Bioautographic Method Research Articles

Detection of Antioxidant and Antimicrobial Components from Crude Extracts of Hibiscus Arnottianus A. Gray flowers using HPTLC-Bioautographic Technique

Abstract: Hibiscus arnottianus belonging to family, malvaceae, is a herb used in traditional medicine for the treatment of inflammation and renal diseases. Methanolic extract of Hibiscus arnottianus flower was fractionated using different solvents of increasing polarity like petroleum ether, ethylacetate, methanol and water. The preliminary phytochemical screening showed the presence of carbohydrates, steroids, flavonoids, tannin. Methanolic extract of hibiscus arnottianus flower was screened for their antimicrobial and antioxidant activity. The test microorganisms includ Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa. It was concluded that Hibiscus arnottianus flowers extract was well effective against all these microorganisms. HPTLC-DPPH assays were used to identify the antioxidant activity of flower extract. This activity was estimated by HPTLC bioautographic method by using the mobile phase Chloroform:Ethyl Acetate:Methanol:Water (2.8:5.2:1.6:0.4 v/v/v/v). There was a successful chromatogram developed and detection of a band in the sample was observed. Later, the band showing antioxidant characteristic property was identified by DPPH Assay.

Impact of ultra-high dilutions from Iranian endemic and commercial calendula on the germination and growth quality of Oryza sativa L.

PurposeThis article deals with producing ultra-diluted compounds (UHDs) prepared from Iranian calendula's characteristic and endemic species. It compares their chemical, biological and biochemical characteristics with the commercial sample of calendula species (grown in the Alps). In the following, these UHDs have been used to improve the quality of germination and growth and reduce contamination of rice (Oryza sativa) seeds in the laboratory environment. MethodsHigh-performance thin-layer chromatography (HPTLC) is used to isolate the active compounds. On the separated results, antioxidant and antibacterial were identified directly on the plate (Bio-autographic method). Direct on the plate)DESI mass spectrometry was used to identify the active compounds. ResultsThe HPTLC reveals that the chromatogram of native C. percica and C. officinalis extract is the most similar to the commercial compounds. The highest antioxidant activity is related to C. officinalis. The best antibacterial activity of the extracts against Staphylococcus aureus and Escherichia coli belongs to C. officinalis and C. tripterocarpa. Rutin, quercitrin, β-campstrole and di-o-caffeoylquinic acid, which are among the flavonoid and terpenoid categories were identified as active compounds. The prepared UHDs from native calendula are biologically more effective than the commercial ones in increasing seed germination efficiency, improving rooting quality and reducing contamination. ConclusionUsing UHDs increases the production of photosynthetic pigments the root length and the number of lateral roots. Also, the amount of protein, gibberellic acid and abscisic acid in seedlings treated using native UHDs of C. officinalis (native or commercial) is higher than the others.

The antioxidant activity of endophytic fungal extract of nutmeg plant (Myristica fragrans Houtt.) from Cimande West Java, Indonesia

The bioproduction of bioactive metabolites from nutmeg endophytic fungi from Cimande, Wesh Java Indonesia was successful. In this research, bioactive antioxidant metabolites were extracted from nutmeg endophytic fungi. Endophytic fungi from nutmeg plant parts were grown on CMMA media. Each fungus was isolated by growing it on PDA media. A total of 21 endophytic fungi isolates were grown on PDB media before being extracted with ethyl acetate as a solvent. The morphology of 21 endophytic fungal isolates was identified based on morphological characteristics. There are 11 Phomopsis sp., 1 Fusarium oxysporum, 5 Colletotrichum sp., 1 Schizophyllum sp., 1 Dematiaceae sp., 1 Coelomycetes sp., and 1 Xylaria sp. The bioautographic TLC method and DPPH-free radical scavenging activity were used to determine antioxidant activity. The antioxidant activity analysis showed that 14 of the 21 endophytic fungus extracts were active. One nutmeg pericarp endophytic fungus showed strong antioxidant activity, with an IC50 of 30.0 g mL-1 and AAI of 1.04. Furthermore, the IC50 values for two fungal extracts from the leaf and pistil nutmeg were less than 100 g.mL-1. The three fungi with IC50 less than 100 g.mL-1 were identified as Phomopsis sp.

Potential of Tetradenia riparia leaf essential oil and its fractions in controlling Aedes aegypti and Rhipicephalus microplus larvae

Tetradenia riparia (Hochst.) Codd (Lamiaceae) is a shrub, commonly known as ginger bush or false myrrh, and several studies have shown that T. riparia exhibits a variety of biological properties. This study aimed to determine the chemical composition of T. riparia essential oil and its fractions, investigate their anticholinesterase activity, and assess their larvicidal activity against the cattle tick Rhipicephalus microplus and the mosquito Aedes aegypti. Eleven essential oil fractions were obtained by fractionation and analyzed by gas chromatography/mass spectrometry. Larvicidal activity against R. microplus and third-instar A. aegypti was assessed using a larval packet test and a larval immersion test, respectively. Anticholinesterase activity was determined by a bioautographic method. Forty-nine compounds were identified in the essential oil, of which the major classes were oxygenated sesquiterpenes (45.95%) and sesquiterpene hydrocarbons (35.20%) and the major components were isospathulenol (17.40%), β-caryophyllene (15.61%), 14-hydroxy-9-epi-caryophyllene (10.07%), 14-hydroxy-α-muurolene (8.32%), and 9β,13β-epoxy-7-abietene (5.53%). Bioassays showed that T. riparia essential oil (LC50 = 1.56 µg/mL) and FR3 (LC50 = 0.30 µg/mL) were the most active against R. microplus and A. aegypti larvae, respectively. The essential oil and FR1, FR2, and FR3 exhibited acetylcholinesterase inhibitory activity. These results indicate that T. riparia essential oil and its fractions hold promise in the development of novel, environmentally safe agents for the control of R. microplus and A. aegypti larvae.

Simultaneous high-performance thin-layer chromatographic method for the estimation of guggulsterones E and Z in AYUSH guggul formulations and confirmation of the antioxidant potential of guggul by thin-layer chromatographic‒bioautographic method

Simultaneous high-performance thin-layer chromatographic method for the estimation of guggulsterones E and Z in AYUSH guggul formulations and confirmation of the antioxidant potential of guggul by thin-layer chromatographic‒bioautographic method

Microscopic Evaluation and Antioxidant Activity of Glyphaea brevis (Spreng.) Monach. (Family Tiliaceae)

Background: Glyphaea brevis has been used traditionally to treat a variety of ailments, some of which are linked to oxidative stress. Despite the numerous studies on the biological activities of G. brevis, no literature was found on the microscopic study of this plant, which is essential for preparation of its monograph. As a result, the antioxidant activity of G. brevis and its qualitative microscopic characteristics were investigated in this study. Methods: The adaxial and abaxial epidermal layers of the G. brevis leaf, as well as transverse sections of the midrib and petiole, were obtained, cleared, and examined under a light microscope at X100 and X400 magnifications. The antioxidant activity of the crude methanol extract and fractions of G. brevis was evaluated via bioautographic method using 1,1-diphenyl-2-picrylhydrazyl- hydrate (DPPH) free radical scavenging activity (FRSA), total phenolic content (TPC) and the total flavonoid content (TFC). Results: Microscopic examination of the leaf revealed the presence of straight and few wavy thin-walled polygonal epidermal cells in the adaxial and abaxial layers, numerous stomata cells ranging from anisocytic, anomocytic, to paracytic in the abaxial layer, and various types of trichomes in both adaxial and abaxial layers. The FRSA and TFC were highest in the crude extract. The ethyl acetate fraction of G. brevis had highest FRSA, whereas the hexane fraction had the least. Conclusion: The microscopic study revealed characters that can be used to identify Glyphaea brevis, while the free radical scavenging activity supports its use in the treatment of many oxidative stress related diseases

Rapid Screening of Lipase Inhibitors from Ophiopogonis Radix Using High-Performance Thin Layer Chromatography by Two Step Gradient Elution Combined with Bioautographic Method.

In this study, a high-performance thin layer chromatography (HPTLC) method by two step gradient elution with two mobile phases was developed for the simultaneous analysis of seven constituents in Ophiopogonis Radix. The chromatography was performed on silica gel 60 F254 plate with dichloromethane-methanol-ethyl acetate-water (70:25:12:3, v/v/v/v) and dichloromethane-methanol (300:1, v/v) as the mobile phase for two step gradient elution. Then, the HPTLC profiles were observed after derivatization with 10% sulfuric acid in ethanol solution. The obtained HPTLC images were further analyzed by chemometric approaches and the samples could be clustered based on regions and/or growth years, which were two important factors affecting the constituents in Ophiopogonis Radix. Furthermore, five compounds including ophiopogonin D, ophiopojaponin C, ophiopogonin D’, ophiopogonin C’ and methylophiopogonanone B were screened as potential lipase inhibitors from Ophiopogonis Radix by the HPTLC-bioautographic method. The binding modes and interactions between the five compounds and lipase were further explored by molecular docking analysis. The developed HPTLC method could be used for quality control of Ophiopogonis Radix and screening of the potential lipase inhibitors.

Tetradenia riparia leaves, flower buds, and stem essential oils to control of Aedes aegypti larvae

Tetradenia riparia (Hochst.) Codd (Lamiaceae) is a species native to the African continent and used as an insect repellent. The objective of the study was to evaluate the larvicidal potential of essential oils (EOs) from the leaves, flower buds, and stem of T. riparia, collected in winter against Aedes aegypti larvae. The EOs were extracted by hydrodistillation (3 h) and identified by GC/MS. The EOs were tested against larvae of A. aegypti at concentrations ranging from 12500 to 1.5 µg/mL for 24 h. The insecticide activity was evaluated by probit analysis, and the anticholinesterase activity was determined by bioautographic method. The results of the class projection indicated sesquiterpenes as the majority class, corresponding to 60.66% (leaves), 64.70% (flower buds) and 83.99% (stem), and the bioassays on A. aegypti larvae indicated LC50 of 1590, 675 and 665 µg/mL, respectively. The anticholinesterase activity indicated that the EO of the leaves inhibited the enzyme at a concentration of 780 µg/mL, and those from the flower buds and stem inhibited up to 1560 µg/mL. The results indicated weak activity of essential oils against A. aegypti larvae.

Evaluation of p-Nitrophenyl butyrate based bioautographic method for the identification of lipase inhibitors from the unexplored plant sources

Evaluation of p-Nitrophenyl butyrate based bioautographic method for the identification of lipase inhibitors from the unexplored plant sources

Crude extract of the tropical tree Gallesia integrifolia (Phytolaccaceae) for the control of Aedes aegypti (Diptera: Culicidae) larvae

Introduction: Phytoinsecticides are alternatives to control insects in different stages, Gallesia integrifolia (Spreng.) Harms, Phytolacaceae family, popularly known as pau d'alho, garlic tree, and guararema in Brazil, is known due to its strong alliaceous odor because of the presence of sulfur molecules in the plant. This species presents biological activity and potential insecticide effect that is still unexploited. Objective: This study aimed to evaluate the biological activity of the ethanolic crude extract from G. integrifolia leaves, flowers, and fruits on the control of Aedes aegypti third-stage larvae and pupae. Methods: The botanical material was collected in city Umuarama, Paraná, Brazil at the coordinates (23º46’16” S & 53º19’38” WO), and altitude of 442 m, the fruits of G. integrifolia were collected in May and the leaves and flowers in December 2017. The crude extracts of G. integrifolia leaves, flowers, and fruits were prepared by dynamic maceration technique. The chemical composition of the extracts was determined by gas chromatography coupled to a mass spectrometry. The insecticidal activity of the crude extracts of G. integrifolia were carried out on larvae and pupae of A. aegypti in concentrations between 0.001 to 25 000 mg/mL, and afterwards the lethal concentrations that kill 50 % (LC50) and 99.9 % (LC99.9) were determined by probit analysis. Anticholinesterase activity was determined by bioautographic method at concentrations from 0.000095 to 50 mg/mL. Results: The yield of G. integrifolia crude extracts were 8.2, 9.1, and 17.3 % for flowers, fruits, and leaves, respectively. The chemical composition of G. integrifolia extracts was characterized by presence of fatty acid esters, phytosterols, vitamins, oxygenated diterpenes and organosulfur compounds. The flower extract presented the high amount of sulfur compounds (20.2 %) such as disulfide, bis (2-sulfhydryl ethyl) (11.9 %), 2,3,5-trithiahexane (6.2 %), 1,2,4-trithiolane (1.1 %), and 2,4-dithiapentane (1.1 %). Regarding the insecticidal activity, flower extract showed highly active with LC99.9 of 0.032 mg/mL and LC99.9 of 0.969 mg/mL on A. aegypti larvae and pupae, respectively, and the highest inhibition of acetylcholinesterase enzyme (0.00019 mg/mL) ex situ. The flower extract presented anticholinesterase and larvicide activity, respectively, 12.8 % and 35.6 % greater than the control temephos. Conclusions: This study opens new perspectives on the use of extracts from G. integrifolia as a bioinsecticide alternative for the control of A. aegypti larvae and pupae.

Tetradenia riparia (Lamiaceae) essential oil: an alternative to Rhipicephalus sanguineus

In Brazil, Rhipicephalus sanguineus resistance to some pyrethroids have been detected, motivating research on new phyto-insecticides such as essential oil from Tetradenia riparia leaves (EOL) and flower buds (EOFB). The essential oils were obtained by hydrodistillation (3h) and identified by GC/MS. In addition, a multivariate exploratory analysis was done to determine the analysis of the major compounds (PCA). The bioassays on R. sanguineus larvae were done by immersion test at different EO concentrations which ranged from 50,000 to 0.47 mg/mL (v/v). The action mechanism of EOs were determined by bioautographic method evaluating the inhibitory potential on the acetylcholinesterase enzyme. The EO yield in leaves was 0.29±0.22 (%) and in flower buds 0.38±0.17 (%). The class projections showed oxygenated sesquiterpenes (43.62%) and diterpenes (15.60%) in EOFB, and hydrocarbon sesquiterpenes (26.44%) and oxygenated monoterpenes (16.44%) in EOL. Four components presented a greater distancing of mass flow: fenchone (11.57 and 6.01 %), α-cadinol (12.21 and 13.69 %), 14-hidroxy-9-epi-caryophyllene (8.56 and 15.38 %), and caryophyllene oxide (1.32 and 4.50 %) in EOL and EOFB, respectively. The lethal concentrations (LCs) to kill R. sanguineus larvae were (LC50: 2.18±0.24 and LC99.9: 9.98±0.10 mg/mL) for EOL, and (LC50: 5.36±2.50 and LC99.9: 20.12±0.54 mg/mL) for EOFB. The action mechanism of EOs by bioautographic methods indicated an inhibition of 0.70 mg/mL (EOL) and 1.40 mg/mL (EOFB) on the acetylcholinesterase enzyme (AChE). Therefore, this species can be considered promising to be part of the chemical larvicides to control this ectoparasite

Development of a thin-layer chromatography bioautographic assay for neuraminidase inhibitors hyphenated with electrostatic field induced spray ionisation-mass spectrometry for identification of active Isatis indigotica root compounds

The identification of neuraminidase inhibitors from natural products is a promising strategy in the field of anti-influenza research. In this study, a new thin-layer chromatography (TLC) bioautographic assay for the screening of neuraminidase inhibitors from natural products was developed. This TLC bioassay is based on the one-step reaction of neuraminidase with the sodium salt of 5‑bromo‑4‑chloro‑3-indolyl-α-d-N-acetylneuraminic acid (substrate) and the subsequent formation of blue coloured products. Neuraminidase inhibitory activity was shown by the development of white spots against the blue TLC background. The key factors affecting the assay (such as enzyme concentration, substrate concentration, incubation time, reaction time, and pH) were investigated and optimised by a combination of a one-factor-at-a-time design and a Box-Behnken design/response surface method. The developed TLC bioautographic method was applied to identify neuraminidase inhibitory compounds in the roots of Isatis indigotica. Eleven active compounds including six alkaloids, three lignans, one sterol, and one fatty acid were identified in situ by direct coupling with an electrostatic field induced spray ionisation-mass spectrometry approach through analysis of their MSn (n = 4) data or comparison with reference substances. The developed TLC bioautographic assay is simple, rapid, and efficient for screening potential neuraminidase inhibitors from natural products.

INVITRO EVALUATION OF ANTIMICROBIAL ACTIVITY OF CLOVE BUDS( EUGINEA AROMATICA)

Bioactive compounds from Eugenia aromaticum were extracted by Soxhlet using DCM ,DCM;WATER,WATER and extracts were examined for its phytocomponents along with Clove oil. These bioactive plant compounds were screened for possible antimicrobial activities against two strains of MDR S. aureus. Antimicrobial activity of extracts using agar diffusion disc variant method. The objective of this study was to evaluate technical variants used in screening methods to determine antibacterial activity of natural products. Thus, a varied range of natural products of plant were tested against two bacterial species,m Staphylococcus aureus ATCC 25923 and klebesella pnemonia ATCC 25922, by two variants of the agar diffusion method (well and disc), two variants of the bio autographic method (direct and indirect) and by microdilution assay. We concluded that the well-variant of the diffusion method was more sensitive than the disc-variant, it was found extract 1 ie,DCM and extract 2 i.e DCM;WATER had shown best results on antimicrobial activity ,phytocvhemical screening test are done for three extractsn invitro evalvation of antimicrobial activity was performed.

Crude ethanolic extracts of different parts of Gallesia integrifolia (Phytolaccaceae) for the control of Rhipicephalus microplus

ABSTRACT The ectoparasite Rhipicephalus microplus has caused huge economic losses in livestock, and its synthetic chemical control resulted in acaricidal resistant ticks, environmental damages and residues in bovine products. Therefore, it is important to search for alternative products to control this parasite. This study aimed to characterize the crude extracts of different parts of Gallesia integrifolia by GC and MS, and to evaluate the acaricidal activity against R. microplus by adult immersion test (AIT) and larval packet immersion test (LPIT). The acaricidal activity was verified by adult immersion test and larval packet test, while the anticholinesterase activity was done by bioautographic method. The results showed greater larvicidal activity of crude extracts from flowers (LC99.9 = 15.82 mg/mL) and fruits (LC99.9 = 16.13 mg/mL), when compared to the leaf crude extract (LC99.9 = 18.39 mg/mL). Product efficiency of flower and fruit extracts at 12.5 mg/mL was 96.9% and 96.2%, respectively, probably due to the greater amount of sulphur compounds in flowers (21.7%) mainly disulphide, bis(2-sulphhydryl ethyl (12.8%), and in fruits (9.1%), mostly 2,3,5-trithiahexane (5.0%). Thus, G. integrifolia is an alternative to be exploited for the control cattle tick.

In silico assessment of potential leads identified from Bauhinia rufescens Lam. as α-glucosidase and α-amylase inhibitors

Introduction Natural products play a pivotal role in innovative drug discovery by providing structural leads for the development of new therapeutic agents against various diseases.The present study aims to focus on the in silico assessment of the therapeutic potential of antidiabetic phytoconstituents which were identified and isolated from the extracts of Bauhinia rufescens Lam, a medicinal plant traditionally used for various pharmacotherapeutic purposes. Method The physicochemical and pharmacokinetic parameters of the previously isolated thirty eight compounds were predicted using SwissADME web tool whereas OSIRIS Property Explorer was used for toxicity risk assessment and drug- likeliness. Twelve compounds were selected for docking on human α-glucosidase and α-amylaseenzymes using Autodock 4.0 software. Furthermore, the active extract was in vivo tested for the antidiabetic activity and then identified usingTLC bioautographic method. Results and Discussion Eriodictyol was found to have the highest potential as an inhibitor against α-amylase with binding energy of −9.92 kcal/mol. Rutin was the most potent against α-glucosidase with binding energy of-9.15 kcal/mol. A considerable number of hydrogen bonds and hydrophobic interactions were computed between the compounds and the enzymes thereby making them energetically favorable and suggesting inhibition of these two enzymes as a plausible molecular mechanism for their antidiabetic effect. Conclusion These two flavonoids could therefore be used as potential leads for structure- based design of new effective hypoglycemic agents.

Atividade antimicrobiana de polifenóis isolados das folhas de Schinopsis brasiliensis (Engl.) guiado por bioautografia

O extrato metanólico das folhas de Schinopsis brasiliensis apresentou atividade antimicrobiana com Concentração mínima inibitória de 31,15 µg/mL frente Staphylococcus aureus, Staphylococcus epidermidis e Staphylococcus saprophyticus. A prospecção fitoquímica das folhas de Schinopsis brasiliensis (Engl.) guiado pelo método bioautográfico permitiu isolar duas moléculas (galato de metila - GM and β-1,2,3,4,6-PentaGaloil-D-Glicose - PGG), as quais apresentaram atividade antimicrobina frente S. aureus, Staphylococcus coagulase negativo e Enterococcus faecalis, com halos de ordem de 14 a 20 mm. Ainda, PGG apresentou atividade antimicrobiana frente Pseudomonas aeruginosa com halos da ordem de 21 mm e GM com halos de ordem de 17 a 18 mm frente Escherichia coli. Novos estudos, tais como a quantificação dos compostos antimicrobianos e identificação de outros metabólitos secundários das folhas de S. brasiliensis, são necessários pelos presentes resultados.

Biocidal potential of Eugenia pyriformis essential oil in the control of Rhipicephalus (Boophilus) microplus in the free-living cycle

ABSTRACT: Brazil has one of the largest commercial cattle herds in the world, which naturally coexist with an enormous number of parasitic species. Southern cattle tick, Rhipicephalus (Boophilus) microplus, is among these species, interfering with animal productivity and causing losses to the beef and dairy cattle sector. The use of chemical acaricides in the control of this mite has resulted in the emergence of resistant populations. In this sense, alternative control measures using plants as sources of botanical acaricides have shown to be effective. Eugenia pyriformis Cambess is a Brazilian plant with antioxidant and antimicrobial activity; however, there are no reports on its acaricidal activity in the literature. The present study aimed to evaluate the acaricidal and larvicidal potential of E. pyriformis leaf essential oil (EO) on southern cattle tick at different stages of the reproductive cycle. E. pyriformis leaves were collected and dried, and had their EO extracted by hydrodistillation (3h) using a modified Clevenger apparatus. Chemical analysis was performed by gas chromatography coupled with mass spectrometry (GC/MS), and 32 compounds belonging to the sesquiterpene class were identified: hydrocarbons (17.98%) and oxygenated forms (81.96%), with spathulenol (43.65%) and caryophyllene oxide (12.17%) as the most common. The EO was evaluated by the Adult Immersion Test at the concentrations (500.00 to 3.12mg/mL) in which the following parameters were measured: mortality of females (%), hatchability of eggs (%), and product efficiency (%). Larvae were assessed by the Larval Packet Test at concentrations ranging from 25.00 to 0.00004mg/mL. Lethal concentrations (LC) required for killing 50 and 99.9% of adult females and larvae were determined using Probit analysis. LC50 and LC99.9 of EO were 0.06 and 24.60mg/mL and 1,208.80 and 2,538mg/mL for larvae and adult females, respectively. Action of the EO in the free-living cycle of R. (B.) microplus larvae was another parameter assessed. To this end, the larvae were deposited in pots containing Brachiaria decumbens and, after migration to the leaf apex, a solution containing LC99.9 (24.60mg/mL) of the EO was sprayed. After 24h, 72.25% of the larvae had died, indicating stability of the EO when subjected to uncontrolled temperature and humidity conditions. The mechanism of action through which the EO killed the larvae and adult females was investigated by the Bioautographic Method, which showed inhibition of 3.15mg/mL of the EO on the acetylcholinesterase (AChE) enzyme. The results found in the present experiment indicate that E. pyriformis essential oil is an alternative in the control of southern cattle tick in the larval (parasitic) and free-living cycle (non-parasitic) stages under field conditions.

Screening and Isolation of Natural Antioxidants from Acer Ginnala Max by TLC-MS/MS Guided Bioautographic Method.

A rapid and simple method has been developed for the screening and identification of natural antioxidants from the leaves of Acer ginnala Maxim (AG). The process is that upon reaction with 1,1-diphenyl-2-picrylhydrazyl (DPPH), the white yellow spots of compounds with potential antioxidant effects will be significantly observed on the thin-layer chromatography (TLC), and possible structures will be presumed by the ESI/MS technique. Using the improved approach, 6 compounds in the AG extract were found to possess a potential antioxidant activity. They were speculated as quercetin-3-O-α-L-(3"-galloyl)-rhamnoside (1), quercetin-3-O-α-L-(2"-galloyl)-rhamnoside (2), quercetin-3-O-α-L-(2"-galloyl)-arabinopyranoside (3), acertannin (4), gallic acid (5), and methyl gallate (6). In addition, we were still found that compounds 2, 3, and 5 had favorable antioxidant activity from the scannogram of the DPPH reaction plate. As a result, the isolated 6 compounds structures were in accordance with the presumed structures. Furthermore, the free radical scavenging capacities of the available identified compounds were also investigated. Compounds 2, 3, and 5 showed significant DPPH.Scavenging capacities, with IC50 values of 2.83 μg/mL, 2.34 μg/mL, and 1.86μg/mL, respectively. The results indicated that this newly improved method could be widely applied for rapid screening and identification of natural antioxidants from Chinese herbal medicines.

English

Superficial candidiasis is a real public health problem, especially in immunocompromised people and HIV-infected patients. Due to the toxic handicap and the high cost of antifungal drug treatment, people use medicinal plants, which are relatively more accessible. Medicinal plants are an important source of novel antimicrobial agents. This study aims to determine the in vitro antimicrobial activity of aqueous and methanolic extracts from different parts of plants species against Candida albicans. Six plants species from the flora of Côte d’Ivoire were screened for anticandidal activities by ethnobotanical study. These plants species were: Bridelia ferruginea, Citrus aurantium, Pycnanthus angolensis, Desmodium adscendens, Zanthoxylum zanthoxyloides Lam. and Mareya micrantha L. Methanolic and aqueous extracts from the powder of leaves and/or barks samples of each species were tested using the bioautographic method in F254 glass silica gel plate, with Miconazole as reference. Bioautography assay was used to account antifungal compounds in plant extracts. Bridelia ferruginea, Pycnanthus angolensis, and Zanthoxylum zanthoxyloides Lam showed good activity. The minimal inhibitory concentrations (MIC) values against Candida albicans ranged between 12.5 and 100 mg/ml. Bioautography results demonstrated that active chemical compounds of the alcoholic extracts of the plants (flavonoids, alcaloids, polyterpenes, polyphenols and sterols) were responsible for antimicrobial activity. The Ivorian pharmacopoeia is full of medicinal remedies. Three plants of our study have shown a good activity on strains of Candida albicans.   Key words: Candida albicans, antifungal activity, plants, bioautography.

Determination of Monensin in Bovine Tissues: A Bridging Study Comparing the Bioautographic Method (FSIS CLG-MON) with a Liquid Chromatography-Tandem Mass Spectrometry Method (OMA 2011.24).

The U.S. Department of Agriculture, Food Safety Inspection Service regulatory method for monensin, Chemistry Laboratory Guidebook CLG-MON, is a semiquantitative bioautographic method adopted in 1991. Official Method of AnalysisSM (OMA) 2011.24, a modern quantitative and confirmatory LC-tandem MS method, uses no chlorinated solvents and has several advantages, including ease of use, ready availability of reagents and materials, shorter run-time, and higher throughput than CLG-MON. Therefore, a bridging study was conducted to support the replacement of method CLG-MON with OMA 2011.24 for regulatory use. Using fortified bovine tissue samples, CLG-MON yielded accuracies of 80-120% in 44 of the 56 samples tested (one sample had no result, six samples had accuracies of >120%, and five samples had accuracies of 40-160%), but the semiquantitative nature of CLG-MON prevented assessment of precision, whereas OMA 2011.24 had accuracies of 88-110% and RSDr of 0.00-15.6%. Incurred residue results corroborated these results, demonstrating improved accuracy (83.3-114%) and good precision (RSDr of 2.6-20.5%) for OMA 2011.24 compared with CLG-MON (accuracy generally within 80-150%, with exceptions). Furthermore, χ2 analysis revealed no statistically significant difference between the two methods. Thus, the microbiological activity of monensin correlated with the determination of monensin A in bovine tissues, and OMA 2011.24 provided improved accuracy and precision over CLG-MON.