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În baza temei tratate a fost selectată literatura de specialitate prezentă în biblioteca USM și în bazele de date NCBI, MedPUB, Google scholar. Sursele de specialitate au fost analizate pornind de la principalele plante medicinale utilizate în tratamentul bolilor respiratorii: Althaea officinalisL., Hedera helix L., Hippophae rhamnoidesL., Inula helenium L., Malva sylvestrisL., Marrubium vulgareL., Origanum vulgare L., Plantago majorL., Primula verisL., Sambucus nigraL., Silybum marianumL., Taraxacum officinale L., Thymus vulgarisL., Tussilago farfara L. Rezultatele studiului au permis identificarea plantelor medicinale cu activitate antiinflamatoare, care ar putea servi drept potențiale surse de profilaxie / tratament în caz de Covid-19. Pentru toate plantele luate în studiu au fost prezentate dovezi științifice cu referire la potențialul antiinflamator al acestora, ceea ce indică asupra posibilității de utilizare a acestor plante în atenuarea simptomaticii în Covid-19.

The Arabidopsis thaliana VEP1 gene product shows about 70% sequence identity to Digitalis lanata progesterone 5beta-reductase, an enzyme considered to catalyze a key step in the biosynthesis of cardiac glycosides. A. thaliana does not accumulate cardenolides but protein extracts prepared from its leaves were capable of reducing progesterone to 5beta-pregnane-3,20-dione. A full-length cDNA clone encoding a Delta(4,5)-steroid 5beta-reductase (At5beta-StR, EC 1.1.1.145/1.3.1.23), a member of the short-chain dehydrogenase/reductase (SDR) family, was isolated from A. thaliana leaves. A SphI/SalI At5beta-StR gene fragment was cloned into the pQE vector system and transformed into Escherichia coli. The gene was functionally expressed and the recombinant His-tagged fusion protein was characterized. K(m) values and specific activities for putative 3-oxo-Delta(4,5)-steroid substrates such as progesterone, cortisol, cortexone and 4-androstene-3,17-dione, and for the co-substrate NADPH were determined. Progesterone was stereo-specifically reduced to 5beta-pregnane-3,20-dione and none of the 3-oxo-Delta(5,6)-steroids tested were accepted as a substrate. The gene encoding At5beta-StR was strongly transcribed in stems and leaves. A three-dimensional model of At5beta-StR highlights a close structural similarity to the related, previously described D. lanata progesterone 5beta-reductase. This homology extends to the active site where single amino acid substitutions might be responsible for the increased catalytic efficiency of At5beta-StR when compared to the activity of the recombinant form of the D. lanata enzyme.

Из мицелиального гриба Aspergillus niger 33-19 CNMN FD 02A, культивируемого в стандартных условиях и после облучения миллиметровыми волнами λ = 7,1, были получены два ферментных препарата со степенью очистки Г10x, отличающихся по уровню амилолитической активности (на 29,9% выше в препарате, подвергнутом облучению), но с идентичной специфической активностью в 138,3 ед/мг и 141,0 ед/мг белка. Очистка α-амилазы методами гель-фильтрации и ионообменной хроматографии привела к увеличению специфической активности в 8,9 раз в контрольном и в 8,2 раза в облученном препаратах, с 25% и 17% выходом, соответственно. SDS-ПААГ белков, выделенных из начальных препаратов, показала появление нового полипептида с молекулярной массой 45 kDa в образце, подвергнутом облучению. Полипептидный спектр очищенной α-амилазы обоих препаратов после ионной хроматографии представляет 2 неизменныe полипептидныe полосы с молекулярной массой 66 и 40,5 kDa, определенных как изоформы α-амилазы., Micromycete Aspergillus niger 33-19 CNMN FD 02A standard cultivated and exposed to λ = 7.1 millimeter waves radiation has been used to obtain two enzyme preparations with the 10x degree of purity, with a 29.9% difference of the α-amylase activity in irradiated preparation but with a similar specific activity of protein of 138.3 U/mg and 141.0 U/mg. The α-amylase purification through gel filtration and ion exchange chromatography has resulted in the increase of 8.9 times of the specific activity for the control and of 8.2 times for the irradiated samples, with the yields of 25% and 17%, respectively. The SDS-PAGE of proteins isolated from initial preparations indicates the expression of new polypeptide of 45 kDa in the irradiated samples. Polypeptide spectrum of α-amylase from both preparations, purified through ion chromatography, shows two unchanged polypeptide bands of 66 and 40.5 kDa, identified as α-amylase isomorphs.

Putrescine N-methyltransferase (PMT) catalyses S-adenosylmethionine (SAM)-dependent methylation of putrescine in tropane alkaloid biosynthesis. PMT presumably evolved from the ubiquitous spermidine synthase (SPDS). SPDS protein structure suggested that only few amino acid exchanges in the active site were necessary to achieve PMT activity. Protein modelling, mutagenesis, and chimeric protein construction were applied to trace back evolution of PMT activity from SPDS. Ten amino acid exchanges in Datura stramonium SPDS dismissed the hypothesis of facile generation of PMT activity in existing SPDS proteins. Chimeric PMT and SPDS enzymes were active and indicated the necessity for a different putrescine binding site when PMT developed.