Objectives: Although hemispheric surgeries are among the most effective procedures for drug-resistant epilepsy (DRE) in the pediatric population, there is a large variability in seizure outcomes at the group level. A recently developed HOPS score provides individualized estimation of likelihood of seizure freedom to complement clinical judgement. The objective of this study was to develop a freely accessible online calculator that accurately predicts the probability of seizure freedom for any patient at 1-, 2-, and 5-years post-hemispherectomy.
View Article and Find Full Text PDFBackground: The diterpenoid alkaloids belong to a highly esteemed group of natural compounds, which display significant biological activities. It is a productive strategy to expand the chemical space of these intriguing natural compounds for drug discovery.
Methods: We prepared a series of new derivatives bearing diverse skeletons and functionalities from the diterpenoid alkaloids deltaline and talatisamine based on a diversity-oriented synthesis strategy.
The diterpenoid alkaloids are a family of extremely important natural products that have long been a research hotspot due to their myriad of intricate structures and diverse biological properties. This chapter systematically summarizes the past 11 years (2009-2019) of studies on the diterpenoid alkaloids, including the "so-called" atypical ones, covering the classification and biogenetic relationships, phytochemistry together with 444 new alkaloids covering 32 novel skeletons and the corrected structures, chemical reactions including conversion toward toxoids, synthetic studies, as well as biological activities. It should be noted that the synthetic studies, especially the total syntheses of various diterpenoid alkaloids, are for the first time reviewed in this treatise.
View Article and Find Full Text PDFThree-dimensional cage-like natural products represent astounding and long-term challenges in the research endeavors of total synthesis. A central issue that synthetic chemists need to address lies in how to efficiently construct the polycyclic frameworks as well as to install the requisite substituent groups. The diterpenoid alkaloids that biogenetically originate from amination of diterpenes and diversify through late-stage skeletal reorganization belong to such a natural product category.
View Article and Find Full Text PDFThis review summarizes the process of the discovery, research, and development of a cardioactive component, mesaconine, from the lateral roots of Aconitum carmichaelii ("Fu Zi"). To date, pre-clinical showed that mesaconine is a novel type of cardiotonic lead drug with relatively high potency, low toxicity, and a new mechanism.
View Article and Find Full Text PDFThe first total synthesis of liangshanone, a hexacyclic ent-kaurane diterpenoid alkaloid, has been completed. Its intricate cagelike framework was assembled through several key transformations, including an oxidative dearomatization/Diels-Alder (OD/DA) cycloaddition sequence, a tandem alkene cleavage/Mannich cyclization, a Robinson-type annulation, and an intramolecular aldol reaction. Notably, an organocatalytic enantioselective α-hydroxymethylation process allowed the preparation of an enantiomerically enriched tricyclic intermediate that should enable asymmetric access to the target natural product.
View Article and Find Full Text PDFWater Sci Technol
October 2019
In this study, a high-concentration simulated organic wastewater, made by dissolving methyl violet in water, was degraded using dielectric barrier discharge (DBD) plasma generated in air and O respectively. The decoloration rate and chemical oxygen demand (COD) of wastewater were evaluated during plasma treatments with the initial concentration of methyl violet of 300 mg L. Results showed that the highest decoloration rate of around 100% within 10 min and the highest COD decrease of 33% within 60 min could be achieved with the O plasma treatment at the discharge voltage of 10 kV, while air plasma treatment showed lower efficiency in decolorizing the methyl violet solution and lower COD decrease (24%) after 60 min treatment.
View Article and Find Full Text PDFContinuous investigations of the roots of Aconitum nagarum var. lasiandrum led to the isolation of two new C₁₉-diterpenoid alkaloids, lasiandrine (1) and lasiandroline (2). Their structures were elucidated on the basis of extensive interpretation of spectroscopic and mass spectrometric data.
View Article and Find Full Text PDFA unified approach to four different (atisine, ajaconine, denudatine, and hetidine) diterpenoid alkaloid skeletons was developed and applied to the total synthesis of the natural products dihydroajaconine (2, atisine type) and gymnandine (4, denudatine type). The synthesis features a biogenetically inspired strategy that relies on C-H oxidation, aza-pinacol coupling, and aza-Prins cyclization as key steps.
View Article and Find Full Text PDFSchistosoma japonicum is a widespread human and animal parasite that causes intestinal and hepatosplenic schistosomiasis linked to colon, liver and bladder cancers, and anemia. Estimated 230 million people are currently infected with Schistosoma spp, with 779 million people at risk of contracting the parasite. Infection occurs when a host comes into contact with cercariae, a planktonic larval stage of the parasite, and can be prevented by inactivating the larvae, commonly by chemical treatment.
View Article and Find Full Text PDFThe cardiac effect of thirty-eight diterpenoid alkaloids was evaluated on the isolated bullfrog heart model. Among them, twelve compounds exhibited appreciable cardiac activity, with compounds 3 and 35 being more active than the reference drug lanatoside. The structure-cardiac activity relationships of the diterpenoid alkaloids were summarized based on our present and previous studies [2]: i) 1α-OMe or 1α-OH, 8-OH, 14-OH, and NH (or NMe) are key structural features important for the cardiac effect of the aconitine-type C19-diterpenoid alkaloids without any esters.
View Article and Find Full Text PDFA new and effective approach toward epoxide opening of a 7,17-seco-7,8-epoxy-C19-diterpenoid alkaloid is herein described. The starting epoxide was prepared from naturally occurring yunnaconitine via a nine-step transformation. Treatment of this epoxide with trifluoroacetic anhydride in dioxane at 110 degrees C followed by reduction with sodium boron hydride generated two epoxide opening compounds 7 and 8.
View Article and Find Full Text PDFThe first total syntheses of the architecturally complex atisane-type diterpenes and biogenetically related atisine-type diterpenoid alkaloids (±)-spiramilactone B, (±)-spiraminol, (±)-dihydroajaconine, and (±)-spiramines C and D are reported. Highlights of the synthesis include a late-stage biomimetic transformation of spiramilactone B, a facile formal lactone migration from the pentacyclic skeleton of spiramilactone E, a highly efficient and diastereoselective 1,7-enyne cycloisomerization to construct the functionalized tetracyclic atisane skeleton, and a tandem retro-Diels-Alder/intramolecular Diels-Alder sequence to achieve the tricyclo[6.2.
View Article and Find Full Text PDFThree new C20-diterpenoid alkaloids vilmorrianines E (1), F (2), and G (3) were isolated from the whole plants of Aconitum vilmorrianum, along with one artifact N-chloromethyl vilmorrianine E hydrochloride (4), as well as two known alkaloids hemsleyaconitines F (5) and G (6). The structures of 1-4 were established by HR-ESI-MS, 1D-, 2D-NMR (HMQC, HMBC, and NOESY), and single-crystal X-ray diffraction analysis. In addition, the structures of naturally occurring 2-O-acetylorochrine (7) and orochrine (8) were revised to be the known alkaloids heterophylloidine (9) and deacetyl heterophylloidine (10), respectively, on the basis of consideration of transannular effect and chemical correlations.
View Article and Find Full Text PDFJ Asian Nat Prod Res
November 2015
Overexpression of ATP-dependent efflux pump P-glycoprotein (P-gp) is the main cause of multidrug resistance (MDR) and chemotherapy failure in cancer treatment. Inhibition of P-gp-mediated drug efflux is an effective way to overcome cancer drug resistance. The present study investigated the reversal effect of the novel tetrandrine derivative W6 on P-gp-mediated MDR.
View Article and Find Full Text PDFStemona alkaloids, featuring polycyclic structures and interesting bioactivities, constitute a distinct class from the Stemonaceae family. In this review, recent advances in the synthesis of these unique alkaloids are briefly discussed, highlighting the application of novel synthetic strategies to access the core structures, as well as creative solutions to the installation of multiple stereogenic centers. The literature reviewed in this article covers the publications from 2010 to November 2014, a period that witnessed the prosperity of the synthesis of Stemona alkaloids.
View Article and Find Full Text PDFContinuous investigations on the whole herbs of Aconitum tanguticum var. trichocarpum led to the isolation of three new C20-diterpenoid alkaloids trichocarpisines A-C (1-3). Their structures were elucidated on the basis of extensive interpretation of the spectroscopic data.
View Article and Find Full Text PDFThe development of new drugs calls for large collections of diverse molecules with considerable complexity. Ring distortion of natural products provides an efficient and facile approach to access new architectures with intriguing biological activities, by harnessing their inherent complexity. In this study, such a strategy has been explored on an abundant C19 -diterpenoid alkaloid, deltaline, enabling the synthesis of 32 new derivatives bearing a broad spectrum of unique scaffolds.
View Article and Find Full Text PDFIn order to affirm the cardioactive components in Fuzi, we identified a group of aminoalcohol- diterpenoid alkaloids in Fuzi using ultra high-performance liquid chromatography coupled with electrospray ionization mass spectrometer (UPLC-ESI-MS) method. Among a total of forty-one isolated ingredients, thirteen major aminoalcohol-diterpenoid alkaloids were identified by comparing their retention times and MS spectra with those of the reference substances. Moreover, Fuzi samples from different places of origin and with different processing methods were examined and their components displayed a pattern of high similarity, though the relative abundance varies probably due to their different processing methods.
View Article and Find Full Text PDFNat Prod Commun
December 2014
Stemona alkaloids form a unique class, which can be attributed to hemiterpenoid pyrrolidine- and monoterpenoid pyrrolidine-class alkaloids originated from L-ornithine and glutamic acid. By the end of 2013, approximately 183 Stemona alkaloids had been isolated from nature. The literature on Stemona alkaloids in the realms of chemical structure, synthesis, and bioactivities has been elegantly summarized and reviewed.
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