gc-ms

The isolation of phytase using Pichia Pastoris under methanol/sorbitol co-feeding induction technique was investigated. The biological activity of extracellular phytase after optimization with co-substrates induction in 4 liters fermentor (NBS) increased to 13250 U/ml. This led to a 509 fold increases in comparison to the other type of phytase. This effect was studied via induction with sorbitol/methanol in fermentation by Pichia Pastoris GS115 (Mut+) at 20 °C. The interference of by products; methylal, hexamine and (S)-(+)-1,2-propanediol with release of phytase in Pichia Pastoris under methanol induction were detected and cannot be repressed by methanol induction alone. The TLC was used for glycerin analysis under methanol/sorbitol induction and the results were lesser compare to that obtained during phytase production under methanol induction alone. This work showed the higher expression of heterologous proteins and by fed batch fermentation; the expression identified an advantage of producing a significant activity of phytase. Practical applications Plant derived products including sorbitol have been used as alternative medicines for the therapeutic treatment of various diseases, food supplements and could be used in many manufacturing processes. It serves as a culture media for bacteria, and helps to distinguish the pathogenic E. coli O157:H7 from its most other strains. Cells growing on methanol require high oxygen consumption. Sorbitol was used as an alternative cheap co-feeding for the production of proteins and is a non-repressing carbon source for AOX1 promoter with no effect on the level of r-protein at its induction phase. This report describes the isolation of phytase using Pichia Pastoris under methanol/sorbitol co-feeding induction techniques, and sorbitol showed to be a promising co-substrate, as it could enhance both cell growth and targeted protein productivity. This co-feeding and fed-batch induction technique was used for recombinant phytase production in a small and large scale production and the metabolites were analyzed.

Morbidity and mortality of the infected patients by multidrug-resistant bacteria have increased, emphasizing the urgency of fight for the discovery of new innovative antibiotics. In this sense, natural products emerge as valuable sources of bioactive compounds. Among the biodiversity, Eryngium pristis Cham. & Schltdl. (Apiaceae Lindl.) is traditionally used to treat thrush and ulcers of throat and mouth, as diuretic and emmenagogue, but scarcely known as an antimicrobial agent. With this context in mind, the goals of this study were to investigate the metabolic profile and the antibacterial activity of ethanolic extract (EE-Ep) and hexane (HF-Ep), dichloromethane (DF-Ep), ethyl acetate (EAF-Ep) and butanol (BF-Ep) fractions from E. pristis leaves. Gas Chromatography-Mass Spectrometry (GC-MS) was performed to stablish the metabolic profile and revealed the presence of 12 and 14 compounds in EAF-Ep and HF-Ep, respectively. β-selinene, spathulenol, globulol, 2-methoxy-4-vinylphenol, α-amyrin, β-amyrin, and lupeol derivative were some of phytochemicals identified. The antibacterial activity was determined by Minimal Inhibitory Concentration (MIC) using the broth micro-dilution against eight ATCC® and five methicillin-resistant Staphylococcus aureus (MRSA) clinical strains. HF-Ep was the most effective (MIC ≤ 5,000 µg/µL), being active against the largest part of tested Gram-positive and Gram-negative bacterial strains, including MRSA, with exception of Escherichia coli (ATCC 25922) and Pseudomonas aeruginosa (ATCC 9027) and (ATCC 27853). These results suggest that E. pristis is a natural source of bioactive compounds for the search of new antibiotics which can be an interesting therapeutic approach to recover patients mainly infected by MRSA strains.

Prescriptions for psychoactive substances such as Pregabalin, Methamphetamine, Caffeine, Clonazepam and Mirtazapine (PM-CCM) are common in the treatment of a variety of disorders. Indeed, the PM-CCM has been used in different therapeutic areas, including insomnia, anxiety, seizure disorders, etc. Unfortunately, these psychoactive substances are present in the illegal street market, leading to a lot of drug abuse among some addicted users, road insecurity and suicide. Hence, it has become essential to validate and develop a rapid and effective method to analyze the PM-CCM, a modified illicit drug, for drug abuse in the forensic sciences. A simple, rapid, specific and sensitive Gas Chromatography-Mass Spectrometry(GC-MS) method has been developed for the identification of Pregabalin, Methamphetamine, Caffeine, Clonazepam and Mirtazapine (PM-CCM) in forensic exhibits. At room temperature, the sample was ultrasonicated for 5 minutes before being extracted with methanol. A highly precise auto-injector is used to inject a very small quantity of samples for analysis. Helium is used as a carrier gas with a flow rate of 1 ml/min. The separation of PM-CCM was performed on SH-RXi-5 MS, ID.25 mm, film thickness. 25 µm, length of 30 m column. The constituents of PM-CCM were identified by the mass-to-charge ratio (m/z ratio) of fragments of the parent compound by comparing them with the NIST-17 MS Library. Separation and identification of PM-CCM were achieved within a 15-minute run. The proposed method has been successfully used for the routine analysis of PM-CCM in complex illicit drug preparations and in forensic exhibits as well. The application of above discussed qualitative analysis method and screening of PM-CCM, modified illicit drug samples demonstrates the potential and applicability of the technique to the fast chemical profiling of illicit samples.  

Objective: The study evaluated the hyperglycaemia-lowering effects, safety, and phytochemical profile of Celtis zenkeri leaf extract in order to justify its antidiabetic folkloric usage. Methods:  Modified OECD test guidelines were used to assess its acute and sub-acute toxicity while its effect on blood parameters such as blood glucose, and haematological and biochemical levels were evaluated using appropriate assays. Both in vitro and in vivo antihyperglycaemic assays were used for the antidiabetic studies while histology of the pancreas, liver, and kidney of the rats was examined after treatment with the extract at 250, 500, and 1000 mg/kg for 21 days.  GC-MS analysis was used to determine the chemical constituents of the extract. Results: The results obtained showed that the leaf extract of C. zenkeri was not toxic in rats at 5000 mg/kg. It elicited a significant decrease in the blood glucose levels of the animals but did not affect the haematological and biochemical components of normal rats. It significantly inhibited α-amylase and α-glucosidase actions and gave comparable activity to glibenclamide (5 mg/kg) at all time points at 200 and 400 mg/kg. The extract comparably reduced blood glucose levels with glibenclamide at 100 and 200 mg/kg on days 10 and 14 in drug-induced diabetic rats and maintained the histoarchitecture of the liver, kidney, and pancreas at 250 and 500 mg/kg.Conclusion: The study justified the ethnomedicinal use of C. zenkeri in diabetes management.

Recent studies have shown that long-term uses of herbs have been associated with a rise in morbidity and mortality rates. While most researches are focused on bioactivity investigations, the toxicity of many plants has not been reported. There is a paucity of data on the potential toxicity of the following plants: Harungana madagascariensis (HM), Pterocarpus osun (PO), Phoenix dactylifera (PD), Annona muricata (AM), and Rutidea parviflora (RP). To evaluate the toxicity of the above-mentioned plants; two tests were employed namely: The Brine shrimp lethality test (BSLT) and the Allium cepa test. A correlation between the oral acute toxicity assay in mice and the LC50 obtained from BSLT has been established. Allium cepa test measures the potential genotoxic effects of plant extracts exerted on the root meristem of A. cepa (onions). Plant extracts were administered in concentrations ranging from 100 to 2500 µg/ml to the A. cepa for 72 h to obtain their Mitotic Indices (MI) and EC50. Results of the MI at 2500 µg/ml for HM, PO, PD, AM, and RP were 3.75, 4.96, 5.96, 6.10, and 6.71 while 281.81, 398.11, 501.19, 630.96, and 707.9 µg/ml were obtained as the respective EC50 values. Furthermore, 10-1000 mcg/ml concentrations were administered in the BSLT and the obtained LC50 values were 116.3, 250, 581.5, 581.5, and 750 µg/ml. The toxicity result demonstrated that the five plants were moderately toxic, with RP exhibiting minimal toxicity values and thus potentially having a good safety profile. The phytochemical screening of these plants revealed the presence of some pharmacologically important classes of compounds that are abundant. Several bioactive and toxic compounds were identified in the GC-MS analysis for some of the plants.