Tools to make Stachybotrys chartarum genetically amendable: Key to unlocking cryptic biosynthetic gene clusters

The soil and indoor fungus Stachybotrys chartarum can induce respiratory disorders, collectively referred to as stachybotryotoxicosis, owing to its prolific production of diverse bioactive secondary metabolites (SMs) or mycotoxins. Although many of these toxins responsible for the harmful effects on animals and humans have been identified in the genus Stachybotrys, however a number of SMs remain elusive. Through in silico analyses, we have identified 37 polyketide synthase (PKS) genes, highlighting that the chemical profile potential of Stachybotrys is far from being fully explored. Additionally, by leveraging phylogenetic analysis of known SMs produced by non-reducing polyketide synthases (NR-PKS) in other filamentous fungi, we showed that Stachybotrys possesses a rich reservoir of untapped SMs. To unravel natural product biosynthesis in S. chartarum, genetic engineering methods are crucial. For this purpose, we have developed a reliable protocol for the genetic transformation of S. chartarum and applied it to the ScPKS14 biosynthetic gene cluster. This cluster is homologous to the already known Claviceps purpurea CpPKS8 BGC, responsible for the production of ergochromes. While no novel SMs were detected, we successfully applied genetic tools, such as the generation of deletionand overexpression strains of single cluster genes. This toolbox can now be readily employed to unravel not only this particular BGC but also other candidate BGCs present in S. chartarum, making this fungus accessible for genetic engineering.

Total synthesis of (±)-auranthine confirmed its refined structure

Auranthine, isolated in 1986 from Penicillium aurantiogriseum, is a fungal benzodiazepine. Through the successful total synthesis of (±)-auranthine, we confirmed the refined structure of natural (-)-auranthine. We established that natural (-)-auranthine is a fused quinazolino benzodiazepine dione 1 featuring an acyclic aliphatic nitrile moiety, thereby disproving the proposed structure 2.

Amide-functionalized 1,2,4-Triazol-5-amines as Covalent Inhibitors of Blood Coagulation Factor XIIa and Thrombin

To counteract thrombosis, new safe and efficient antithrombotics are required. We herein report the design, synthesis, and biological activity of a series of amide-functionalized acylated 1,2,4-triazol-5-amines as selective inhibitors of blood coagulation factor XIIa and thrombin. The introduction of an amide moiety into the main scaffold of 3-aryl aminotriazoles added certain three-dimensional properties to synthesized compounds and allowed them to reach binding sites in FXIIa and thrombin previously unaddressed by non-functionalized 1,2,4-triazol-5-amines. Among synthesized compounds, one quinoxaline-derived aminotriazole bearing N-butylamide moiety inhibited FXIIa with the IC50 value of 28 nM, whereas the N-phenylamide-derived aminotriazole inhibited thrombin with the IC50 value of 41 nM. Performed mass-shift experiments and molecular modeling studies proved the covalent mechanism of FXIIa and thrombin inhibition by synthesized compounds. In plasma coagulation tests, developed aminotriazoles showed anticoagulant properties mainly affecting the intrinsic blood coagulation pathway, activation of which is associated with thrombosis but is negligible for hemostasis.

Insights into Ergochromes of the Plant Pathogen Claviceps purpurea

Claviceps purpurea is an ergot fungus known for its neurotropic alkaloids, which have been identified as the main cause of ergotism, a livestock and human disease triggered by ergot consumption. Tetrahydroxanthone dimers, the so-called ergopigments, presumably also contribute to this toxic effect. Overexpression of the cluster-specific transcription factor responsible for the formation of these pigments in C. purpurea led to the isolation of three new metabolites (8-10). The new pigments were characterized utilizing HRMS, NMR techniques, and CD spectroscopy and shown to be xanthone dimers. Secalonic acid A and its 2,4'- and 4,4'-linked isomers were also isolated, and their absolute configuration was investigated. The contribution of secalonic acid A, its isomers, and new metabolites to the toxicity of C. purpurea was investigated in HepG2 and CCF-STTG1 cells. Along with cytotoxic properties, secalonic acid A was found to inhibit topoisomerase I and II activity.

Ion identity molecular networking for mass spectrometry-based metabolomics in the GNPS environment

Molecular networking connects mass spectra of molecules based on the similarity of their fragmentation patterns. However, during ionization, molecules commonly form multiple ion species with different fragmentation behavior. As a result, the fragmentation spectra of these ion species often remain unconnected in tandem mass spectrometry-based molecular networks, leading to redundant and disconnected sub-networks of the same compound classes. To overcome this bottleneck, we develop Ion Identity Molecular Networking (IIMN) that integrates chromatographic peak shape correlation analysis into molecular networks to connect and collapse different ion species of the same molecule. The new feature relationships improve network connectivity for structurally related molecules, can be used to reveal unknown ion-ligand complexes, enhance annotation within molecular networks, and facilitate the expansion of spectral reference libraries. IIMN is integrated into various open source feature finding tools and the GNPS environment. Moreover, IIMN-based spectral libraries with a broad coverage of ion species are publicly available.

Auranthine, a Benzodiazepinone from Penicillium aurantiogriseum: Refined Structure, Absolute Configuration, and Cytotoxicity

The structure of the known Penicillium aurantiogriseum-derived secondary metabolite auranthine was refined using a combination of synthetic, spectroscopic, and X-ray diffractometric approaches. Thus, auranthine was shown to be a fused quinazolino benzodiazepinedione (2) bearing an acyclic aliphatic nitrile moiety, thereby significantly differing from the originally proposed structure 1 published in 1986. Its absolute configuration was confirmed by CD spectroscopy and DFT calculations. The cultivation of P. aurantiogriseum was optimized, allowing high production of auranthine. The cytotoxicity profile of auranthine and its semisynthetic analogues is reported. The refined structure of auranthine provides a valid target for the total synthesis of this underexplored natural product and its derivatives.

Detection of the Cytotoxic Penitrems A-F in Cheese from the European Single Market by HPLC-MS/MS

Penitrems are fungal indole diterpene-derived tremorgenic secondary metabolites, which are mainly produced by Penicillium spp. Several cases of intoxications with penitrems and subsequent occurrences of penitrem A in foodstuff underline the need for reliable quantitation methods for the detection of these mycotoxins in food. In this study, a simple and fast high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for the quantitative analysis of penitrems A-F in cheese was developed. Therefore, penitrems A-F were isolated from Penicillium crustosum as analytical reference standards. The analysis of 60 cheese samples from the European single market (EU) revealed the occurrence of penitrem A in 10% of the analyzed samples with an average concentration of 28.4 μg/kg and a maximum concentration of 429 μg/kg. In addition to penitrem A, other members of the group of penitrems, namely, penitrems B, C, D, E, and F, were for the first time quantitatively detected in food samples, although in lower concentrations and with lower incidence in comparison to penitrem A. Moreover, we report cytotoxic effects of all penitrems on two cell lines (HepG2 and CCF-STTG1). This clearly underlines their relevance and the importance to analyze food samples in order to get insights into the human exposure toward these mycotoxins.

Comparative genomics of geographically distant Fusarium fujikuroi isolates revealed two distinct pathotypes correlating with secondary metabolite profiles

Fusarium fujikuroi causes bakanae ("foolish seedling") disease of rice which is characterized by hyper-elongation of seedlings resulting from production of gibberellic acids (GAs) by the fungus. This plant pathogen is also known for production of harmful mycotoxins, such as fusarins, fusaric acid, apicidin F and beauvericin. Recently, we generated the first de novo genome sequence of F. fujikuroi strain IMI 58289 combined with extensive transcriptional, epigenetic, proteomic and chemical product analyses. GA production was shown to provide a selective advantage during infection of the preferred host plant rice. Here, we provide genome sequences of eight additional F. fujikuroi isolates from distant geographic regions. The isolates differ in the size of chromosomes, most likely due to variability of subtelomeric regions, the type of asexual spores (microconidia and/or macroconidia), and the number and expression of secondary metabolite gene clusters. Whilst most of the isolates caused the typical bakanae symptoms, one isolate, B14, caused stunting and early withering of infected seedlings. In contrast to the other isolates, B14 produced no GAs but high amounts of fumonisins during infection on rice. Furthermore, it differed from the other isolates by the presence of three additional polyketide synthase (PKS) genes (PKS40, PKS43, PKS51) and the absence of the F. fujikuroi-specific apicidin F (NRPS31) gene cluster. Analysis of additional field isolates confirmed the strong correlation between the pathotype (bakanae or stunting/withering), and the ability to produce either GAs or fumonisins. Deletion of the fumonisin and fusaric acid-specific PKS genes in B14 reduced the stunting/withering symptoms, whereas deletion of the PKS51 gene resulted in elevated symptom development. Phylogenetic analyses revealed two subclades of F. fujikuroi strains according to their pathotype and secondary metabolite profiles.

[The Effect of Social-Psychological Factors on the Development of Occupational Stress]

The article presents data on social-psychological factors which cause the occupational stress. The results showed that there is a link between the level of work motivation and the physiological cost of work. We observed a number of peculiarities of occupational stress development caused by psychoemotional tension depending on the class of intensity of intellectual labor; we also studied biological age of the subjects. The speed of ageing of the employees who work under conditions of emotional stress (direct or indirect responsibility for the safety of other people) was found to increase. The study suggested promising directions of occupational stress prevention.

[The physiological features of overstrain formation in mental work and its prevention]

Psychophysiological and biochemical studies have shown that significant neuro- emotional loads produce such functional status, which can be called overstrain. It was found out at the first time that the physiological and biochemical characteristics of overstrain based on the main parameters in mental work. The research proved the preventive measures of human body overstrain and can help to prevent the diseases related to work.

Diuretic activity and toxicity of some Verbascum nigrum extracts and fractions

CONTEXT

Verbascum nigrum L. (Scrophulariaceae) is a perennial plant used in folk medicine for the treatment of kidney diseases due to its presumable diuretic properties.

OBJECTIVE

We investigated the diuretic activity and toxicity of extracts from different parts of V. nigrum and identified a group of compounds responsible for the biological effect.

MATERIALS AND METHODS

Five ethanol extracts from herb, roots, flowers, leaves and stems as well as five fractions of polar compounds isolated from herb of V. nigrum were orally administrated as a single dose of 50 mg/kg to rats. Urinary excretion and electrolyte content were measured at 3 and 6 h after the treatment. The acute toxicity of the V. nigrum extracts and fractions was evaluated in mice.

RESULTS

All extracts, except the one prepared from the roots, showed a significant increase of the urine output within first 3 h after their administration. The extract from stems was the most active, inducing urine output of 14.6 ± 0.8 ml/kg BW versus 5.2 ± 1.4 ml/kg BW of the control. It also demonstrated saluretic activity with a natriuretic index 4.1 and a kaliuretic index 3.8. The diuretic activity was correlated with the flavonoid content in the plant organs. Flavonoid fractions demonstrated significant activity; the higher content of flavonoids (expressed as hesperidin) translated into more pronounced diuretic (35.9 ± 2.1 ml/kg BW) and saluretic effects (natriuretic index 4.5 and kaliuretic index 5.4).

CONCLUSION

The diuretic activity of traditionally used V. nigrum was validated experimentally. The pharmacological effect was attributed to flavonoids, which accumulated in aerial parts of the plant, mainly in stems.

[Forecasting decrease in performance and health disorders under exposure to work intensity factors in accordance with work conditions class]

Results of complex physiologic and ergonomic, clinical and functional studies helped to justify approaches to quantitative evaluation and assessment of posssible decrease in performance and health disorders in workers in accordance with work conditions class of mental work. Linear regression dependence was established between work intensity class and performance decrease. The linear regression equation obtained enables to calculate a percentage of performance decrease in various work intensity classes. Intensive direct correlation was revealed between work intensity value and a percentage of individuals with diagnosed occupationally induced diseases.

[Labor physiology role in workers of different type labor activity workability and health. Progress and prospects]

There are presented the data of workers overstrain and fatigue conditions mechanisms based on physiological, psychological and ergonomic aspects of work processes in different types of activities (mental, visual-strained, physical). 15-year historical analysis, current state and prospects of labor physiology methods development are shown. Complex physiological and ergonomic investigations have allowed developing the measures of work ability raise and diseases prevention for workers various professions. Obtained results provided the basis of development of regulatory documents in area of human organism strain physiological norms, consequences of psycho-emotional stress and overstrain prevention taking into account working conditions class.

[The analysis of the structure of nurse personnel work time in the rehabilitation treatment department]

The workload of medical nurse is increased significantly due to such actual organizational technical conditions of work as the implementation of hi-tech technologies and outfits in the rehabilitation departments, the increase of proportion of patients with painful course of illness, the wide application of combination methods of rehabilitation treatment. The modern approaches to the organization of nursing process call for broadened standardization of all its aspects. The investigation of the structure of basic work time of nurse personnel the principle of differentiation of working operation on depended, interdependent and independent nurse interventions is to be used. Actually, only small part of the nurse depended rehabilitation interventions such as the volume of medical procedure supply is allowed for. The working hours efforts to the implementation of interdependent and independent nurse interventions are not considered. The attention should be paid to the alteration of the structure of auxiliary work time and the new system of circulation of documents in the inpatient department. In this connection the need for a revision of available standards with a glance to the new demands and changed conditions of medical care rendering.

[Social and psychologic factors of occupational stress forming in emotional exertion activities]

The authors studied psycho-social factors influencing mental workers who bear high responsibilities for others' safety. Working in time deficit, inadequate worker's involvement into work process management, less career prospects, low possibility to improve work process, controversies in occupational tasks and roles were proved to be the most important occupational stress factors. Prevalence of occupational stress factors appeared not to be dependent on work intensity class. Findings were increasing influence of occupational motivation on physiologic parameters change in work process.

[Using AELTIS-synchro-02 device in the therapy of chronic bacterial prostatitis]

The treatment of chronic bacterial prostatitis combined antibacterial drugs and physiotherapy (low-energy laser radiation, electrostimulation of the prostate). Treatment of chronic bacterial prostatitis with medication and complex two-channel bio-synchronized electrolaser therapy with application of the unit AELTIS-synchro-02 raises efficacy of treatment with chronic bacterial prostatitis due to combined effect of antibacterial drugs and bacteriostatic and immunomodulating actions of the physical factors applied. These normalize microcirculation in the region of the prostatic gland, improve a draining function of the prostatic ducts, allows achievement of good results in 88.2% patients.

[Clinical and hemodynamic effect of piracetam (Nootropil) in elderly and very old patients with coronary heart disease in the outpatient rehabilitative period]

The clinical and hemodynamic efficiency of piracetam (nootporil) used in the long-term combined therapy of elderly and senile patients with chronic coronary heart diseases was studied outpatiently. This drug led to a significant enhancement of the antianginal effect of the basic treatment, to more regression of clinical signs of chronic circulatory insufficiency, to positive central hemodynamic changes, higher exercise tolerance, lower energy consumption index per performance unit, increased adaptive potential of the circulatory system, and maintained optimal cerebral blood flow.

[Administration of solcoseryl in the complex treatment and intrahospital rehabilitation of patients with myocardial infarction]

Clinical efficacy of solcoseryl was studied in 58 patients with acute myocardial infarction. Forty patients receiving no solcoseryl were included into a control group. The agent contributed to a reduction in the frequency of anginal episodes, a more rapid improvement of circulatory failure signs, and an increase in exercise tolerance.