Asperterpenoid A (1), a novel sesterterpenoid with a new carbon skeleton, has been isolated from a mangrove endophytic fungus Aspergillus sp. 16-5c. Its structure was characterized by extensive spectroscopic methods, and the absolute configuration was determined by single crystal X-ray diffraction analysis. Asperterpenoid A (1) exhibited strong inhibitory activity against Mycobacterium tuberculosis protein tyrosine phosphatase B (mPTPB) with an IC(50) value of 2.2 μM.
Six new isocoumarins, compounds1–4and14–15, two new benzofurans,16–17, along with nine known isocoumarin analogues,5–13were obtained from the mangrove endophytic fungusTalaromyces amestolkiaeYX1.
Diaporisoindoles A (1) and B (2), two novel isoprenylisoindole alkaloids, and an unusual diisoprenylisoindole dimer diaporisoindole C (3), together with a precursor tenellone C (4) were all isolated from the endophytic fungus Diaporthe sp. SYSU-HQ3. The absolute configurations of 1-4 were elucidated by spectroscopic analysis, X-ray diffraction, and quantum chemical calculations. Diaporisoindole A (1) and tenellone C (4) exhibited inhibitory activity against Mycobacterium tuberculosis protein tyrosine phosphatase B with IC values of 4.2 and 5.2 μM.
Asperterpenol A (1) and asperterpenol B (2), two novel sesterterpenoids with an unusual 5/8/6/6 tetracyclic ring skeleton, were isolated from a mangrove endophytic fungus Aspergillus sp. 085242. The structures were elucidated on the basis of spectroscopic methods and the absolute configurations determined by single-crystal X-ray diffraction analysis. Compounds 1 and 2 inhibit acetylcholinesterase with IC50 values of 2.3 and 3.0 μM, respectively.
Diaporindenes A-D (1-4), four unusual 2,3-dihydro-1 H-indene isomers, a novel isoprenylisobenzofuran A (5), two new isoprenylisoindole alkaloids diaporisoindoles D and E (6 and 7), and a new benzophenone derivative tenellone D (11), together with four known biogenetic agents (8-10 and 12), were all separated from the endophytic fungus Diaporthe sp. SYSU-HQ3 guided by ultraperformance liquid chromatography high-resolution mass spectrometry. The absolute configurations of 1-7 and 11 were defined by X-ray diffraction, quantum chemical calculations, and spectroscopic analysis. Diaporindenes A-D (1-4) possessed an unprecedented chemical skeleton featuring a 2,3-dihydro-1 H-indene ring and a 1,4-benzodioxan moiety. All of the isolates (1-12) were tested for their inhibitory effects on the production of nitric oxide in lipopolysaccharide-induced microglial cells (RAW 264.7 cells). Compounds 1-5, 8, and 9 were found to exhibit significant inhibitory effects against nitric oxide production with IC values from 4.2 to 9.0 μM and SI values from 3.5 to 6.9. In addition, the structure-activity relationships of all compounds were summarized.
Two new sesterterpenoids, aspterpenacids A (1) and B (2), with an unusual carbon skeleton of a 5/3/7/6/5 ring system were isolated from the mangrove endophytic fungus Aspergillus terreus H010. Their structures were elucidated on the basis of spectroscopic methods, single-crystal X-ray diffraction analysis, and electronic circular dichroism calculations. A biogenetic pathway for 1 and 2 is proposed. Both 1 and 2 showed no significant antibacterial activity or cytotoxicity at 50 μM.
Previous studies have demonstrated that the difference between resting-state brain activations depends on whether the subject was eyes open (EO) or eyes closed (EC). However, whether the spontaneous fluctuations are directly related to these two different resting states are still largely unclear. In the present study, we acquired resting-state functional magnetic resonance imaging data from 24 healthy subjects (11 males, 20.17 ± 2.74 years) under the EO and EC states. The amplitude of the spontaneous brain activity in low-frequency band was subsequently investigated by using the metric of fractional amplitude of low frequency fluctuation (fALFF) for each subject under each state. A support vector machine (SVM) analysis was then applied to evaluate whether the category of resting states could be determined from the brain spontaneous fluctuations. We demonstrated that these two resting states could be decoded from the identified pattern of brain spontaneous fluctuations, predominantly based on fALFF in the sensorimotor module. Specifically, we observed prominent relationships between increased fALFF for EC and decreased fALFF for EO in sensorimotor regions. Overall, the present results indicate that a SVM performs well in the discrimination between the brain spontaneous fluctuations of distinct resting states and provide new insight into the neural substrate of the resting states during EC and EO.
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