Fast Atom Bombardment Research Articles

Early Days in the Hunt Laboratory at UVA, 1969-1980

Arriving at the University of Virginia in the autumn of 1969, Donald Hunt began his 50+ year career in academics with the study of organometallic chemistry, on which he had done his PhD thesis, and mass spectrometry, to which he was introduced while a postdoc in Klaus Biemann’s laboratory at the Massachusetts Institute of Technology. In the 1970s, Hunt’s lab pioneered the use of negative chemical ionization (CI) to enhance sensitivity for studying organic molecules, developed a system for simultaneously obtaining positive and negative CI spectra to augment structure elucidation, and built a prototype triple quadrupole instrument so effective at collisional dissociation that its commercial counterpart became the analytical instrument of choice for mixture analysis for the next decade and beyond. Foreseeing that the future lay in the analysis of biological molecules, by the end of the decade Hunt shifted his focus to peptides. The analysis of protein fragments had suddenly become more accessible thanks to the advent of the triple quadrupole and Barber’s invention of fast atom bombardment. As the ‘80s began and Hunt and his team sought to pursue larger and larger pieces of proteins, his attention turned to the development of mass spectrometers with greater mass range. While recounting their memories of these events, several of Hunt’s students and colleagues pay tribute to his support for them as individuals, as well as to his infectious enthusiasm for scientific endeavors that he so generously shared.

Synthesis, Characterization, and Biological Studies of Metal Complexes of Dicoumarol Derivatives of Gatifloxacin

Copper(II) complexes were prepared using gatifloxacin and dicoumarin derivatives to investigate their biological activities and to conduct X-ray studies. The complexes were synthesized through classical thermal methods. Biologically potent ligands were synthesized by the reaction of dicoumarin derivative with different aldehydes in ethanol. Cu(II) complexes were formed by mixing ethanolic solution of ligands and gatifloxacin with metal solutions in a 1:1 mole ratio. The structures of the dicoumarin derivatives and their Cu(II) complexes were analyzed by infrared, 1H NMR, 13C NMR, and mass spectrometry. The thermal behavior of the new mixed ligand Cu(II) complexes was investigated by thermogravimetric, fast atom bombardment (FAB) mass, and X-ray analysis. The iron-reducing antioxidant potential (FRAP) (antioxidant activity) of all compounds was evaluated. All the synthesized compounds were screened for antibacterial activity against Escherichia coli; Pseudomonas aeruginosa; Streptococcus pyogenes; minimum inhibitory concentration values for Candida albicans; and Aspergillus niger were determined using the Luria Broth dilution method. The ligands and their complexes were evaluated for antioxidant and antibacterial activity in vitro. The complexes exhibited better results than their respective counterparts.. KEYWORDS :Antimicrobial, Antioxidant, Fast atom bombardment mass, Thermal analysis, Thermo gravimetric analysis, X-ray.

Unsymmetrical thiourea derivatives: synthesis and evaluation as promising antioxidant and enzyme inhibitors.

Background: Unsymmetrical thioureas 1-20 were synthesized and then characterized by various spectroscopy techniques such as UV, IR, fast atom bombardment (FAB)-MS, high-resolutionFAB-MS, 1H-NMRand 13C-NMR. Methods: Synthetic compounds 1-20 were tested for their ability for antioxidant, lipoxygenaseand xanthine oxidase activities. Results: Compounds 1, 2, 9, 12 and 15 exhibited strong antioxidant potential, whereascompounds 1-3, 9, 12, 15 and 19 showed good to moderate lipoxygenase activity. Ten compounds demonstrated moderate xanthine oxidase inhibition. Conclusion: Compound 15 displayed the highest potency among the series, exhibiting good antioxidant, lipoxygenase and xanthine oxidase activities. Theoretical calculations using density functional theory and molecular docking studies supported the experimental findings, indicating the potential of the synthesized compounds as potent antioxidants, lipoxygenases and xanthine oxidase agents.

Thermal Transport and Mechanical Stress Mapping of a Compression Bonded GaN/Diamond Interface for Vertical Power Devices.

Bonding diamond to the back side of gallium nitride (GaN) electronics has been shown to improve thermal management in lateral devices; however, engineering challenges remain with the bonding process and characterizing the bond quality for vertical device architectures. Here, integration of these two materials is achieved by room-temperature compression bonding centimeter-scale GaN and a diamond die via an intermetallic bonding layer of Ti/Au. Recent attempts at GaN/diamond bonding have utilized a modified surface activation bonding (SAB) method, which requires Ar fast atom bombardment immediately followed by bonding within the same tool under ultrahigh vacuum (UHV) conditions. The method presented here does not require a dedicated SAB tool yet still achieves bonding via a room-temperature metal-metal compression process. Imaging of the buried interface and the total bonding area is achieved via transmission electron microscopy (TEM) and confocal acoustic scanning microscopy (C-SAM), respectively. The thermal transport quality of the bond is extracted from spatially resolved frequency-domain thermoreflectance (FDTR) with the bonded areas boasting a thermal boundary conductance of >100 MW/m2·K. Additionally, Raman maps of GaN near the GaN-diamond interface reveal a low level of compressive stress, <80 MPa, in well-bonded regions. FDTR and Raman were coutilized to map these buried interfaces and revealed some poor thermally bonded areas bordered by high-stress regions, highlighting the importance of spatial sampling for a complete picture of bond quality. Overall, this work demonstrates a novel method for thermal management in vertical GaN devices that maintains low intrinsic stresses while boasting high thermal boundary conductances.

A104 ATYPICAL PRESENTATION OF HSD3B7 DEFICIENCY

Abstract Background Bile acid synthesis disorders are the result of deficient activity of one of 17 enzymes required for conversion of cholesterol into bile acids. One such bile acid synthesis disorder is 3β-hydroxy-Δ5-C27-steroid oxidoreductase (HSD3B7) deficiency, an autosomal recessive inherited disorder caused by a defect in 3β-hydroxy-Δ5-C27-steroid dehydrogenase (C27 3β-HSD) enzyme. Ultimately, this bile acid synthesis disorder is due to a HSD3B7 gene mutation. With only 53 cases reported between 1993 and 2015, HSD3B7 deficiency is rare. Additionally, the existing literature is primarily in the form of case reports, with the majority of patients with HSD3B7 deficiency presenting in the neonatal period, often with cholestatic jaundice. Aims To showcase an atypical presentation of HSD3B7 deficiency, in an 11 year old male with recurrent epistaxis and a coagulopathy of vitamin K deficiency. Additionally, to complete a review of the literature available on HSD3B7 deficiency. Methods Case report, chart review, and literature review. Results 11 year old male who initially presented to Pediatric Hematology with prolonged PTT and INR in the context of recurrent epistaxis and easy bruising. Upon further work up, the patient was found to have low levels of vitamin K dependent factors, as well as low vitamin levels of A, D, and E. Additionally, the patient had elevation of AST, ALT, GGT, ALP, and total bilirubin. Normalization of the INR and PTT were achieved with vitamin K supplementation. Genetic testing was sent to work up the abnormal liver enzymes and revealed HSD3B7 deficiency. Fast atom bombardment ionization was subsequently completed and confirmed the diagnosis. Conclusions There is limited clinical data available regarding HSD3B7 deficiency. The classic presentation of this bile acid synthesis disorder is in a neonate with cholestatic jaundice, hepatomegaly, fat-soluble vitamin deficiencies, and lipid malabsorption. Therefore, the initial presentation of an 11 year old with recurrent epistaxis and prolonged INR and PTT is thus an atypical presentation of HSD3B7 deficiency. This case report demonstrates that there is diversity in the age of presentation and accompanying signs and symptoms in HSD3B7 deficiency. Funding Agencies None

Biosurfactants—An Overview

AbstractThe large structural and functional variety of bio‐surfactants (BS), which are produced by microorganisms, leads to the use of several methods to study these amphiphilic molecules. This review seeks to consolidate information on various surface‐active product extraction techniques, microbiological screening methodologies, and analytical terminologies utilized in this sector. The potential benefits and drawbacks of various approaches for studying cell biomass or microbial culture broth for the generation of surface‐reactive chemicals are also discussed. Additionally, the most popular techniques for detection, structural characterization, and purification of a variety of BS are introduced. A number of straightforward techniques are described in detail, including dialysis, ion exchange, solvent extraction, ultrafiltration, lyophilization, and thin layer chromatography (TLC). In addition to more sophisticated techniques like nuclear magnetic resonance (NMR), fast atom bombardment mass spectroscopy (FAB‐MS), gas chromatography‐mass spectroscopy (GC‐MS), high‐pressure liquid chromatography (HPLC), and infrared (IR), proteolysis and sequencing of amino acid are also explained. In this field of study, it is quite necessary to combine several analytical techniques, and it often takes multiple iterations to purify, isolate, and characterize different surface‐active substances. The numerous approaches that are essential for researching bio‐surfactants are covered in this review.

Long-Wavelength Absorbing Benzimidazolo-Chlorin for Enhanced Photodynamic Therapy.

In this study, we condensed methyl pyropheophorbide-a (2) with 1,2-phenylenediamine to synthesize benzimidazolo-chlorin (3a) as an effective near-infrared photosensitizer (PS) with an absorption maximum of 730 nm. The ability of 3a to generate singlet oxygen, as well as its photodynamic effect on A549 and HeLa cells, was investigated. PS exhibited strong phototoxicity and negligible dark toxicity. Its structure was examined by UV-visible spectroscopy, nuclear magnetic resonance, and high-resolution fast atom bombardment mass spectrometry.

Production of a New Biosurfactant by a New Yeast Species Isolated from Prunus mume Sieb. et Zucc.

Biosurfactants reduce surface and interfacial tension due to their amphiphilic properties and are an eco-friendly alternative for chemical surfactants. In this study, a new yeast strain JAF-11 that produces a biosurfactant was selected using drop collapse method, and the properties of the extracts were investigated. The nucleotide sequences of the strain were compared with closely related strains and identified based on the D1/D2 domain of the large subunit ribosomal DNA (LSU) and internal transcribed spacer (ITS) regions. Neodothiora populina CPC 39399T, the closest species with strain JAF-11, showed a sequence similarity of 97.75% for LSU and 94.27% for ITS, respectively. The result suggests that the strain JAF-11 represents a distinct species that cannot be assigned to any existing genus or species in the family Dothideaceae. Strain JAF-11 produced a biosurfactant reducing the surface tension of water from 72 mN/m to 34.5 mN/m on the sixth day of culture and the result of measuring the critical micelle concentration (CMC) by extracting the crude biosurfactant was found to be 24 mg/l. The molecular weight 502 of the purified biosurfactant was confirmed by measuring the fast atom bombardment mass spectrum. The chemical structure was analyzed by measuring 1H nuclear magnetic resonance (NMR), 13C NMR, and two-dimensional NMRs of the compound. The molecular formula was C26H46O9, and it was composed of one octanoyl group and two hexanoyl groups to myo-inositol moiety. The new biosurfactant is the first report of a compound produced by a new yeast strain, JAF-11.

Decay time extension of terahertz electromagnetic waves emitted from coherent longitudinal optical phonons in GaAs epitaxial layers with the use of fast atom bombardment

We succeeded in extending the decay time of terahertz electromagnetic waves from coherent longitudinal optical (LO) phonons in GaAs epitaxial layers with the use of fast atom bombardment, a treatment method for introducing defects and/or disorders at the surface. The decay time becomes long, up to 4.81 ± 0.15 ps, with the bombardment time of 4.0 min. This value is 2.4-times larger than the decay time of 2.04 ± 0.04 ps of the reference sample (untreated sample). We attribute the origin of the present phenomenon to the fact that the reduction of the photogenerated carrier scattering effect on the coherent LO phonon, which is caused by the presence of the surface defects and disorders formed by the fast atom bombardment, results in the extending of the decay time of the terahertz wave from the coherent LO phonon.

A Brief Review on Liquid Chromatography-Mass Spectrometry/LCMS and its Application

Liquid Chromatography- Mass Spectrometry is a powerful analytical technique having high Sensitivity and Specificity. LC-MS combines the separation capabilities of Liquid Chromatography with the mass analysis capabilities of Mass Spectrometry. Liquid Chromatography separates the mixture, which is having multiple components, and then Mass Spectrometry provides the Spectral information which is used to identify each separated component. Interfaces are used in LC-MS system to transfer the maximum amount of analyte, remove a significant portion of the mobile phase, and preserves the chemical identity. Different types of Interfaces are used which include Atmospheric-Pressure Ionization, Electrospray Ionization, Atmospheric Pressure Chemical Ionization, Thermospray and Plasma Spray Ionization, Particle Beam Ionization, Continuous Flow Fast Atom Bombardment. LC-MS having a wide range of application in various field which include Pharmaceutical, Drug Development, Forensic Science, Cosmetic, Petrochemistry, Environment, Food Analysis, Biochemical Application. In this article Principle, Instrument and Application are discussed briefly.

Stereocalpin B, a New Cyclic Depsipeptide from the Antarctic Lichen Ramalina terebrata.

Stereocalpin B, a new cyclic depsipeptide (1), and a new dibenzofuran derivative (3), were isolated from the Antarctic lichen, Ramalina terebrata (Ramalinaceae), along with a known cyclic depsipeptide (2). The structures of new compounds were characterized by comprehensive spectrometric analyses; high-resolution fast atom bombardment mass spectrometry (HR-FABMS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Stereocalpin B (1) existed in a rotameric equilibrium, which was confirmed using nuclear Overhauser effect spectroscopy (NOESY)/exchange spectroscopy (EXSY) spectrum. Absolute configurations of the amino acid units in 1 were assigned using the advanced Marfey’s method and subsequent NOESY analysis of the 5-hydroxy-2,4-dimethyl-3-oxo-decanoic acid residue confirmed the complete stereochemistry of 1. Compounds 1-3 exhibited moderate antimicrobial activities against E. coli, with the IC50 values ranging from 18–30 μg/mL. Compound 2 exhibited cell growth inhibition against HCT116 cell lines, with the IC50 value of 20 ± 1.20 μM, and compounds 1 and 2 also showed potent anti-inflammatory activities against lipopolysaccharide (LPS)-induced RAW264.7 macrophages with the IC50 values ranging from 5–7 μM.

In vitro anticancer and antibacterial potentials of selected medicinal plants and isolation and characterization of a natural compound from Withania coagulans.

In the current study, five different plants, Syzygium Cumini, Fagonia cretica, Acacia modesta, Withania coagulans, and Olea europaea aqueous extracts were prepared and applied against the anticancer and antibacterial activities. It was observed that O.Europaea extract shows the highest anticancer activity with cell viability of 21.5%. All the five plants extract was also used against the inhibition of Bacillus subtilis where O.Europaea extract shows a promising inhibitory activity of 3.2cm followed by W.coagulans. Furthermore, W.coagulans was subjected to the process of column chromatography as a result a withanolide was isolated. The fast atom bombardment mass spectrometry (FAB-MS) and high resolution fast atom bombardment (HRFAB-MS) [M+1] indicated molecular weight at m/z 453 and molecular formula C28H37O5. The UV-Vis. spectrum shows absorbance at 210nm suggesting the presence of conjugated system, and Fourier-transform infrared spectroscopy (FTIR) was recorded to explore the functional groups. Similarly, 1D and 2D NMR spectroscopy techniques such as 1H, 13C NMR, correlation spectroscopy (COSY-45°), heteronuclear single quantum correlation (HSQC), heteronuclear multiple bond correlation (HMBC) and Nuclear Overhauser effect Spectroscopy (NOESY) techniques was carried out to determine the unknown natural product. The collective data of all these techniques established the structure of the unknown compound and recognized as a withanolide.

Research progress of tannins in traditional Chinese medicines in recent ten years

In this paper, the newly isolated tannins were sorted after a review of the literature concerning tannins in recent 10 years, and their research progress was summarized in terms of extraction, isolation, pharmacological activity and metabolism. Hydrolysable tannins and condensed tannins are the main structural types. Modern research shows that tannins have many pharmacological effects, such as bacteriostasis, antioxidation, antitumor, antivirus and blood glucose reduction, and have broad development prospects. They are usually extracted by water, ethanol and acetone and isolated and purified by macroporous resin and gel column chromatography. The packings commonly adopted for the column chromatography mainly included Sephadex LH-20, Diaion HP-20, MCI-gel CHP-20 and Toyopearl HW-40. Modern analytical techniques such as nuclear magnetic resonance spectroscopy(NMR), fast atom bombardment mass spectrometry(FAB-MS) and circular dichroism(CD) are generally used for the structural identification of tannins. Howe-ver, their isolation, purification and structural identification are still challenging. It is necessary to use a variety of high-throughput screening methods to explore their pharmacological activities and to explore the material basis responsible for their functions through experiments in vivo.

Hemilability in neutral RuCl2(η1−P∩O)2(N∩N) complexes: Physicochemical, trans/cis-isomerization, thermal and A DFT/TD-DFT

Hemilabile neutral Ru(II) complexes of type trans-RuCl2(η1P∩O)2N∩N, (P∩O = Ph2PCH2CH-(OCH3)2,N∩N = 1,3-diaminopropane (1) and 1,2-diaminopropane (2) were made available in high yield. The hemilabile phenomena in P∩O ligand formed RuCl2(η2P∩O)2, the trans to cis isomerization and Halochromism reactions were monitored individually via liquid 31P{1H} NMR. The desired new complexes were identified by UV–Vis, CV, CHN-elemental analysis, fast atom bombardment mass spectrometry (FAB-MS), 1H-, 31P-{1H}, 13C{1H}-NMR and TG/DTA. Moreover, complex 1 was subjected to DFT-optimization, HOMO/LUMO, density of state (DOS), and molecular electrostatic potential (MEP) computations. The experimental thermal behavior was also determined by TG/DTA in an open atmosphere. The time-dependent density functional theory (TD-DFT) was matched successfully to the Absorption behavior of complex 1 in CH2Cl2.

Purpurogallin의 감마선 조사에 따라 생성되는 항산화 물질

Gamma irradiation is a promising technique for improving the quality, safety, and shelf-life of foods. However, research on radiation-induced systemic degradation related to changes in the chemical structure and biological activity is still limited. In this study, radiolytic degradation and antioxidant activity enhancement of purpurogallin were studied in response to varying dose of gamma irradiation. Pure purpurogallin in methanol was exposed to gamma rays from 10 to 100 kGy. Purpurogallin reaction mixture was completely degraded when irradiated with 50 kGy and showed an increased antioxidation activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+). It also exhibited hydroxyl radical scavenging ability. The structure of the newly-formed simple phenolic compound, pyrogallol (2) from gamma irradiated purpurogallin at 50 kGy was characterized using 1H, 13C, heteronuclear singles quantum coherence (HSQC), and heteronuclear multiple bond correlation (HMBC) NMR, and fast atom bombardment mass (FABMS) spectroscopy. Compared to the parent purpurogallin, the small phenolic molecule (2) exhibited significantly enhanced antioxidant activity against DPPH, ABTS+, and hydroxyl radical scavenging activities with SC50 values of 9.5±0.3, 12.6±0.4, and 48.1±0.9 μM, respectively. These results indicate that degradation of purpurogallin induced by gamma irradiation might enhance its antioxidant property.

Inhibition of jack bean urease by amphiphilic peptides

In the current study, amphiphilic peptides were designed and screened against Jack bean urease by using computer aided drug discovery approach. The result showed that out of thirty-eight amphiphilic peptides 1, 3, 12, 18, 30, and 33 exhibit stronger binding affinity with the active site of the enzyme through chelation of charged amino acids with the nickel ions i.e., Ni+2 841 and Ni+2 842 as well as hydrophobic contacts of the nonpolar tail with the nonpolar residues in the active site. The selected amphiphilic peptides were synthesized by solid-phase peptide synthesis strategy, characterized by fast atomic bombardment mass spectroscopy (FAB-MS) and nuclear magnetic resonance spectroscopy (1H and 13C-NMR) and in vitro urease inhibitory activity of amphiphilic peptides was studied. Amphiphilic peptides 12 and 33 showed excellent urease inhibitory activity, (p < 0.001) with IC50 values 20.5 ± 0.01, and 28.1 ± 0.03 µM respectively, which was considerably better than thiourea used as positive control.

Successful treatment of infantile oxysterol 7\u03b1-hydroxylase deficiency with oral chenodeoxycholic acid

BackgroundDeficiency of oxysterol 7α-hydroxylase, encoded by CYP7B1, is associated with fatal infantile progressive intrahepatic cholestasis and hereditary spastic paraplegia type 5. Most reported patients with CYP7B1 mutations presenting with liver disease in infancy have died of liver failure. However, it was recently reported that two patients treated with chenodeoxycholic acid survived. Correlations between the phenotype and genotype of CYP7B1 deficiency have not been clearly established.Case presentationA 5-month-7-day-old Chinese baby from non-consanguineous parents was referred for progressive cholestasis and prolonged prothrombin time from one month of age. Genetic testing revealed compound heterozygous mutations c.187C > T(p.R63X)/c.334C > T(p.R112X) in CYP7B1, and fast atom bombardment mass spectrometry analysis of the urinary bile acid confirmed the presence of atypical hepatotoxic 3β-hydroxy-Δ5-bile acids. While awaiting liver transplantation she was orally administered chenodeoxycholic acid. Her liver function rapidly improved, urine atypical bile acids normalized, and she thrived well until the last follow-up at 23 months of age. Her 15-year-old brother, with no history of infantile cholestasis but harboring the same mutations in CYP7B1, had gait abnormality from 13 years of age. Neurological examination revealed hyper-reflexia and spasticity of the lower limbs. Brain MRI revealed enlarged perivascular space in the bilateral basal ganglia and white matter of frontal parietal.ConclusionsIn summary, these findings highlight that the phenotype of CYP7B1 deficiency varies widely, even in siblings and that early administration of chenodeoxycholic acid may improve prognosis.

Guaianolide Sesquiterpene Lactones from Centaurothamnus maximus.

Centaurothamnus maximus (family Asteraceae), is a leafy shrub indigenous to the southwestern Arabian Peninsula. With a paucity of phytochemical data on this species, we set out to chemically characterize the plant. From the aerial parts, two newly identified guaianolides were isolated: 3β-hydroxy-4α(acetoxy)-4β(hydroxymethyl)-8α-(4-hydroxy methacrylate)-1αH,5αH, 6αH-gual-10(14),11(13)-dien-6,12-olide (1) and 15-descarboxy picrolide A (2). Seven previously reported compounds were also isolated: 3β, 4α, 8α-trihydroxy-4-(hydroxymethyl)-lαH, 5αH, 6βH, 7αH-guai-10(14),11(13)-dien-6,12-olide (3), chlorohyssopifolin B (4), cynaropikrin (5), hydroxyjanerin (6), chlorojanerin (7), isorhamnetin (8), and quercetagetin-3,6-dimethyl ether-4’-O-β-d-pyranoglucoside (9). Chemical structures were elucidated using spectroscopic techniques, including High Resolution Fast Atom Bombardment Mass Spectrometry (HR-FAB-MS), 1D NMR; 1H, 13C NMR, Distortionless Enhancement by Polarization Transfer (DEPT), and 2D NMR (1H-1H COSY, HMQC, HMBC) analyses. In addition, a biosynthetic pathway for compounds 1–9 is proposed. The chemotaxonomic significance of the reported sesquiterpenoids and flavonoids considering reports from other Centaurea species is examined.

Масс-спектрометрия как современный метод анализа полимеров

Работа посвящена изучению места современных масс-спектрометрических методов в области исследования полимеров. Исследованы вопросы развития методов и показано, что практически до конца ХХ века масс-спектрометрия применялась для изучения полимеров крайне ограниченно из-за нелетучести полимеров. Рассмотрен метод пиролитической масс-спектрометрии как наиболее распространённый для определения молекулярно-массового распределения, определения концевых групп и других общих задач. Также описаны более современные методы “мягкой” ионизации, позволяющие ионизировать полимеры из конденсированного состояния с одновременной десорбцией в газовую фазу. Обзор литературы показал, что подобные методы практически полностью вытеснили или значительно дополнили инструментарий исследователя полимерных материалов. В работе со ссылками на литературу описаны матрично-активированная лазерная десорбция/ионизация (MALDI), полевая десорбция (FD), бомбардировка быстрыми атомами (SIMS), ионизация электораспылением (ESI). Также в качестве более классического метода описана пиролитическая масс-спектрометрия с прямым вводом и в сочетании с газохроматографическим разделением. Показано, что масс-спектрометрия наиболее универсальный и чувствительный метод при любых задачах в области анализа и исследования полимерных материалов.

Lavencidin, a polyene macrolide antibiotic from Streptomyces lavendulae FRI-5.

In our screening program for new biologically active compounds, a new polyene macrolide, lavencidin (1), along with known compound RKGS-A2215A (2), was isolated from the fermentation broth of Streptomyces lavendulae FRI-5 by changing the composition of liquid medium normally used for the strain. Their structures were elucidated by spectral methods (high-resolution fast-atom bombardment mass spectrometry (HRFABMS) and nuclear magnetic resonance (NMR)). Compound 1 includes a conjugated pentaene moiety together with six hydroxy groups and a carboxylic acid as a side chain. Lavencidin (1) showed moderate growth-inhibitory activity against yeast and was cytotoxic against human cancer cell lines with low-micromolar IC50 values.