98%
921
2 minutes
20
-12-oxo-Phytodieneoic acid-α-monoglyceride () was isolated from . The chemical structure of was elucidated based on exhaustive 1D and 2D NMR spectroscopic measurements and supported by FDMS and HRFDMS data. The absolute configuration of the -OPDA moiety in was determined by comparison of H NMR spectra and ECD measurements. With respect to the absolute configuration of the β-position of the glycerol backbone, the 2:3 ratio of () to () was determined by making ester-bonded derivatives with ()-(+)-α-methoxy-α-trifluoromethylphenylacetyl chloride and comparing H NMR spectra. Wounding stress did not increase endogenous levels of , and it was revealed had an inhibitory effect of post germination growth. Notably, the endogenous amount of was higher than the amounts of (+)-7--jasmonic acid and (+)--OPDA in intact plants. also showed antimicrobial activity against Gram-positive bacteria, but jasmonic acid did not. It was also found that α-linolenic acid-α-monoglyceride was converted into in the plant, which implied α-linolenic acid-α-monoglyceride was a biosynthetic intermediate of .
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acs.jnatprod.3c01237 | DOI Listing |
J Nat Prod
September 2025
College of Pharmacy, Chungbuk National University, Cheongju 28160, Republic of Korea.
LC-HRMS/MS-based molecular-network-guided chemical investigation of led to the isolation of seven undescribed tetrasaccharide-type resin glycosides (-). Their structures were elucidated using 1D and 2D NMR and HRESIMS analysis. Isolated resin glycosides were comprised of d-glucose, d-fucose, d-quinovose, and l-rhamnose, and these monosaccharides were partially acylated with acetyl, isobutyryl, -hexanoyl, and niloyl organic acids.
View Article and Find Full Text PDFRev Sci Instrum
September 2025
Department of Physics, University of Strathclyde, Glasgow, G1 1XJ, United Kingdom.
The calibration of the JET x-ray spectrometer is presented. The absolute throughput, diffractor focusing, and instrument function of the spectrometer are presented, and the quality of the ion temperature measurement is re-assessed, particularly at the lower end. The addition of a second diffractor enables the simultaneous measurements of the spectra from H- and He-like nickel, which widens the spatial coverage of the core-ion temperature measurements for high-performance plasmas at a fixed Bragg angle range.
View Article and Find Full Text PDFJ Nat Med
September 2025
College of Life Sciences, Shanghai Normal University, Shanghai, 2014018, People's Republic of China.
Two new (1-2) and eight known pterosins (3-10) were obtained from the aerial parts of Hypolepis punctata. One compound (11) was synthesized from compound 4. Their structures were established by spectroscopic methods and the absolute configuration was further determined by single-crystal X-ray diffraction analysis for compounds 1, 3 and 4.
View Article and Find Full Text PDFJAMA Neurol
September 2025
Department of Radiology, University of Washington, Seattle.
Importance: Recent longitudinal studies in patients with unruptured intracranial aneurysms (UIAs) suggested that aneurysm wall enhancement (AWE) on magnetic resonance imaging (MRI) predicts growth and rupture. However, because these studies were limited by small sample size and short follow-up duration, it remains unclear whether this radiological biomarker has predictive value for UIA instability.
Objective: To determine the 4-year risk of instability of UIAs with AWE and investigate whether AWE is an independent predictor of UIA instability.
Org Lett
September 2025
School of Science and Engineering, Shenzhen Key Laboratory of Innovative Drug Synthesis, The Chinese University of Hong Kong, Shenzhen, Shenzhen 518172, P. R. China.
The first asymmetric total synthesis of 5,10-seco-neoansamycin A, a 19-membered cyclic octaketide, was achieved in 20 steps (with several steps being telescoped) and 6.7% overall yield starting from the reported compound, thus leading to the assignment of its absolute configuration. This convergent synthetic approach features late-stage macrolactamization, a judicious application of an asymmetric aldol reaction.
View Article and Find Full Text PDF