Background
Concomitant positive patch test reactions in patients sensitized to isobornyl acrylate (IBOA) have rarely been documented.
Objectives
To report concomitant sensitizations in patients with ...allergic contact dermatitis (ACD) from the glucose sensor FreeStyle Libre and sensitized to IBOA.
Methods
In 2019, 26 patients with suspected ACD from FreeStyle Libre were patch tested to a baseline series and to a (meth) acrylate series containing IBOA and 2‐phenoxyethyl acrylate (PEA) 0.1% pet. Diabetes devices and patch test preparations were analyzed with gas chromatography – mass spectrometry (GC‐MS) for the presence of IBOA and PEA.
Results
Of the 26 patients, 18 (69%) were sensitized to IBOA, and eight (44%) and 11 (61%) of these were co‐sensitized to sesquiterpene lactones and fragrances, respectively. Ten patients (56%) were co‐sensitized to PEA, which, contrary to IBOA, could not be detected in any device. The PEA test material was shown to be contaminated with IBOA.
Conclusions
Contact allergy to IBOA appears to be declining and IBOA‐sensitized patients are most often co‐sensitized to sesquiterpene lactones and fragrances. Vigilance is required when patch testing (acrylate) materials obtained from industry, as these might be contaminated and, hence, alter the results and their interpretation.
Highlights
In 2019, allergic contact dermatitis from the glucose sensor FreeStyle Libre could still be largely attributed to isobornyl acrylate (IBOA), although the sensitization rate appears to be declining.
IBOA‐sensitized patients are rarely co‐sensitized to other (meth) acrylates, but rather to sesquiterpene lactones, and fragrance terpenes, indicating that future research might need to focus on non‐acrylate sensitizers in medical devices.
Vigilance is required when patch testing (acrylate) materials obtained from the industry, as these might be contaminated, thereby altering the results and their interpretation.
Eight previously undescribed sesquiterpene lactones (1–8), together with six known ones (9–14) were isolated from the aerial parts of Tithonia diversifolia (Hemsl.) A. Gray. The absolute ...configurations of these compounds were elucidated using HRMS, NMR spectroscopy, optical rotation measurements, X-ray crystallography, and ECD. Among them, sesquiterpene lactones 2–4 share a unique carbon skeleton with a rare C-3/C-4 ring-opened structure. Compounds 1 and 8 showed moderate inhibitory effects toward CT26 murine colon carcinoma cells by promoting lipid ROS production, highlighting their potential as ferroptosis inducers.
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•Eight undescribed sesquiterpene lactones were isolated from Tithonia diversifolia•2–4 were 3,4-seco-sesquiterpene lactones•1 and 8 could promote lipid ROS production, acting as new ferroptosis inducers
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•Complete NMR assignment of semi-synthetic eremantholides.•Total clarification of hydrogen NMR signals: multiplicity and J values.•Original data to the literature.
Five eremantholides ...were prepared from natural furanoheliangolides by reductions with Stryker's reagent, in previous works. We thus decided to perform a detailed and complete assignment of all 1H and 13C NMR data for those compounds. Through NMR experiments such as 1H NMR, 13C {1H} NMR, gCOSY, gHMQC, gHMBC, J-resolved, among others, it was achieved an unequivocal assignment of 1H and 13C NMR data for all studied substances, with measurement of all H/H homonuclear coupling constants and the clarification of all hydrogen signals multiplicities. Those data were not completely available yet in the literature.
We report the first biocatalytic modification of sesquiterpene lactones (STLs) found in the chicory plants, specifically lactucin (Lc), 11β,13-dihydrolactucin (DHLc), lactucopicrin (Lp), and ...11β,13-dihydrolactucopicrin (DHLp). The selective O-acylation of their primary alcohol group was carried out by the lipase B from Candida antarctica (CAL-B) using various aliphatic vinyl esters as acyl donors. Perillyl alcohol, a simpler monoterpenoid, served as a model to set up the desired O-acetylation reaction by comparing the use of acetic acid and vinyl acetate as acyl donors. Similar conditions were then applied to DHLc, where five novel ester chains were selectively introduced onto the primary alcohol group, with conversions going from >99 % (acetate and propionate) to 69 % (octanoate). The synthesis of the corresponding O-acetyl esters of Lc, Lp, and DHLp was also successfully achieved with near-quantitative conversion. Molecular docking simulations were then performed to elucidate the preferred enzyme-substrate binding modes in the acylation reactions with STLs, as well as to understand their interactions with crucial amino acid residues at the active site. Our methodology enables the selective O-acylation of the primary alcohol group in four different STLs, offering possibilities for synthesizing novel derivatives with significant potential applications in pharmaceuticals or as biocontrol agents.
Purpurolides D–F (1–3), three new polyoxygenated bergamotanes bearing a 6/4/5/5 tetracyclic ring system, were isolated from the endophytic fungus Penicillium purpurogenum IMM 003. Their structures ...were unambiguously elucidated based on extensive spectroscopic data analyses, 13C NMR chemical shifts calculations coupled with the DP4+ probability method, and the calculated and experimental electronic circular dichroism (ECD) spectra. Compounds 1–3 showed significant inhibitory activity against pancreatic lipase (PL). The result highlights that the presence of 3-hydroxylated decanoic acid moiety at C-14 is important for increasing the inhibition potency against PL.
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•We investigated the fresh berries of Maesobotrya dusenii.•We isolated three new picrotoxane-type sesquiterpenoids.•The structure of the new compounds designated picrotoximaesines A-C ...were elucidated by spectroscopic analysis.
The phytochemical investigation of the methanolic berry extract of Maesobotrya dusenii has led to the isolation and characterization of three novel picrotoxane-type sesquiterpenoids named picrotoximaesins B-D (2–4) alongside with five known compounds. The structures of the compounds were determined by analyses of their spectroscopic (1D and 2D NMR) and spectrometric (HRMS) data in conjunction with literature records. The relative configurations were established by the biosynthetic pathway of picrotoxane-type sesquiterpene, comparison with analogues described in the literature and by using their NOESY spectra.
Glioblastoma (GBM) has a high mortality rate despite the availability of various cancer treatment options. Although cancer stem cells (CSCs) have been associated with poor prognosis and metastasis, ...and play an important role in the resistance to existing anticancer drugs and radiation; no CSC-targeting drugs are currently approved in clinical practice. Therefore, the development of antiproliferative agents against CSCs is urgently required. In this study, we evaluated the antiproliferative activities of 21 sesquiterpenoids against human GBM U-251 MG CSCs and U-251 MG non-CSCs. Particularly, the guaianolide sesquiterpene lactone cynaropicrin (1) showed strong antiproliferative activity against U-251 MG CSCs (IC50 = 20.4 µM) and U-251 MG non-CSCs (IC50 = 10.9 µM). Accordingly, we synthesized six derivatives of 1 and investigated their structure–activity relationships. Most of the guaianolide sesquiterpene lactones with the α-methylene-γ-butyrolactone moiety showed antiproliferative activities against U-251 MG cells. We conclude that the 5,7,5-ring and the α-methylene-γ-butyrolactone moiety are both important for antiproliferative activities against U-251 MG cells. The results of this study suggest that the α,β-unsaturated carbonyl moiety, which has recently become a research hotspot in drug discovery, is the active center of 1. Therefore, we consider 1 as a potential lead for developing novel drugs targeting CSCs.
Eight samples of
leaves were collected at different locations in Yunnan and Sichuan provinces in China, and their chemical constituents were investigated. Thirteen previously undescribed ...sesquiterpene lactones-seven germacranolides, three eudesmanolides, two guaianolides, and a 2-norelemanolide-were isolated, and their structures were elucidated based on extensive spectroscopic analyses. The major constituents in the six samples from northwestern Yunnan and Sichuan are hiyodorilactones A and B, whereas that in the two samples from the region near Kunming, Yunnan is eupatoriopicrin. These results and previously reported results suggest the presence of locality-dependent intra-specific diversity in the chemical constituents of
leaves.
There were five sesquiterpene lactones, belonging to the eudesmanolide class, isolated from the halophyte
DC. The structures of the compounds were determined using spectroscopic methods, including 1D ...and 2D NMR spectra, MS data, and optical rotation values. Compounds
and
were characterized by the position of
-hydroxyphenylacetyl group in the sugar moiety. In the evaluation of anti-inflammatory effects on LPS-activated RAW264.7 macrophages, compound
, 5α,6βH-eudesma-3,11(13)-dien-12,6α-olide, potently suppressed the expression of iNOS and COS-2, as well as the production of TNF-α, IL-6, and IL-10. Treatment of
regulates the Nrf2/HO-1 pathway.
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