Search results
Search for "steroids" in Full Text gives 57 result(s) in Beilstein Journal of Organic Chemistry.
Microwave-assisted synthesis of biologically relevant steroidal 17-exo-pyrazol-5'-ones from a norpregnene precursor by a side-chain elongation/heterocyclization sequence
Beilstein J. Org. Chem. 2018, 14, 2589–2596, doi:10.3762/bjoc.14.236
- the reference compound, cisplatin. Keywords: antiproliferative activity; Knorr reaction; microwave; pyrazol-5-ones; steroids; Introduction 17-exo-Heterocyclic androstanes with five or six-membered heterocyclic rings connected directly to C-17 of the sterane core represent a remarkable subclass of
Hypervalent organoiodine compounds: from reagents to valuable building blocks in synthesis
Beilstein J. Org. Chem. 2018, 14, 1508–1528, doi:10.3762/bjoc.14.128
- -stage modification of complex products such as steroids. On the other hand, both the alkyne and the iodoarene moiety can be modified through post-transformation reactions thereby increasing the molecular diversity accessible with this process. The mechanism of the reaction (Scheme 11b) would first
- 98% to afford α-benzoyloxy propargylic derivatives 39. Again the strategy can be applied to the late-stage modification of steroids with high levels of diastereoselectivity. λ3-Iodane reagents: azidobenziodoxolone (ABX) and chlorobenziodoxolone In a similar manner to the previously described
The first Pd-catalyzed Buchwald–Hartwig aminations at C-2 or C-4 in the estrone series
Beilstein J. Org. Chem. 2018, 14, 998–1003, doi:10.3762/bjoc.14.85
- several aminated steroids in the literature, but the efficient generation of a C(sp2)–N bond on the aromatic ring A of estrone derivatives still remains a challenge. Aminoestrones substituted at C-2 or C-4 are mainly produced by the reduction or hydrogenation of the corresponding nitro derivatives [5
- ]. Thus 13α-estrone is a suitable compound for the development of biologically active steroids lacking estrogenicity. Literature reveals that besides the inversion of C-13, the introduction of an amino group onto C-2 or C-4 of estrone also leads to significant decreases in its binding affinity for nuclear
Synthesis and in vitro biochemical evaluation of oxime bond-linked daunorubicin–GnRH-III conjugates developed for targeted drug delivery
Beilstein J. Org. Chem. 2018, 14, 756–771, doi:10.3762/bjoc.14.64
- regulatory pituitary glycoprotein luteinizing hormone (LH) and follicle stimulating hormone (FSH) which act on the gonads and regulate the production of the sex steroids androgen and estrogen [2]. In the last decades a large number of synthetic GnRH-I-analogues has been designed with the purpose to interact
Latest development in the synthesis of ursodeoxycholic acid (UDCA): a critical review
Beilstein J. Org. Chem. 2018, 14, 470–483, doi:10.3762/bjoc.14.33
- containing 5β-steroids. Their structure contains multiple hydroxy substituents: the position and the stereochemistry of these OH groups influence the solubility and biochemical properties of the compounds. In CA, for example, the OH groups on the steroidal ring are all in α-position with respect to the ring
- bacterial-catalysed 12α-dehydroxylation was reported by Edenharder in 1983 [54]. He found eight strains of the Bacteroides genus that specifically dehydroxylate CA to CDCA. However, no other studies have been carried out concerning this topic. A method for the production of 12-dehydro steroids by the action
Synthesis of ergostane-type brassinosteroids with modifications in ring A
Beilstein J. Org. Chem. 2017, 13, 2326–2331, doi:10.3762/bjoc.13.229
- -Steroids of type 3 The possible existence of Δ2-steroids of type 3 (Scheme 1) as biosynthetic intermediates of BS was proposed in 1981 [9], but it lasted until 2003 when the corresponding compound named secasterol was found in seedlings of Secale cereale [10]. In subsequent years, a number of related Δ2-6
- epibrassinolide (2) into the corresponding Δ2-steroids. The first route comprised the selective protection of the side chain diol in 1 and 2 through exhaustive acetylation followed by saponification of the intermediate tetraacetates under controlled conditions [14]. Next, a Corey–Winter reaction [15] of the
- cyclic thiocarbonate 15 as a key reaction step gave the expected Δ2-olefin 16 in an excellent yield (Scheme 2). Subsequent deacetylation of 16 then afforded 24-episecasterol (17). An alternative procedure to Δ2-steroids was applied for the preparation of the B-ring lactone derivative 21 (Scheme 3). The
Glycoscience@Synchrotron: Synchrotron radiation applied to structural glycoscience
Beilstein J. Org. Chem. 2017, 13, 1145–1167, doi:10.3762/bjoc.13.114
- the biosynthesis of glycosidic linkage requires the transfer of a sugar residue from a donor to an acceptor [35]. Acceptor substrates are carbohydrates, proteins, lipids, DNA, flavonol, antibiotics and steroids. In contrast, glycosyl donor substrates are mostly sugar nucleotides, such as UDP-GlcNAc
Opportunities and challenges for the sustainable production of structurally complex diterpenoids in recombinant microbial systems
Beilstein J. Org. Chem. 2017, 13, 845–854, doi:10.3762/bjoc.13.85
- the comparably short chains of dolichols [39]. The vast majority of terpenes, steroids and other isoprenoids like cholesterols and carotenoids are obtained from E-condensations [35]. Head-to-tail connection of single IPP and DMAPP by geranyl diphosphate synthase (GPPS) results in geranyl diphosphate
Lipids: fatty acids and derivatives, polyketides and isoprenoids
Beilstein J. Org. Chem. 2017, 13, 793–794, doi:10.3762/bjoc.13.78
- in addition to that in eukaryotic organisms membranes are of utmost importance also for cell compartmentation, i.e., the inner structure of a cell. A large portion of these membranes is composed of steroids that influence membrane properties, such as fluidity and permeability, but have a
- fundamentally different biosynthetic origin from fatty acids since they are made via terpene biosynthetic pathways. Nevertheless, steroids are highly apolar yet may contain a polar headgroup such as a 3-hydroxy function (as in lanosterol). Besides membrane formation, the highly apolar character of lipids has
Secondary metabolome and its defensive role in the aeolidoidean Phyllodesmium longicirrum, (Gastropoda, Heterobranchia, Nudibranchia)
Beilstein J. Org. Chem. 2017, 13, 502–519, doi:10.3762/bjoc.13.50
- chemistry. Herein we report the isolation of a total of 19 secondary metabolites from a single specimen of this species, i.e., steroids 1–4, cembranoid diterpenes 5–13, complex biscembranoids 14 and 15, and the chatancin-type diterpenes 16–19. These compounds resemble those from soft corals of the genus
- of the new metabolites 1, 5, 9, 14, 15 and stereochemical assignment of 12 Repeated fractionation of VLC fractions 5–8 resulted in the isolation of a range of secondary metabolites, i.e., four steroids 1–4, nine cembranoid diterpenes 5–13 and two biscembranoids 14 and 15, as well as four polycyclic
- -secogorgostan-11-ol. Chemical structures of the polyhydroxylated steroids 2–4 were established by comparison of the NMR and MS data obtained in our laboratory (Supporting Information File 1, Figures S6–11) with the reported values [27][28]. Compound 5 was isolated as colorless oil (1.5 mg). The specific optical
From steroids to aqueous supramolecular chemistry: an autobiographical career review
Beilstein J. Org. Chem. 2016, 12, 684–701, doi:10.3762/bjoc.12.69
- sheer delight. Subsequently I went on to study my Ph.D. degree. I opted for the same university, but switched to the Pharmacy Department to work on the synthesis of steroids under the tutelage of Dr. Philip J. Cox and Dr. Steve M. MacManus. Phil, an X-ray crystallographer, was my director of studies and
- he needed new steroids synthesized and structurally characterized [2][3]. So he brought on-board Steve – a natural products chemist – to guide me through the synthesis of the different targets. The overall goal of my work was the development of new steroidal contraceptives, and the key structural
- spectroscopic difference between these molecules and how these compared to analogous steroids whereby the cyclopropane group in the A-ring is replaced with a conjugating C=C double bond. To cut a long story short, vinyl cyclopropanes are conjugated, albeit to a lesser degree than dienes, and NMR, IR and UV–vis
Biosynthesis of α-pyrones
Beilstein J. Org. Chem. 2016, 12, 571–588, doi:10.3762/bjoc.12.56
- are an important group of steroids containing an α-pyrone moiety. The α-pyrone ring is here connected to a steroid nucleus, as exemplified in bufalin (31, Figure 7). These α-pyrones were detected in several plants, as well as in animals. The vast amount of derivatives shows also very diverse
A journey in bioinspired supramolecular chemistry: from molecular tweezers to small molecules that target myotonic dystrophy
Beilstein J. Org. Chem. 2016, 12, 125–138, doi:10.3762/bjoc.12.14
- of steroids, to determining hydrocarbon pKa values using electrochemistry. The lesson learned, and one I tried to put into practice in my independent career (see below), is that it is very much possible to run a research group focused in quite different areas of chemistry. With an NSF-NATO
Inclusion complexes of 2-methoxyestradiol with dimethylated and permethylated β-cyclodextrins: models for cyclodextrin–steroid interaction
Beilstein J. Org. Chem. 2015, 11, 2616–2630, doi:10.3762/bjoc.11.281
- bioactive steroids and our search further revealed that no representative CD–steroid structures containing more common CDs and steroidal guests (e.g., cortisone, prednisolone, estradiol, or their derivatives) have been reported hitherto. Very recently, an account of the crystal structure of a host
- comprising a γ-CD duplex system connected by two disulfide bonds that forms stable complexes with steroids appeared [19]. However, no crystal structure of any of its inclusion complexes was reported. Finally, the lack of published studies on the potential for CDs to improve the aqueous solubility of 2ME also
Copper-catalyzed asymmetric conjugate addition of organometallic reagents to extended Michael acceptors
Beilstein J. Org. Chem. 2015, 11, 2418–2434, doi:10.3762/bjoc.11.263
- were employed in total synthesis strategies (Figure 3). Wieland and Anner took advantage of the reaction selectivity in the synthesis of steroids as early as 1967 [14]. For instance, the product (rac)-13 was obtained in 43% yield by reacting a methylmagnesium bromide with the steroid derivative 12 in
Dicarboxylic esters: Useful tools for the biocatalyzed synthesis of hybrid compounds and polymers
Beilstein J. Org. Chem. 2015, 11, 1583–1595, doi:10.3762/bjoc.11.174
- esterifications of sugars and steroids, using acylating agents different from simple aliphatic acids [7][8][9]. Specifically, years ago Dordick and coworkers proposed the so-called ‘combinatorial biocatalysis’ as an approach to easily produce small libraries of derivatives of bioactive natural compounds using a
Electrochemical oxidation of cholesterol
Beilstein J. Org. Chem. 2015, 11, 392–402, doi:10.3762/bjoc.11.45
- material) as the main product in addition to other products (e.g. 15-oxo 5, 16-oxo 6 and other oxo-steroids). The electrooxidation of cholesterol derivatives also produced ketones but the detailed product analysis was not reported. It seems that the active species for the ketone formation in Gif systems is
- chlorination of some Δ5-steroids (Scheme 5) was reported by Milisavljević and Vukićević [40]. The electrolyses were carried out in dichloromethane under galvanostatic conditions with a graphite anode in an undivided cell. The supporting electrolyte tetraethylamonium chloride was a source of chloride ions
- , which were anodically oxidized to chlorine. The electrophilic addition of chlorine to the double bond of the investigated compounds cholesteryl acetate (1a), cholesteryl benzoate (1b), 3β-chloro-5-cholestene (1c), and 5-cholestene (1d), gave the corresponding 5α,6β-dichloro steroids in good yields (70
3α,5α-Cyclocholestan-6β-yl ethers as donors of the cholesterol moiety for the electrochemical synthesis of cholesterol glycoconjugates
Beilstein J. Org. Chem. 2015, 11, 162–168, doi:10.3762/bjoc.11.16
- derivatives show similar reactivities to those of previously studied 3α,5α-cyclocholestan-6β-thioethers. Keywords: cholesterol; electrochemical oxidation; glycosylation; i-cholesteryl ethers; i-steroids; Introduction We have recently elaborated an electrochemical method for the preparation of glycosides and
- glycoconjugates from 3β-hydroxy-Δ5-steroids (sterols). The method consists of electrooxidation of a proper cholesterol derivative in the presence of an unactivated sugar with a free hydroxy group at the anomeric position (formation of glycosides) or at any other position (preferentially a primary position) that
Application of cyclic phosphonamide reagents in the total synthesis of natural products and biologically active molecules
Beilstein J. Org. Chem. 2014, 10, 1848–1877, doi:10.3762/bjoc.10.195
Syntheses of fluorooxindole and 2-fluoro-2-arylacetic acid derivatives from diethyl 2-fluoromalonate ester
Beilstein J. Org. Chem. 2014, 10, 1213–1219, doi:10.3762/bjoc.10.119
- use of 1,3-diketone, 1,3-ketoester and 1,3-diester derivatives in retrosynthetic planning is widespread in general organic chemistry and numerous terpenes, heterocycles and steroids originate from such simple yet synthetically versatile substrates [16][17][18][19]. In contrast, despite the
Self-assembly of 2,3-dihydroxycholestane steroids into supramolecular organogels as a soft template for the in-situ generation of silicate nanomaterials
Beilstein J. Org. Chem. 2013, 9, 1826–1836, doi:10.3762/bjoc.9.213
- stimuli such as light, ultrasound or chemical stimuli [8][9][10][11][12]. A wide variety of structurally diverse molecules have the ability to form physical gels (e.g., saccharides, peptides, ureas, nucleobases, steroids, dendrimers, etc. [13]). Although a great effort has been made to investigate the
- scope and thermal stability To assess the scope of the gelation ability of steroids 1–4 in a simple way, the test tube method was first used with 28 selected organic solvents ranging from hydrocarbons to alcohols (Table 1, entries 1–28). While steroids 2–4 were unable to gelate any of these solvents
- -to-head interactions and found two possible arrangements with minimal energies. In the first one, both molecules interact with the α faces of the steroids pointing to the same side (Figure 6, system A). In the second case the α faces are oriented to opposite sides (Figure 6, system B). Both dimers
New tridecapeptides of the theonellapeptolide family from the Indonesian sponge Theonella swinhoei
Beilstein J. Org. Chem. 2013, 9, 1643–1651, doi:10.3762/bjoc.9.188
- treasure troves of secondary metabolites. The chemical diversity of the isolated compounds ranges from unusual steroids (exemplified by the 4-methylene sterol theonellasterol [2][3] and truncated side-chain sulfated steroids [4]), to complex macrocyclic polyketides (as the well-known swinholide A, now a
- , Indonesia), which proved to be rich in aurantosides [6] and 4-methylene steroids [18], while polyketide macrolides and peptide-based derivatives were extremely rare if not absent. Remarkably, the chemical analysis of a different specimen of T. swinhoei, collected in the same area as the previous one
Recent progress in the discovery of small molecules for the treatment of amyotrophic lateral sclerosis (ALS)
Beilstein J. Org. Chem. 2013, 9, 717–732, doi:10.3762/bjoc.9.82
- , and lifespan were not affected by either 37 treatment or gonadectomy, suggesting that steroids have little effect on ALS disease pathology [78]. These conflicting results may be explained by the specific compounds that were used or the analyses that were performed. Interestingly, these studies
Some aspects of radical chemistry in the assembly of complex molecular architectures
Beilstein J. Org. Chem. 2013, 9, 557–576, doi:10.3762/bjoc.9.61
- . Synthesis of bicyclic cyclobutane motifs. Construction of the CD rings of steroids. Rapid assembly of polyquinanes. Formation of a polycyclic structure via an allene intermediate. A polycyclic structure via the alkylative Birch reduction. Synthesis of polycyclic pyrimidines and indoline structures
Synthesis of meso-substituted dihydro-1,3-oxazinoporphyrins
Beilstein J. Org. Chem. 2013, 9, 496–502, doi:10.3762/bjoc.9.53
- derived from porphyrins [11][12]. Previously, a large number of these molecules have been synthesized by the coupling of diverse pharmaceutically important moieties, such as carbohydrates [13][14][15], amino acid residues [16][17][18][19], steroids [20][21], glycosides [22][23][24], nitroxyl derivatives
Other Beilstein-Institut Open Science Activities
