostly Grades I and II, and occurred in most patients after administration of the trial drug. There was no significant difference in the incidence of adverse reactions between the two arms. Conclusions The preliminary results of this phase IIa exploratory study suggest that gambogic acid has a favorable safety profile when administered at 45 mg/m2. The DCR was greater in patients receiving gambogic acid on Days 1-5 of a 2-week cycle, but the incidence of adverse reactions was similar irrespective of the administration schedule.

Antroquinonol mitigates an accelerated and progressive IgA nephropathy model in mice by activating the Nrf2 pathway and inhibiting T cells and NLRP3 inflammasome

High levels of reactive oxygen species (ROS), systemic T cell activation, and macrophage infiltration in the kidney are implicated in the acceleration and progression of IgA nephropathy (IgAN), the most frequent type of primary glomerulonephritis. However, the pathogenic mechanism of IgAN is still little understood, and it remains a challenge to establish a specific therapeutic strategy for this type of glomerular disorder. Recently, we showed that antroquinonol (Antroq), a pure active compound from Antrodia camphorata mycelium, inhibits renal inflammation and reduces oxidative stress in a mouse model of renal fibrosis. But the anti-inflammatory and immune-regulatory effects of Antroq on the acceleration and progression of primary glomerular disorders have not been determined. In this study, we show that Antroq administration substantially impeded the development of severe renal lesions, such as intense glomerular proliferation, crescents, sclerosis, and periglomerular interstitial inflammation, in mice with induced accelerated and progressive IgAN (AcP-IgAN). Further mechanistic analysis in AcP-IgAN mice showed that, early in the developmental stage of the AcP-IgAN model, Antroq promoted the Nrf2 antioxidant pathway and inhibited the activation of T cells and NLRP3 inflammasome. Significantly improved proteinuria/renal function and histopathology in AcP-IgAN mice of an established stage supported potential therapeutic effects of Antroq on the disease. In addition, Antroq was shown to inhibit activation of NLRP3 inflammasome in vitro by an IgA immune complex (IC) partly involving a reduced ROS production in IgA-IC-primed macrophages, and this finding may be helpful in the understanding of the mode of action of Antroq in the treated AcP-IgAN mice.

Allium ursinum L.: Bioassay-Guided Isolation and Identification of a Galactolipid and a Phytosterol Exerting Antiaggregatory Effects

Aims: We wanted to investigate the possible antithrombotic effects and elucidate the chemical identity of the active principles involved in inhibitory effects against adenosine diphosphate (ADP)-induced aggregation of human platelets by wild garlic, Allium ursinum L. Methods: For this purpose, a bioassay-guided isolation procedure was used followed by spectrometric identification of pure active compounds. For the bioassay, blood was taken from healthy human volunteers and platelet-rich plasma was prepared for turbidimetric platelet aggregation tests. Platelet-rich plasma, stimulated with 20 µmol/l of ADP, was treated with extracts of different polarities, fractions and isolated single compounds from A. ursinum. The extracts were investigated by thin-layer chromatography (TLC), HPLC, mass spectroscopy, electrospray ionization mass spectrometry (ESI-MS) and 1/2-dimensional ¹H/¹³C-nuclear magnetic resonance (NMR) spectroscopic techniques. Results: Fresh A. ursinum leaves were extracted with ethanol, which was the potent form that effectively inhibited ADP-induced aggregation of human platelets. This ethanolic extract was subjected to liquid-liquid partition. Whilst the aqueous phase, containing the moiety of cysteine sulphoxide and thiosulphinate derivatives, showed only weak activity on platelet aggregation, the ethyl-acetate and particularly the chloroform partitions showed the highest aggregation-inhibiting potency. Thus, in our bioassay, the effects of alliins/allicins could be neglected. The chloroform phase, possessing the strongest activity, was separated into 28 fractions by gradient-elution open column chromatography on silica gel. The most active fractions 11–17 were separated again, yielding 10 subfractions. This afforded 1,2-di-O-α-linolenoyl-3-O-β-D-galactopyranosyl-sn-glycerol and β-sitosterol-3-O-β-D-glucopyranoside, the structures of which were determined by ESI-MS and 1/2-dimensional ¹H/¹³C NMR spectroscopic techniques. Furthermore, the minute amounts of volatile oil of A. ursinum leaves obtained by steam distillation according to Ph. Eur. could be evaluated as a third aggregation-inhibiting principle. Conclusion: In our study, for the first time, 2 active, non-sulphur-containing constituents of wild garlic, namely a galactolipid and a phytosterol, could be identified exhibiting inhibitory action on ADP-induced aggregation in human blood platelets. As a major constituent, the galactolipid, 1,2-di-O-α-linolenoyl-3-O-β-D-galactopyranosyl-sn-glycerol, not yet found in Allium sp., appears as a new, highly useful marker substance for A. ursinum drugs, or their pharmaceutical or food preparations, as shown by our orientating TLC analyses.

Antimicrobial screening of some Egyptian plants and active flavones from Lagerstroemia indica leaves

One hundred and twenty four plant extracts were evaluated for their antimicrobial activity against four pathogenic bacteria (Staphylococcus aureus (ATCC 8095), Salmonella enteritides (ATCC 13076), Escherichia coli (ATCC 25922), and Listeria monocytogenes (ATCC 15313)) and Candida albicans yeast (ATCC 10231) using the disk diffusion and broth microdilution methods. Of the plant extracts, fourteen exhibited antimicrobial activity against two or more of the five microorganisms tested. Only the methanol extract of Lagerstroemia indica leaves exhibited antimicrobial activity against all pathogenic bacteria and C. albicans yeast that were tested. Purification of the methanol extract of L. indica leaves using antimicrobial assay-guided isolation yielded one pure active compound. The chemical structure of the isolated active compound was found to be '4-methoxy apigenin-8-C-β-D-glucopyranoside; cytisoside according to detailed spectroscopic analysis of its nuclear magnetic resonance and mass spectrometry data. The compound exhibited antimicrobial activity against C. albicans (minimum lethal concentration (MLC): 32 μg/mL), S. aureus (MLC: 16 μg/mL), S. enteritides (MLC: 16 μg/mL), E. coli (MLC: 16 μg/mL), and L. monocytogenes (MLC: 16 μg/mL). The present study found that the methanol extract of L. indica leaves holds great promise as a potential source of beneficial antimicrobial components for different applications.

Influence of new fungicides – metiram and pyraclostrobin – on Saccharomyces cerevisiae yeast growth and alcoholic fermentation course for wine productionInfluencia de los nuevos fungicidas – metiram y piraclostrobín – en el crecimiento de la levadura Saccharomyces cerevisiae y en el curso de la fermentación alcohólica para la elaboración de vino

The influence of different concentrations of two new fungicides (metiram and pyraclostrobin) on the fermentative activity of Saccharomyces cerevisiae yeast during winemaking process has been evaluated through in vitro assays. These fungicides were assayed as pure active compounds (single and in combination) and as a commercial formulation which contains both fungicides (55% metiram + 5% pyraclostrobin). The presence of pyraclostrobin pure standard in the culture medium, at the highest concentration evaluated (10 mg/L), increased the biomass and ethanol production rate. No effect on the alcoholic fermentation was observed for metiram pure standard due to its low solubility in the synthetic medium. However, a total inhibition of yeast growth was observed in presence of ≥40 mg/L of the commercial formulation. Se analizó, mediante ensayos in vitro, la influencia de diferentes concentraciones de dos nuevos fungicidas - metiram y piraclostrobín - sobre la actividad fermentativa de la levadura Saccharomyces cerevisiae en la elaboración de vino. Estos fungicidas fueron evaluados como materias activas puras, tanto de forma individual como combinada, y como producto fitosanitario comercial formulado con ambas materias activas (55% metiram + 5% piraclostrobín). La presencia de piraclostrobín en el medio de cultivo a la concentración más alta evaluada (10 mg/L) provocó una mayor producción de biomasa y etanol. El metiram, debido a su baja solubilidad en el medio sintético, no mostró ningún efecto sobre la fermentación alcohólica. Por otro lado, concentraciones ≥40 mg/L de la formulación comercial provocaron una inhibición total del crecimiento de la levadura.

Magnetic scaffold for drug targeting: evaluation of cephalosporins controlled release profile

The great problem associated with drug administration is the inability to target a specific area of the body. To reach an acceptable therapeutic level, large doses of the drug must be administered. Only a part of the dose will actually reach the intended disease. Magnetic targeting simplifies drug administration procedures, increases the concentration of the drug at target sites and decreases the concentration of the drug at non-target sites. This study was focused to evaluate the controlled release profile of cephalosporins from magnetic diethylaminoethyl-cellulose hybrid material (magnetic scaffold). Dissolution behavior of these magnetic scaffolds was evaluated using a modified HPLC system. It was found that in all cases, at large time values, the cephalosporin’s concentration was much below the solubility plateau for the pure active compound, demonstrating that the adsorption on the surface of magnetic scaffolds is a valuable procedure to attain controlled release

An open-labeled, randomized, multicentered, phase IIa study for advanced cancer treatment by gambogic acid injection (THS).

e13095 Background: Gamboge acid is a pure active compound isolated from the Camboge (Garcinia Morella Desv.), a traditional Chinese herb medicine. Based on preliminary results of the completed phas...

Hybrid inorganic/organic nanomaterial for controlled cephalosporins release

The dynamics of cephalosporins controlled release from a new hybrid inorganic/organic nanomaterial was investigated. Magnetic Fe3O4 nanoparticles were synthesized using the sol-gel method, while a hybrid nanostructured Fe3O4/oleic acid – core/shell – material was prepared under microwave conditions and further characterized by High Resolution Transmission Electron Microscopy. The dimensions of Fe3O4/oleic acid nanoparticles were in the 5-20 nm range. After drying at 105 o C for 24 hours, the hybrid nanomaterial was dispersed in CHCl3 and then various cephalosporins were deposited on the magnetic nanofluid in a concentration of 0,3%. The controlled release properties of the nanostructured core/shell material were studied by means of conductometric and UV-VIS techniques. In all cases, at large time values (more than 4000 seconds), the cephalosporin concentration was much below the solubility plateau for the pure active compound, demonstrating that the adsorption on a hybrid nanostructurated material is a valuable procedure to attain controlled delivery of these compounds in the dispersion medium.

The ethanol extract of Scutellaria baicalensis and the active compounds induce cell cycle arrest and apoptosis including upregulation of p53 and Bax in human lung cancer cells

Despite a lack of scientific authentication, Scutellaria baicalensis is clinically used in Chinese medicine as a traditional adjuvant to chemotherapy of lung cancer. In this study, cytotoxicity assays demonstrated that crude ethanolic extracts of S. baicalensis were selectively toxic to human lung cancer cell lines A549, SK-LU-1 and SK-MES-1 compared with normal human lung fibroblasts. The active compounds baicalin, baicalein and wogonin did not exhibit such selectivity. Following exposure to the crude extracts, cellular protein expression in the cancer cell lines was assessed using 2D gel electrophoresis coupled with MALDI-TOF-MS/Protein Fingerprinting. The altered protein expression indicated that cell growth arrest and apoptosis were potential mechanisms of cytotoxicity. These observations were supported by PI staining cell cycle analysis using flow cytometry and Annexin-V apoptotic analysis by fluorescence microscopy of cancer cells treated with the crude extract and pure active compounds. Moreover, specific immunoblotting identification showed the decreased expression of cyclin A results in the S phase arrest of A549 whereas the G 0/G 1 phase arrest in SK-MES-1 cells results from the decreased expression of cyclin D1. Following treatment, increased expression in the cancer cells of key proteins related to the enhancement of apoptosis was observed for p53 and Bax. These results provide further insight into the molecular mechanisms underlying the clinical use of this herb as an adjuvant to lung cancer therapy.

Analysis of additivity and synergism in the anti-plasmodial effect of purified compounds from plant extracts

In the search for antimalarials from ethnobotanical origin, plant extracts are chemically fractionated and biological tests guide the isolation of pure active compounds. To establish the responsibility of isolated active compound(s) to the whole antiplasmodial activity of a crude extract, the literature in this field was scanned and results were analysed quantitatively to find the contribution of the pure compound to the activity of the whole extract. It was found that, generally, the activity of isolated molecules could not account on their own for the activity of the crude extract. It is suggested that future research should take into account the “drugs beside the drug”, looking for those products (otherwise discarded along the fractionation process) able to boost the activity of isolated active compounds.

High Performance Thin Layer Chromatography (HPTLC) profile of an insecticidal compound of Trochus radiatus and assessment of mucus-associated bacterial extracts

The current study is based on the screening of novel insecticides from new sources that have not being exploited hitherto. The major objectives of this research work were to extract marine molluscs, Lambis lambis, Trochus radiatus and Chicoreus ramosus, from Tuticorin coastal waters using different solvents to test their insecticidal properties and partially purify the active components. The ethyl acetate extracts of L. lambis and T. radiatus showed 100% mortality of Sitophilus oryzae, at a concentration of 200 μg ml−1. The LC50 values for ethyl acetate extracts of L. lambis, T. radiatus and C. ramosus were found to be 67.08, 348.86 and 571.42 μg ml−1, respectively. With regard to bacterial metabolites, at a concentration of 200 μg ml−1 the ethyl acetate extract of A3 was able to elicit an activity of 40% and that of strain A1 – 20%. The LC50 values of the bacterial metabolites were also investigated. Upon chromatographic separation of active ethyl acetate extracts of T. radiatus, the 100% methanol column-purified fraction was found to have an activity of 30% at a concentration of 10 μg against S. oryzae. The purity of the partially pure active compound was observed to be 72.78% on analysis with high pressure thin layer chromatography.

Environmental Effects on Charge Densities of Biologically Active Molecules: Do Molecule Crystal Environments Indeed Approximate Protein Surroundings?

In the present paper, we investigate whether crystal and enzyme environments influence the electron density (ED) of active compounds in a similar manner. This supposition is essential for high-resolution X-ray studies, which use the EDs obtained from crystals of the pure active compound as approximations for the ED of the active compound in its complex with the target enzyme. The EDs of such complexes determine the molecular recognition process between the targeted enzyme and active compound and are, hence, extremely useful tools for rational drug design. The approximation of such EDs by data obtained from crystals of the pure active compound is needed since high-resolution X-ray experiments of the target-ligand complexes are still extremely demanding. Quantum mechanical/molecular mechanical (QM/MM) and pure QM calculations are employed to determine the EDs of two inhibitors, the reversible trans-4-(aminomethyl)cyclohexane-1-carboxylic acid (AMCHA) and the irreversible E64c in four different environments (the enzyme-inhibitor complex, crystals of the pure compounds, a continuum solvation model, and the gas phase). Our investigation shows that the environment inside of the crystal of the pure active compound generally influences the ED of an active compound in a very similar way as the enzyme surrounding in the complex between the active compound and target enzyme. However, this does not hold any more if the geometrical arrangement of the inhibitor in the enzyme differs significantly from that in the crystal. While EDs computed for gas-phase environments deviate strongly from those in crystal and protein surroundings, polar solvent environments provide rather similar electron distributions. Thus, such continuum solvation models are very well suited to compute density databases which are to be employed for the determination of the ED of macromolecules.

Ethnoveterinary use of southern African plants and scientific evaluation of their medicinal properties

Aim of the study Livestock keepers in many developing countries with restricted access to orthodox veterinary healthcare services commonly use traditional remedies to treat their animals when disease is encountered. This review collates the documented use of plants in South Africa for healing various ailments in domestic animals, and records bioactivity testing that has been carried out on these plants. Materials and methods A literature survey was conducted on the use of plants in South African ethnoveterinary medicine (EVM), as well as on biological activity investigations relating to their ethnoveterinary use where available. Results The ethnoveterinary application of plants, and results of screening studies of EVM plant extracts in various bioassays is presented. For diseases such as coughs, wounds, skin diseases, mild diarrhoea and reproductive disorders, EVM may be a cheap and easily accessible alternative to expensive pharmaceuticals. Studies on biological activity of EVM plants can provide indications of promising leads for extracts that can be developed into standardized medications to be used on a commercial basis. Isolation studies on active plants may yield pure active compounds that could be chemically modified to optimize medicinal value and reduce possible toxic effects. Conclusion In South Africa, a large proportion of the population relies on traditional remedies to treat themselves and their animals for common diseases. Only a small percentage of EVM plants have been analysed for biological activity or toxic effects, and hence research in this field offers fertile possibilities for future investigation.

Isolation and characterization of new lactam compounds that inhibit lung and colon cancer cells from adlay (Coix lachryma-jobi L. var. ma-yuen Stapf) bran

Five active compounds that inhibit cancer cells were isolated from adlay bran (Coix lachryma-jobi L. var. ma-yuen Stapf), and their structures and activities in vitro were characterized. The ethyl acetate-soluble fraction of methanol extracts of adlay bran (ABM-EtOAc) exhibited a stronger anti-proliferative effect on human lung cancer cell A549, human colorectal carcinoma cell HT-29, and COLO 205 than other fractions by MTT (3-4,5-dimethylthiazol-2-yl-2,5-diphenyl-tetrazolium bromide) assay. Assay-guided isolation gave five lactams including three that were previously undocumented; coixspirolactam A (1), coixspirolactam B (2), and coixspirolactam C (3); one isolated from the natural plant for the first time, coixlactam (4); and one known compound, methyl dioxindole-3-acetate (5). Pure active compounds were identified by spectral analysis including IR, 1H and 13C NMR, UV–vis, MS and 2D NMR techniques. All the compounds were tested for their anti-proliferative effect on A549, HT-29 and COLO 205 cells. These compounds showed anti-cancer activities with IC50 values between 28.6 and 72.6μg/mL.

Synergistic antimycobacterial activities of sesquiterpene lactones from Laurus spp.

The aim of this study was to determine the antimycobacterial potential of laurel oil, its fractions and its two sesquiterpene lactones against several mycobacterial strains and clinical isolates, and to establish the possibility of occurrence of some synergistic effects between those lactones using a modification of the fluorometric Alamar Blue microassay (FMABA). The in vitro antimycobacterial activity of whole oil and its fractions and pure active compounds were determined by FMABA. A bioassay-guided fractionation of the traditional preparation of laurel oil from Madeira Islands was performed, yielding pure compounds chemically identified by standard procedures. Synergism of pure compounds was established by X/Y quotient analysis adapted to FMABA. Sesquiterpene lactones, costunolide and dehydrocostuslactone, were the compounds responsible for the antimycobacterial activity against Mycobacterium tuberculosis H37Rv with MICs of 6.25 and 12.5 mg/L, respectively. Antimycobacterial activity against drug-resistant M. tuberculosis clinical isolates was better for the mixture than for pure compounds. Both lactones presented synergistic activity, i.e. analysis of relative fluorescence units presented an X/Y value <0.5 at a concentration of 1/8 MIC of each compound in the combination. Establishment of synergism by FMABA represents another application of the microplate Alamar Blue assay.

Comparative Analysis of the Effects of Locally Used Herbicides and Their Active Ingredients on a Wild-Type Wine Saccharomyces cerevisiae Strain

Herbicides are released to the environment with potential ecotoxicological risks for mammals. Yeast is a good model to elucidate toxicity mechanisms. We investigated how three commercial herbicides (Proper Energy, Pointer, and Silglif) and their active ingredients (respectively, fenoxaprop-P-ethyl, tribenuron methyl, and glyphosate) can affect biological activities of an oenological Saccharomyces cerevisiae strain, which may be resident on grape vineyards of the same geographical areas where herbicides are used. The use of commercial grade herbicides employed in Italy allowed us to reproduce the same conditions applied in crops; at the same time, assaying pure single active compounds made it possible to compare the effects obtained with commercial formulations. Interestingly, we found that while pure active compounds affect cell growth and metabolism at a lower extent, commercial preparations have a significant major negative influence on yeast biology.

Preparation and Characterization of the Nanocomposites SiO2/H-Bond Hydrogensulphate (Hydrogenselenate)

The nanocomposites representing interesting H-bond compounds (Na 3 H(SO 4 ) 2 , RbHSO 4 , RbHSeO 4 , and Rb 3 H(SeO 4 ) 2 ) in the silica matrix were prepared by the sol-gel method. Resulting samples were characterised by X-ray diffraction, IR spectroscopy and electron microscopy. Transition temperatures of the nanocomposites were determined using DSC and compared with the T c of the pure bulk active compounds. The shifts of the T c towards lower temperatures or the disappearing of the certain effects in the case nanocomposites were observed. A possible explanation of these phenomena was proposed using the analogy with the superparamagnetic compounds.

Isolation and characterization of structurally novel antimutagenic flavonoids from spinach (Spinacia oleracea).

Thirteen compounds, isolated from spinach (Spinacia oleracea), acted as antimutagens against the dietary carcinogen 2-amino-3-methylimidazo[4,5-f]quinoline in Salmonella typhimurium TA 98. The antimutagens were purified by preparative and micropreparative HPLC from a methanol/water (70:30, v/v) extract of dry spinach (commercial product) after removal of lipophilic compounds such as chlorophylls and carotenoids by solid-phase extraction (SPE). Pure active compounds were identified by instrumental analysis including FT-IR, (1)H and (13)C NMR, UV-vis spectroscopy, and mass spectrometry. All of these compounds were flavonoids and related compounds that could be attributed to five groups: (A, methylenedioxyflavonol glucuronides) 5,3'-dihydroxy-4'-methoxy-6,7-methylenedioxyflavonol 3-O-beta-glucuronide (compound 1), 5,2',3'-trihydroxy-4'-methoxy-6,7-methylenedioxyflavonol 3-O-beta-glucuronide (compound 2), 5-hydroxy-3',4'-dimethoxy-6,7-methylenedioxyflavonol 3-O-beta-glucuronide (compound 3); (B, flavonol glucuronides) 5,6,3'-trihydroxy-7,4'-dimethoxyflavonol 3-O-beta-glucuronide (compound 4), 5,6-dihydroxy-7,3',4'-trimethoxyflavonol 3-O-beta-glucuronide (compound 5); (C, flavonol disaccharides) 5,6,4'-trihydroxy-7,3'-dimethoxyflavonol 3-O-disaccharide (compound 6), 5,6,3',4'-tetrahydroxy-7-methoxyflavonol 3-O-disaccharide (compounds 7 and 8); (D, flavanones) 5,8,4'-trihydroxyflavanone (compound 9), 7,8,4'-trihydroxyflavanone (compound 10); (E, flavonoid-related compounds) compounds 11, 12, and 13 with incompletely elucidated structures. The yield of compound 1 was 0.3%, related to dry weight, whereas the yields of compounds 2-13 ranged between 0.017 and 0.069%. IC(50) values (antimutagenic potencies) of the flavonol glucuronides ranged between 24.2 and 58.2 microM, whereas the flavonol disaccharides (compounds 7 and 8), the flavanones (compounds 9 and 10), and the flavonoid-related glycosidic compounds 11-13 were only weakly active. The aglycons of compounds 7 and 8, however, were potent antimutagens (IC(50) = 10.4 and 13.0 microM, respectively).

Subtilin C: an Antibiotic Concentrate from Bacillus subtilis

A CONSIDERABLE literature1, dating back to 1897, has established the activity of Bacillus subtilis strains against a variety of bacteria as well as viruses. A limited amount of work has been done on the isolation of the active constituents of B. subtilis cultures, and although several concentrates with distinct properties have been described, no pure active compounds have yet been defined.