scholarly journals Aspergiloid I, an unprecedented spirolactone norditerpenoid from the plant-derived endophytic fungus Aspergillus sp. YXf3

2014 ◽  
Vol 10 ◽  
pp. 2677-2682 ◽  
Author(s):  
Zhi Kai Guo ◽  
Rong Wang ◽  
Wei Huang ◽  
Xiao Nian Li ◽  
Rong Jiang ◽  
...  

An unusual C18 norditerpenoid, aspergiloid I (1), was isolated from the culture broth of Aspergillus sp. YXf3, an endophytic fungus derived from Ginkgo biloba. Its structure was unambiguously established by analysis of HRMS–ESI and spectroscopic data, and the absolute configuration was determined by low-temperature (100 K) single crystal X-ray diffraction with Cu Kα radiation. This compound is structurally characterized by a new carbon skeleton with an unprecedented 6/5/6 tricyclic ring system bearing an α,β-unsaturated spirolactone moiety in ring B, and represents a new subclass of norditerpenoid, the skeleton of which is named aspergilane. The hypothetical biosynthetic pathway for 1 was also proposed. The cytotoxic, antimicrobial, anti-oxidant and enzyme inhibitory activities of 1 were evaluated.

2018 ◽  
Vol 13 (1) ◽  
pp. 1934578X1801300 ◽  
Author(s):  
Zhong Wang ◽  
Peng Fan ◽  
Tong-Dan Xue ◽  
Lin-Lin Meng ◽  
Wen-Bin Gao ◽  
...  

Two new isocoumarin derivatives, 6,8-dihydroxy-7-methyl-1-oxo-1H-isochromene-3-carboxylic acid (1) and 6,8-dihydroxy-3-methoxy-3,7- dimethyl-isochroman-1-one (2), together with five known compounds (3-7), were isolated from the endophytic fungus Pestalotiopsis coffeae derived from the Chinese plant fishtail palm. The structures of these compounds were determined mainly by analysis of their NMR spectroscopic data. The structure of compound 2 was further confirmed by X-ray diffraction.


2017 ◽  
Vol 12 (12) ◽  
pp. 1934578X1701201 ◽  
Author(s):  
Wei-Hua Yuan ◽  
Ying Zhang ◽  
Peng Zhang ◽  
Ru-Ru Ding

A new chlorinated 11-noreremophilane-type sesquiterpene (1) together with 3-epiisopetasol, PR-amide and mycophenolic acid (2–4) were isolated from endophytic fungus Penicillium citreonigrum. The structures of 1–4 were elucidated by a combination of spectroscopic data and single-crystal X-ray diffraction analysis. Among them, compounds 1 and 4 showed moderate antioxidant capacities compared with ascorbic acid at 0.2 mM concentration.


2016 ◽  
Vol 12 ◽  
pp. 2077-2085 ◽  
Author(s):  
Ze’en Xiao ◽  
Senhua Chen ◽  
Runlin Cai ◽  
Shao’e Lin ◽  
Kui Hong ◽  
...  

The chemical investigation of the mangrove endophytic fungus Aspergillus sp. 085242 afforded eight isocoumarin derivatives 1–8 and one isoquinoline 9. Asperisocoumarins A and B (1 and 2) were new furoisocoumarins, and asperisocoumarins E and F (5 and 6) were new isocoumarins. Their structures were established by analysis of their spectroscopic data and the absolute configuration of compound 2 was unambiguously determined by X-ray structure analysis and ECD calculation. Moreover, the absolute configurations of compounds 3–5 were assigned by comparison of their ECD spectra with isocoumarins described in the literature. Asperisocoumarins C and D (3 and 4) were fully characterized spectroscopically and isolated from a natural source for the first time. Asperisocoumarins A–D (1–4) related to the class of furo[3,2-h]isocoumarins are rarely occurring in natural sources. Compounds 2, 5, and 6 showed moderate α-glucosidase inhibitory activity with IC50 of 87.8, 52.3, and 95.6 μM, respectively. In addition, compounds 1 and 3 exhibited weak radical scavenging activity with EC50 values of 125 and 138 μM, respectively.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Dong-Lin Zhao ◽  
Lu-Jia Yang ◽  
Ting Shi ◽  
Chao-Yi Wang ◽  
Chang-Lun Shao ◽  
...  

Abstract Two new harziane diterpene lactones, possessing a 6/5/7/5-fused carbocyclic core containing a lactone ring system, harzianelactones A and B (1 and 2), and five new harziane diterpenes, harzianones A–D (3–6) and harziane (7), were isolated from the soft coral-derived fungus Trichoderma harzianum XS-20090075. Their structures were determined by extensive NMR spectroscopic data, ECD and OR calculations, as well as X-ray diffraction. The isolated compounds exhibited potent phytotoxicity against seedling growth of amaranth and lettuce. Harziane diterpenes were rarely reported for their remarkably bioactivities, and it was the first report to study the phytotoxicity of harziane diterpenes, which provide a new application of such compounds in agriculture for future research.


RSC Advances ◽  
2016 ◽  
Vol 6 (36) ◽  
pp. 30277-30284 ◽  
Author(s):  
Zhi-Wen Liu ◽  
Xiao-Jun Huang ◽  
Han-Lin Xiao ◽  
Guo Liu ◽  
Jian Zhang ◽  
...  

The structures and absolute configurations of seven new iboga-type alkaloids 1–7 were determined by spectroscopic data, Mosher's method, single crystal X-ray diffraction and ECD analyses.


Author(s):  
Ruyi Ding ◽  
Cui Xu ◽  
Xu Chen ◽  
Mengyun Bao ◽  
Xiaoting Qiu

The 2-carboxy-6-hydroxyoctahydroindole moiety is an essential residue for the antithrombotic activity of aeruginosins, which are a class of cyanobacteria-derived bioactive linear tetrapeptides. The biosynthetic pathway of the 2-carboxy-6-hydroxyoctahydroindole moiety has not yet been resolved. AerF was indicated to be involved in the biosynthesis of the 2-carboxy-6-hydroxyoctahydroindole moiety. This study reports the cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of AerF fromMicrocystis aeruginosawith a C-terminal His6tag. The crystal diffracted to a maximum resolution of 1.38 Å and belonged to the tetragonal space groupP4322, with unit-cell parametersa=b= 101.581,c= 116.094 Å. The calculated Matthews coefficient and solvent content of the crystal were 2.47 Å3 Da−1and 50.32%, respectively. The initial model of the structure was obtained by the molecular-replacement method and refinement of the structure is in progress.


2012 ◽  
Vol 67 (6) ◽  
pp. 589-593 ◽  
Author(s):  
Daniel Winkelhaus ◽  
Beate Neumann ◽  
Norbert W. Mitzel

The reaction of (C6F5)2BCl with 8-lithio-N,N-dimethyl-1-naphthylamine (1) afforded the fivemembered ring system 8-bis(pentafluorophenyl)boryl-N,N-dimethyl-1-naphthylamine (2) with an intramolecular dative B-N bond. The compound was characterised by elemental analysis, NMR spectroscopy and single-crystal X-ray diffraction.


Planta Medica ◽  
2021 ◽  
Author(s):  
Hanli Ruan ◽  
Ying Gao ◽  
Ruihua Mao ◽  
Ye Liu ◽  
Ming Zhou

Two new cytochalasans with a rare 6/6/5/5/7 pentacyclic ring system, named chaetoconvosins C−D (1−2), together with two known congeners (3−4), were isolated from the fermentation of an endophytic fungus, Chaetomium sp. SG-01, harbored in the fibrous roots of Schisandra glaucescens Diels. Their structures including the absolute configuration were elucidated by extensive spectroscopic (HRESIMS, NMR, and ECD) and X-ray crystallographic analyses. The TRAIL sensitivity of 1–4 in a TRAIL-resistant HT29 colorectal cancer cell line was evaluated, which revealed that co-treatment of 1–4 at 50 µM with TRAIL (150 ng/mL) reduced the HT29 cell viability by 19.0%, 24.1%, 17.9%, and 15.5%, respectively, compared to treatment with 1–4 alone.


1982 ◽  
Vol 37 (11) ◽  
pp. 1393-1401 ◽  
Author(s):  
Beatrix Milewski-Mahrla ◽  
Hubert Schmidbaur

Reactions of pentamethylantimony (CH3)5Sb with carboxylic acids in the molar ratio 1:2 afford one equivalent of methane and essentially quantitative yields of crystalline tetramothylstibonium hydrogendicarboxylates. Six new compounds of this series have been synthesized using benzoic, o-phthalic, salicylic, 4-ethoxy-salicylic, oxalic, and malic acid, and characterized by analytical and spectroscopic data. An ionic structure with strong hydrogen bonds in the anionic components is proposed.The crystal structures of the hydrogen-dibenzoato (1), hydrogen-ortho-plithalato (2) and 4-ethoxy-hydrogen-salicylate (3) were determined by single crystal X-ray diffraction. The compounds can be described as having ionic lattices with some donor-acceptor inter­actions between the stibonium centers and the carboxylate oxygen atoms. The anions are characterized by strong hydrogen bonds O...H...O. Thus, the (CH3)4Sb-tetrahedron in 1 is distorted by two benzoate oxygon atoms (at 304(2) and 340(2) pin). The cation in 2 is largely undistorted and the anion has a hydrogenphthalate hydrogen bond of d(O...H...O) = 232 pm. The cation-anion contact in 3 is as short as d(Sb-O) = 289 pm rendering the Sb atom pentacoordinate.


Marine Drugs ◽  
2020 ◽  
Vol 18 (11) ◽  
pp. 549
Author(s):  
Vimal Nair ◽  
Min Cheol Kim ◽  
James A. Golen ◽  
Arnold L. Rheingold ◽  
Gabriel A. Castro ◽  
...  

A new cytotoxic thiodepsipeptide, verrucosamide (1), was isolated along with the known, related cyclic peptide thiocoraline, from the extract of a marine-derived actinomycete, a Verrucosispora sp., our strain CNX-026. The new peptide, which is composed of two rare seven-membered 1,4-thiazepane rings, was elucidated by a combination of spectral methods and the absolute configuration was determined by a single X-ray diffraction study. Verrucosamide (1) showed moderate cytotoxicity and selectivity in the NCI 60 cell line bioassay. The most susceptible cell lines were MDA-MB-468 breast carcinoma with an LD50 of 1.26 µM, and COLO 205 colon adenocarcinoma with an LD50 of 1.4 µM. Also isolated along with verrucosamide were three small 3-hydroxy(alkoxy)-quinaldic acid derivatives that appear to be products of the same biosynthetic pathway.


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