Mass spectrometric analysis of Odonthobuthus Doriae scorpion venom and its non-neutralized fractions after interaction with commercial antivenom.

It is believed that antivenoms play a crucial role in neutralizing venoms. However, uncontrolled clinical effects appear in patients stung by scorpions after the injection of antivenom. In this research, non-neutralized components of the venom of the Iranian scorpion Odonthobuthus doriae were analyzed after interacting with the commercial antivenom available in the market. The venom and antivenom interaction was performed, then centrifuged, and the supernatant was analyzed by high-performance liquid chromatography (HPLC). Two peaks of Odonthobuthus doriae venom were observed in the chromatogram of the supernatant. Two components were isolated by HPLC and analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) instruments. Peptide sequencing was done by Liquid Chromatography Quadrupole Time-of-Flight Tandem Mass Spectrometry (LC-Q-TOF MS/MS). Results indicate that the components of scorpion venom mainly have a molecular weight below 10 kDa, consisting of toxic peptides that disrupt the function of sodium and potassium channels. The MALDI-TOF MS results show that two toxic peptides with molecular masses of 6941 Da and 6396 Da were not neutralized by the antivenom. According to the MS/MS sequencing data, the components have been related to peptides A0A5P8U2Q6_MESEU and A0A0U4FP89_ODODO, which belong to the sodium and potassium channels toxins family, respectively.

Nanoencapsulated Thymus daenensis and Mentha piperita essential oil for bacterial and biofilm eradication using microfluidic technology.

The use of essential oil (EO) nanoemulsions is expanding to meet customer demand for all-natural antibacterial agents. Thymus daenensis (T) and Mentha piperita (M) EOs were employed to make nanoemulsions (TEO and MEO NE), using Tween 80/Span 80 as surfactant/cosurfactant and a high-speed homogenizer. The TEO and MEO NEs were then characterized in terms of particle size (121, 113 nm), surface charge (-11.2 and -12.6 mV), morphology, and stability over time. Then, the antibacterial activity of EOs and their nanoformulations against Escherichia coli (E. coli) were evaluated based on various residence times, and concentrations on a microfluidic chip. The release of cytoplasmic constituents was used to compare the antibacterial activity of bulk EOs and nanoformulations. After completing MIC, MBC, and time-killing assays, the inhibitory effect of nanoformulations on E. coli biofilm formation was examined. Remarkable intensification was observed by employing a microfluidic chip owing to high-contact surface area provision between nanoemulsions and bacteria. Once compared to the conventional method for 3 h operation, the bacterial activity was nearly completely inhibited in a 24-min residence time using nanoemulsions. After 6 min of treatment, the cell membrane began to rupture, indicating that nanoemulsions could improve the antibacterial activity of bulk essential oils.

Non-thermal plasma radiation-induced changes in antibiotic susceptibility and protein profile of Staphylococcus aureus.

Background and Objectives: Plasma radiation is a widely used technique for sterilization or decontamination in various industries, as well as in some healthcare settings such as dentistry. The primary aim of this study was to assess the potential of plasma radiation to create a new population of Staphylococcus aureus cells with distinct characteristics that could lead to novel healthcare challenges. Materials and Methods: A homemade non-thermal plasma apparatus was applied and the effects of plasma treatment on S. aureus ATCC25923 was assessed. Plasma radiation was applied under controlled conditions to ensure that some bacterial cells remained viable. The treatment was repeated 10 times, with each round followed by a recovery phase to collect any surviving bacterial cells. To assess the potential changes in the bacterial population, we examined the antibiotic susceptibility pattern, micro-structural characteristics using scanning electron microscopy (SEM), and total protein profile using the matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) technique. Results: The experimental results revealed slight variations in the antibiotic susceptibility patterns of certain cell wall agents (imipenem, cephalothin, and cefepime), as well as in the MALDI-TOF spectra. However, no changes were observed in the SEM images. Conclusion: The insufficient application of non-thermal plasma in bacterial decontamination may lead to physiological changes that could enrich or select certain subpopulations of S. aureus.

Determination of the epitopic peptides of fig mosaic virus and the single-chain variable fragment antibody by mass spectrometry.

The study of antibody-antigen interactions, through epitope mapping, enhances our understanding of antibody neutralization and antigenic determinant recognition. Epitope mapping, employing monoclonal antibodies and mass spectrometry, has emerged as a rapid and precise method to investigate viral antigenic determinants. In this report, we propose an approach to improve the accuracy of epitopic peptide interaction rate recognition. To achieve this, we investigated the interaction between the nucleocapsid protein of fig mosaic virus (FMV-NP) and single-chain variable fragment antibodies (scFv-Ab). These scFv-Ab maintain high specificity similar to whole monoclonal antibodies, but they are smaller in size. We coupled this with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The experimental design involved using two different enzymes to digest FMV-NP separately. The resulting peptides were then incubated separately with the desired scFv-Ab at different incubation times and antibody concentrations. This allowed us to monitor the relative rate of epitopic peptide interaction with the antibody. The results demonstrated that, at a 1:1 ratio and after 2 h of interaction, the residues 122-136, 148-157, and 265-276 exhibited high-rate epitopic peptide binding, with reductions in peak intensity of 78%, 21%, and 22%, respectively. Conversely, the residues 250-264 showed low-rate binding, with a 15% reduction in peak intensity. This epitope mapping approach, utilizing scFv-Ab, two different enzymes, and various incubation times, offers a precise and dependable analysis for monitoring and recognizing the binding kinetics of antigenic determinants. Furthermore, this method can be applied to study any kind of antigens.

Detection of structural and conformational changes in ALS-causing mutant profilin-1 with hydrogen/deuterium exchange mass spectrometry and bioinformatics techniques.

The hydrogen/deuterium exchange (HDX) is a reliable method to survey the dynamic behavior of proteins and epitope mapping. Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) is a quantifying tool to assay for HDX in the protein of interest. We combined HDX-MALDI-TOF MS and molecular docking/MD simulation to identify accessible amino acids and analyze their contribution into the structural changes of profilin-1 (PFN-1). The molecular docking/MD simulations are computational tools for enabling the analysis of the type of amino acids that may be involved via HDX identified under the lowest binding energy condition. Glycine to valine amino acid (G117V) substitution mutation is linked to amyotrophic lateral sclerosis (ALS). This mutation is found to be in the actin-binding site of PFN-1 and prevents the dimerization/polymerization of actin and invokes a pathologic toxicity that leads to ALS. In this study, we sought to understand the PFN-1 protein dynamic behavior using purified wild type and mutant PFN-1 proteins. The data obtained from HDX-MALDI-TOF MS for PFN-1WT and PFN-1G117V at various time intervals, from seconds to hours, revealed multiple peaks corresponding to molecular weights from monomers to multimers. PFN-1/Benzaldehyde complexes identified 20 accessible amino acids to HDX that participate in the docking simulation in the surface of WT and mutant PFN-1. Consistent results from HDX-MALDI-TOF MS and docking simulation predict candidate amino acid(s) involved in the dimerization/polymerization of PFNG117V. This information may shed critical light on the structural and conformational changes with details of amino acid epitopes for mutant PFN-1s' dimerization, oligomerization, and aggregation.

Synthesis and Decarboxylation of Functionalized 2-Pyridone-3-carboxylic Acids and Evaluation of their Antimicrobial Activity and Molecular Docking.

The functionalized 2-pyridone-3-carboxylic acids were synthesized starting from 3-formylchromone. Meanwhile, a decarboxylation reaction of 2-pyridone-3-carboxylic acid was performed by potassium carbonate in toluene. All compounds were evaluated against two Gram-negative bacteria (Escherichia coli (E. coli), Acinetobacter baumannii (A. baumannii)) and two Gram-positive (Staphylococcus aureus (S. aureus)) and fungus (Candida albicans (C. albicans)) using serial broth dilution method. The antimicrobial screening revealed that S. aureus is the highest sensitive microorganism towards the synthesized compounds. Among all analogs, derivatives, 4p and 5c showed excellent activities in comparison with the other compounds against S. aureus. Molecular docking showed that the most active anti S. aureus are compounds 4p and 5c exhibiting primary interaction as with fluoroquinolones by cross-linking over DNA gyrase active site via metal ion bridge and H-bonding interaction with Ser84 and Glu88 from GyrA subunit along with Arg458 and Asp437 located at GyrB subunit. In addition, based on the molecular dynamic simulation as like the standard fluoroquinolones, the mentioned compounds were stabilized for significant amount of simulation time over DNA gyrase which potentiate the importance of the mentioned residues in the DNA gate region of DNA gyrase.

Mutant Profilin1 Aggregation in Amyotrophic Lateral Sclerosis: An in Vivo Biochemical Analysis.

INTRODUCTION: Profilin1 (PFN1) is a ubiquitously expressed protein known for its function as a regulator of actin polymerization and dynamics. A recent discovery linked mutant PFN1 to Amyotrophic Lateral Sclerosis (ALS), which is a fatal and progressive motor neuron disease. We have also demonstrated that Gly118Val mutation in PFN1 is a cause of ALS, and the formation of aggregates containing mutant PFN1 may be a mechanism for motor neuron death. Hence, we were interested in investigating the aggregation of PFN1 further and searching for co-aggregated proteins in our mouse model overexpressing mutant PFN1. METHODS: We investigated protein aggregation in several tissues of transgenic and notransgenic mice using western blotting. To further understand the neurotoxicity of mutant PFN1, we conducted a pull-down assay using an insoluble fraction of spinal cord lysates from hPFN1G118V transgenic mice. For this assay, we expressed His6-tagged PFN1WT and PFN1G118V in E. coli and purified these proteins using the Ni-NTA column. RESULTS: In this study, we demonstrated that mutant PFN1 forms aggregate in the brain and spinal cord of hPFN1G118V mice, while WT-PFN1 remains soluble. Among these tissues, spinal cord lysates were found to have PFN1 bands at higher molecular weights recognized with anti-PFN1. Moreover, the pull-down assay using His6-PFN1G118V showed that Myelin Binding Protein (MBP) was present in the insoluble fraction. CONCLUSION: Our analysis of PFN1 aggregation in vivo revealed further details of mutant PFN1 aggregation and its possible complex formation with other proteins, providing new insights into the ALS mechanism.

Chemical composition of essential oils from the underground parts of Glycyrrhiza echinata L. accessions growing wild in Northern Iran.

Glycyrrhiza echinata L. is a perennial plant of considerable commercial importance in medicine, pharmaceuticals, cosmetics, and tobacco industries and the production of food additives as flavoring and sweetening agent. This study, variation on composition and yield of essential oil from the underground parts of five accessions of G. echinata growing wild in northern Iran was investigated. Results showed high variability for the main constituents of essential oil among accessions of G. echinata. The presence of α-pinene and myrcene in two accessions suggests that these volatiles could serve as chemotaxonomic markers and also might be considered as potentially relevant for taste. The presence of ß-caryophyllene and α- caryophyllene in three accessions could be strong potential for being used in medical applications (anticancer and analgesic properties). Generally, the essential oils from G. echinata and other species could be very competitive targets for phytochemical and food studies.

Characterization and Antibacterial Activity of Phthalides from the Roots of the Medicinal Herb Levisticum officinale W.D.J. Koch.

A new phthalide, namely 7-methoxy-3-propylidenephthalide (1), along with two known compounds (2, 3) were isolated from the roots of the edible herb Levisticum officinale W.D.J. Koch, commonly known as lovage and well known in traditional medicine for its spasmolytic and diuretic effects. The structure of the new compound was established by HRMS and 1D & 2D NMR (1H 1H COSY, HMQC, and HMBC) spectroscopic analysis. All compounds are reported for the first time from L. officinale. Compounds 1-3 were tested against two Gram negative (Escherichia coli, Pseudomonas aeruginosa) and two Gram positive (Staphylococcus aureus and vancomycin-resistant Enterococcus [VRE] faecium) bacteria strains. Compound 3 was active against S. aureus, E. coli and vancomycin-resistant E. faecium with MIC values of 16, 64, and 128 µg/mL, respectively.

Conjugation of Single-Chain Variable Fragment Antibody to Magnetic Nanoparticles and Screening of Fig Mosaic Virus by MALDI TOF Mass Spectrometry.

The ability of mass spectrometry for discrimination between protein and peptide masses which are unique to specific pathogens provides an accurate and fast method for the detection of different types of pathogens, especially viruses. Capsid proteins are specific to each virus and can be used as a biomarker for detection of this pathogen. On the other hand, single-chain variable fragment (scFv) antibodies have been recently used to enhance the accuracy of immunoassay techniques. So conjugation of mass spectrometry and scFv antibody provides a very accurate and fast method for the detection of viruses. In this report, for the first time, we have immobilized scFv antibody of fig mosaic virus (FMV) on the magnetic nanoparticles (MNPs) to extract the virus capsid protein from complex biological media and subsequently identified this protein through both its intact molecular mass and peptide mass fingerprint (PMF) by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS).

Comparison study of root canal disinfection by cold plasma jet and photodynamic therapy.

INTRODUCTION: This study evaluated and compared the antibacterial effect of plasma and photodynamic therapy (PDT) in root canals infected with Enterococcus faecalis. METHODS: One hundred single-rooted extracted human teeth (no treatment) were selected and sterilized. Root canals of teeth were prepared with the crown-down technique and contaminated with Enterococcus faecalis after sterilization, and incubated for one week. To investigate the effect of disinfection, 60 specimens were randomly selected for three disinfection groups: He and He/O2 plasma (n = 20) in 5-s groups (control, 2, 4, 6 and 8 min treatments) and PDT (n = 20) in 2-s groups (control and PDT treatment). Next, for comparison, 40 remaining teeth were divided into four groups: control, 8 min He plasma, 8 min He/O2, and PDT. Results of antibacterial action were reported by CFU/mL analysis and the structural changes of biofilm were evaluated by SEM. RESULTS: All groups showed a significant reduction of bacteria after treatment, and He/O2 plasma was more effective against E. faecalis, followed by PDT and He plasma respectively, further confirmed by SEM. CONCLUSION: He/O2 plasma is a strong sterilization method against E. faecalis biofilm and can, therefore, be an effective therapy in endodontics.

Changes in biophysical characteristics of PFN1 due to mutation causing amyotrophic lateral sclerosis.

Single amino acid mutations in profilin 1 (PFN1) have been found to cause amyotrophic lateral sclerosis (ALS). Recently, we developed a mouse model for ALS using a PFN1 mutation (glycine 118 to valine, G118V), and we are now interested in understanding how PFN1 becomes toxically lethal with only one amino acid substitution. Therefore, we studied mutation-related changes in the PFN1 protein and hypothesized that such changes significantly disturb its structure. Initially, we expressed and studied the purified PFN1WT and PFN1G118V proteins from bacterial culture. We found that the PFN1G118V protein has a different mean residue ellipticity, as measured by far-UV circular dichroism, accompanied by a spectral shift. The intrinsic fluorescence of PFN1G118V showed a small fluctuation in maximum fluorescence absorption and intensity. Moreover, we examined the time course of PFN1 aggregation using SDS-PAGE, western blotting, and MALDI-TOF/TOF and found that compared with PFN1WT, PFN1G118V had an increased tendency to form aggregates. Dynamic light scattering data confirmed this, showing a larger size distribution for PFN1G118V. Our data explain why PFN1G118V tends to aggregate, a phenotype that may be the basis for its neurotoxicity.

Tracking leading anti-Candida compounds in plant samples; Plumbago europaea.

BACKGROUND AND OBJECTIVES: Due to the importance of finding new and more effective antifungal and antibacterial compounds against invasive vaginitis strains, this study was conducted for fast screening of plant samples. MATERIALS AND METHODS: Thirty Iranian plant samples were successively extracted by n-hexane, ethyl acetate and methanol to obtain a total of 90 extracts. Each extract was prepared in six concentrations and evaluated for antifungal activity via a micro-broth dilution method. Further phytochemical study of the aerial parts of Plumbago europaea, as the most promising source of anti-Candida compounds (with minimum inhibitory concentration of about 7µg/ml), was carried out and antifungal activity in the ethyl acetate extract was tracked using a combination of HPLC time-based fractionation and Thin Layer Chromatography-Bioautography via a bioassay-guided fractionation procedure. The compounds in the active region of the chromatogram were purified by a combination of column chromatography and preparative TLC, and then structure elucidation was achieved by 1D and 2D NMR, mass spectrometry and UV spectra. RESULTS: Seven compounds were isolated and identified: (1) plumbagin, (2) isoplumbagin, (3) 5, 8-dihydroxy-2-methyl-[1, 4] naphthoquinone, (4) droserone, (5) 7-methyljuglone, (6) Isozeylanone, and (7) methylene-3, 3'-diplumbagin. Antimicrobial activity of the purified compounds were also evaluated against C. albicans (MIC values ranging from 2 to 2500 µM) and Gardnerella vaginalis (MIC values ranging from 20 to 2500 µM). CONCLUSION: These naphthoquinone compounds could be surveyed for finding new and more effective anti-vaginitis agents via drug design approaches.

Resistant/susceptible classification of respiratory tract pathogenic bacteria based on volatile organic compounds profiling.

Resistance to antibiotics is an emerging and growing threat. To address this threat, attempts are being made by researchers to identify the Volatile Organic Compounds (VOCs) of bacteria. It is believed that unique combinations could be found among the VOCs produced by each microorganism. The current study aimed to identify and compare the VOCs of antibiotic-resistant and standard strains of Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii and Klebsiella pneumoniae. A polymer of divinylbenzene /carboxen /polydimethylsiloxane was applied for absorption of volatile compounds in headspace bacterial samples in form of a solid phase micro-extraction fiber holder. Gas chromatography-mass spectrometry technique was used for identification of volatile compounds. The analysis of the VOCs indicated that some VOCs appeared only in standard strains while others were common only among resistant strains. Exclusive VOCs to a specific strain were also detected. This study demonstrated that resistant strains of bacteria produced VOCs that were different from those of the standard strains. In addition, VOCs released by bacteria after passing the logarithmic growth phase showed no significant differences. The identification of VOCs can be a precise way to differentiate bacterial species, also it can be said that the VOCs produced by different pathogenic microorganisms can be the suitable biomarkers for their detection.

Synthesis of 4-N-α-coumaryl amino acids and investigation of their antioxidant, antimicrobial activities and fluorescence spectra.

An efficient metal-free approach for the synthesis of N-coumaryl amino acids and the first one-step synthesis of 4-hydrazinocoumarin from 4-hydroxycoumarin was developed. The nucleophilic addition of amino acid methyl esters to 4-tosylcoumarins produced a series of 4-N-α-coumaryl amino acids in good to excellent yields without racemization. The antioxidant activities of the synthesized compounds were investigated using DPPH and FRAP methods. 4-Hydrazinocoumarin and N-coumaryl tyrosine had the best antioxidant activity. The antimicrobial activities of the compounds against Gram-positive was stronger than Gram-negative. 4-Hydrazinocoumarin showed the best antibacterial effect.

Antibacterial hydroxypropyl methyl cellulose edible films containing nanoemulsions of Thymus daenensis essential oil for food packaging.

Edible films containing essential oils (EO) as natural antibacterial agents are promising systems for food preservation. In this work, nanoemulsions of Thymus daenensis EO (wild; F1 and cultivated; F2) were loaded in hydroxyl propyl methyl cellulose (HPMC) films and the effect of different parameters (polymer, plasticizer, and EO concentration) on the film properties were analyzed and optimized. Prepared HPMC films were characterized in terms of EO loading, morphology, mechanical properties, and the antibacterial activity. The results of SEM showed uniform incorporation of nanoemulsions into the edible film. Investigation of the mechanical properties of two edible films revealed a plasticizing effect of T. daenensis EO on the films. Also, edible films had noticeable antimicrobial activity against selected microorganisms, i.e. 47.0±2.5mm and 22.6±0.5mm zone of inhibition against S. aureus for films containing F1 and F2, respectively. Incorporation of nanoemulsions into the HPMC films can be used for active food preservation.

Medicinal plants and their isolated compounds showing anti-Trichomonas vaginalis- activity.

Trichomonas vaginalis is a major of non-viral sexually-transmitted infection and an important cause of serious obstetrical and gynecological complications. Treatment options for trichomoniasis are limited to nitroimidazole compounds. The increasing resistance and allergic reactions to nitroimidazole and recurrent trichomoniasis make it essential to identify and develop new drugs against trichomoniasis. Medicinal plants are an important source for discovery of new medications. This review discusses the anti-trichomonas effects of medicinal plants and their chemical constituents to find better options against this pathogenic protozoon. Electronic databases were searched to collect all data from the year 2000 through September 2015 for in vitro, in vivo and clinical studies on the effect of medicinal plants on T. vaginalis. A total of 95 in vitro and clinical studies were identified. Only four human studies were found in this review. The Asteracea, Lamiaceae and Myrtaceae families contained the greatest number of plants with anti-trichomonas activity. Persea americana, Ocimum basilicum and Verbascum thapsus were the most efficacious against T. vaginalis. Plant metabolites containing alkaloids, isoflavonoid glucosides, essential oils, lipids, saponins and sesquiterpene lactones were found to possess anti-trichomonas properties. Assessing the structure-activity of highly-potent anti-trichomonas phytochemicals is suggested for finding natural, semisynthetic and synthetic anti-trichomonas compounds. Further clinical studies are necessary for confirmation of natural anti-trichomonas substances and completion of their safety profiles.

Ultrasonic nanoemulsification of food grade trans-cinnamaldehyde: 1,8-Cineol and investigation of the mechanism of antibacterial activity.

Using ultrasonic technology, trans-cinnamaldehyde as a natural antibacterial compound was used to prepare nano size emulsions to increase its bioavailability and therefore bactericidal action. Nanoemulsions containing trans-cinnamaldehyde as an active agent and 1,8 cineol as co additive oil (Ostwald ripening inhibitor) were formulated using probe sonicator. Three different determining factors, namely time of sonication, surfactant to oil ratio and type of emulsifier (Tween 80 and Tween 20) were investigated to enhance the stability profile. In addition, the effect of changes in the particle size and emulsifier on the antibacterial activity against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus were examined using agar dilution method. Then, the effect of optimized formulation on the membrane fluidity and cell constituent release, were investigated by analysis of membrane lipids using GC-MS and IR spectrometry, respectively. The data showed that a 15min sonication of the formulation containing Tween 80 as emulsifier with surfactant to oil ratio of 2:1 (w/w) resulted in a significant stability for 6months with considerably small particle size of 27.76±0.37nm. Furthermore, the nanoemulsion showed great antibacterial activity and could reduce the minimum inhibitory concentration (MIC) from 8 to 1mg/mL against E. coli and S. aureus, and from 16 to 2mg/mL against P. aeruginosa. Interestingly, E. coli's membrane fluidity increased dramatically after treatment with the optimum nanoemulsion (T804). This study revealed that nanoemulsion of trans-cinnamaldehyde and 1,8 cineol has substantial antibacterial activity against selected microorganisms.

Synthesis and in Vitro Antibacterial Evaluation of Novel 4-Substituted 1-Menthyl-1,2,3-triazoles.

Menthyl 1,4-disubstituted 1,2,3-triazole derivatives of hydroxybenzaldehydes, phenols and bile acids were synthesized via click chemistry. The novel synthesized compounds were evaluated for their in vitro antibacterial activity against Enterococcus faecium, and Staphylococcus aureus as Gram-positive bacteria. Some derivatives illustrated strong inhibitory effect against E. faecium with the minimum inhibitory concentration (MIC) values ranged from 1-3 µM, where cefixime as a positive control revealed MIC value of 35 µM. The structures of the synthesized compounds were confirmed by different spectroscopic techniques including 1H-NMR, 13C-NMR, high resolution (HR)-MS, IR and X-ray crystallographic analysis.

Labdane Diterpenoids from Salvia leriifolia: Absolute Configuration, Antimicrobial and Cytotoxic Activities.

Fractionation of an n-hexane extract of the aerial parts of Salvia leriifolia led to the isolation of two new (1, 2) and two known (3, 4) labdane diterpenoids, together with three other known compounds. The structures were established by a combination of 1D and 2D NMR, and HRESIMS. The structures of 1 and 3 were confirmed by single-crystal X-ray analysis. The absolute configuration of 1-4 was established by electronic circular dichroism spectroscopy. Compounds 1-4 were evaluated for their cytotoxic activities against MCF-7 human breast cancer cells. Labdanes 3 and 4 were additionally tested against MDA-MB231 human breast cancer and DU-145 human prostate cancer cell lines. Compound 4 showed IC50 values of 25, 50, and 50 µM against MCF-7, MDA-MB231, and DU-145 cells, respectively. Compounds 1-4 were tested for activity against gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria. Compound 3 showed an MIC of 213 µM against methicillin-resistant S. aureus.