High-resolution Mass Spectral Data Research Articles

Metabolomics of the Bio-Degradation Process of Aflatoxin B1 by Actinomycetes at an Initial pH of 6.0

Contamination of food and feed by Aflatoxin B1 (AFB1) is a cause of serious economic and health problems. Different processes have been used to degrade AFB1. In this study, biological degradation of AFB1 was carried out using three Actinomycete species, Rhodococcus erythropolis ATCC 4277, Streptomyces lividans TK 24, and S. aureofaciens ATCC 10762, in liquid cultures. Biodegradation of AFB1 was optimised under a range of temperatures from 25 to 40 °C and pH values of 4.0 to 8.0. An initial concentration of 20 µg/mL of AFB1 was used in this study. The amount of AFB1 remaining was measured against time by thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC), coupled with UV and mass spectrometry (LC-MS). All species were able to degrade the AFB1, and no significant difference was found between them. AFB1 remained in the liquid culture for R. erythropolis, S. lividans and S. aureofaciens were 0.81 µg/mL, 2.41 µg/mL and 2.78 µg/mL respectively, at the end of the first 24 h. Degradation occurred at all incubation temperatures and the pH with the optimal conditions for R. erythropolis was achieved at 30 °C and pH 6, whereas for S. lividans and S. aureofaciens the optimum conditions for degradation were 30 °C and pH 5. Analysis of the degradative route indicated that each microorganism has a different way of degrading AFB1. The metabolites produced by R. erythropolis were significantly different from the other two microorganisms. Products of degradation were identified through metabolomic studies by utilizing high-resolution mass spectral data. Mass spectrometric analysis indicated that the degradation of AFB1 was associated with the appearance of a range of lower molecular weight compounds. The pathway of degradation or chemical alteration of AFB1 was followed by means of high resolution Fourier transform mass spectrometry (HR-FTMS) analysis as well as through the MS2 fragmentation to unravel the degradative pathway for AFB1. AFB1 bio-degradation was coupled with the accumulation of intermediates of fatty acid metabolism and glycolysis. A plausible mechanism of degradation of AFB1 by Rhodococcus was hypothesized.

Didemnaketals f and g, new bioactive spiroketals from a red sea ascidian didemnum species.

In continuation of our ongoing efforts to identify bioactive compounds from Red Sea marine organisms, a new collection of the ascidian Didemnum species was investigated. Chromatographic fractionation and HPLC purification of the CH2Cl2 fraction of an organic extract of the ascidian resulted in the identification of two new spiroketals, didemnaketals F (1) and G (2). The structure determination of the compounds was completed by extensive study of 1D (1H, 13C, and DEPT) and 2D (COSY, HSQC, and HMBC) NMR experiments in addition to high-resolution mass spectral data. Didemnaketal F (1) and G (2) differ from the previously reported compounds of this class by the lack the terminal methyl ester at C-1 and the methyl functionality at C-2. Instead, 1 and 2 possess a methyl ketone moiety instead of the terminal ester. Furthermore, didemnaketal F possesses a disubstituted double bond between C-2 and C-3, while the double bond was replaced by a secondary alcohol at C-3 in didemnaketal G. In addition, they possess the unique spiroketal/hemiketal functionality which was previously reported in didemnaketal E. Didemnaketals F (1) and G (2) displayed moderate activity against HeLa cells with of IC50s of 49.9 and 14.0 µM, respectively. In addition, didemnaketal F (1) displayed potent antimicrobial activity against E. coli and C. albicans. These findings provide further insight into the biosynthetic capabilities of this ascidian and the chemical diversity as well as the biological activity of this class of compounds.

Sesquiterpene lactones from roots of Lactuca georgica

The wild lettuce Lactuca georgica Grossh. is a member of the section Lactuca of the genus Lactuca L. (Compositae). It belongs to the subsection Lactuca, along with Lactuca sativa L. and several other closely related species, and it is of interest for cultivated lettuce improvement. From roots of L. georgica 15 sesquiterpene lactone aglycones and glycosides were isolated, including 10 lactucin-type guaianolides. This is the first report on the co-occurrence in Lactuca species of seven lactucin derivatives esterified at C-8 with acetic, methacrylic and 4-hydroxyphenylacetic acids. Therefore, the esters can be regarded as characteristic for L. georgica. The new natural product lactucin-8-O-methacrylate and its 11β,13-dihydroderivative were characterized in detail following a comparative analysis of their 1D- and 2D-NMR and high resolution mass spectral data. Moreover, a case of mistaken identification of the former in a species of the family Bignoniaceae is discussed.

Synthesis, characterization, and biological activities of 4-imino-3-arylazo-4H-pyrimido[2,1-b][1,3]benzothiazole-2-oles

4-Imino-3,4-dihydro-2H-pyrimido[2,1-b][1,3]benzothiazole-2-one (3) was synthesized by the reaction of 2-aminobenzothiazole with ethyl cyanoacetate in solvent free conditions at 150 °C. A series of pyrimido benzothiazole-based azo dyes 4(a–m) were obtained by the coupling of carbocyclic amine-based diazonium chloride with compound (3). The synthesized dyes were purified and characterized by elemental analysis, FT-IR, 1H NMR, and high-resolution mass spectral data. The solvatochromic behaviors of dyes in various solvents were examined. All the azo dyes exhibited pronounced in vitro antibacterial activities against Gram-positive and Gram-negative bacteria, as well as fungi. The results revealed that most of the compounds exhibited good levels of antibacterial activity. Compounds 4d and 4h showed excellent levels of antimicrobial activity with MIC values of 8.25 μg/mL.

Synthesis of novel ring-A fused hybrids of oleanolic acid with capabilities to arrest cell cycle and induce apoptosis in breast cancer cells

Six novel oleanolic acid ring-A fused hybrids (5–10) have been synthesized by employing a four step protocol with the introduction of benzylidene functionality at C-2 as the key step. Their structures were established by high resolution NMR and Mass spectral data. The synthesized compounds have been screened against seven human cancer cell lines including ME-180 & HeLa (cervix), MCF-7, MDA-MB-453 & MDA-MB-231 (breast), PC-3 (prostate) and HT-29 (colon) using MTT assay. Most significantly, compound 10 showed potent activity against the three breast cancer cell lines. The IC50 value (10.60 μM) of compound 10 against MCF-7 found to be much lower than that of the standards and parent compound. Flow cytometric analysis reveals that compound 10 arrests cell cycle in S phase and induces apoptosis in MCF cells.

Synthesis and Pharmacological Evaluation of Some Novel Thebaine Derivatives: N‐(Tetrazol‐1H‐5‐yl)‐6,14‐endoethenotetrahydrothebaine Incorporating the 1,3,4‐Oxadiazole or the 1,3,4‐Thiadiazole Moiety

In this study, we synthesized some novel N-(tetrazol-1H-5-yl)-6,14-endoethenotetrahydrothebaine 7α-substituted 1,3,4-oxadiazole and 1,3,4-thiadiazole derivatives as potential analgesic agents. The structures of the compounds were established on the basis of their IR, ¹H NMR, ¹³C NMR, 2D NMR, and high-resolution mass spectral data. The analgesic activity was evaluated by a rat-hot plate test model and a rat tail-flick model. Compound 12 showed analgesic activity higher than that of morphine. In addition to a histopathological and biochemical evaluation, the LD₅₀ dose for the most active compound 12 was determined.

Aerosol Chemical Composition in Cloud Events by High Resolution Time-of-Flight Aerosol Mass Spectrometry

This study presents results of direct observations of aerosol chemical composition in clouds. A high-resolution time-of-flight aerosol mass spectrometer was used to make measurements of cloud interstitial particles (INT) and mixed cloud interstitial and droplet residual particles (TOT). The differences between these two are the cloud droplet residuals (RES). Positive matrix factorization analysis of high-resolution mass spectral data sets and theoretical calculations were performed to yield distributions of chemical composition of the INT and RES particles. We observed that less oxidized hydrocarbon-like organic aerosols (HOA) were mainly distributed into the INT particles, whereas more oxidized low-volatile oxygenated OA (LVOOA) mainly in the RES particles. Nitrates existed as organic nitrate and in chemical form of NH(4)NO(3). Organic nitrates accounted for 45% of total nitrates in the INT particles, in clear contrast to 26% in the RES particles. Meanwhile, sulfates coexist in forms of acidic NH(4)HSO(4) and neutralized (NH(4))(2)SO(4). Acidic sulfate made up 64.8% of total sulfates in the INT particles, much higher than 10.7% in the RES particles. The results indicate a possible joint effect of activation ability of aerosol particles, cloud processing, and particle size effects on cloud formation.

Powerful GC-TOF-MS Techniques for Screening, Identification and Quantification of Halogenated Natural Products

Comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GC×GC TOFMS) and gas chromatography/high-resolution time-of-flight mass spectrometry (GC-HRT) were used to detect and identify halogenated natural products (HNPs) in tissue homogenate, in this case brominated analytes present in a marine snail. Two classes of brominated anthropogenic compounds, polybrominated diphenyl ethers (PBDEs) and brominated dibenzofurans, were analyzed for comparison. Following conventional preparation, the sample was analyzed using GC×GC-TOF-MS. Isotope ratio scripts were used to compile a list of putatively brominated analytes from amongst the thousands of features resolved in the two-dimensional chromatogram. The structured nature of the chromatogram was exploited to propose identifications for several classes of brominated compounds, and include additional candidates that fell marginally outside the script tolerances. The sample was subsequently analyzed by GC-HRT. The high-resolution mass spectral data confirmed many formula assignments, facilitated confident assignment of an alternate formula when an original proposal did not hold, and enabled unknown identification. Identified HNPs include hydroxylated and methoxylated PBDE analogs, polybrominated dibenzo-p-dioxins (PBDDs) and hydroxyl-PBDDs, permitting the environmental occurrence and fate of such compounds to be studied.

FluShuffle and FluResort: new algorithms to identify reassorted strains of the influenza virus by mass spectrometry

BackgroundInfluenza is one of the oldest and deadliest infectious diseases known to man. Reassorted strains of the virus pose the greatest risk to both human and animal health and have been associated with all pandemics of the past century, with the possible exception of the 1918 pandemic, resulting in tens of millions of deaths. We have developed and tested new computer algorithms, FluShuffle and FluResort, which enable reassorted viruses to be identified by the most rapid and direct means possible. These algorithms enable reassorted influenza, and other, viruses to be rapidly identified to allow prevention strategies and treatments to be more efficiently implemented.ResultsThe FluShuffle and FluResort algorithms were tested with both experimental and simulated mass spectra of whole virus digests. FluShuffle considers different combinations of viral protein identities that match the mass spectral data using a Gibbs sampling algorithm employing a mixed protein Markov chain Monte Carlo (MCMC) method. FluResort utilizes those identities to calculate the weighted distance of each across two or more different phylogenetic trees constructed through viral protein sequence alignments. Each weighted mean distance value is normalized by conversion to a Z-score to establish a reassorted strain.ConclusionsThe new FluShuffle and FluResort algorithms can correctly identify the origins of influenza viral proteins and the number of reassortment events required to produce the strains from the high resolution mass spectral data of whole virus proteolytic digestions. This has been demonstrated in the case of constructed vaccine strains as well as common human seasonal strains of the virus. The algorithms significantly improve the capability of the proteotyping approach to identify reassorted viruses that pose the greatest pandemic risk.

Synthesis and Characterization of New Thebaine Derivatives: 2-(6,14-endo-Ethenotetrahydrothebaine-7α;-yl)-5-(N-Arylamino)-1,3,4-Thiadiazoles

We have synthesized a series of novel 2-(6,14-endo-ethenotetrahydrothebaine-7α-yl)-5-N-arylamino-1,3,4-thiadiazoles (5a–n) as potential narcotic analgesics, which are analogs of morphine. The synthesized compounds exhibit rigid morphine structures, including a 6,14-endo-entheno bridge and a 5-N-arylamino-1,3,4-thiadiazol-2-yl group at C-7 position that adopted S-configuration. The structures and stereochemistry of the compounds were completely assigned using one- and two-dimensional NMR experiments (1H NMR, APT, COSY, NOESY, HMQC, and HMBC), FTIR, and high-resolution mass spectral (HRMS) data. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

Spectral Analysis and Chemical Studies of the Sweet Constituent, Rebaudioside A

Aim: To study NMR spectral analysis and hydrolysis products of Rebaudioside A ( 1) that has been isolated from Stevia rebaudiana. Study Design: Acquiring NMR and high resolution mass spectral (HRMS) data of Rebaudioside A for structural characterization, and identification of hydrolysis products. Place of Study : Organic Chemistry Department of The Coca-Cola Company, Atlanta, GA 30313, USA. Methodology: The 1D ( 1 H & 13 C) and 2D (COSY, HSQC, and HMBC) NMR spectral data of was acquired using Varian Unity Plus 600 MHz instrument using standard pulse sequences. Hydrolysis studies were performed on Rebaudioside A using acid, base and enzymatic studies to identify partial degradation products, aglycone and sugar residues. Results: The proton and carbon values of Rebaudioside A were assigned based on NMR and HRMS data as well as chemical studies. The aglycone was identified as steviol on the basis of enzymatic hydrolysis, sugar was identified as D-glucose from acid hydrolysis and the partial hydrolyzed product was identified as Rebaudioside B from alkaline hydrolysis.

Synthesis and Evaluation of Anti-inflammatory and Analgesic Activities of a Novel Series of Coumarin Mannich Bases

A novel series of coumarinyl Mannich bases (3a-1) have been synthesized by reacting 3-acetyl coumarin (1) with various substituted secondary amines (2a-1) in presence of paraformaldehyde. The structures of the newly synthesized compounds were characterized by IR, 1H NMR, 13C NMR and HRMS (high resolution mass spectral) data. Title compounds were screened for in vivo acute anti-inflammatory activity using the carrageenan-induced rat paw edema assay model. Among the compounds tested, 3-[3-(diethylamino)propanoyl]-2H-chromen-2-one (3a)and 3-[3-(piperidine-1-yl) propanoyl]-2H-chromen-2-one (3c) showed 63.1 and 66.7% inhibition, respectively, as compared to the standard drug diclofenac (CAS 15307-86-5, 68.8%). These potent compounds showed encouraging analgesic andantipyretic activities.

Submicron aerosol analysis and organic source apportionment in an urban atmosphere in Pearl River Delta of China using high-resolution aerosol mass spectrometry

[1] The Pearl River Delta (PRD) region in South China is one of the most economically developed regions in China while also noted for its severe air pollution, especially in the urban environments. In order to understand in depth the aerosol chemistry and the emission sources in PRD, an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) was deployed at an urban site in the Hong Kong–Shenzhen metropolitan area between 25 October and 2 December 2009. Ten minute–resolved measurement data were analyzed, and an average mass concentration of 44.5 ± 34.0 μg m−3 was calculated for the entire campaign. On average, organic matter was the most abundant PM1 component accounting for 39.7% of the total mass, followed by sulfate (24.5%), black carbon (measured by aethalometer, 14.0%), ammonium (10.2%), nitrate (10.0%), and chloride (1.6%). Moreover, organic matter comprised an increasing fraction of the PM1 loading as the PM1 loading increased, denoting its key role in particulate pollution in this region. Calculations of organic elemental composition based on the high-resolution organic mass spectra obtained indicated that C, H, O, and N on average contributed 33.8%, 55.1%, 10.2%, and 0.9%, respectively, to the total atomic numbers of organic aerosol (OA), which corresponded to an OM/OC ratio (the ratio of organic matter mass/organic carbon mass) of 1.57 ± 0.08. Positive matrix factorization analysis was then conducted on the high-resolution organic mass spectral data set. Four OA components were identified, including a hydrocarbon-like (HOA), a biomass burning (BBOA), and two oxygenated (LV-OOA and SV-OOA) components, which on average accounted for 29.5%, 24.1%, 18.8%, and 27.6%, respectively, of the total organic mass. The HOA was found to have contributions from both fossil fuel combustion and cooking emissions, while the BBOA was well correlated with acetonitrile, a known biomass burning marker. The LV-OOA and SV-OOA corresponded to more aged and fresher secondary organic aerosol, respectively. The diurnal variations of the LV-OOA and SV-OOA showed significant increase in concentration in the daytime, denoting their substantial photochemical formation. Back trajectory analysis indicated that the short-range regional transport from the northeast was the key factor leading to severe submicron aerosol pollution in this area. The HR-ToF-AMS measurement results in this campaign are completely compared with a previous paper that reports the HR-ToF-AMS measurement results at a rural site in PRD in the same season, based on which the regional pollution characteristics of submicron particle in PRD were analyzed.

FluTyper-an algorithm for automated typing and subtyping of the influenza virus from high resolution mass spectral data

BackgroundHigh resolution mass spectrometry has been employed to rapidly and accurately type and subtype influenza viruses. The detection of signature peptides with unique theoretical masses enables the unequivocal assignment of the type and subtype of a given strain. This analysis has, to date, required the manual inspection of mass spectra of whole virus and antigen digests.ResultsA computer algorithm, FluTyper, has been designed and implemented to achieve the automated analysis of MALDI mass spectra recorded for proteolytic digests of the whole influenza virus and antigens. FluTyper incorporates the use of established signature peptides and newly developed naïve Bayes classifiers for four common influenza antigens, hemagglutinin, neuraminidase, nucleoprotein, and matrix protein 1, to type and subtype the influenza virus based on their detection within proteolytic peptide mass maps. Theoretical and experimental testing of the classifiers demonstrates their applicability at protein coverage rates normally achievable in mass mapping experiments. The application of FluTyper to whole virus and antigen digests of a range of different strains of the influenza virus is demonstrated.ConclusionsFluTyper algorithm facilitates the rapid and automated typing and subtyping of the influenza virus from mass spectral data. The newly developed naïve Bayes classifiers increase the confidence of influenza virus subtyping, especially where signature peptides are not detected. FluTyper is expected to popularize the use of mass spectrometry to characterize influenza viruses.

A high-throughput de novo sequencing approach for shotgun proteomics using high-resolution tandem mass spectrometry

BackgroundHigh-resolution tandem mass spectra can now be readily acquired with hybrid instruments, such as LTQ-Orbitrap and LTQ-FT, in high-throughput shotgun proteomics workflows. The improved spectral quality enables more accurate de novo sequencing for identification of post-translational modifications and amino acid polymorphisms.ResultsIn this study, a new de novo sequencing algorithm, called Vonode, has been developed specifically for analysis of such high-resolution tandem mass spectra. To fully exploit the high mass accuracy of these spectra, a unique scoring system is proposed to evaluate sequence tags based primarily on mass accuracy information of fragment ions. Consensus sequence tags were inferred for 11,422 spectra with an average peptide length of 5.5 residues from a total of 40,297 input spectra acquired in a 24-hour proteomics measurement of Rhodopseudomonas palustris. The accuracy of inferred consensus sequence tags was 84%. According to our comparison, the performance of Vonode was shown to be superior to the PepNovo v2.0 algorithm, in terms of the number of de novo sequenced spectra and the sequencing accuracy.ConclusionsHere, we improved de novo sequencing performance by developing a new algorithm specifically for high-resolution tandem mass spectral data. The Vonode algorithm is freely available for download at http://compbio.ornl.gov/Vonode.

Analysis of tandem mass spectra by FTMS for improved large-scale proteomics with superior protein quantification.

Using a newly developed dual-cell quadrupole linear ion trap-orbitrap hybrid mass spectrometer (dcQLT-orbitrap), we demonstrate the utility of collecting high-resolution tandem mass spectral data for large-scale shotgun proteomics. Multiple nanoLC-MS/MS experiments on both an older generation quadrupole linear ion trap-orbitrap hybrid (QLT-orbitrap) and the dcQLT-orbitrap, using both resonant-excitation CAD and beam-type CAD (HCD), were performed. Resulting from various technological advances (e.g., a stacked ring ion guide AP inlet, a dual cell QLT), the dcQLT-orbitrap exhibited increased duty cycle (approximately 1.5-2 times) and sensitivity for both CAD (ion trap detection) and HCD (orbitrap detection) methods. As compared to the older system, the dcQLT-orbitrap produced significantly more unique peptide identifications for both methods (approximately 30% improvement for CAD and approximately 115% improvement for HCD). The sizable improvement of the HCD method on the dcQLT-orbitrap system outperforms the current standard method of CAD with ion trap detection for large-scale analysis. Finally, we demonstrate that the increased HCD performance translates to a direct and substantial improvement in protein quantitation precision using isobaric tags.

Application of multiple statistical tests to enhance mass spectrometry-based biomarker discovery.

BackgroundMass spectrometry-based biomarker discovery has long been hampered by the difficulty in reconciling lists of discriminatory peaks identified by different laboratories for the same diseases studied. We describe a multi-statistical analysis procedure that combines several independent computational methods. This approach capitalizes on the strengths of each to analyze the same high-resolution mass spectral data set to discover consensus differential mass peaks that should be robust biomarkers for distinguishing between disease states.ResultsThe proposed methodology was applied to a pilot narcolepsy study using logistic regression, hierarchical clustering, t-test, and CART. Consensus, differential mass peaks with high predictive power were identified across three of the four statistical platforms. Based on the diagnostic accuracy measures investigated, the performance of the consensus-peak model was a compromise between logistic regression and CART, which produced better models than hierarchical clustering and t-test. However, consensus peaks confer a higher level of confidence in their ability to distinguish between disease states since they do not represent peaks that are a result of biases to a particular statistical algorithm. Instead, they were selected as differential across differing data distribution assumptions, demonstrating their true discriminatory potential.ConclusionThe methodology described here is applicable to any high-resolution MALDI mass spectrometry-derived data set with minimal mass drift which is essential for peak-to-peak comparison studies. Four statistical approaches with differing data distribution assumptions were applied to the same raw data set to obtain consensus peaks that were found to be statistically differential between the two groups compared. These consensus peaks demonstrated high diagnostic accuracy when used to form a predictive model as evaluated by receiver operating characteristics curve analysis. They should demonstrate a higher discriminatory ability as they are not biased to a particular algorithm. Thus, they are prime candidates for downstream identification and validation efforts.

Identification of methyl triclosan and halogenated analogues in male common carp ( Cyprinus carpio) from Las Vegas Bay and semipermeable membrane devices from Las Vegas Wash, Nevada

Methyl triclosan and four halogenated analogues have been identified in extracts of individual whole-body male carp ( Cyprinus carpio) tissue that were collected from Las Vegas Bay, Nevada, and Semipermeable Membrane Devices (SPMD) that were deployed in Las Vegas Wash, Nevada. Methyl triclosan is believed to be the microbially methylated product of the antibacterial agent triclosan (2, 4, 4'-trichloro-4-hydroxydiphenyl ether, Chemical Abstract Service Registry Number 3380-34-5, Irgasan DP300). The presence of methyl triclosan and four halogenated analogues was confirmed in SPMD extracts by comparing low- and high-resolution mass spectral data and Kovats retention indices of methyl triclosan with commercially obtained triclosan that was derivatized to the methyl ether with ethereal diazomethane. The four halogenated analogues of methyl triclosan detected in both whole-body tissue and SPMD extracts were tentatively identified by high resolution mass spectrometry. Methyl triclosan was detected in all 29 male common carp from Las Vegas Bay with a mean concentration of 596 μg kg − 1 wet weight (ww) which is more than an order of magnitude higher than previously reported concentrations in the literature. The halogenated analogs were detected less frequently (21%–76%) and at much lower concentrations (< 51 μg kg − 1 ww). None of these compounds were detected in common carp from a Lake Mead reference site in Overton Arm, Nevada.

Nine acetylenic alcohols isolated from the Okinawan marine sponge of the genus Petrosia ( Strongylophora )

Nine new acetylenic alcohols 1–9 were isolated from a marine sponge belonging to the genus Petrosia (Strongylophora). The structures were elucidated mainly based on the analysis of one-and two-dimensional NMR spectral data. To determine the position of the central double bonds in 1–8, each compound was cleaved with OsO4 and HIO4, and the resulting aldehyde was converted to the corresponding 2,4-dinitrophenylhydrazone. Analysis of the high-resolution mass and 13C NMR spectral data of each 2,4-dinitrophenylhydrazone clarified the position of the central double bonds in 1–8.

Inhibitory Effects of Methyl Brevifolincarboxylate Isolated from Phyllanthus niruri L. on Platelet Aggregation

A platelet-aggregatory inhibitor was isolated from the 50% MeOH extract of Phyllanthus niruri L. leaf. Its structure was determined to be methyl brevifolincarboxylate on the basis of the 1H-, 13C-NMR, and high-resolution mass spectral data. We compared the antiplatelet aggregatory effects of the constituent with adenosine, a well-known inhibitor of platelet aggregation. Platelet aggregation was induced by collagen or adenosine 5'-diphosphate as an activating agent; the extent of inhibition was monitored with a platelet aggregometer employing a laser-scattering method. The inhibitory effects of methyl brevifolincarboxylate were found to be as potent as adenosine that is known to act on an A2A subtype receptor.