High-resolution Mass Spectrometric Analysis Research Articles

Triterpenoids from The Bark of Garcinia porecta and their Cytotoxic Activity against MCF7 Breast Cancer Lines

The <em>Garcinia</em> genus is a well known tropical plant in the Indo-Malesiana region and mainly distributed in tropical countries including Indonesia, Thailand, and Malaysia. Previous phytochemical studies on <em>Garcinia </em>species have led to the identification and isolation of mainly prenylated xanthones. This research describes the isolation and structure elucidation of isolated triterpenoids compounds from the bark of <em>Garcinia porecta</em>. Dried powder bark of <em>G. porecta </em>was extracted with methanol and then partitioned with <em>n</em>-hexane, ethyl acetate, and <em>n</em>-butanol. The <em>n</em>-hexane extract then was separated and purified with chromatography techniques to obtain isolated compounds <strong>1</strong><strong> </strong>and<strong> 2</strong>. The chemical structure of isolated compounds was elucidated by spectroscopic methods including one and two-dimensional NMR as well as high-resolution mass spectrometric analysis and identified as lanosterol (<strong>1</strong>) dan arabidiol (<strong>2</strong>), respectively. These triterpenoids were isolated from this plant for the first time. Compound <strong>1</strong> and <strong>2</strong> showed weak cytotoxic activity against MCF-7 breast cancer cells with IC<sub>50</sub> values of 60.09 dan 46.17 µM, respectively.

The identification and chromatographic separation of a new highly analogous impurity of the active pharmaceutical ingredient icatibant

Icatibant is a peptidomimetic drug serving as a bradykinin-receptor antagonist and is approved in Europe and the United States for the treatment of hereditary angioedema attacks. We have detected an impurity with a high structural similarity to icatibant in pharmaceutical dosage forms using an optimized chromatographic method based on reversed phase high performance liquid chromatography with UV detection. The abundance of the impurity was around 1% relative to the icatibant peak following storage at room temperature for 1 month, and raised up to ~16% upon temperature stressing at 100 °C. The impurity was isolated by fraction collection and further purified by solid phase extraction for structural identification. NMR and high resolution mass spectrometric analyses revealed that this impurity results from isomerization in the N-terminal single amino acid residue. The new impurity may warrant particular attention due to its exceptional similarity to the active ingredient icatibant.

Terpenes and lignans from the roots of Solanum melongena L.

Phytochemical investigation of the roots of Solanum melongena L. resulted in the isolation of ten terpenes and sixteen lignans, including a new triterpene saponin, officinoterpenoside E (1) and twenty-five known compounds (2-26). All compounds were firstly isolated from S. melongena except 2, 13, 21, 22. The structures of these compounds were determined by 1 D and 2 D NMR spectra referring to the literatures, together with high-resolution mass spectrometric analysis. All compounds were evaluated for the cytotoxicity against three cancer cell lines (HepG2, Hela, and MCF-7) in vitro. The results showed that compounds 1, 6, 20, 25 and 26 exhibited moderate cytotoxicity against HepG2, Hela and MCF-7 cells with IC50 values in the range of 16.8 ± 1.7 to 29.1 ± 1.9 μM. Therefore, these terpenoids and lignans may have potential biological activity, and also seemed to be of great chemotaxonomic value for S. melongena.

Physico-chemical Characterization, Profiling of Total Lipids and Triacylglycerol Molecular Species of Omega-3 Fatty Acid Rich <i>B. arvensis</i> Seed Oil from India

Buglossoides arvensis is indigenous to India and its seed oil is rich in unique and nutritionally important omega-3 fatty acid namely, stearidonic acid (SDA). It is a non-conventional oil seed plant and needs to be agronomically adapt for commercial utilization. In the present study, oil extracted from the agronomically adapted high yielding cultivar of B. arvensis seeds was analyzed for its oil content, fatty acid (FA) composition, physico-chemical characteristics, total lipids and triacylglycerol molecular species. The oil content, peroxide, acid, iodine, p-anisidine values and tocopherol content of the oil were 18.53% (w/w), 2.06 meq of active oxygen / kg of oil, 2.55 mg KOH/g oil, 217.2 g I2/100g oil, 10.7 and 774.8 mg/kg oil respectively. Oxidative stability as determined by the induction period was found to be 3.1 h. Polyunsaturated fatty acid (PUFA) content of the oil was 81.3% (of total FA), comprising of α-linolenic acid (ALA; 48.5%), SDA (18.6%), linoleic acid (LA; 10.3%) and γ-linolenic acid (GLA; 3.9%). Profiling of lipid classes showed neutral lipids (89.3%, w/w) as most abundant lipid class followed by glycolipids (7.4%, w/w) and phospholipids (3.3%, w/w). High resolution mass spectrometric analysis of triacylglycerol (TAG) molecular species showed TAGs with C54 carbons in the acyl chain as most abundant. Positional distribution analysis showed GLA and SDA predominantly at the sn-2 position of triacylglycerol. FTIR analysis revealed common characteristics molecular features similar to PUFA rich oils. Overall, the results suggest that B. arvensis seed oil is an excellent ω3-ω6-ω3 or ALA-SDA-GLA source for food and nutraceutical industries.

SIP-Metaproteomics: Linking Microbial Taxonomy, Function, and Activity.

Stable isotope probing combined with metaproteomics enables the detection and characterization of active key species in microbial populations under near-natural conditions, which greatly helps to understand the metabolic functions of complex microbial communities. This is achieved by providing growth substrates labeled with heavy isotopes such as 13C, which will be assimilated into microbial biomass. After subsequent extraction of proteins and proteolytic cleavage into peptides, the heavy isotope enrichment can be detected by high-resolution mass spectrometric analysis, and linked to the functional and taxonomic characterization of these biomarkers. Here we provide protocols for obtaining isotopically labeled proteins and for downstream SIP-metaproteomics analysis.

Endogenous Anti-Inflammatory Very-Long-Chain Dicarboxylic Acids: Potential Chemopreventive Lipids.

In a paradigm shift, cancer research efforts are being dedicated to the discovery of chemopreventive agents. The goal of this approach is to delay or prevent the progression of augmented cell division to established cancer. Research has focused on dietary supplements, drugs, and endogenous lipids that possess anti-inflammatory properties. We undertook a lipidomics analysis of potential endogenous anti-inflammatory/anti-proliferative lipids in human plasma. We performed high-resolution mass spectrometric lipidomics analyses of plasma samples from controls and patients with colorectal, kidney, pancreatic, glioblastoma, and breast cancers. We present evidence that endogenous very-long-chain dicarboxylic acids (VLCDCA) are anti-inflammatory lipids that possess chemopreventative properties. In a family of VLCDCAs, we characterized VLCDCA 28:4, which is decreased in the plasma of patients with colorectal, kidney, and pancreatic cancers. The structure of this biomarker was validated by derivatization strategies, synthesis of the analytical standard, and tandem mass spectrometry. Our data suggest that VLCDCA 28:4 may be a useful blood biomarker for a number of cancers and that resupplying this lipid, via a prodrug for example, may offer a new anti-inflammatory therapeutic strategy for delaying or preventing the progression of cancer and other inflammatory diseases.

New lignans from the roots of Datura metel L

Two new lignans (1-2) and a new natural product (3), as well as eighteen known compounds (4-21), were isolated from the roots of Datura metel L. Compounds 8, 11, 12, 14, 16, 17, 19 and 21 were isolated from Datura metel L for the first time. These compounds’ chemical structures were elucidated by spectroscopic methods, including 1D and 2D NMR spectra with references to the literature, as well as high-resolution mass spectrometric analysis. All compounds were tested for cytotoxic activity using an MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenylt etrazolium bromide) assay.

Development of Validated and Stability-Indicating LC-DAD and LC-MS/MS Methods for Determination of Avanafil in Pharmaceutical Preparations and Identification of a Novel Degradation Product by LCMS-IT-TOF.

Avanafil (AVA), one of the most effective drugs prescribed for erectile dysfunction, is a pyrimidine-derivative PDE5 inhibitor. In the current work, new LC methods were developed and validated for quantitative determination of avanafil and qualitative determination of its degradation products. The quantitative determination of avanafil was carried out using liquid chromatography with photodiode array detection (LC-DAD) and liquid chromatography-tandem mass spectrometry LC-MS/MS methods, and fully validated according to the ICH Q2 (R1) guideline, while qualitative determination was performed using a liquid chromatography mass spectrometry-ion trap-time of flight (LCMS-IT-TOF) instrument. The separation of avanafil and its degradation products was carried out using the same reversed-phase chromatographic conditions, in which a second-generation C18-bonded monolithic silica column (Chromolith® High Resolution RP-18e, 100 × 4.6 mm, Merck KGaA) was used as stationary phase. Briefly, the methods enable quantitation of avanafil with high accuracy (recovery > 95%) and precision (RSD% < 2.0), within the ranges of 0.5–20 μg/mL for LC-DAD and 150–6000 ng/mL for LC-MS/MS. In the forced degradation studies, over and above currently existing data, a new oxidation-based degradation product, whose predicted m/z is 367.1168, was identified and its structure was confirmed by high-resolution mass spectrometric analysis. As the main advantage, either an LC-DAD or LC-MS/MS instrument can be chosen for interference-free quantitation of AVA, according to the facilities in quality-control laboratories.

Two new triterpenoids from the stems of Celastrus orbiculatus Thunb

Two new triterpenoids, named as 3β-(E)-p-caffeoylnepeticin (1) and 3β-(E)-3,4-dimethoxycinnamate-20(S)-dammarenediol II (2), along with three known compounds 3, 4 and 5 were isolated from the stems of Celastrus orbiculatus Thunb. The structures of these compounds were elucidated by spectroscopic methods including IR, 1D and 2D NMR as well as by high-resolution mass spectrometric analysis. The anti-inflammatory activities and the cytotoxic effects were evaluated on lipopolysaccharide induced nitric oxide production in RAW 264.7 cells and two tumor cell lines (MCF-7 and A2780s), respectively. Results showed that compounds 1 and 3 exhibited weak anti-inflammatory activity with the IC50 value of 18.50 and 10.51 μM respectively, while all compounds were inactive in both cell lines (IC50 > 20 μM).

Molecular profiling of crude oil by using Distillation Precipitation Fractionation Mass Spectrometry (DPF-MS)

Molecular profiling of crude oil is a tremendous challenge due to its inherent complexity. An accurate molecular fingerprint of a crude oil may facilitate rational design of crude oil recovery efforts, such as enhanced oil recovery, improve the efficiencies of the refining processes, and enable a better assessment of the value of the crude oil. Herein, a new approach (Distillation Precipitation Fractionation Mass Spectrometry (DPF-MS) method) is introduced for the molecular level characterization of crude oil. This method involves the separation of crude oil into six fractions followed by high-resolution mass spectral analysis optimized for each individual fraction. The separation methods are distillation, precipitation, and fractionation in an auto column followed by solid phase extraction. Initially, the fractions were examined by using Fourier transform infrared spectroscopy to determine the bulk chemical nature of each individual fraction, such as the extent of aromaticity, degree of polarity, etc. Based on this bulk information, model compounds representative of compounds in each fraction were selected and employed to develop the optimal high-resolution mass spectrometric analysis method for each fraction. An especially important aspect of this work was the optimization of the ionization method separately for each fraction by using appropriate model compounds so that most compounds in each fraction are ionized at approximately the same efficiency to generate only one type of stable ions (either molecular ions, protonated molecules or cations formed by hydride abstraction) containing the intact analyte molecule. This allows the DPF-MS method to produce reasonably accurate relative abundances for compounds present in each fraction, thereby making the method semi-quantitative. The compositional data thus obtained for the individual fractions were utilized to provide meaningful molecular level information for the crude oil. Inclusion of a mass balance for each fraction allows for data consolidation, which provides an accurate overall analysis of the crude oil, including average molecular weight and weight percentages of different compound classes.

Green Tea Inhibits Uterine Contractility in Ex Vivo (Non-Pregnant) Mice Models

Green tea is widely known for its beneficial biologic effect and there have been some reports on the beneficial effect on the reproductive system. There have however been no reports on green tea effects on uterine contractility. This study is therefore aimed at the investigation of green tea extract on the amplitude and frequency of uterine contractility. Green tea bags were macerated in boiling water for 5 min and concentrated to dryness. The extract (0.33 -1333.21 µg/mL) was tested on the isolated mouse uterus. The contractility parameters investigated included spontaneous contraction, oxytocin (60 pg/mL) induced contraction and high KCl (80 mM)-induced contraction. High resolution mass spectrometric (HRMS) determination of secondary metabolites was also performed on the extract. The extract inhibited both the amplitude and frequency of uterine contractility studied, however minimal inhibitory effect was observed with KCl-induced contraction. The HRMS analysis revealed the presence of twenty-five (25) significant compounds, 23 of which were identified and 2 were unknown. Compounds were observed to belong to a diverse range of phytochemical classes including pteridine, flavonoids, cyclitols, and coumarins, with the majority of detected compounds belonging to the flavonoid class. The results obtained in this study have shown that green tea extract inhibits uterine contractility possibly due to the presence of the flavonoids, and through interaction with calcium and/or prostaglandins

Novel Type III Polyketide Synthases Biosynthesize Methylated Polyketides in Mycobacterium marinum

Mycobacterial pathogenesis is hallmarked by lipidic polyketides that decorate the cell envelope and mediate infection. However, factors mediating persistence remain largely unknown. Dynamic cell wall remodeling could facilitate the different pathogenic phases. Recent studies have implicated type III polyketide synthases (PKSs) in cell wall alterations in several bacteria. Comparative genome analysis revealed several type III pks gene clusters in mycobacteria. In this study, we report the functional characterization of two novel type III PKSs, MMAR_2470 and MMAR_2474, in Mycobacterium marinum. These type III pkss belong to a unique pks genomic cluster conserved exclusively in pathogenic mycobacteria. Cell-free reconstitution assays and high-resolution mass spectrometric analyses revealed methylated polyketide products in independent reactions of both proteins. MMAR_2474 protein exceptionally biosynthesized methylated alkyl-resorcinol and methylated acyl-phloroglucinol products from the same catalytic core. Structure-based homology modeling, product docking, and mutational studies identified residues that could facilitate the distinctive catalysis of these proteins. Functional investigations in heterologous mycobacterial strain implicated MMAR_2474 protein to be vital for mycobacterial survival in stationary biofilms. Our investigations provide new insights into type III PKSs conserved in pathogenic mycobacterial species.

New lignan from the rattan stems of Schisandra chinensis

A new lignan named schilignan F (1), together with twelve known ones (2–13), were isolated from the rattan stems of Schisandra chinensis. Their chemical structures were elucidated by spectroscopic methods including one and two-dimensional NMR spectra referring to the literatures as well as high-resolution mass spectrometric analysis. All compounds were evaluated for their cytotoxicities against human Hela cancer cell lines in vitro. The results showed that compounds 2, 6 and 8 exhibited weak cytotoxic activity with IC50 values of 30.6, 86.3 and 41.0 μM, and cisplatin showed cytotoxic activity with IC50 value of 27.3 μM.

High Resolution Mass Spectrometric Analysis of Secoiridoids and Metabolites as Biomarkers of Acute Olive Oil Intake-An Approach to Study Interindividual Variability in Humans.

Phenolic compounds are minor components of extra virgin olive oil (EVOO). Secoiridoids are the major components contributing to the phenolic content of EVOO. Information is lacking regarding their potential as biomarkers for EVOO intake. Healthy volunteers (n = 9) ingested 50mL of EVOO in a single dose containing 322mg kg-1 total phenolic content (caffeic acid equivalents) and 6mg 20 g-1 hydroxytyrosol and its derivatives. Plasma is collected before (0h) and at 0.5, 1, 2, 4, and 6h after ingestion. Urine samples are collected prior to ingestion (0h) and at 0-4, 4-8, 8-15, and 15-24h. Samples are analyzed by UPLC coupled with an Exactive Orbitrap MS. Partial least squares discriminant analysis with orthogonal signal correction is applied to screen for metabolites that allow sample discrimination. Plasma biomarkers and urine biomarkers are selected although individual variability is observed among volunteers. Results are in accordance with in vitro experiments performed (in vitro digestion and hepatic microsomal activity assays). Plasma (elenolic acid + H2 ; p-HPEA-EA + H2 + glucuronide) and urinary (3,4-DHPEA-EA, 3,4-DHPEA-EA + H2 +glucuronide, methyl 3,4-DHPEA-EA + H2 +glucuronide) secoiridoid compounds are selected as biomarkers to monitor EVOO intake showing good predictive ability according to multivariate analysis.

A Cytotoxic Rocaglate Compound from The Stembark of Aglaia argentea (Meliaceae)

The Aglaia genus belong to Meliceae family is unique plant species because the presence of rocaglate and rocaglamide which is so far isolated only from Aglaia genus, indicate that type of this compound as a chemical marker for the genus of Aglaia. This type of compound known to have strong activity, such as insecticide and cytotoxic. This study describe the isolation, structure elucidation, and cytotoxic activity of an isolated rocaglate compound. Dried stembark of A. argentea extracted with methanol and partition between n-hexane, ethyl acetate, and n-butanol, respectively The extracts were tested against P-388 murine leukemia cells and the ethyl acetat showed strongest activity with IC50 value of 15.5 mg/mL. The ethyl acetate then was separated and purified with chromatography technique to obtain isolated compound 1. The chemical structure of isolated compounds were elucidated by spectroscopic methods including one and two-dimensional NMR as well as high-resolution mass spectrometric analysis and identified as a methyl rocaglate. Compound 1 showed strong cytotoxic activity with an IC50 value of &lt; 0.1 μg/mL.

Ultrasensitive High-Resolution Mass Spectrometric Analysis of a DNA Adduct of the Carcinogen Benzo[a]pyrene in Human Lung.

Benzo[a]pyrene (BaP), an archetypical polycyclic aromatic hydrocarbon, is classified as "carcinogenic to humans" and is ubiquitous in the environment, as evident by the measurable levels of BaP metabolites in virtually all human urine samples examined. BaP carcinogenicity is believed to occur mainly through its covalent modification of DNA, resulting in the formation of BPDE-N2-dG, an adduct formed between deoxyguanosine and a diol epoxide metabolite of BaP, with subsequent mutation of critical growth control genes. In spite of the liquid chromatography-mass spectrometry (LC-MS)-based detection of BPDE-N2-dG in BaP-treated rodents, and indirectly through high-performance liquid chromatography (HPLC)-fluorescence detection of BaP-7,8,9,10-tetraols released from human DNA upon acid hydrolysis, BPDE-N2-dG adducts have rarely if ever been observed directly in human samples using LC-MS techniques, even though sophisticated methodologies have been employed which should have had sufficient sensitivity. With this in mind, we developed a liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) methodology employing high-resolution/accurate mass analysis for detecting ultratrace levels of these adducts. These efforts are directly translatable to the development of sensitive detection of other small molecules using trap-based LC-ESI-MS/MS detection. The developed methodology had a limit of detection (LOD) of 1 amol of BPDE-N2-dG on-column, corresponding to 1 BPDE-N2-dG adduct per 1011 nucleotides (1 adduct per 10 human lung cells) using 40 μg of human lung DNA. To our knowledge, this is the most sensitive DNA adduct quantitation method yet reported, exceeding the sensitivity of the 32P-postlabeling assay (∼1 adduct per 1010 nucleotides). Twenty-nine human lung DNA samples resulted in 20 positive measurements above the LOD, with smoker and nonsmoker DNA containing 3.1 and 1.3 BPDE-N2-dG adducts per 1011 nucleotides, respectively.

Lipidomics of equine amniotic fluid: Identification of amphiphilic (O-acyl)-ω-hydroxy-fatty acids

Amniotic fluid is essential for the growth and maturation of the fetus prior to parturition. While our knowledge of human amniotic fluid is extensive, current data for equine amniotic fluid is limited. We therefore undertook a detailed lipidomics analysis of equine amniotic fluid. Using a non-targeted high-resolution mass spectrometric lipidomics analysis of equine amniotic fluid, we were able to characterize a diverse array of individual lipids. This non-biased analytical approach detected, for the first time, the presence of (O-acyl)-ω-hydroxy-fatty acids (OAHFA) with up to 52 carbon chain lengths in amniotic fluid. The identities of these lipid amphiphiles were validated both by high-resolution mass spectrometry and by tandem mass spectrometry (<2 ppm mass error) which identified the fatty acid and hydroxy-fatty acid components of individual OAHFAs. The only previous identification of OAHFAs has been in sperm and meibomian glands, and their sebaceous secretions, suggesting that these lipids may have unique functional roles in highly specialized compartments. The amphiphilic and surfactant properties of these unique lipids could provide an interface between amniotic lipids and fetal skin and/or lungs. The potential roles of OAHFAs as well as their source in amniotic fluid remain to be explored based upon these novel lipidomics findings but our study of the developmental time course of amniotic OAHFAs suggest that they may act as lubricants in delivery and/or a role in the development of fetal lung function around parturition.

Benzoylsalicylic acid derivatives as defense activators in tobacco and Arabidopsis

Systemic acquired resistance (SAR) is a long lasting inducible whole plant immunity often induced by either pathogens or chemical elicitors. Salicylic acid (SA) is a known SAR signal against a broad spectrum of pathogens in plants. In a recent study, we have reported that benzoylsalicylic acid (BzSA) is a SAR inducer in tobacco and Arabidopsis plants. Here, we have synthesized BzSA derivatives using SA and benzoyl chlorides of various moieties as substrates. The chemical structures of BzSA derivatives were elucidated using Infrared spectroscopy (IR), Nuclear magnetic spectroscopy (NMR) and High-resolution mass spectrometer (HRMS) analysis. The bioefficacy of BzSA derivatives in inducing defense response against tobacco mosaic virus (TMV) was investigated in tobacco and SA abolished transgenic NahG Arabidopsis plants. Interestingly, pre-treatment of local leaves of tobacco with BzSA derivatives enhanced the expression of SAR genes such as NPR1 [Non-expressor of pathogenesis-related (PR) genes 1], PR and other defense marker genes (HSR203, SIPK, WIPK) in systemic leaves. Pre-treatment of BzSA derivatives reduced the spread of TMV infection to uninfected areas by restricting lesion number and diameter both in local and systemic leaves of tobacco in a dose-dependent manner. Furthermore, pre-treatment of BzSA derivatives in local leaves of SA deficient Arabidopsis NahG plants induced SAR through AtPR1 and AtPR5 gene expression and reduced leaf necrosis and curling symptoms in systemic leaves as compared to BzSA. These results suggest that BzSA derivatives are potent SAR inducers against TMV in tobacco and Arabidopsis.

New cytotoxic protolimonoids from the stem bark of Aglaia argentea (Meliaceae)

Two new protolimonoid compounds, namely, argentinin A (1) and B (2) along with five known triterpenoid compounds, dammar-24-en-3α-ol (3), 3-epi-cabraleahydroxy lactone (4), (E)-25-hydroperoxydammar-23-en-3β,20-diol (5), mixture of eichlerianic acid and shoreic acid (6a and 6b), and dammar-24-en-3α,20-diol (7), were isolated from the stem bark of Aglaia argentea. The structure of new compounds were elucidated by spectroscopic methods including one and two-dimensional NMR as well as high-resolution mass spectrometric analysis. All of the compounds were tested for their cytotoxic effects against P-388 murine leukemia cells in vitro. Among those isolated compounds, argentinin A (1) showed the strongest activity with an IC50 value of 1.27μg/mL (3.05μM).

Abstract 721: Minimally invasive test and composite biomarker for early detection of serous ovarian carcinoma

Abstract Background: Current screening programs for early detection of high grade epithelial ovarian cancer (HGOvC) among high-risk populations have failed to show improvement in HGOvC mortality, therefore these women are offered risk-reducing bilateral salpingo-oophorectomy (RRBSO) at 35- 40 years. Stratification of high-risk population, especially BRCA mutation carriers, may enable personalized risk counseling and individualization of timing of RRBSO. In most cases, the precursor lesions of HGOvC arise in the epithelium of the fallopian tube (FT) fimbriae rather than intra-peritoneally. It is therefore plausible that proteins, RNA or DNA from early-stage tumor cells may be identifiable in fluid samples obtained from the lumen of the gynecological tract, thus making it possible to identify curable, early stage lesions. Aims: (1) Test the feasibility of uterine lavage as a minimally invasive test for early detection of ovarian cancer, and (2) Identify novel early-detection biomarkers in the uterine lavage fluid (UtLF). Methods: We developed a method for sampling of gynecologic tract fluid termed uterine lavage fluid (UtLF), which is a simple, reproducible, low-cost office procedure that can be performed routinely during gynecologic follow-up visits. We have already collected UtLF from 140 HGOvC patients and control women undergoing gynecologic surgical procedures for non-malignant indications. Deep proteomic profiling of UtLF is performed by isolation of microparticles from body fluids, followed by solubilization, trypsin digestion and high resolution mass spectrometric (MS) analysis (on the Q-Exactive MS). Machine learning algorithms have been used to extract a classifier that can predict the diagnosis of ovarian cancer. Results: Uterine lavage appears to be a feasible, low burden procedure. The MS approach has identified thousands of proteins in each UtLF specimen, in a high throughput manner. The label-free quantification algorithm (MaxQuant) enables a quantitative comparison between samples from cases and controls. We have derived a 20-protein classifier with an area under the curve (AUC) of Receiver Operating Characteristics (ROC) curve of 0.91 at 20% error. The composite biomarker has been applied to an independent validation set with a negative predictive value (NPV) of 92% and positive predictive value (PPV) of 45%. Conclusions: A minimally invasive technique of uterine lavage to collect unique diagnostic samples, coupled with state-of-the-art proteomics methods, results in a highly sensitive and specific composite biomarker which may be developed in to a screening tool for early detection of serous ovarian cancer in high-risk populations. Citation Format: Keren Bahar-Shany, Georgina D. Barnabas, Limor Helpman, Ariella Yakobson-Siton, Tamar Perri, Ram Eitan, Jacob Korach, Tamar Geiger, Keren Levanon. Minimally invasive test and composite biomarker for early detection of serous ovarian carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 721. doi:10.1158/1538-7445.AM2017-721