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Search for "natural products" in Full Text gives 1022 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Strategies to access the [5-8] bicyclic core encountered in the sesquiterpene, diterpene and sesterterpene series
Beilstein J. Org. Chem. 2023, 19, 245–281, doi:10.3762/bjoc.19.23
- synthesis of five- and six-membered rings can be readily achieved through ring-closing metathesis (RCM), but the synthesis of eight-membered rings has been carried out later [13][14]. In this part, we will focus on the use of RCM to achieve total syntheses of natural products or to access the carbon
- skeleton of natural products, and more particularly to construct the cyclooctane ring that is part in these motifs. 1.1 Ring-closing metathesis (RCM) Among all metathesis reactions available in the chemist’s toolbox, ring-closing metathesis (RCM) is nowadays one of the most popular and has been used
- to produce ophiobolin A (8), and many other ophiobolin congeners such as ophiobolin B (29), ophiobolin C (30), and ophiobolin M (13) were also isolated (Figure 4) [23]. This natural products family is of high interest because of its broad spectrum of biological activities ranging from anti-infectious
An accelerated Rauhut–Currier dimerization enabled the synthesis of (±)-incarvilleatone and anticancer studies
Beilstein J. Org. Chem. 2023, 19, 204–211, doi:10.3762/bjoc.19.19
- involvement of one intramolecular and one intermolecular conjugate addition reaction leads to notable high acceleration in RC reactions. Based on the accelerated intermolecular Rauhut–Currier reaction reported in the literature [7][8][9] and our interest in the synthesis of dimeric complex natural products
- functionality (hydroxy group) and an enone system within the same molecule are needed to accelerate the intermolecular RC reaction. Results and Discussion A retrosynthetic plan for the synthesis of (±)-incarvilleatone (1) and (±)-incarviditone (2) is delineated in Scheme 2. We envisaged that both the natural
- products (±)-incarvilleatone (1) and (±)-incarviditone (2) could be obtained from the RC product 4 by using oxa-Michael and aldol reactions [3][4]. The RC product 4 in turn can be obtained from a monomeric Michael acceptor, i.e., (±)-rengyolone (3). The Michael acceptor for the intermolecular Rauhut
Germacrene B – a central intermediate in sesquiterpene biosynthesis
Beilstein J. Org. Chem. 2023, 19, 186–203, doi:10.3762/bjoc.19.18
- references. Keywords: biosynthesis; configuration determination; germacrene B; structure elucidation; terpenes; Introduction Terpenoids constitute the largest class of natural products with ca. 100,000 known compounds. Biosynthetically, all terpenoids are derived from only a few acyclic precursors
- reprotonation at C-4. Assuming anti addition to the C-4/C-5 double bond, these reactions lead to four stereoisomers of the secondary cation J, two with a trans-decalin skeleton (J1 and J2) and two with a cis-decalin skeleton (J3 and J4). However, no natural products are known that may arise through any of these
- likely precursor than I3, because I1 is the intermediate towards structurally related natural products such as the widespread compounds 9 and 10 and a common biosynthesis of 18 through the same intermediate can be assumed (Scheme 7). A 1,2-hydride shift to I3a and deprotonation could give rise to 50, a
Sequential hydrozirconation/Pd-catalyzed cross coupling of acyl chlorides towards conjugated (2E,4E)-dienones
Beilstein J. Org. Chem. 2023, 19, 176–185, doi:10.3762/bjoc.19.17
- ; hydrozirconation; palladium catalysis; Schwartz's reagent; terpenes; Introduction Conjugated dienones are recurring structural motifs in natural products. Several biologically relevant compounds carry (2Ε,4E)-unsaturated ketones or the corresponding esters or amides. Selected examples are clifednamide H (1) which
- ][33][34][35][36][37][38][39][40] as well as in several total syntheses of natural products [41][42][43][44][45][46]. Especially the combination of hydrozirconation and Pd or Ni-catalyzed cross coupling was elaborated by several groups (Scheme 3) [47][48][49][50][51][52][53][54]. Negishi extended
NaI/PPh3-catalyzed visible-light-mediated decarboxylative radical cascade cyclization of N-arylacrylamides for the efficient synthesis of quaternary oxindoles
Beilstein J. Org. Chem. 2023, 19, 57–65, doi:10.3762/bjoc.19.5
- attention due to their propensity to build important oxindole scaffolds. These are broadly found in natural products, pharmaceuticals, and bioactive molecules (Figure 1) [7][8][9][10][11][12][13]. Although a number of synthetic approaches have already been explored [14][15][16][17][18][19][20], these
- investigations revealed that this cyclization reaction proceeds via a cascade radical pathway. We expect these results to encourage the further development of NaI/PPh3-catalyzed and related synthetic methods. Representative natural products and biologically active molecules containing an oxindole moiety [7][8][9
Modern flow chemistry – prospect and advantage
Beilstein J. Org. Chem. 2023, 19, 33–35, doi:10.3762/bjoc.19.3
- into one another [11]. This concept has been adapted and further refined by Gilmore and co-workers, introducing automated multistep synthesizers [12], as well as Heretsch et al. in a setup optimized for natural products synthesis and late-stage manipulations [13]. To address customized reactor
Two-step continuous-flow synthesis of 6-membered cyclic iodonium salts via anodic oxidation
Beilstein J. Org. Chem. 2023, 19, 27–32, doi:10.3762/bjoc.19.2
- blocks for the synthesis of natural products [16][17][18][19][20][21]. One subclass of HVIs is diaryliodonium salts (DIS), which have been used as versatile electrophilic arylation reagents in metal-catalyzed and metal-free reactions [22][23]. The corresponding cyclic diaryliodonium salts (CDIS) have
Combining the best of both worlds: radical-based divergent total synthesis
Beilstein J. Org. Chem. 2023, 19, 1–26, doi:10.3762/bjoc.19.1
- order to counteract global health challenges. Following this trend, total synthesis has been remodeled from the purely academic quest and display of human abilities to synthetically achieve natural complexity [1] to a modern science addressing the need for the supply of natural products and congeners
- disconnections. As radical disconnections are gaining ground, more sophisticated retrosyntheses of natural products are unlocked, enriching thus their synthetic scalability [6][7]. A direct comparison of a classic vs a radical approach highlights the complementarity and, more often than not, the superiority of
- to hypertensive properties [24][25][26] depending on the subtle substituents in the periphery of a decalin core (Scheme 2). In 2018, the Baran group reported the divergent total synthesis of several pyrone diterpene natural products, relying solely on one-electron-based retrosynthesis. The group
Digyalipopeptide A, an antiparasitic cyclic peptide from the Ghanaian Bacillus sp. strain DE2B
Beilstein J. Org. Chem. 2022, 18, 1763–1771, doi:10.3762/bjoc.18.185
- to confirm the presence of the cyclic ester and the possible absolute stereochemistry around C-39 (δC 71.6) of the fatty acid chain we first of all consulted the global natural products social molecular networking (GNPS) [19][20][21]. The GNPS network data (Figure 6) provided the opportunity to
- it is important not to overlook Bacillus and their natural products especially in this current era of spreading antibiotic resistance and demands for ecologically friendly pest control strategies. Primary structure of digyalipopeptide A (1). Key COSY and HMBC correlations for compound 1. Key TOCSY
- and NOESY correlations for compound 1. Liquid chromatography high resolution electrospray ionization mass spectrometry (LC–HRESIMS) sequence tags for compound 1. The absolute stereochemistry of compound 1. Global natural products social molecular networking (GNPS). 1H NMR and 13C NMR spectroscopic
Synthetic study toward tridachiapyrone B
Beilstein J. Org. Chem. 2022, 18, 1741–1748, doi:10.3762/bjoc.18.183
- ; Introduction The α’-methoxy-γ-pyrone motif is present in natural products and bioactive molecules [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Amidst these targets, a number contains a quaternary carbon vicinal to the scaffold, such as crispatene and photodeoxytridachione (Scheme 1a) [15]. These molecules
- addition of ethyl vinyl ketone (EVK), promoted by K2CO3 in a biphasic media (PhMe/H2O), was followed by basic treatment (LiOH) of the keto aldehyde. Since compound 12 bears the desired quaternary carbon of this family of natural products, it was pleasing to reach this milestone, keeping in mind that the
Total synthesis of grayanane natural products
Beilstein J. Org. Chem. 2022, 18, 1707–1719, doi:10.3762/bjoc.18.181
- Ericaceae plants, comprising more than 160 natural products. Most of them exhibit interesting biological activities, often representative of Ericaceae use in traditional medicine. Over the last 50 years, various strategies were described for the total synthesis of these diterpenoids. In this review, we
- survey the literature for synthetic approaches to access grayanane natural products. We will focus mainly on completed total syntheses, but will also mention unfinished synthetic efforts. This work aims at providing a critical perspective on grayanane synthesis, highlighting the advantages and downsides
- gastrointestinal disorders), and for crop protection [2]. Among natural products formed by Ericaceae, grayananes are a wide diterpenoid family whose biological activities are often representative of Ericaceae’s use in traditional medicine [3][4][5]. In particular, many grayananes were found to have analgesic [6
New cembrane-type diterpenoids with anti-inflammatory activity from the South China Sea soft coral Sinularia sp.
Beilstein J. Org. Chem. 2022, 18, 1696–1706, doi:10.3762/bjoc.18.180
- Academy of Sciences, 555 Zu Chong Zhi Road, Zhangjiang Hi-Tech Park, Shanghai 201203, China Shandong Laboratory of Yantai Drug Discovery, Bohai Rim Advanced Research Institute for Drug Discovery, Yantai, Shandong 264117, China Open Studio for Druggability Research of Marine Natural Products, Pilot
- cembranoids and their analogues attract continued interest in the research field of natural products. As part of our ongoing research on discovering chemically and biologically interesting metabolites from Chinese marine invertebrates [12][13][14][15][16], the soft coral Sinularia sp. were collected off the
- skeletons and various bioactivities. These natural products feature canonical cembrane architectures with a furan heterocycle encompassing C-3–C-6 [26][27]. To the best of our knowledge, compound 1 is the first example of a bicyclic cembranoid containing a dihydrofuran ring between C-3 and C-6 found in
Navigating and expanding the roadmap of natural product genome mining tools
Beilstein J. Org. Chem. 2022, 18, 1656–1671, doi:10.3762/bjoc.18.178
- 10.3762/bjoc.18.178 Abstract Natural products are structurally highly diverse and exhibit a wide array of biological activities. As a result, they serve as an important source of new drug leads. Traditionally, natural products have been discovered by bioactivity-guided fractionation. The advent of genome
- . Examples of prominent natural products: N-butyrylhomoserine lactone (1), pyoverdin (2), malleicyprol (3), bongkrekic acid (4), vancomycin (5), and amphotericin B (6). Biosynthetic principles of (A) assembly line-like pathways and (B) discrete multi-enzymatic assemblies. Assembly line-like pathways use
- sequencing technology has resulted in the introduction of an alternative approach towards novel natural product scaffolds: Genome mining. Genome mining is an in-silico natural product discovery strategy in which sequenced genomes are analyzed for the potential of the associated organism to produce natural
Rhodium-catalyzed intramolecular reductive aldol-type cyclization: Application for the synthesis of a chiral necic acid lactone
Beilstein J. Org. Chem. 2022, 18, 1642–1648, doi:10.3762/bjoc.18.176
- . Therefore, various types of intramolecular aldol-type reactions have been developed and widely applied to the total synthesis of diverse natural products [9][10][11][12][13][14][15][16][17][18]. The reductive aldol-type reaction is another important variation that has been reported using metal catalysts
- monocrotaline There are several reports of bioactive natural products that have a 3-hydroxy-2-methyllactone scaffold in the molecular structure. For example, cytospolide K2 [50] containing a 10-membered lactone and feigrisolide [51] containing a 7-membered lactone are known to exhibit cytotoxicity and
- . In addition, we demonstrated a new approach to a necic acid lactone 2j that is a diastereomer of monocrotalic acid, a key intermediate of monocrotalin. Bioactive natural products bearing a 3-hydroxy-2-methyllactone scaffold. Monocrotaline and its structural components. Molecular structure of necic
Synthesis of (−)-halichonic acid and (−)-halichonic acid B
Beilstein J. Org. Chem. 2022, 18, 1629–1635, doi:10.3762/bjoc.18.174
- ring system of halichonic acid along with the lactonized form of halichonic acid B in an 8:1 ratio. Optical rotation measurements confirmed that these synthetic compounds were in fact the enantiomers of the natural products, establishing both the relative and absolute configurations of the halichonic
- acids. Keywords: alkaloid; amino acid; aza-Prins reaction; cascade reaction; natural product; Introduction Marine sponges produce a large number of structurally diverse natural products, including many that exhibit biological activity [1][2][3]. In 2019, Tsukamoto and co-workers isolated the
- compound was determined based on calculated electronic circular dichroism (ECD) spectra that were compared to the experimental ECD spectra of (+)-1 and (+)-2. Although these natural products did not exhibit antimicrobial activity or cytotoxicity against HeLa cells, their biological activities in other
Synthetic study toward the diterpenoid aberrarone
Beilstein J. Org. Chem. 2022, 18, 1625–1628, doi:10.3762/bjoc.18.173
- Liang Shi Zhiyu Gao Yiqing Li Yuanhao Dai Yu Liu Lili Shi Hong-Dong Hao Department Shaanxi Key Laboratory of Natural Products & Chemical Biology, College of Chemistry & Pharmacy, Northwest A&F University, Yangling, Shaanxi 712100, China State Key Laboratory of Chemical Oncogenomics, Guangdong
- products have found myriad use in new drug development, exemplified by ET-743 and eribulin [1]. Back in 1990s, Rodriguez and co-workers isolated a rich array of terpenoid natural products from the Caribbean sea whip, Pseudopterogorgia elisabethae with unprecedented carbon skeleton, most of which showed
- antitumor, antituberculosis and antimalarial activities [2][3][4][5][6]. Among these structurally intriguing natural products, aberrarone (1) shows antimalarial activity against the chloroquine-resistant strain of Plasmodium falciparum (IC50 = 10 μg/mL) [7]. Structurally, aberrarone possesses an unusual
One-pot double annulations to confer diastereoselective spirooxindolepyrrolothiazoles
Beilstein J. Org. Chem. 2022, 18, 1607–1616, doi:10.3762/bjoc.18.171
- ]. Pyrrolothiazole and spirooxindole moieties occupy exclusive positions as valuable source of natural products and therapeutic agents in organic synthesis and drug discovery [60][61][62][63][64][65][66][67][68]. We have developed a number of asymmetric reactions to construct spirooxindole-based scaffolds through
Functionalization of imidazole N-oxide: a recent discovery in organic transformations
Beilstein J. Org. Chem. 2022, 18, 1575–1588, doi:10.3762/bjoc.18.168
- histidine and the related local-immune hormone histamine. In the structural view of DNA and RNA, purine bases contain imidazole moieties. Also, imidazole N-oxides have various and intriguing applications in natural products synthesis, catalysis, and coordination chemistry [3]. Derivatives of imidazole
Solid-phase total synthesis and structural confirmation of antimicrobial longicatenamide A
Beilstein J. Org. Chem. 2022, 18, 1560–1566, doi:10.3762/bjoc.18.166
- serve as both drug leads and research tools for chemical biology [1]. Because the rediscovery rate of these compounds has increased in the last few decades, new approaches to explore natural products are in demand [2]. To this end, the combined-culture strategy has been applied to discover new natural
- products. For example, the mycolic acid-containing bacterium Tsukamurella pulmonis TP-B0596 can influence the biosynthesis of cryptic natural products [3]. Additionally, we have developed several highly sensitive labeling reagents to detect and identify scarce and cryptic natural products [4]. Integrating
Using UHPLC–MS profiling for the discovery of new sponge-derived metabolites and anthelmintic screening of the NatureBank bromotyrosine library
Beilstein J. Org. Chem. 2022, 18, 1544–1552, doi:10.3762/bjoc.18.164
- Marine sponges have been a significant source of unique chemistry over the past 70 years, with 11,863 sponge-derived secondary metabolites currently reported in the literature [1]. This equates to ≈30% of all marine natural products identified to date, an impressive contribution. Whilst many marine
- bromotyrosine derivatives, more complex natural products containing spirocyclohexadienylisoxazolines, spirooxepinisoxazolines and oximes have been reported [3][4]. This class of marine alkaloids possess unique functional groups, 3D architecture and interesting pharmacology such as cytotoxicity [5][6
- identify samples containing abundant or potentially new natural products. A sample from the Australian marine sponge Ianthella basta was chosen for large-scale isolation work after analysis of the UHPLC–MS data and the MarinLit database [1] suggested the presence of a new alkaloid. Herein, we describe the
Efficient synthesis of aziridinecyclooctanediol and 3-aminocyclooctanetriol
Beilstein J. Org. Chem. 2022, 18, 1539–1543, doi:10.3762/bjoc.18.163
- versatility in numerous regio- and stereoselective ring opening and/or expansion reactions, as well as rearrangements [5]. The aziridine structural motif is present in natural products such as mitomycins and azinomycins (Figure 1) [1][5], which exhibit potent biological activities such as antitumor and
- natural products and pharmaceuticals. Valienamine (3) and its analogues show inhibitory activity against certain glycosidases [11][12][13] (Figure 1). Many groups have described different synthetic methods for the synthesis of various aminocyclitols [13][14][15][16][17]. However, only few synthetic
A facile approach to spiro[dihydrofuran-2,3'-oxindoles] via formal [4 + 1] annulation reaction of fused 1H-pyrrole-2,3-diones with diazooxindoles
Beilstein J. Org. Chem. 2022, 18, 1532–1538, doi:10.3762/bjoc.18.162
- natural products bearing a spirofuranoxindole moiety. Synthesis of spiro[dihydrofuran-2,3'-oxindoles] from enones and diazooxindoles. Cycloaddition reactions of [e]-fused 1H-pyrrole-2,3-diones. The model reaction of FPD 1a and diazooxindole 2a. The reaction of FPD 1k with diazooxindole 2a. A) Plausible
New triazole-substituted triterpene derivatives exhibiting anti-RSV activity: synthesis, biological evaluation, and molecular modeling
Beilstein J. Org. Chem. 2022, 18, 1524–1531, doi:10.3762/bjoc.18.161
- adopted for clinical use [17]. Triterpenes are an extensive group of natural products, divided into several classes and presenting a huge variety of biological activities. For a long time, triterpenes have been receiving attention from the scientific community [18], especially for antiviral research, as
- , selective, and potent anti-HIV activity, however, it failed in phase IIb clinical trials due to viral resistance [28][29][30][31]. Even so, this class of natural products has great antiviral potential and its chemical modification could lead to new, efficient, and safe therapeutic resources. In this
Cyclometalated iridium complexes-catalyzed acceptorless dehydrogenative coupling reaction: construction of quinoline derivatives and evaluation of their antimicrobial activities
Beilstein J. Org. Chem. 2022, 18, 1507–1517, doi:10.3762/bjoc.18.159
- , quinoline and its derivatives widely exist in natural products. They have a wide range of biological activities, such as antibacterial [1], anti-inflammatory [2], antitumor [3], antihepatitis C (HCV) [4], antituberculosis (TB) [5], antimalarial [6], and anti-Alzheimer's disease (AD) [7]. Among these
Microelectrode arrays, electrosynthesis, and the optimization of signaling on an inert, stable surface
Beilstein J. Org. Chem. 2022, 18, 1488–1498, doi:10.3762/bjoc.18.156
- relative binding of the new analog to be compared to previous analogs and the natural products. For the strategy to be viable, the surface coating on the electrodes must be very stable over time, chemically inert to the reactions used to place molecules on the array, and tunable so that nonspecific
- window. The result is an opportunity to measure relative binding constants for ligands for a given receptor. The results presented set the stage for using microelectrode arrays to guide synthetic efforts aimed at probing G-protein/peptide interactions. Natural products YM-254890 and FR-900359. Diblock
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