Antimicrobial and Cytotoxic Activities of the Secondary Metabolites of Endophytic Fungi Isolated from the Medicinal Plant Hyssopus officinalis.

According to the World Health Organization, it is estimated that by 2050, drug-resistant infections could cause up to 10 million deaths annually. Therefore, finding a new generation of antibiotics is crucial. Natural compounds from endophytic fungi are considered a potential source of new-generation antibiotics. The antimicrobial and cytotoxic effects of ethyl acetate extracts of nine endophytic fungal isolates obtained from Hyssopus officinalis were investigated for bioassay-guided isolation of the natural compounds. An extract of isolate VII showed the highest antimicrobial activities against Gram-positive bacteria Bacillus subtilis and Staphylococcus aureus (30.12 ± 0.20 mm and 35.21 ± 0.20 mm) and Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa (30.41 ± 0.23 mm and 25.12 ± 0.25 mm) among the tested extracts of isolates. Molecular identification of isolate VII confirmed it as Chaetomium elatum based on sequencing of its ITS genes, and it was discovered that this was the first time C. elatum had been isolated from H. officinalis. This isolate was cultured at a large scale for the isolation and identification of the active compound. Penicillic acid was isolated for the first time from C. elatum and its chemical structure was established by NMR spectroscopy. The penicillic acid showed strong antibacterial activities against Bacillus subtilis and Staphylococcus aureus with 20.68 mm and 25.51 mm inhibition zones, respectively. In addition, MIC and MBC values and antibiofilm activities of penicillic acid were determined. It was found that penicillic acid reduced the level of biofilms in proportion to antibacterial activity.

Expression of recombinant PreS2-S protein from the hepatitis B virus surface antigen in Pichia pastoris

The aim of this work is the expression of the PreS2-S region of surface antigen of hepatitis B virus (HBV) in yeast Pichia pastoris. A cDNA fragment encoding the Pres2-S protein of HBV was cloned to yeast transfer vectors. Based on cloned new plasmids pPIC3.5-PreS2-S (8707 bp) and pPIC9-PreS2-S (8980 bp) the recombinant strains of P. pastoris producing the PreS2-S region of surface antigen of HBV were obtained. The PAGE electrophoresis and immunoblotting of obtained recombinant PreS2-S protein confirm the molecular weight (34 kDa) and high specificity to the HBV antibodies)AU)

El objetivo de este trabajo es la expresión de la región PreS2-S del antígeno de superficie del virus de la hepatitis B en la levadura Pichia pastoris. Se clonó un fragmento de ADNc que codifica la proteína PreS2-S del VHB en vectores de transferencia de levadura. A partir de los nuevos plásmidos clonados pPIC3.5-PreS2-S (8707 pb) y pPIC9-PreS2-S (8980 pb) se obtuvieron las cepas recombinantes de P. pastoris productoras de la región PreS2-S del antígeno de superficie del VHB. La electroforesis PAGE y la inmunotransferencia de la proteína PreS2-S recombinante obtenida confirman el peso molecular (34 kDa) y la alta especificidad a los anticuerpos contra el VHB(AU)

A comparative study on chemical composition and antimicrobial activity of essential oils from three Phlomis species from Uzbekistan.

Essential oils obtained from the aerial parts of Phlomis bucharica, P. salicifolia and P. sewerzowii were determined using GC-FID and GC-MS methods. A total of 76 components were identified in the three species representing 97.12, 88.34, and 96.41% of the whole oil, respectively. High percentages of thymol (20.41%) and camphor (14.46%) exist in P. bucharica oil. Methyl palmitate predominates in P. salicifolia oil representing 51.15% whereas thymol (35.76%) is the major constituent in P. sewerzowii essential oil. GC-MS analyses showed that P. bucharica and P. sewerzowii are more closely related comparable to P. salicifolia. The antimicrobial activity of the essential oils was assessed against different microorganisms using agar-disc diffusion and broth microdilution assay. Among the three tested species, the essential oil of P. salicifolia showed the highest antibacterial activity.

Chemical composition, antimicrobial and antioxidant activities of the essential oils of three Uzbek Lamiaceae species.

The chemical composition of the essential oil from the aerial parts of three Lamiaceae species from Uzbekistan was investigated by GC-MS analysis. ß-Linalool (26.6%), α-terpineol (10.0%), coumarin (8.9%) and 4,5,7,7α-tetrahydro-4,4,7α-trimethyl-2(6H)-benzofuranone (5.4%) resulted as the main components of Ajuga turkestanica essential oil, while camphene (17.1%), 1,8-cineole (15.9%), ß-cymene (7.9%) and limonene (7.4%) in Phlomis regelii. The essential oil of Thymus seravschanicus was dominated by thymol (37.5%), phellandral (26.0%), τ-terpinene (6.6%) and ß-cymene (5.2%). The essential oils had considerable antimicrobial activity against different bacterial strains and fungi. Among the tested samples of essential oils, P. regelii essential oil has the significant antioxidant activity with IC50 value of 117.8 ± 8.02 µg/mL.

Component composition of the extracts and essential oils from the Alhagi canescens, growing in Uzbekistan and their antimicrobial activity.

The volatile compounds of hexane, benzene extracts and essential oils (EOs) isolated by steam- and hydrodistillation methods from aerial part of Alhagi canescens were studied by GC-MS analysis. Seventeen components were found in the hexane and benzene extracts, among them palmitic acid (25.2 and 22.1%), neophytadiene (7.3 and 22.3%), cis-chrysanthenyl acetate (11.0% in benzene), cis-geranyl acetate (7.8% in benzene) were major components. The first time fifty-six volatile compounds were identified in the EOs and camphor (5.9 and 27.8%), bicyclogermacrene (13.4 and 4.0%), α-copaene (6.1 and 2.6%), (-)-germacrene D (10.8 and 3.6%) and eucalyptol (3.7 and 8.1%) were the main components. The benzene, hexane extracts and EOs were screened for their antibacterial and antifungal activity. The benzene extract possess the highest antibacterial activity against Bacillus subtilis (12.12 ± 0.20) and Staphylococcus aureus (10.04 ± 0.10).