Organism-derived phthalate derivatives as bioactive natural products

Multi-omics analysis of the correlation between surface microbiome and metabolome in Saccharina latissima (Laminariales, Phaeophyceae)

The microbiome of Saccharina latissima, an important brown macroalgal species in Europe, significantly influences its health, fitness, and pathogen resistance. Yet, comprehensive studies on the diversity and function of microbial communities (bacteria, eukaryotes, and fungi) associated with this species are lacking. Using metabarcoding, we investigated the epimicrobiota of S. latissima and correlated microbial diversity with metabolomic patterns (liquid chromatography coupled to tandem mass spectrometry). Specific epibacterial and eukaryotic communities inhabit the S. latissima surface, alongside a core microbiota, while fungal communities show lower and more heterogeneous diversity. Metabolomic analysis revealed a large diversity of mass features, including putatively annotated fatty acids, amino derivatives, amino acids, and naphthofurans. Multiple-factor analysis linked microbial diversity with surface metabolome variations, driven mainly by fungi and bacteria. Two taxa groups were identified: one associated with bacterial consortia and the other with fungal consortia, each correlated with specific metabolites. This study demonstrated a core bacterial and eukaryotic microbiota associated with a core metabolome and highlighted interindividual variations. Annotating the surface metabolome using Natural Products databases suggested numerous metabolites potentially involved in interspecies chemical interactions. Our findings establish a link between microbial community structure and function, identifying two microbial consortia potentially involved in the chemical defense of S. latissima.

Toxicity of bioactive compounds from Halocnemum strobilaceum against A549 lung cancer cells

This study investigates the toxicity of bioactive compounds isolated from the halophytic plant Halocnemum strobilaceum against A549 lung cancer cells. Sequential extraction using petroleum ether, chloroform, and methanol yielded various fractions, with the petroleum ether extract demonstrating the highest cytotoxicity. Through bioassay-guided fractionation and isolation techniques, including vacuum liquid chromatography and column chromatography, three compounds were identified: (1) Di(2-ethylhexyl) phthalate, (2) isorhamnetin-3-glucoside, and (3) quercetin-3-glucoside. The cytotoxic effects of these compounds were assessed using the MTT assay, revealing significant toxicity on A549 cells, with quercetin-3-glucoside exhibiting 78% cytotoxicity and isorhamnetin-3-glucoside showing 69% cytotoxicity at a concentration of 100 μg/mL. These findings suggest that the toxic effects of H. strobilaceum may be attributed to the presence of bioactive compounds, such as flavonoids and polyphenols, known for their antioxidant and free-radical scavenging capabilities. This highlights the potential of H. strobilaceum as a source of novel anti-cancer agents, warranting further studies to elucidate the mechanisms of action and explore therapeutic applications.

Potential mechanisms and modifications of dietary antioxidants on the associations between co-exposure to plastic additives and diabetes

BACKGROUND

The association of plastic additive mixture exposure with diabetes and the modifying effects of dietary antioxidants are unclear.

METHODS

The data from the NHANES 2011-2018 were retrieved, and phthalates and organophosphate esters (OPEs) were selected as exposures. The coexposure effect was analyzed by the environmental risk score (ERS) and quantile g-computation. To mitigate any potential bias caused by using the internal weights, another version of ERS was constructed using the cross-validation approach. The level of dietary antioxidant intake was measured by the composite dietary antioxidant index (CDAI). The biological mechanism underlying the association was studied by the adverse outcome pathway (AOP) framework.

RESULTS

Fifteen chemicals (ten phthalates and five OPEs) were measured in 2824 adult participants. A higher ERS was significantly associated with an increased risk of diabetes (OR per 1-SD increment of ERS: 1.25, 95% CI: 1.13-1.39). This association apparently interacted with the CDAI level (ORlow: 1.83, 95% CI: 1.37-2.55; ORhigh: 1.28, 95% CI: 1.15-1.45; Pinteraction = 0.038). Moreover, quantile g-computation also revealed higher level of combined exposure was positively associated with diabetes (OR: 1.27, 95% CI: 1.05-2.87), and the addition of dietary antioxidants showed a null association (OR: 1.09, 95% CI: 0.85-2.34). The AOP study identified TCPP and TCEP as key chemicals that cause aberrant glucose metabolism and insulin signaling pathways and result in diabetes.

CONCLUSIONS

Coexposure to phthalates and OPEs is positively associated with diabetes, where an antioxidative diet plays a modifying role. Several potential mechanisms have been proposed by AOP framework.

Joint metabolomic and transcriptomic analysis identify unique phenolic acid and flavonoid compounds associated with resistance to fusarium wilt in cucumber (Cucumis sativus L.)

Introduction

Fusarium wilt (FW) caused by Fusarium oxysporum f. sp. cucumerinum (Foc) is a destructive soil-borne disease in cucumber (Cucumis sativus. L). However, there remains limited knowledge on the molecular mechanisms underlying FW resistance-mediated defense responses in cucumber.

Methods

In this study, metabolome and transcriptome profiling were carried out for two FW resistant (NR) and susceptible (NS), near isogenic lines (NILs) before and after Foc inoculation. NILs have shown consistent and stable resistance in multiple resistance tests conducted in the greenhouse and in the laboratory. A widely targeted metabolomic analysis identified differentially accumulated metabolites (DAMs) with significantly greater NR accumulation in response to Foc infection, including many phenolic acid and flavonoid compounds from the flavonoid biosynthesis pathway.

Results

Transcriptome analysis identified differentially expressed genes (DEGs) between the NILs upon Foc inoculation including genes for secondary metabolite biosynthesis and transcription factor genes regulating the flavonoid biosynthesis pathway. Joint analysis of the metabolomic and transcriptomic data identified DAMs and DEGs closely associated with the biosynthesis of phenolic acid and flavonoid DAMs. The association of these compounds with NR-conferred FW resistance was exemplified by in vivo assays. These assays found two phenolic acid compounds, bis (2-ethylhexyl) phthalate and diisooctyl phthalate, as well as the flavonoid compound gallocatechin 3-O-gallate to have significant inhibitory effects on Foc growth. The antifungal effects of these three compounds represent a novel finding.

Discussion

Therefore, phenolic acids and flavonoids play important roles in NR mediated FW resistance breeding in cucumber.

Dibutyl phthalate released by solitary female locusts mediates sexual communication at low density

Sex pheromones play a crucial role in mate location and reproductive success. Insects face challenges in finding mates in low-density environments. The population dynamics of locusts vary greatly, ranging from solitary individuals to high-density swarms, leading to multiple-trait divergence between solitary and gregarious phases. However, differences in sexual communication between solitary and gregarious locusts have not been sufficiently explored. Herein, we found that solitary locusts but not gregarious ones heavily rely on a single compound, dibutyl phthalate (DBP), for sexual communication. DBP is abundantly released by solitary female locusts and elicits strong attraction of male solitary and gregarious locusts. Solitary adult males display much higher electrophysiological responses to DBP than adult females. Additionally, LmigOr13 was identified as the DBP-specific odorant receptor expressed in neurons housed in basiconic sensilla. Male LmigOr13-/- mutants generated by CRISPR/Cas9 have low electrophysiological responses and behavioral attraction to DBP in both laboratory and field cage experiments. Notably, the attractiveness of DBP to male locusts becomes more evident at lower population densities imposed by controlling the cage size. This finding sheds light on the utilization of a sex pheromone to promote reproductive success in extremely low-density conditions and provides important insights into alternative approaches for population monitoring of locusts.

Quantitative identification of the co-exposure effects of e-waste pollutants on human oxidative stress by explainable machine learning

Global electronic waste (e-waste) generation continues to grow. The various pollutants released during precarious e-waste disposal activities can contribute to human oxidative stress. This study encompassed 129 individuals residing near e-waste dismantling sites in China, with elevated urinary concentrations of e-waste-related pollutants including heavy metals, polycyclic aromatic hydrocarbons (PAHs), organophosphorus flame retardants (OPFRs), bisphenols (BPs), and phthalate esters (PAEs). Utilizing an explainable machine learning framework, the study quantified the co-exposure effects of these pollutants, finding that approximately 23% and 18% of the variance in oxidative DNA damage and lipid peroxidation, respectively, was attributable to these substances. Heavy metals emerged as the most critical factor in inducing oxidative stress, followed by PAHs and PAEs for oxidative DNA damage, and BPs, OPFRs, and PAEs for lipid peroxidation. The interactions between different pollutant classes were found to be weak, attributable to their disparate biological pathways. In contrast, the interactions among congeneric pollutants were strong, stemming from their shared pathways and resultant synergistic or additive effects on oxidative stress. An intelligent analysis system for e-waste pollutants was also developed, which enables more efficient processing of large-scale and dynamic datasets in evolving environments. This study offered an enticing peek into the intricacies of co-exposure effect of e-waste pollutants.

Isolation of Two Plasticizers, Bis(2-ethylhexyl) Terephthalate and Bis(2-ethylhexyl) Phthalate, from Capparis spinosa L. Leaves

Many plants have been known to be contaminated and accumulate plasticizers from the environment, including water sources, soil, and atmosphere. Plasticizers are used to confer elasticity and flexibility to various fiber and plastic products. Consumption of plasticizers can lead to many adverse effects on human health, including reproductive and developmental toxicity, endocrine disruption, and cancer. Herein, we report for the first time that two plasticizers, bis(2-ethylhexyl) terephthalate (DEHT) and bis(2-ethylhexyl) phthalate (DEHP), have been isolated from the leaves of Capparis spinosa L. (the caper bush), a plant that is widely used in food seasonings and traditional medicine. 297 mg/kg of DEHT and 48 mg/kg of DEHP were isolated from dried and grounded C. spinosa L. leaves using column chromatography and semi-preparative high-performance liquid chromatography. Our study adds to the increase in the detection of plasticizers in our food and medicinal plants and to the alarming concern about their potential adverse effects on human health.

Gas chromatography - Mass spectrometry (GC-MS) profiling reveals newly described bioactive compounds in Citrullus colocynthis (L.) seeds oil extracts

Citrullus colocynthis (L.) (C. colocynthis), commonly known as Handal in Yemen and other Arabic countries, is a plant with a wide range of pharmacological properties. These properties are attributed to secondary metabolites, known as phytochemicals, present in the plant. In this study, the seed of C. colocynthis were extracted using dichloromethane, and the resulting oil extract was screened to identify active phytoconstituents using gas chromatography - Mass spectrometry (GC-MS). The gas chromatography - Mass spectrometry is used to identification of the phytoconstituents and the spectrum of unknown compounds were compared with the compounds stored in the National Institute of Standards and Technology Mass Spectral database (NIST) and WILEY library of GC-MS. A total of fifty five compounds appeared in GC-MS chromatogram, twenty-four major bioactive compounds were identified in the present study. The major components of the oil extract were found to be carotenes, phenols, esters, and steroids. From the GC-MS chromatogram of dichloromethane seeds oil extract, some of the identified components possess pharmacological actions as per information available in the literature. One of the major component identified in the C. colocynthis seed oil extract was isooctylphthalate (58%), which exhibit strong antimicrobials effect. Therefore, C. colocynthis is considered to be a natural source of isooctylphthalate. From the results, this study is the first to report the presence of various bioactive components of phytopharmaceutical importance in C. colocynthis.

Antimicrobial and Cytotoxic Potential of Helminthosporin from Rumex abyssiniscus Jacq. Discovered as a Novel Source of Syringic Acid and Bis(2-ethyloctyl) Phthalate

Rumex abyssinicus Jacq. is a perennial medicinal herb widely used in traditional medicine to treat many diseases. Phytochemicals of the plant were isolated using column chromatography and thin layer chromatography techniques. Extract, fractions and pure compounds were screened for antimicrobial activity against sensitive and multi-drug resistant microbes and their cytotoxicity was performed on different cancer cell lines. The mechanism of action of purified helminthosporin as well as the potent fraction containing a mixture of two compounds was assessed. Fraction R7C3 was the most potent antibacterial with the lowest MIC value of 0.12 µg/mL. Helminthosporin was the most potent compound with the lowest MIC value of 1.95 µg/mL. The compound was more potent than the antibiotic chloramphenicol against multi-drug resistant (MDR) bacteria with MIC equal to 16 µg/mL. The fraction and helminthosporin were shown to destroy the cell wall of the yeast and bacteria, and DNA fragmentation effect on the genome of Candida albicans and Bacillus cereus. Helminthosporin was the most cytotoxic compound with IC₅₀ ˂ 10 µM. Fraction R7C3 showed the most potent cytotoxic effects on all cancer cell lines, with IC₅₀ ranging from ˂1 to 4.35 ng/mL. Our study is the first report on the mechanism of action of helminthosporin, a potent candidate in the development of new drugs against multi-resistant bacteria and cancer cells. In addition, this study uncovered Rumex abyssinicus as a new source of syringic acid and bis(2-ethyloctyl) phthalate.

Complexes of ortho-Phthalic Acid in Spontaneous Animal Tumors

The presence of diethyl-, dibutyl-, and 2-ethylhexyl phthalates in spontaneous animal tumors was determined for the first time. Small-cell breast cancer of the dog and Ehrlich ascites carcinoma with the cells are particularly rich of these compounds. It is assumed that the level of phthalates in these cells is due to the activity of expression of nuclear receptors for estrogens and progesterone, as well as the peculiarities of the metabolism of xenobiotics. The accumulation of these compounds in tumor cells can increase their malignancy. The data obtained can be used for development of new diagnostic and therapeutic technologies.

Metabolite profiling of Bruguiera cylindrica reveals presence of potential bioactive compounds

Bruguiera cylindrica parts are commonly used in Chinese and Indian traditional medicine to treat diarrhea, fever, and many ailments. The present study aims non targeted analysis of key secondary metabolites of B. cylindrica by gas chromatography mass spectrometry (GC-MS) and ultra-high performance liquid chromatography hybrid quadrupole-Exactive-Orbitrap high resolution mass spectrometry (UHPLC-Q-Exactive Orbitrap HRMS). GC-MS and UHPLC-Q-Exactive Orbitrap HRMS were utilized for metabolic profiling of ethyl acetate extract of B. cylindrica leaves. Key metabolites in the extract were identified and predicted based on chemical similarity using online databases such as ChemSpider and mzCloud. Thirty-six compounds belonging to different classes of secondary metabolites viz. flavonoids, fatty acids, fatty acid amides, carboxylic acids, and alkaloids were identified in the extract. Pentacyclic triterpenes like betulin, ursolic acid and a tropine, an alkaloid with potential pharmacological and therapeutic activities such as anticancer properties, neuromuscular blockers and antioxidants, were also identified. This study combined GC-MS and UHPLC-Q-Exactive Orbitrap HRMS with available online database for effective and rapid identification of bioactive metabolites in the ethyl acetate extract of mangrove without individual standard application. This is the first report on the HRMS based secondary metabolic profiling of B. cylindrica, with comprehensive map of its biologically important metabolites.

Plant growth promoting potential of butyl isobutyl phthalate and Streptomyces sp. from Rumex dentatus on rice

Rice (Oryza sativa L.) is one of the most important staple foods consumed in many countries of the world. It is mostly consumed in developing countries where different chemical fertilizers are used to improve the productivity of the crop plant. In the present study, endophytic actinomycetes isolated from Rumex dentatus were identified morphologically and by scanning electron microscopy. Butyl isobutyl phthalate (BIBP) was isolated from the root endophyte Streptomyces sp. JR9 using column chromatography and HPLC methods. The compound was tested for its effect on rice seed germination. BIBP, extracts, and isolates were evaluated for their plant growth effect on rice in a growth chamber. Isolates were also screened in vitro for phosphate solubilization activity and enzyme production. Indole-3-acetic acid (IAA) and BIBP produced in extracts were quantified and detected using high performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS) methods, respectively. BIBP was found to increase the germination of rice seeds by 6 to 12% in treated samples and displayed potent effect at lowest concentration (0.437 µM). Both the compound and the extract depicted significant increases in almost all growth parameters at lowest concentration of 0.125 µg/mL and 62.5 µg/mL, respectively. BIBP also increased significantly shoot length, fresh root, fresh shoot, and dried shoot weight at high concentrations and was more potent than the standard phytohormone IAA. HPLC quantification showed 7.952 µg/mg and 0.371 µg/mg of IAA in extracts of Streptomyces sp. JR9 and the stem endophyte Streptomyces sp. KS3, respectively. IAA containing extract of JR9 increased significantly most growth parameters at lowest concentration (125 µg/mL). The extract of KS3 depicted significant increases in almost all growth parameters at high concentration (500 µg/mL). Our investigation showed that streptomycetes isolated from R. dentatus and BIBP are potent growth promoting agents and can be used in agriculture as bio-fertilizer to improve the growth and productivity of rice. KEY POINTS: • Butyl isobutyl phthalate (BIBP) isolated from endophytic Streptomyces sp. JR9 is a potent rice seed germination activator and promotes significantly the growth of rice • Isolated endophytes showed the ability to produce enzymes and phytohormone IAA • Isolates enhanced significantly the growth of rice.

In Vitro Antibacterial and Antioxidant Activities and Molecular Docking Analysis of Phytochemicals from Cadia purpurea Roots

Phytochemicals and antibacterial and antioxidant activities of Cadia purpurea roots were investigated herein for the first time. The phytochemical study led to the isolation of two compounds, di-(2-methylheptyl) phthalate (1) and 13-O-pyrrolecarboxyl lupanine (2), from methanol roots extract of C. purpurea. The antibacterial activity results revealed that the n-hexane extract presented a better inhibitory value (13.8 ± 0.0 mm) followed by chloroform (11.1 ± 0.4 mm) and chloroform : methanol (1 : 1) (10.7 ± 0.1 mm) extracts against E. coli at the maximum dose of 100 mg/mL. While, methanolic and ethanolic extracts displayed a mild activity against same bacterium at same dose. The methicillin resistant S. aureus was found with almost total resistance to all extracts up to the 100 mg/mL. The chloroform : methanol (1 : 1), chloroform, and n-hexane extracts recorded inhibition zone values (8.0 ± 0.0–10.0 ± 0.1 mm, 7.7 ± 0.0–9.8 ± 0.1 mm, and 7.3 ± 0.2–8.9 ± 0.2 mm, respectively) better than chloramphenicol (7.2 ± 0.6 mm at 30 μg dose) against P. aeruginosa. The alcoholic extracts also exhibited an activity better than chloramphenicol up to 25 mg/mL against same bacterium. Compound 2 produced a comparable inhibition value (9.6 ± 0.0 mm to 18.5 ± 0.0 mm) to that of chloramphenicol (21.5 ± 0.3 mm) against E. coli at doses up to 1.0 mg/mL; whereas, compound 1 showed a slight activity (7.1 ± 0.1 mm–10.3 ± 0.0 mm). Both compounds were found generally inactive against S. aureus, while they provided an activity better than chloramphenicol (7.2 ± 0.6 mm) against P. aeruginosa with inhibition zones ranging from 7.1 ± 0.0 mm to 9.0 ± 0.1 mm for compound 1 and 7.2 ± 0.0 mm to 10.6 ± 0.0 mm for compound 2. Ethanolic and methanolic extracts exhibited a better DPPH radical scavenging activity (IC50 values of 12.9 and 16.03 μg/mL, respectively) and strong ferric ion reducing power (with absorbance of 0.788 ± 0.000 and 0.810 ± 0.001, respectively) at a concentration of 500 μg/mL compared to the other extracts. Compound 1 also possessed a better anti-DPPH trapping activity (IC50, 7.99 μg/mL) than compound 2 (IC50, 58.34 μg/mL). The compounds, however, indicated a weak ferric ion reduction power even at higher amount. In general, the observed antibacterial and antioxidant activities of isolated compounds and extracts were found to be dose-dependent. Conducting further biochemical investigations on all parts of this plant could provide opportunities of finding extra alkaloidal compounds and other phthalate derivatives with better biological activity.

Therapeutic prospects of endophytic Bacillus species from Berberis lycium against oxidative stress and microbial pathogens

Endophytes are microorganisms residing within plant tissues. Bacterial endophytes are important sources for production of pharmaceutically important metabolites. Berberis lycium is an important medicinal plant and there exist no report regarding isolation and determination of bioactive potential of its bacterial endophytes. Therefore the present study was aimed to isolate and identify bacterial endophytes from Berberis lycium. The study resulted in isolation of 20 strains of bacterial endophytes. Based on their antibacterial activity three strains were identified as Bacillus cereus (LBL6), Bacillus thuringiensis (SBL3) and Bacillus anthracis (SBL4) on basis of 16SrRNA gene using universal primers. Crude ethyl acetate extracts of LBL6, SBL3 and SBL4 were further evaluated for antioxidant and antifungal activities. Moderate antioxidant activity (56 %) at a concentration of 1000 µg/mL was observed for LBL6 followed by 45 and 43 % activity by SBL4 and SBL3 respectively. Significant antifungal activity was observed against Aspergillus niger (60 %) and Aspergillus flavus (56 %) at concentration of 4 mg/mL of SBL3 and SBL4 respectively. GCMS analysis of extract (LBL6) exhibited presence of 12 bioactive secondary metabolites corresponding to antimicrobial, antifungal, antioxidant, antitumor and anticancer activities. In conclusion, present study highlighted the importance of Berberis lycium to host diverse bacterial endophytes of pharmaceutical importance.

Potential effect of fish oil to preserve expression of cell cycle and tight junction regulating genes in colon after di-isononyl phthalate ingestion in albino Wistar rats

Di-isononyl phthalate (DIP) is considered a high molecular-weight subtype of phthalates that are commonly used and could easily affect the gastrointestinal tract (GIT). Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are the main active components of fish oil (FO), and their anti-inflammatory potential was previously documented. The current study was designed to investigate the protective potential of fish oil against the impacts of DIP exposure on the colon of albino Wistar rats. Sixty albino Wistar rats were divided into Control group received corn oil for ten days. Di-isononyl phthalate treated group received DIP. Di-isononyl phthalate + fish oil treated group received both DIP and FO. FO was found to preserve the histological architecture, tight junction and cell cycle of the colon. In conclusion, the current study provided an evidence that FO has a protective potential against DIP further examinations to be done to fully understand the molecular basis of this potential as a step for further clinical applications.

In vitro evaluation of cytotoxic effects of di (2-ethylhexyl) phthalate (DEHP) produced by Bacillus velezensis strain RP137 isolated from Persian Gulf

Phthalates are widely used in polymer science and have potential toxicity related to their chemical structures. However, lots of evidence indicate that phthalate derivatives are undoubtedly produced as secondary metabolites by organisms, including plants, animals, and microorganisms. In the present study, Bacillus velezensis strain RP137 was cultured under optimized conditions. Its biomass was extracted with ethyl acetate with one fraction showing cytotoxic properties. A pure compound was isolated from the active fraction using combined silica gel and LH20 size exclusion column chromatography. Structural evaluation including FT-IR, ¹H NMR, ¹³C NMR, HR-MS and CHN analysis identified the purified compound as di(2-ethylhexyl)phthalate (DEHP) with the formula C₂₄H₃₈O₄ and the molecular weight of 389.29 Da. The microorganism-derived (stereospecific) DEHP was strongly reduced the proliferation and induced cytotoxic effects on various eukaryotic cell lines in compare to the synthetic racemic mixture of the compound when assessed by MTT assay. Furthermore, crystal violet assay and morphological changes confirmed the cytotoxic effect of DEHP. Interestingly, non-malignant SV40-immortalized fibroblast cells were less affected by the purified DEHP. Further evaluation on the antibacterial activity of DEHP documented no effect toward Gram-positive (S. aureus) and Gram-negative (E. coli and P. aeruginosa) pathogens even at a high concentration of 100 μM. In conclusion, existence of DEHP as byproduct of microorganism's metabolism can seriously be considered as a warning to human health.

Bioactive natural derivatives of phthalate ester

The advantages and emergent interest in organism-derived bioactive molecules have recently renewed scientific research attention in this field. Since 1967, about 52 different derivatives of phthalate ester (PE) have been reported from different taxonomic groups. Anthropogenic derivatives of the PEs are confined to petroleum products, as a plasticizer. These derivatives exhibit a potential toxicity on the living system, particularly those having a reduced molecular weight. An organism-derived PE differs chemically from that of synthetic ones in terms of the abundance of ¹⁴C and its bond structure, leading to its varied activities in the biological system. The study of the biosynthetic pathway and the optimization of parameters for product enhancement have advocated their organism-derived nature. Various bioactivities of such organisms-derived derivatives of phthalates such as antibacterial, antifungal, an inducer of apoptosis and cell cycle arrest, antioxidant, cytotoxic, antitumor, allopathic, larvicidal, antifouling, chemotactic, antimelanogenic, antiviral, and anti-inflammatory activities have been well documented. This is the first review that focuses on the positive bioactivities of such organism-derived PEs in detail. There is enormous scope for research in this field to search for the utilization of such organism-derived phthalate derivatives will have potential bioactivity, their possible use to improve their efficacy.

Streptomyces diastaticus isolated from the marine crustacean Portunus sanguinolentus with potential antibiofilm activity against Candida albicans

Biofilm-mediated multidrug resistance has turned into major challenge for the treatment of C. albicans infections. In the present study, actinomycetes (SS5) isolated from marine crustacean were investigated for their ability to inhibit C. albicans biofilm formation. Cultural, morphological and 16S rRNA analysis revealed that the isolated strain was Streptomyces diastaticus. Ethyl acetate bioactive fractions (6 µg mL^-1) from SS5 showed potent antibiofilm activity against C. albicans. Light microscopic and CLSM analysis further substantiated the antibiofilm activity of the bioactive fraction against C. albicans. The bioactive fraction was subjected to FTIR and GC-MS for characterization. From GC-MS analysis, the presence of 31 compounds were revealed, among which the alkanes are predominantly present. Hence, further investigation for the potential of these bioactive compounds against C. albicans biofilm will help in the identification of promising candidate for the prevention of biofilm-mediated infection.

A Fluorescent Compound from the Exuviae of the Scorpion, Liocheles australasiae

Most scorpions fluoresce under UV light. To date, two types of fluorescent compounds have been identified in scorpions, but it has been assumed that other unknown compounds may be responsible for the fluorescence. In this study, we isolated a fluorescent compound from the exuviae of the scorpion Liocheles australasiae identified as a macrocyclic diphthalate ester with a molecular mass of 496.2 Da. The same compound was also detected in extracts from four other scorpion species. This suggests that this compound is shared by multiple scorpion species, although its contribution to the cuticle fluorescence may be relatively small.

Triclosan: antimicrobial mechanisms, antibiotics interactions, clinical applications, and human health

The large-scale applications of Triclosan in industrial and household products have created many health and environmental concerns. Despite the fears of its drug-resistance and other issues, Triclosan is still an effective drug against many infectious organisms. Knowing the cross-interactions of Triclosan with different antibiotics, bacteria, and humans can provide much-needed information for the risk assessment of this drug. We review the current understanding of the antimicrobial mechanisms of Triclosan, how microbes become resistant to Triclosan, and the synergistic and antagonistic effects of Triclosan with different antibiotics. Current literature on the clinical applications of Triclosan and its effect on fetus/child development are also summarized.