Toporkova, Yana Y.Askarova, Elena K.Gorina, Svetlana S.Mukhtarova, Lucia S....
12页
查看更多>>摘要：Nonclassical P450s of the CYP74 family catalyse the secondary conversions of fatty acid hydroperoxides to bioactive oxylipins in plants. The model organism, spikemoss Selaginella moellendorffii Hieron, possesses at least ten CYP74 genes of novel J, K, L, and M subfamilies. The cloning of three CYP74L genes and catalytic properties of recombinant proteins are described in the present work. The CYP74L1 possessed mainly hydroperoxide lyase (HPL) activity towards the 13(S)-hydroperoxide of a linolenic acids (13-HPOT) and nearly equal HPL and allene oxide synthase (AOS) activities towards the 13(S)-hydroperoxide of linoleic acids (13-HPOD). The 9-hydroperoxides were poor substrates for CYP74L1 and led to the production of mainly the a ketols (AOS products) and minorities of HPL and epoxyalcohol synthase (EAS) products. The CYP74L2 possessed the AOS activity towards all tested hydroperoxides. CYP74L3 possessed low HPL/EAS activity. Besides, the aerial parts of S. moellendorffii plants possessed complex oxylipins patterns including divinyl ethers, epoxyalcohols, and 12-oxo-phytodienoic acid. Characterization of the CYP74L enzymes and oxylipin pattern updates the knowledge on the complex oxylipin biosynthetic machinery in the surviving oldest taxa of vascular plants.
查看更多>>摘要：Eight undescribed triterpenoids (pterohoonoids A H) including four oleananes, one nor-oleanane and three norursanes, along with seven known analogues, were isolated from the whole plants of Pterocephalus hookeri (Dipsacaceae). The structures with relative stereochemistries of these molecules were elucidated mainly by spectroscopic analyses, and the absolute configurations of the undescribed ones were assigned by a variety of methods, including time-dependent density functional theory (TD-DFT) based electronic circular dichroism (ECD) calculation, Rh-2(OCOCF3)4-induced ECD experiment and chemical transformation. The inhibitory effects toward the diabetes target alpha-glucosidase of all the isolates were assessed, and four of them exhibited pronounced activity with IC50 values ranging from 6.8 to 55.8 mu M. In addition, four compounds also showed inhibition against the nitric oxide (NO) production induced by lipopolysaccharide (LPS) in RAW264.7 macrophage cells (IC50 = 12.4-63.7 mu M). Further assays demonstrated that the most active compound pterohoonoid A inhibited the release of two key pro-inflammatory cytokines TNF-alpha and IL-6 in a dose-dependent manner.
查看更多>>摘要：Phytochemical investigation of the ethanol extract from wild Momordica charantia vines has resulted in isolation of seven cucurbitane-type triterpenoids, including six undescribed compounds, kuguaovins H.M, and the known compound, momordicoside K. The structures of the isolated compounds were elucidated on the basis of spectroscopic analyses, including 1D and 2D NMR, and MS experiments. The chemical structure of momordicoside K was determined for the first time by X-ray crystallographic analysis and its absolute configuration assigned. The cytotoxicity against four human tumor cell lines and anti-inflammatory activities on LPS-stimulated RAW264.7 macrophages were evaluated. Of the isolates, kaguaovin L exhibited potential cytotoxicity against MCF-7, HEp-2, Hep-G2, and WiDr cancer cell lines and showed moderate anti-NO production activity. In addition, kuguaovins H and J also showed the stimulatory effect of GLP-1 secretion on the murine intestinal secretin tumor cell line (STC-1).
查看更多>>摘要：Development of the kiwifruit industry has been severely hindered by the canker disease, which is caused by the bacterium Pseudomonas syringae pv. Actinidiae (Psa). However, endophytic fungi associated with healthy kiwi plants may protect host plants through the production of metabolites with potent anti-Psa activity. In the current study, four undescribed isobenzofuranones, namely sporulactones A-D, two undescribed isocoumarins, namely sporulactones E and F, together with eight known analogs were isolated from the kiwi endophytic fungus Paraphaeosphaeria sporulosa. The structures with absolute configurations were established by extensive spectroscopic methods, quantum chemistry calculations, and X-ray diffraction experiments. In addition, five of the compounds exhibited anti-Psa activity, with minimum inhibitory concentration (MIC) values ranging from 25 to 100 mu g/mL. These findings suggest that the small polyketide metabolites produced by P. sporulosa play an important role in the antibacterial properties of the endophyte.
查看更多>>摘要：Lemongrass essential oil has antifungal and anti-cancerous properties. Heat-shock protein (HSP90), an ATPdependent molecular chaperone found in eukaryotes, is involved in protein folding, stability, and disease, making it a promising research topic. Both in silico and in vitro approaches were used to provide a clear insight into the HSP90-ATPase 3D structures, activity, and their interaction with the essential oil constituents among various species such as fungi (S. cerevisiae), parasites (P. falciparum), and humans. For in silico studies, sequence alignment, docking (AutoDock), and absorption, distribution, metabolism, and excretion (ADME) properties were evaluated to obtain hit compounds specifically against each HSP90-ATPase. The hit compounds obtained were evaluated for their efficacy in the in vitro studies of S. cerevisiae. In vitro studies were carried out targeting HSP90-ATPases via lemongrass essential oil components individually and in combination as a function of concentration and various salt concentrations. Results suggest that sequence alignment exists of over 75% among these three species. The best docking score was possessed by Geraniol and its constituent (geldanamycin >= -4.93 kcal/mol) (a known antifungal and antitumor against HSP90) in all the above species. Lemongrass oil and the combination of Geraniol and Citral at concentrations of 80 mu g/mL showed the maximum inhibition of ATPase and HSP90-ATPase activity compared to their individual treatment. Therefore, both in silico and in vitro studies provide clear evidence of specific inhibitory action of lemongrass oil, Geraniol, and Citral against the ATPase and HSP90-ATPase activities and might show potential as antifungal and antitumor drugs.
查看更多>>摘要：Epigenetic modifiers are proved to be effective specialized products-mining tools by rationally regulating the gene expression of fungal biosynthetic pathways. Chemical investigation on the histone deacetylase inhibitor (HDI) vorinostat (also known as SAHA)-modified cultures of the basidiomycete Cyathus stercoreus (Schwein.) De Toni (Nidulariaceae) led to the isolation of nine previously undescribed sesquiterpenes, and four previously described ones. The structures of the nine undescribed compounds were determined by extensive NMR spectroscopic analysis, HRESIMS analysis, as well as ECD and NMR calculations. Notably, the isolated sesquiterpenes are exclusive or overproduced from the epigenetic modified cultures compared to the negative control cultures. Additionally, the skeleton types of the isolated sesquiterpenes include protoilludalane, illudalane, 1,11-seco-protoilludalane, 10,11-seco-illudalane, and 14(11 -> 10)abeo-illudalane. It is noteworthy that the 14(11 -> 10)abeoilludalane skeleton is reported for the first time. Cystercorodiol A, 4-O-acetylcybrodol, cystercorotone, and cybrodol showed weak inhibitory activity against the bacterium Escherichia coli ATCC25922 with the inhibitory rates 34.7%, 33.0%, 32.3%, and 29.6% at the concentration 200 mu M, respectively. This study suggested that epigenetic modifiers are also an effective tool for specialized metabolite-mining in basidiomycetes.
查看更多>>摘要：Three steroidal saponins detected by LC-MS were isolated from the leaves of Agave desmetiana hort. The three saponins were characterized as; Tigogenin 3 - [{O - beta - D -xylopyranosyl (1 -> 2) - alpha - L-rhamnopyranosyl (1 -> 3)}-beta-D-glucopyranoside), Tigogenin- 3 - ([O-alpha-L-rhamnopyranosyl (1 -> 3) - beta - D -glalactopyranosyl (1 -> 2)] - beta - D - glucopyranoside) and Tigogenin- 3 -([{O - alpha - L - rhamnopyranosyl (1 -> 4)} - beta - D - gal-actopyranosyl (1 -> 3) - beta - D - xylopyranosyl (1 -> 2)] - beta - D - glucopyranoside). Identification and structure elucidation of the isolates were done via 1D and 2D NMR techniques, and chemical methods. Cytotoxic activity for the crude saponins and the three isolated compounds were evaluated against Hepg-2 and Mcf-7 cell lines. Compound 2 proved to be the most cytotoxic against tested cell lines with an IC50 2.97 and 2.49 mu g/ml respectively.
Gezer, EmreUner, GoklemKucuksolak, MelisKurt, Mustafa Unver...
9页
查看更多>>摘要：Polyether ionophores represent a large group of naturally occurring compounds mainly produced by Streptomyces species. With previously proven varieties of bioactivity including antibacterial, antifungal, antiparasitic, antiviral and anti-tumor effects, the discovery of undescribed polyethers leading to development of efficient therapeutics has become important. As part of our research on polyether-rich Streptomyces cacaoi, we previously performed modification studies on fermentation conditions to induce synthesis of specialized metabolites. Here, we report four undescribed and nine known polyether compounds from S. cacaoi grown in optimized conditions. Antimicrobial activity assays revealed that four compounds, including the undescribed (6), showed strong inhibitory effects over both Bacillus subtilis and methicillin-resistant Staphylococcus aureus (MRSA) growth. Additionally, K41-A and its C15-demethoxy derivative exhibited significant cytotoxicity. These results signified that selectivity of C15-demethoxy K41-A towards cancer cells was higher than K41-A, which prompted us to conduct mechanistic experiments. These studies showed that this uninvestigated compound acts as a multitarget compound by inhibiting autophagic flux, inducing reactive oxygen species formation, abolishing proteasome activity, and stimulating ER stress. Consequently, the optimized fermentation conditions of S. cacaoi led to the isolation of undescribed and known polyethers displaying promising activities.
查看更多>>摘要：Conium divaricatum, even though exhibiting morphological differences in comparison to its congener of European origin Conium maculatum, is still considered a disputed taxon often referred to as a synonym of the latter. Herein, essential oils of various plant tissues from several populations of both taxa were comparatively investigated, showing distinct chemical profiles. In the case of C. divaricatum, the essential oils were dominated by hydrocarbon esters, among which the main constituents 4 '-oxodecyl hexanoate, 4 '-oxododecyl hexanoate and 4 ' oxooctyl hexanoate were isolated and identified as undescribed natural products. In contrast, the essential oils of C. maculatum were dominated by hydrocarbon alkanes, alkenes and ketones, as well as the polyacetylene (Z)falcarinol. Even though determination of the total alkaloids content and toxicity assessment against the crustacean Artemia salina did not reveal significant differences, the distinct chemical profiles and the morphological differences observed for both taxa, strongly support their distinction as separate species.
查看更多>>摘要：Two undescribed phenolic derivatives musaones A and B, six undescribed gamma-butyrolactone musaolides A-F, together with two undescribed cyclopentanone musaolides G and H were isolated from the solid culture of an endophytic strain Phaeosphaeriopsis musae M. Arzanlou & Crous (Phaeosphaeriaceae). Their structures were unambiguously elucidated by extensive spectral analyses. The absolute configurations of two diastereomers musaolides G and H were assigned by comparing their experimental and calculated ECD data. Moreover, the in vitro alpha-glucosidase inhibition and cytotoxic activities of isolated compounds (except musaolide D) were evaluated to understand their biological effects, wherein musaone B and musaolide F displayed promising alpha-glucosidase inhibition with IC50 values of 37.3 +/- 0.59 mu M and 105.18 +/- 2.76 mu M respectively, compared to the positive control acarbose (24.99 +/- 1.28 mu M).
NSTL
Elsevier