Eight previously undescribed chromones eleusineketones A-H (1-8), as well as eight known compounds (9-16), were isolated from the endophytic fungus Bipolaris eleusines. These planar structures were created using an in-depth analysis of their spectral data, which included 1D, 2D, and HRESIMS data. Furthermore, the absolute configurations of compounds 1, 2, and 6 were determined by spectroscopic analysis and quantum chemical computational approaches, and compound 5 was determined by single-crystal X-ray diffraction analysis.
View Article and Find Full Text PDFNat Prod Bioprospect
October 2023
A series of terpenoids (1-17), comprising six new compounds designated bipolariterpenes A-F (1-6) and eleven recognized compounds (7-17), were isolated from the wheat culture of the potato endophytic fungus Bipolaris eleusines. Their structures and stereochemistry were clarified by HRESIMS, NMR, DP4 + probability analyses, and computations for electronic circular dichroism (ECD). All compounds are made up of six meroterpenoids, four sesterterpenes and seven sesquiterpenes.
View Article and Find Full Text PDFFour undescribed cytochalasins () were isolated from the endophytic fungus . Structurally, boerelasin A () represents the first example of a cytochalasin with a rare 5/5 bicyclic carbon core. Boerelasin B () possesses an unprecedented 5/6/5/6/8 pentacyclic ring system.
View Article and Find Full Text PDFThree hitherto undescribed Stemona alkaloids, named stemajapines A-C (1-3), along with six known alkaloids (4-9), were isolated and identified from the roots of Stemona japonica (Blume) Miq. (Stemonaceae). Their structures were established by the analysis of the mass data, NMR spectra, and computational chemistry.
View Article and Find Full Text PDFA series of oxygenated yohimbane alkaloids, including three new compounds, ophiorrhines H-J (1-3), and seven known compounds, were isolated from the aerial parts of Ophiorrhiza japonica. The structures with absolute configurations were elucidated by extensive MS and NMR spectroscopic methods, as well as the single crystal X-ray diffraction and ECD calculations. Ophiorrhines H (1) and I (2) represent key oxygenated intermediates in the formation of aromatic ring E in the demethoxycarbonyl-3,14-dihydrogambirtannine (10).
View Article and Find Full Text PDFFifteen undescribed Stemona alkaloids, named as stemarines A-O (1-15), along with 25 known alkaloids (16-40), were isolated and identified from the roots of Stemona mairei (H.Lév.)K.
View Article and Find Full Text PDFThere is a previously neglected influence of geochemical conditions on plant phytochemistry. In particular, high concentrations of dissolved salts can affect their biosynthesis of natural products. Detoxification is most likely an important aspect for the plant, but additional natural products can also give it an expanded range of bioactivities.
View Article and Find Full Text PDFA total of eleven new dimeric chromanones, paecilins F-P (-), were isolated from the endophytic fungus E10, along with four known analogs (, -). Their structures and absolute configurations were determined by extensive experimental spectroscopic methods, single-crystal X-ray diffraction, and equivalent circulating density (ECD) calculations. In addition, the structure of paecilin A, which was reported to be a symmetric C8-C8' dimeric pattern, was revised by analysis of the nuclear magnetic resonance (NMR) data, and single-crystal X-ray diffraction.
View Article and Find Full Text PDFEight undescribed phenylpropanoid-dihydrochalcone hybrids, namely (+)- and (-)-malahupin A, (+)- and (-)-malahupin B, (±)-malahupin C, malahupinosides A and B, 7‴-epi-malahupinoside B, together with two known compounds, phloretin and phlorizin, were isolated from the leaves of the folk medicinal plant Malus hupehensis. Their structures were elucidated by extensive NMR and MS spectroscopic methods, chiral-phase analysis, and ECD calculations. Compounds (+)-malahupin B and malahupinoside B showed weak inhibition activities against the nitric oxide production in liposaccharide-induced murine RAW264.
View Article and Find Full Text PDFNat Prod Bioprospect
July 2022
Five undescribed alkaloids were isolated from the seeds of Cephalotaxus oliveri along with 27 known ones. The new structures were elucidated based on spectroscopic data including 1D and 2D NMR, MS and calculated ECD spectra. Among them, (+)-acetylcephalofortine C was an enantiomeric Cephalotaxine alkaloids.
View Article and Find Full Text PDFFour new eremophilane-type sesquiterpenes, boeremialanes A-D (-) were obtained from solid substrate cultures of (Didymellaceae), an endophytic fungus isolated from (Liliaceae). Boeremialanes A-C (-) are highly oxygenated eremophilanes with a benzoate unit attached at the C-13 position and are rarely found in nature. Their structures and absolute configurations were determined by extensive spectroscopic methods, electronic circular dichroism (ECD), and nuclear magnetic resonance (NMR) calculations with DP4+ analysis.
View Article and Find Full Text PDFContinued interest in bioactive alkaloids led to the isolation of two undescribed alkaloids, ophiorrhines F () and G (), from the aerial parts of Their structures were elucidated based on spectroscopic methods, electronic circular dichroism, and calculated NMR with DP4+ analysis. These two alkaloids represent key biological genetic intermediates in the formation of ring C in the ophiorrhines. Compound exhibited good inhibition on LPS-induced B cell proliferation with an IC value of 0.
View Article and Find Full Text PDFObjective: This study examined the association between iron status and a set of breast cancer risk factors among U.S. adult women aged 20-80 years.
View Article and Find Full Text PDFFour new leucine-derived cytochalasans, possessing a 5,6,5,8-ring () and a 5,6,11-ring core (-), were isolated from a cultivated endophytic fungus sp. strain WH2D4 (Xylariaceae). This fungus was isolated from leaves of the neotropical tree species (Sw.
View Article and Find Full Text PDFBackground: Mastectomy techniques have been extended to nipple-sparing mastectomy (NSM). This study aimed to assess the actual application of NSM in China and identify the factors influencing postoperative complications.
Methods: The clinical data of 615 patients (641 surgeries) undergoing NSM from January 1st, 2018 to December 31st, 2018 at 28 centers nationwide were retrospectively analyzed to obtain the rate of NSM and investigate factors related to NSM surgery.
Meloyunnanines A-C, three alkaloids with an unprecedented skeleton, were isolated from fruits of . The structures featuring a caged-6/6/5/6/5/5 ring system were elucidated by the analysis of comprehensive spectroscopic and X-ray data. Biosynthetically, meloyunnanines A-C were assigned to monoterpenoid quinoline alkaloids (MQAs), derived from monoterpenoid indole alkaloids through oxidation and rearrangement.
View Article and Find Full Text PDFContinued interest in bioactive alkaloids led to the isolation of four undescribed alkaloids along with 74 known ones from the aerial parts of Tabernaemontana bufalina Lour. The structures of the yet undescribed alkaloids were elucidated based on NMR, IR, UV, MS and CD spectroscopic data and X-ray crystal diffraction and, according to the plant source, named as taberhaines A-D (1-4). The known compounds comprised of 66 monoterpenoid indole, three carboline and five isoquinoline alkaloids.
View Article and Find Full Text PDFFour unprecedented yellow alkaloids named as taberbovines A-D (1-4) were isolated from stems of Tabernaemontana bovina Lour. Their structures were elucidated by the comprehensive spectroscopic data, computational chemistry, and X-ray crystal diffraction. Alkaloids 1-4 possessed a unique 6/6/5/6/5 ring system and were assigned to monoterpenoid quinolines.
View Article and Find Full Text PDFThree new monoterpene indole alkaloids, 3α-hydroxymethyl-ibogamine (1), 3α-acetatemethoxyl-ibogamine (2), 16α-hydroxyl-ibogamine (3) together with six known alkaloids were isolated from the branches and leaves of Tabernaemontana divaricata (Apocynaceae). The structures of these alkaloids were determined by spectroscopic analyses. All isolated compounds showed no significant cytotoxicity against SGC-7901 gastric cancer, HeLa, and A-549 lung cancer cell lines (IC > 20 µM).
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