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Investigation of extracts from bulbils of Dioscorea bulbifera L. yielded two new norclerodane diterpenoids, diosbulbin N acetate (1) and epi-diosbulbin B (3), together with eleven known compounds. Their structures were established based on spectroscopy. The absolute configurations of 1 and diosbulbin B (2) were determined by X-ray crystallographic analysis using Cu Kα radiation. The absolute configuration of 3 was determined by comparison of its ECD spectrum to that of 2. Isolated phenanthrenes 7, 9 and 10 exhibited moderate cytotoxicity against the HelaS3 cell line with IC50 values of 9.03 ± 0.04, 27.13 ± 6.86 and 10.88 ± 2.75 µM, respectively. In addition, 7-9 and 11 showed potent inhibition of NO production by LPS-induced RAW 264.7 macrophages. [ABSTRACT FROM AUTHOR]

AbstractDendroochreatene (1), a new phenanthrene derivative with a spirolactone ring, was isolated from the whole Dendrobium ochreatum plant together with 11 known compounds (2–12). The structure of the new compound was elucidated spectroscopically and phenolic compounds were firstly reported from D. ochreatum. Moscatilin (4), major compound isolated from D. ochreatum, was found to be cytotoxic toward H460 lung-cancer cells, with an IC50 value of 147.3 ± 0.9 µM, while loddigesiinol C (7), C-α-methoxy derivative was inactive. [ABSTRACT FROM AUTHOR]

Dendrobium officinale Kimura & Migo in the genus Dendrobium of Orchidaceae is an important medicinal plant that produces various bibenzyl and phenanthrene derivatives. In some orchids, these derivatives have been reported to increase with fungal infection. Bibenzyl biosynthesis is regulated by bibenzyl synthase (BBS). Although six genes of the BBS family have been registered from D. officinale, their gene regulation mechanisms are unclear. The infection of Dendrobium with mycorrhizal fungi also reportedly increases the expression of genes involved in biosynthesis; however, the effect of mycorrhizal fungi on bibenzyl production is unknown. The present study examined the effects of three mycorrhizal fungi isolated from D. officinale on BBS gene expression and bibenzyl production over time. One of the Tulasnellaceae operational taxonomic units induced BBS gene expression and increased two representative bibenzyls, gigantol and dendrophenol, at specific time points. Furthermore, 19 BBS sequences were cloned from 12 Dendrobium species, and a phylogenetic analysis was performed. The results indicated that repeated BBS gene duplication occurred during the evolution of the genus, and further duplication occurred after speciation. These results suggest that it is possible to optimize metabolite production by selecting suitable symbiotic fungi. [ABSTRACT FROM AUTHOR]

The transmetalation triggered rhodium‐catalyzed C−H bond activation and tandem annulation of 2‐biphenylboronic acids with sulfoxonium ylides or iodonium ylides has been developed. Various products of phenanthrenes were constructed under redox‐neutral conditions in 34–86% yields. Several mechanism exploration experiments and derivatization reactions were conducted in sequence to gain a deeper understanding of the process and the potential of this transformation. It offers an alternative approach for the synthesis of phenanthrene derivatives. [ABSTRACT FROM AUTHOR]

We report an effective synthetic route to multi-substituted phenanthrenes via an internal redox reaction/ring expansion sequence. The interesting feature of the present system is that it allows for the divergent synthesis of the target skeleton depending on the selected Lewis acid catalyst. When benzylidene malonates with a cyclic structure at the ortho-position were treated with BF3.OEt2, three sequential processes (internal redox reaction/elimination of the alkoxy group/ring expansion) proceeded to give phenanthrene derivatives in which the alkoxycarbonyl (CO2R) group and the alkyl (R) group were in close proximity to each other, in good chemical yields. In sharp contrast, treatment with Bi(OTf)3 exclusively led to the formation of another type of phenanthrene, whose R group was positioned distal to the CO2R group. [ABSTRACT FROM AUTHOR]

Photoinduced tuning of aromaticity and correlative molecular properties has attracted enormous interest in recent years both for modulating photochromism properties and designing novel photochromic materials. Here, we report the synthesis and photochemical characterization of diaryl[5]helicene‐based diarylethene molecular switches. 3,4‐Bis(2,4‐dimethyl‐5‐phenylthiophen‐3‐yl)dibenzo[c,g]phenanthrene derivative 1 a showed no photochromic reaction, whereas 3,4‐bis(2‐methyl‐5‐phenylthiophen‐3‐yl)dibenzo[c,g]phenanthrene derivative 2 a and 3,4‐bis(5‐methyl‐2‐phenylthiazol‐4‐yl)dibenzo[c,g]phenanthrene derivative 3 a exhibited reversible photochromism in different aprotic solvents with specific light irradiation. Meanwhile, the diarylethene compounds 2 a and 3 a underwent turn‐off mode fluorescence photoswitching together with photoisomerization upon light irradiation. Remarkably, the photoinduced changes in the aromaticity of [5]helicene as a central ethene bridge along with the relative smaller activation energy and higher frequency factor facilitated the thermal bleaching rates of diarylethene switches 2 and 3 in solution. This research provides new insight for designing aromatic diarylethene photoswitches for reversible fluorescence switching, photoinduced changes in aromaticity and further fast thermal back reactions. [ABSTRACT FROM AUTHOR]

A palladium‐catalyzed domino approach toward synthetically challenging phenanthrene derivatives has been developed. The procedure involves a sequence of oxidative homocoupling, cyclization, and oxidation starting from deoxybenzoin derivatives halogenated in the ortho position. Good assembly efficiency and good functional group tolerance have been observed with yields from moderate to excellent. A plausible reaction mechanism has been proposed based on experimental results and literature data. [ABSTRACT FROM AUTHOR]

A gold‐catalyzed cascade cyclization of naphthalene‐tethered allenynes gave strained fused phenanthrene derivatives. The reaction proceeds through the nucleophilic reaction of an alkyne with the activated allene to generate a vinyl cation intermediate, followed by arylation with a tethered naphthalene ring to form the 4H‐cyclopenta[def]phenanthrene (CPP) scaffold. When using aryl‐substituted substrates on the alkyne terminus, the gold‐catalyzed reaction produced dibenzofluorene derivatives along with the CPP derivatives. Selective formation of CPP and dibenzofluorene derivatives depending on the reaction conditions is also presented. [ABSTRACT FROM AUTHOR]

Annulations of unsaturated systems through C–H activation represent a powerful tool for producing multicyclic scaffolds. Having coordinating centers in both annulation partners (a dual coordination strategy) would afford remarkable selectivities in the outcomes. Along this concept, we report herein a Pd-catalyzed regioselective rollover cascade dual C–H annulation of o-arylphenols with alkynols for constructing phenanthrene scaffolds. Control, KIE and deuteration studies were conducted to determine the reaction mechanism, and downstream transformations and scaled-up reactions were carried out to assess the robustness of the transformation. [ABSTRACT FROM AUTHOR]

Using palladium-catalyzed Suzuki polycondensation, we synthesized new light-emitting fluorene copolymers containing the dicyano derivatives of stilbene and phenanthrene and characterized them by gel permeation chromatography, UV-vis absorption spectroscopy, spectrofluorimetry, and cyclic voltammetry. The photoluminescence spectra of the synthesized polymers show significant energy transfer from the fluorene segments to the dicyanostilbene and 9,10-dicyanophenanthrene units, which is in agreement with the data of theoretical calculations. OLEDs based on these polymers were fabricated with an ITO/PEDOT-PSS (35 nm)/p-TPD (30 nm)/PVK (5 nm)/light emitting layer (70–75 nm)/PF-PO (20 nm)/LiF (1 nm)/Al (80 nm) configuration. Examination of their electroluminescence revealed that copolymers of fluorene with dicyanostilbene show yellow-green luminescence, while polymers with 9,10-dicyanophenanthrene have a greenish-blue emission. The 9,10-dicyanophenanthrene units have a more rigid structure compared to dicyanostilbene and, in OLEDs based on them, an increase in maximum brightness is observed with an increase in the content of the additive to the polymer chain. In particular, the device using fluorene copolymer with 9,10-dicyanophenanthrene (2.5 mol%) exhibited a maximum brightness of 9230 cd/m2 and a maximum current efficiency of 3.33 cd/A. [ABSTRACT FROM AUTHOR]

Two previously undescribed dihydrophenanthrene derivatives (1 and 2) were isolated along with twelve known analogues from the whole plant of Dendrobium terminale. The structures of the new compounds were elucidated on the basis of detailed spectroscopic analysis. The NMR data of known phenanthrene derivatives (7 and 9) were revised by 2D NMR. The isolated compounds were evaluated for cytotoxicity against three kinds of tumor cell lines (sw1990, HCT-116, and HepG2). Especially compounds 11 and 14 showed stronger antitumor effects, and the structure-activity relationship of these compounds was discussed. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic, caused by SARS-CoV-2, addressed the lack of specific antiviral drugs against coronaviruses. In this study, bioguided fractionation performed on both ethyl acetate and aqueous sub-extracts of Juncus acutus stems led to identifying luteolin as a highly active antiviral molecule against human coronavirus HCoV-229E. The apolar sub-extract (CH2Cl2) containing phenanthrene derivatives did not show antiviral activity against this coronavirus. Infection tests on Huh-7 cells, expressing or not the cellular protease TMPRSS2, using luciferase reporter virus HCoV-229E-Luc showed that luteolin exhibited a dose-dependent inhibition of infection. Respective IC50 values of 1.77 µM and 1.95 µM were determined. Under its glycosylated form (luteolin-7-O-glucoside), luteolin was inactive against HCoV-229E. Time of addition assay showed that utmost anti-HCoV-229E activity of luteolin was achieved when added at the post-inoculation step, indicating that luteolin acts as an inhibitor of the replication step of HCoV-229E. Unfortunately, no obvious antiviral activity for luteolin was found against SARS-CoV-2 and MERS-CoV in this study. In conclusion, luteolin isolated from Juncus acutus is a new inhibitor of alphacoronavirus HCoV-229E. [ABSTRACT FROM AUTHOR]

To identify potential drug candidates, secondary metabolites of Dendrobium nobile were performed. As a result, two previously undescribed phenanthrene derivatives with a spirolactone ring (1 and 2), along with four known compounds, N-trans-cinnamoyltyramine (3), N-trans-p-coumaroyltyramine (4), N-trans-feruloyltyramine (5), and moscatilin (6), were isolated from Dendrobium nobile. The structures of the undescribed compounds were elucidated using NMR spectroscopy, electronic circular dichroism (ECD) calculations, and extensive spectroscopic data analysis. The cytotoxic effects of compounds on human tongue squamous cells OSC-19 were determined using MTT at concentrations of 2.5 μM, 5 μM, 10 μM, and 20 μM. Compound 6 exhibited potent inhibitory activity against OSC-19 cells with an IC50 of 1.32 μM. Migration assays and western blot assays demonstrated that compound 6 effectively inhibited migration by down-regulating MMP2 and MMP9 at concentrations of 0.5 μM and 1 μM. To investigate its effect on apoptosis, we performed AO/PI staining, flow cytometry, and WB experiments. The results showed that increasing concentrations led to increased red fluorescence, decreased green fluorescence, increased apoptosis rate, decreased expression of bcl-2, caspase 3, caspase 9, and parp proteins, and increased bax expression. Furthermore, the phosphorylation of JNK and P38 was activated, suggesting that compound 6 may induce apoptosis via the MAPK pathway. [ABSTRACT FROM AUTHOR]

Complexation between (18-crown-6)stilbene and alkanediammonium ions +H3N(CH2)nNH3+ (n = 2−4) resulting in the pseudo-sandwich 2:1 stilbene—dication complexes and 1:1 stilbene—dication complexes was studied by NMR spectroscopy. The stability of the complexes decreases as the methylene chain length in the alkanediammonium ion increases. UV photolysis of the bis-ligand complexes produces two major products, viz., the rctt isomer of a biscrown-containing cyclobutane derivative formed as a result of intra-supramolecular [2+2] photocycloaddition and a crown-containing phenanthrene derivative (product of electrocyclization reaction). The effective quantum yields of both cyclization reactions occurring in the pseudo-sandwich complexes increase as the number of methylene units in the dication decreases. [ABSTRACT FROM AUTHOR]

Medicinal plants possess range of phytochemicals accountable for their diverse biological activities. Presently, such compounds have been isolated from medicinal plants, characterized and evaluated for their pharmacological potential. In the present study, the efforts have been made to isolate the compound(s) from Grewia tiliaefolia Vahl., plant known for its ameliorative effect on brain related diseases such as anxiety, depression, cognitive disorders and Parkinson's disease. Plant extract was subjected to isolation of compound(s) using column chromatography and isolated compound was characterized by NMR FTIR and LCMS. The isolated compound was novel with the IUPAC name of the compound is propyl 3-hydroxy-10,13-dimethyl-6,7,8,9,10,11,12,13,14,15,16,17-dodecahydro-3H-cyclopenta[a]phenanthrene-17-carboxylate, designated as A-1 and has not been reported before. A-1 was further evaluated for its antioxidant potential using in vitro antioxidant assays (2,2-diphenyl-1-picryl-hydrazyl-hydrate, DPPH assay and reducing power assay, RPA). Also, Acetylcholinesterase (AChE) inhibitory potential of A-1 and extract was analysed. Results showed that A-1 exhibited significantly higher antioxidant activity in both DPPH and RPA assay as compared to plant extract. In case of AChE inhibitory activity again, A-1 has shown significantly higher activity as compared to plant extract. In silico study was conducted to predict its action on proteins playing crucial role in neurological and neurodegenerative disorders such as gamma amino butyric acid (GABA) receptor and glutamate α amino-3-hydroxyl-5-methyl-4-isoxazolepropionic acid (Glu AMPA) receptor in epilepsy and AChE enzyme in Alzheimer's diseases. The compound has shown interaction in following order: AChE > GABA receptor > Glu AMPA receptor. Further, molecular dynamic simulations and ADME studies of A-1 and AChE enzyme revealed that A-1 yielded good results in all parameters and hence can relieve Alzheimer's like symptoms. [ABSTRACT FROM AUTHOR]

A series of amphiphilic salen complexes, [L1a,bM] and [L2a,bM], were designed and synthesized. These complexes consist of two or four hydrophilic triethylene glycol (TEG) chains and a hydrophobic π-extended metallosalen core based on naphthalene or phenanthrene. The obtained amphiphilic complexes, [L1bM] (M = Ni, Cu, Zn), formed a monolayer at the air–water interface, while the monocationic [L1bCo(MeNH2)2](OTf) did not form a well-defined monolayer. The number of hydrophilic TEG chains also had an influence on the monolayerformation behavior; the tetra-TEG derivatives, [L1bNi] and [L2bNi], showed a pressure rise at a less compressed region than the bis-TEG derivatives, [L1aNi] and [L2aNi]. In addition, the investigation of their compressibility and compression modulus suggested that the tetra-TEG derivatives, [L1bNi] and [L2bNi], are more flexible than the corresponding bis-TEG analogues, [L1aNi] and [L2aNi], and that the phenanthrene derivatives [L1a,bNi] were more rigid than the corresponding naphthalene analogues, [L2a,bNi]. The Langmuir–Blodgett (LB) films of one of the complexes, [L1bNi], showed CD spectra slightly different from that in solution, which may originate from the unique anisotropic environment of the air–water interface. Thus, we demonstrated the possibility of controlling the chiroptical properties of metal complexes by mechanical compression. [ABSTRACT FROM AUTHOR]

Arundina graminifolia (D. Don) Hochr. is an ethnic medicine that has been used as an antidote for food poisoning and urinary tract infection by Dai minorities for centuries. However, its pharmacological mechanism of antibacterial activity and efficacy components are not clearly defined. Thirteen compounds were isolated from the whole plant of A. graminifolia and their structures were identified by spectroscopic analysis, and their antibacterial effects against Escherichia coli and Staphylococcus aureus were tested by micro-broth dilution method. Four compounds (6, 11, 12 and 13) possessed excellent antibacterial activities. Among them, blestiarene A (11) and densiflorol B (13) triggered significant bacteriostatic efficacy with the minimum inhibitory concentration between 25-50 μg/mL (positive drug amoxicillin 0.3-0.6 μg/mL). Mechanism research showed that compound 11 and 13 increased the level of reactive oxygen species and altered the bacterial membrane structure, leading to leakage of alkaline phosphatase and DNA, which consequently caused the death of bacteria. In addition, density functional theory calculation showed that the electron affinity of the antibacterial agent was positively correlated with antibacterial activity. Our work highlighted the antibacterial potential of natural phenanthrenes with membrane disrupt mechanism, and the tested phenanthrene derivatives could serve as lead compounds for the novel bactericides. [Display omitted] • Phenanthrenes from Arundina gramnifolia exhibited prominent antibacterial activity • Blestriarene A and densiflorol B disrupted cell membrane, inducing production of ROS • The structure-activity relationship helped to understand the antibacterial mechanism [ABSTRACT FROM AUTHOR]

Ten undescribed diterpenoids (1 – 10) and three undescribed phenanthrene derivatives (11 – 13), together with seven known compounds, were isolated from the roots of Baliospermum solanifolium. Their structures were determined by a combination of spectroscopic data analysis, electronic circular dichroism calculations and single-crystal X-ray diffraction studies. Compounds 1 – 7 (baliosperoids A–G) represent the examples of 20-nor- ent -podocarpane class first discovered in nature. In particular, compound 7 possesses a unique 2,3-seco ring system incorporating γ -butanolide moiety. All isolates were assessed for their cytotoxic activities against HT-29, HCT-116, HCT-15, MCF-7, and A549 cell lines as well as their inhibitory effects on lipopolysaccharide-induced NO production in RAW264.7 cells. Compound 1 , a 20-nor- ent -podocarpane-type diterpenoid possessing a Δ1,2 double bond, not only exhibited considerable proliferation inhibition against five human cancer cell lines, with IC 50 values ranging from 4.13 to 23.45 μM, but also displayed the most potent inhibitory activity on NO production with IC 50 value at the nanomolar level (0.63 ± 0.21 μM). Ten previously undescribed diterpenoids and three previously undescribed phenanthrene derivatives were isolated from the roots of Baliospermum solanifolium. Compounds 1 – 7 , namely baliosperoids A–G, represent the examples of 20-nor- ent -podocarpane class first found in nature. [Display omitted] • 13 previously undescribed compounds were isolated from Baliospermum solanifolium. • Compounds 1 – 7 represent the examples of 20-nor- ent -podocarpane class first found in nature. • Compound 7 possesses a unique 2,3-seco ring system incorporating γ -butanolide moiety. • ECD calculation and X-ray diffraction were used for structure determination. • Compound 1 displayed inhibitory activity on NO production with IC 50 value at the nanomolar level. [ABSTRACT FROM AUTHOR]

A mild and transition‐metal‐free one‐pot strategy is established to prepare polysubstituted naphthalene and phenanthrene derivatives from methyl enol ethers (MEE) with alkynes. Significantly, this protocol is promoted by boron trifluoride diethyl etherate (BF3⋅Et2O) at room temperature. A wide variety of diversely functionalized naphthalene and phenanthrene derivatives were obtained in good to excellent yields. A plausible mechanism involving a spiro quinonoid intermediate is proposed. Due to fluorescent nature of naphthalene, selected compounds were screened for the solvatochromism study. Notably, positive solvatochromism effect was observed in the case of nitro‐substituted naphthalene derivative (3 h) with respect to different polarity of solvents. [ABSTRACT FROM AUTHOR]

Lung cancer continues to be the world's leading cause of cancer death and the treatment of non-small cell lung cancer (NSCLC) has attracted much attention. The tubers of Bletilla striata are regarded as "an excellent medicine for lung diseases" and as the first choice to treat several lung diseases. In this study, seventeen phenanthrene derivatives, including two new compounds (1 and 2), were isolated from the tubers of B. striata. Most compounds showed cytotoxicity against A549 cells. An EdU proliferation assay, a cell cycle assay, a wound healing assay, a transwell migration assay, a flow cytometry assay, and a western blot assay were performed to further investigate the effect of compound 1 on A549 cells. The results showed that compound 1 inhibited cell proliferation and migration and promoted cell apoptosis in A549 cells. The mechanisms might correlate with the regulation of the Akt, MEK/ERK, and Bcl-2/Bax signaling pathways. These results suggested that the phenanthrenes of B. striata might be important and effective substances in the treatment of NSCLC. [ABSTRACT FROM AUTHOR]

In recent years, traditional Chinese medicines and active natural ingredients have been increasingly recognized for their medication effect worldwide. Phenanthrene derivatives, one of the main active ingredients in many Chinese herbal medicines such as Dendrobium, Bletilla, Juncaceae, have achieved great attention by botanists, biologists, and pharmacists due to their chemical structural diversity and practical biological activities. Nearly 200 natural phenanthrene compounds found from natural Chinese medicine plants are discussed in this review. Plants in the Orchidaceae, Juncaceae, Dioscoreaceae, and Lauraceae families, among others, produce phenanthrene chemicals. Furthermore, their medicinal effects and mechanisms of action are summarized, emphasizing anti-inflammatory, anti-bacterial, anti-cancer, and anti-oxidative activities. It provides a foundation for further exploring and developing new drugs with phenanthrene compounds as the essential core structure.

Bletilla formosana (Hayata) Schltr, popularly known as "Xiao Baiji", is commonly consumed as a food ingredient and herbal medicine with the treatment of haemorrhages, chapped skin, colds, and burns in China. The phytochemical investigation of B. formosana rhizome result in the isolation and identification of 35 chemical compounds, of which biphenyl, phenanthrene and their derivatives are the most abundant structural types. Among the isolated compounds, 12 compounds showed superior antioxidative activities in Ferric reducing/antioxidant power (FRAP), 2,2-diphenyl-1-picryhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) scavenging assay. Furthermore, compounds 18 – 20 (phenanthrenes) and 34 (lignin) had significantly antioxidant capacity and cytoprotective effects through decreasing reactive oxygen species (ROS) content and up-regulating the levels of catalase (CAT), superoxide dismutase (SOD) and glutathione (GSH) in H 2 O 2 -induced HepG2 cells. In addition, compounds 8 , 10 , 16 (dihydrophenanthrenes), 18 – 20 (phenanthrenes), 27 – 28 (phenolics), 34 – 35 (lignin) showed the significant anti-inflammatory by inhibiting productions of interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in the lipopolysaccharide (LPS)-induced RAW264.7 macrophage cells. These results confirmed most of isolated compounds displayed significant antioxidant, cytoprotective and anti-inflammatory activities. Among phenanthrenes (18 – 20) were a prominent type found in the rhizomes of B. formosana. And the more phenolic hydroxyl and methoxy groups of phenanthrene and their derivatives, the better activities. This suggested that Bletilla formosana rhizome can be used as an edible and medicine homologous plant with antioxidant and anti-inflammatory functions, and can be developed into functional and health nutrition products. [Display omitted] [ABSTRACT FROM AUTHOR]

This paper details how two new small molecules, based on phenanthrene, were developed, and tailored for light-emitting device applications. An account is provided of both the compound synthesis and the methodologies employed in device fabrication. The ink formulation was improved by the use of triflate counterions. Standard bottom emitting devices were constructed on ITO glass along with top emitting devices on a sputter coated silver on glass substrate. Both structures exhibit UV emissions from the synthesized molecules. Successful EL emission within the UV spectrum range has been achieved by spray coating these active molecules onto glass slides. The optimized solution-processed devices produce UV emission using a semi-transparent silver nanowire top electrode. This results in electroluminescence (EL) peaking at 398 nm, with a maximum EL emission intensity of 20.5 μW/cm2. [Display omitted] • Synthesized two novel UV light-emitting organic materials achieving high electroluminescent intensity of 20.5 μW/cm2. • Spray coating process suitable for top emitting OLECs with AgNW top electrodes demonstrated. • Hexyl imidazolium moiety enhances solubility and enables uniform spray-coated thin films without aggregation or pinholes. [ABSTRACT FROM AUTHOR]

Alkylated polycyclic aromatic hydrocarbons are abundant in crude oil and are enriched during petroleum refinement but knowledge of their cardiotoxicity remains limited. Polycyclic aromatic hydrocarbons (PAHs) are considered the main hazardous components in crude oil and the tricyclic PAH phenanthrene has been singled out for its direct effects on cardiac tissue in mammals and fish. Here we test the impact of the monomethylated phenanthrene, 3-methylphenanthrene (3-MP), on the contractile and electrical function of the atrium and ventricle of a polar fish, the navaga cod (Eleginus nawaga). Using patch-clamp electrophysiology in atrial and ventricular cardiomyocytes we show that 3-MP is a potent inhibitor of the delayed rectifier current I Kr (IC50 = 0.25 μM) and prolongs ventricular action potential duration. Unlike the parent compound phenanthrene, 3-MP did not reduce the amplitude of the L-type Ca2+ current (I Ca) but it accelerated current inactivation thus reducing charge transfer across the myocyte membrane and compromising pressure development of the whole heart. 3-MP was a potent inhibitor (IC50 = 4.7 μM) of the sodium current (I Na), slowing the upstroke of the action potential in isolated cells, slowing conduction velocity across the atrium measured with optical mapping, and increasing atrio-ventricular delay in a working whole heart preparation. Together, these findings reveal the strong cardiotoxic potential of this phenanthrene derivative on the fish heart. As 3-MP and other alkylated phenanthrenes comprise a large fraction of the PAHs in crude oil mixtures, these findings are worrisome for Arctic species facing increasing incidence of spills and leaks from the petroleum industry. 3-MP is also a major component of polluted air but is not routinely measured. This is also of concern if the hearts of humans and other terrestrial animals respond to this PAH in a similar manner to fish. [Display omitted] • 3-MP is a potent inhibitor of I Kr and prolongs action potential duration which is pro-arrhythmic. • Unlike phenanthrene, 3-MP does not cause reduction of I Ca amplitude. • 3-MP greatly accelerates I Ca inactivation, reducing cellular Ca2+-influx and contractile activity of the whole heart. • 3-MP is a potent inhibitor of I Na slowing conduction velocity which is pro-arrhythmic. • More robust environmental monitoring of individual PAHs will improve risk apportionment and inform mitigation policy. [ABSTRACT FROM AUTHOR]

X‐shaped phenanthrene derivatives containing aryl substituents at the 1,3,6,8‐positions were synthesized through Suzuki coupling reactions of two types of phenanthrenes possessing bromine and chlorine substituents. X‐shaped phenanthrenes, with four t‐butylphenyl, 9,9‐dimethyl‐9H‐fluoren‐2‐yl or 4‐diphenylaminophenyl (DPAP) groups, are highly emissive in the blue region and their fluorescence efficiencies increase as the extent of aryl π‐conjugation increases. To assess the effects of donor (D) and acceptor (A) groups at the 1,8‐ and 3,6‐positions on intramolecular charge‐transfer emission, two D−A compounds with two DPAP D‐groups and two 4‐pyridyl (Py) A‐groups were synthesized. Results of electrochemical studies reveal that the phenanthrene with four DPAP groups does not undergo oxidative polymerization in dichloromethane, but the two D−A analogs possessing both DPAP and Py groups do undergo oxidative polymerization, producing films which have electrochromic properties. [ABSTRACT FROM AUTHOR]

A phenanthrene unit has been functionalized by several methylthiophene units in order to bring it a photochromic behavior. These compounds were characterized by NMR, absorption and emission spectroscopies, theoretical calculations as well as cyclic voltammetry. The association of a phenanthrene group with a photochromic center could open the door to a new generation of organic field‐effect transistors. [ABSTRACT FROM AUTHOR]

Entada abyssinica Steud. Ex A. Rich (Leguminosae) is a medicinal plant used traditionally for the treatment of infections. A phytochemical investigation of the methanol extract of E. abyssinica root bark led to the isolation of a new phenanthrene derivative named phenentada (1), together with seven known compounds (8 S, 13 E)-kolavic acid 15-methyl ester (2) and 8 S-kolavic acid 15-methyl ester (3) obtained as mixture, 8 S-kolavic acid 15-methyl ester (3), 8 S-kolavic acid 18-methyl ester (4), 13,14,15,16-tetranorclerod-3-ene-12,18-dioic acid (5), 1′,26′-bis-[(S)-2,3-dihydroxypropyl] hexacosanedioate (6), campesterol (7) and 3-O-β-d-glucopyranosylstigmasterol (8). Their structures were determined by NMR spectroscopy (1D and 2D), mass spectrometry (HRESIMS) and by comparison with previously reported data. The crude extract and some isolated compounds were evaluated for their in vitro antimicrobial activities by the microdilution method while, the antioxidant activity was evaluated by the DPPH methods. Regarding the antimicrobial activity, the crude extract showed significant inhibitory activities against bacteria strains (MIC 7.81–31.3 μg mL−1) and yeasts (MIC 15.6–31.3 μg mL−1) whereas all compounds tested exhibited significant activity against Staphylococcus epidermidis. Moreover, compounds 4, 5 and 6 and the mixture 2/3 showed significant antimicrobial activity on Candida parapsilosis strain (MIC = 3.12 μg mL−1), as well as selected antifungal property against candida pathogenic fungi strains. On the other hand, compounds (1) demonstrated the best bioactivities against Candida albicans and Salmonella enterica with MIC = 3.12 μg mL−1 while the mixture 2/3 appeared to have the highest inhibition on gram (+) bacteria strain S. epidermidis with MIC of 0.78 μg mL−1 and compound 5 (MIC = 1.56 μg mL−1) against the gram (−) bacteria strain. Furthermore, the SC50 values measured by the antioxidant test for all samples varied between 47.21 and 52.44 μg mL−1 for DPPH. These results support the traditional uses of E. abyssinica in the management of several diseases including the claim in the skin disease treatment. Additionally, here is reported the first time isolation of a phenanthrene derivative in the Fabaceae family to the best of our knowledge. [ABSTRACT FROM AUTHOR]

The topic of organic solar cells is emerging thanks to their promising properties being low-cost, lightweight and most importantly, eco-friendly. Optimization of active layers has a crucial role in maintaining and improving the efficiency of solar cells. In this study, we investigated the photovoltaic effects of eight novel derivatives for organic solar cells application. The study was based on the π-conjugated donor–acceptor (D–A) structure. The studied molecules act as donors, whereas the PCBM is the acceptor. The studied dipyridine phenanthrene derivatives differ by various functional groups at both terminals. The dipyridine phenanthrene derivatives, abbreviated as DiPP1 to DiPP8, consist of phenanthrene as the core, 2-vinylpyridine as the conjugated π-bridge and two terminal functional groups (viz., –OH, –NO, –Cl, –NH2, –NO2, –CN, –COOH, –COOCH3, –COCH3). In this work, DFT and TD-DFT applying B3LYP/6-311G(d) and WB79XD/6-311G(d) levels of theories were employed with the Gaussian 09W programme. Geometries and optoelectronic properties were studied by analyzing HOMO energy (EHOMO), LUMO energy (ELUMO), bandgap energy (Egap), open-circuit voltage (Voc) and light-harvesting efficiency (LHE) to test their applicability in solar cells. [ABSTRACT FROM AUTHOR]

Two reactive phenanthrene derivatives, 4-(1H phenanthrol [9,10-d] imidazole-2-yl) benzaldehyde (PIB) and 6,9-dimethoxyphenanthro[9,10-c]furan-1,3-dione (PA) with high fluorescent quantum yields were prepared and used as fluorescent marker in fluorescence microscopy. In particular, silane modified μmZeolite-L containing amino group (-NH2) in the surface were labeled with the phenanthrene derivatives allowing good imaging resolution and spectroscopy measurements. The presence of a large Stokes shift of the probes due to their intramolecular charge-transfer character gives an advantage of the compounds in confocal laser fluorescence microscopy due to easy signal separation in excitation and emission wavelengths. On the other hand, these results open up the possibility of using these probes for visualization of Zeolite-based materials commonly used as catalysts in thermal and photochemical reactions. [ABSTRACT FROM AUTHOR]

The phenanthrene nucleus is extensively found in diverse natural products and its versatility is not just limited to pharmaceutically beneficial molecules but has proved efficient in the development and synthesis of dyes, plastics, pesticides and explosives. Such a relevant nucleus has attracted researchers to probe into the construction of phenanthrene nucleus. The past two decades have witnessed continuous efforts in this direction with the exploration of various synthetic strategies enabling access to the privileged core. The review focuses on bringing the advances made in 20 years in these synthetic protocols and the mechanism involved in the generation of phenanthrene and its derivatives under one roof. In addition, it also provides a comparative study of the diverse approaches and vivid reactions employed for phenanthrene synthesis providing a better understanding and creating newer ideas towards the development of new chemical entities (NCEs). [ABSTRACT FROM AUTHOR]

A group of phenanthrene derivatives with different deformed types, including four previously undescribed derivatives (1 – 4), an undescribed natural product (5) and five known compounds (6 – 10), were isolated from the leaves and stems of Strophioblachia fimbricalyx by molecular networking based on UPLC-MS/MS method. Their structures were established by 1D/2D NMR spectroscopy, HRESIMS, quantum chemistry calculation, and single crystal X-ray diffraction. In biogenic pathways, series of deformed phenanthrenes were all suspected to be derived from 6/6/6 tricyclic phenanthrenes with a gem-dimethyl unit in one ring as characteristic components of Strophioblachia. Fimbricalyxone (1) and trigoxyphin M (6) with a 6/6/5 tricyclic carbon skeleton were reported for the first time from the genus and fimbricalyxanhydride C (2) is the first example of anhydride type bearing a rare 8,9-oxycycle. All the isolates were evaluated for their cytotoxic activity against three tumor cell lines, and compounds 8 and 10 exhibited significant activity with IC 50 values of 4.65–9.02 μM, and the structure–activity relationship of the deformed phenanthrenes was discussed. In addition, the X-ray structure of 8 and 10 and the antineoplastic activity of 10 are reported herein for the first time. Trigohowilol G (10) inhibiting the proliferation of A549 cells might be related to cell cycle distribution and the induction of S phase arrest, and it induced cell apoptosis through Bad/Bax/Cleaved PARP1 pathway. [Display omitted] • Structurally diverse phenanthrenes were obtained from Strophioblachia fimbricalyx. • They were all derived from 6/6/6 tricyclic phenanthrenes in biogenic pathways. • Trigohowilol G (10) showed stronger cytotoxic activities by inducing cell apoptosis. [ABSTRACT FROM AUTHOR]

Herein we report a novel palladium-catalyzed reaction that results in phenanthrene derivatives using aryl iodides, ortho-bromobenzoyl chlorides and norbornadiene in one pot. This dramatic transformation undergoes ortho-C–H activation, decarbonylation and subsequent a retro-Diels–Alder process. Pleasantly, this protocol has a wider substrate range, shorter reaction times and higher yields of products than previously reported methods.

The photoelectrocyclization of conjugated vinyl biaryls has proven to be a valuable and efficient strategy for generating phenanthrene derivatives. Contained in this review is an overview of the mechanism for the transformation and a discussion of the reaction scope with a focus on the electrocyclization itself, rearomatization, and the application of the reaction in natural product synthesis. 1 Introduction 2 The Synthesis of Conjugated Vinyl Biaryls 3 Mechanistic Studies 4 Substrate Scope 5 Applications 6 Conclusions [ABSTRACT FROM AUTHOR]

A new phenanthrene, 2,3,7-trihydroxy-4,8-dimethoxyphenanthrene (1), was isolated from Pleione maculata. Its structure was determined on the basis of NMR (1D and 2D) and HR-ESI-MS data. The new compound was also evaluated for its α-glucosidase inhibitory activity. Compared with the positive control, the new compound even slightly exceeded the effect of acarbose. [ABSTRACT FROM AUTHOR]

A new phenanthropyran, dioscorone B (1), and a new phenanthrene (2), together with seven known compounds (3–9), were isolated from the 75% ethanol extract of Dioscorea septemloba rhizomes. The chemical structures of these compounds were elucidated by comprehensive spectroscopic methods including NMR, HRESIMS, IR, and UV spectra. Compounds 1–5 were first isolated from genus Dioscorea. The proton and carbon chemical shifts of compounds 1–9 were unambiguously assigned based on the 1D-NMR and 2D-NMR data. Compounds 1–5 and 8–9 were first tested for their antioxidant activities. Compounds 1 and 2 showed excellent activities with IC50 values of 0.07 ± 0.10 μM and 0.13 ± 0.09 μM, respectively. [ABSTRACT FROM AUTHOR]

Maxillaria densa is a native American orchid extended in high mountains and humid forests. The objective of this review is to provide a critical analysis on ethnopharmacology, phytochemistry and pharmacology of the species, focusing on its potential for biotrading. The study was conducted exploring the PubMed, Scopus, SciELO and SciFinder databases and specialized websites, looking for bioactive molecules and thus confirming what properties and compounds contain this plant. M. densa is traditionally used for the treatment of stomach pains, such as antidiarrheal and antispasmodic. The extracts obtained from M. densa show the presence of six active ingredients derived from phenanthrene, an aromatic polycyclic hydrocarbon. The biological activity studies carried out have shown spasmolytic, antinociceptive and relaxing effects. M. densa grows in coffee crops under shade, which are considered sustainable production systems, increasing the chances of green businesses for local farmers. From the mentioned findings, M. densa presents a potential as a source of bioactive molecules and as an ornamental flower, opening a new perspective in the Bioeconomy field. [ABSTRACT FROM AUTHOR]

Phytochemical investigation of the whole plant of Dendrobium scabrilingue resulted in the isolation of two new compounds namely dendroscabrols A (1) and B (2), along with eight known compounds (3–10). The structures of these compounds were determined by NMR and HR-ESI-MS experiments. All of the isolates were evaluated for their α-glucosidase inhibitory effect. Dendroscabrol B (2) and RF-3192C (10) showed the most potent α-glucosidase inhibitory activity. Dendroscabrol A (1), gigantol (5), coelonin (7) and lusianthridin (9) also exhibited strong activity as compared with the positive control acarbose. [ABSTRACT FROM AUTHOR]

Our previous experimental work indicated that the presence of ester functionality in phenanthrene derivatives D-1 and D-2 leads to potent cytotoxicity against the Caco-2 cell line. The present work is based on th-is experimental result. First, we optimized the structures of the studied molecules using the density functional theory method. Then we performed a study about their potential biological importance by evaluating the binding mode and exploring their intermolecular interactions with appropriate proteins using molecular docking calculations. Consequently, we confirmed the results obtained from experimental studies. In particular, our study indicated that many promising proteins are able to bind and interact with the phenanthrene skeleton from the binding site. Methyl 8-methyl-9,10-phenanthrenequinone-3-carboxylate D-1 and methyl 8-methyldibenzo[a,c]phenazine- 3-carboxylate D-2 displayed strong cytotoxicity. However, the best affinity is noted for B-Raf proto-oncogene serine/threonine-protein kinase (-9.8 Kcal/mol for molecule D-1 and -11.1 Kcal/mol for molecule D-2), which is higher than that of any other protein used. Especially, this protein is involved in sending signals inside cells that are involved in directing cell growth and is found to be a significant target in both types of studied cancers. [ABSTRACT FROM AUTHOR]

Eulophia nuda Lindl. (Orchidaceae) is a small perennial terrestrial herb found in central and Southeast Asian regions usually known for its ethnomedicinal uses by folklore and local healers in India and different regions of the world. E. nuda tubers have been used for the treatment of tumors, scrofulous glands of neck, rheumatoid arthritis, bronchitis, blood diseases, vermifuge, etc. Phytochemical properties of this plant are not much explored. Very few compounds such as phenanthrene derivatives and benzylated phenanthrene derivatives have been isolated from this plant. Pharmacologically, this plant is active in respect of cytotoxic, antioxidant, antiglycation and DNAprotection properties. The traditional knowledge and various phytochemical and pharmacological activities of this plant have been at the focus of research. The aim of present review is to systematically appraise about the literature available till date on this plant about its traditional uses, phytochemistry and pharmacology of its crude extract and isolated compounds. [ABSTRACT FROM AUTHOR]

We prepared amide-heterocycle (HC) compounds having various aromatic π-electron systems (Ar), such as phenyl, naphthyl, furyl, thienyl and phenanthryl moieties, and converted them as ligands to difluoroboronated complexes, Ar@HCs. Blue fluorescence from Ar@HCs was observed in solution and the solid state, and the fluorescence quantum yields (Φf) and lifetimes (τf) were determined. The Φf values in CHCl3 were as small as 0.1 except for the phenanthrene derivatives (0.4–0.6). Observation of the triplet–triplet absorption upon laser flash photolysis of Ar@HCs in solution indicated that the fluorescence process competes with intersystem crossing to the triplet state. Blue fluorescence in the solid state was observed with the Φf values of 0.3–0.7. Based on the crystallographic data, the relationship between the crystal structures and emission features of Ar@HCs in the solid state is discussed. [ABSTRACT FROM AUTHOR]

Five phenanthrene and two dihydrophenanthrene derivatives were isolated from the diethyl ether extract of fresh rhizomes of Dioscorea communis (L.), among them a phenanthrentriol 1 reported for the first time from Dioscoreaceae family and two dihydrophenanthrene derivatives 6 and 7 reported also for the first time from Dioscorea species. The structures of isolated compounds were elucidated using UV, IR, 1D-, 2D-NMR, and MS techniques. The anticholinesterase activity of extracts and four compounds was evaluated for the first time against acetylcholinesterase (AChE), and butyrylcholinesterase (BChE) enzymes using Ellman method. Moreover, the antioxidant activity of extracts and three compounds has been investigated using DPPH radical scavenging, ABTS cation radical decolorization, CUPRAC, reducing power and β-carotene bleaching assays. [ABSTRACT FROM AUTHOR]

Photolysis of exo -1-(1 a ,9 b -dihydro-1 H -cyclopropa[ l ]phenanthren-1-yl)cyclopropan-1-ol and exo -1-(1 a ,9 b -dihydro-1 H -cyclopropa[ l ]phenanthren-1-yl)cyclobutan-1-ol in benzene- d6 produces (1-hydroxycyclopropyl)- and (1-hydroxycyclobutyl)carbene respectively. It was observed that (1-hydroxycyclopropyl)carbene rearranges to cyclobutanone whereas (1-hydroxycyclobutyl)carbene forms cyclopentanone. Formation of both ketones is attributed to tautomerization of the corresponding enols that arise from ring expansion of the carbenes. Products assignable to intramolecular C–H insertions were not detected in the photolysates. Two cyclopropanated phenanthrene derivatives have been synthesized and photolyzed in solution to produce (1-hydroxycyclopropyl)- and (1-hydroxycyclobutyl)carbene. The carbenes rearrange by ring expansion. [ABSTRACT FROM AUTHOR]

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As bifunctional materials, phenanthrene derivatives 2,7-diphenylphenanthrene and 2,7-di(styryl)phenanthrene (DPPa and DSPa) were designed and studied. Both materials show charge transport properties and strong solid-state emission. The hole mobility was measured to be 1.6 and 0.4 cm2 V−1 s−1 for DPPa and DSPa, respectively. While the photoluminescence quantum yield of DPPa and DSPa was as high as 37.13% and 62.36%, respectively. [ABSTRACT FROM AUTHOR]

Abstract Two luminescent Charge Transfer (CT) cocrystals involving planar phenanthrene derivatives namely, formyl phenanthrene (FP) and acetyl phenanthrene (AP) as donors (D) and 1,2,4,5-tetracyanobenzene (TCNB) as an acceptor (A) building block, are formed by molecular self-assembly. Detailed structural and spectroscopic measurements elucidated the mixed stack sequence DADAD in the CT cocrystals. The solid supramolecular architecture for both the cocrystals forms 2D sheet, supported by the extended network of C-H···O, and C-H···N hydrogen bonds as evidenced by the crystallographic observation. Interestingly, the two cocrystals display tunable emissions compared to the blue emissions of donor compounds, which correlate with the formation of excited CT state between the donor and acceptor motifs as a result of mixed stack orientation. The nature of the CT interactions in the two cocrystals was further explored by applying density functional theoretical (DFT) studies. Such a supramolecular cocrystal approach provides a facile platform towards the design of new luminescent two component CT complexes with desired functionalities. Graphical abstract Two luminescent CT complexes have been fabricated based on the phenathrene derivative that showed tunable photophysical properties due to mixed sandwich motifs. fx1 Highlights • Two luminescent charge-transfer cocrystals were prepared by cocrystallization. • Different stacking modes were formed by the donors and acceptor. • Optical properties of cocrystals were improved compared to pristine donors. • Relationship between stacking modes and optical properties are thoroughly investigated. [ABSTRACT FROM AUTHOR]

ABSRACT Twelve undescribed compounds including six phenanthrene derivatives (parviphenanthrines A-F), two stilbene derivatives (parvistilbines A-B), three esters (parviesters A-C), and one sesquiterpenoid (parvidiol A) were isolated from the roots of Stemona parviflora , together with twenty-two known ones. The structures of the undescribed compounds were elucidated based on the analyses of their spectroscopic data. The absolute configuration of parviphenanthrine A was determined by the quantum ECD calculations. Parviphenanthrines A and E , stemanthrene A , stilbostenin E , 4-hydroxy-benzenepropanol- α -benzoate , and (E)-4-hydroxycinnamic acid methyl ester showed nematocidal activity against Meloidogyne incognita with IC 50 values of 14.02 ± 0.32, 2.51 ± 0.13, 17.10 ± 0.65, 2.05 ± 0.07, 4.22 ± 0.31, and 1.07 ± 0.05 μ M, respectively. Graphical abstract Image 1 Highlights • 34 non-alkaloids, including twelve undescribed ones, isolated from Stemona parviflora. • The phytochemicals from Stemona genus were categorized into 11 structural classes. • The phenols were also the main bioactive constituents with nematicidal bioactivity. • The phenols showed better safety profiles than alkaloids. [ABSTRACT FROM AUTHOR]

A series of new fused‐heterocycle phenanthrene derivatives, namely 9‐(o‐benzofuryl)phenanthrene (Compd. 1), 9,10‐bis(o‐benzofuryl)phenanthrene (Compd. 2), 9‐(o‐dibenzofuryl)phenanthrene (Compd. 3) and 9‐(o‐benzothienyl)phenanthrene (Compd. 4) were designed and synthesized in an effort to obtain aggregation‐induced emission enhancement (AIEE) of ultraviolet (UV) light. The results have shown that Compd. 1 and 2 possess the AIEE of UV‐blue light while Compd. 3 presents UV‐AIEE characteristic. However, Compd. 4 is AIEE‐inactive due to sulfur's heavy atom effect. Based on the absorption and fluorescence in both solution and aggregation, it was found that there is no direct correlation of the intramolecular change‐transfer (ICT) and AIEE properties. Associated with the single‐crystal analyses, it was confirmed that the twisted molecular configuration leading to rigid stacking arrangement with larger intermolecular distance is not immediately relevent to AIEE intensity. It was the degree of the restricted intramolecular rotation (DRIR) in the aggregation that shows direct proportional to the AIEE intensity, in the order of Compd. 1 (5.4‐fold increase) > Compd. 3 (3.2‐fold increase) > Compd. 2 (2.6‐fold increase). UV electroluminescence (EL) from organic light‐emitting diode (OLED) consisting of Compd. 3 as emitting layer was firstly reported. The ultraviolet AIEE (UV‐AIEE) is firstly reported based on the newly synthesized fused‐heterocycle phenanthrene derivatives. The degree of the restricted intramolecular rotation (DRIR) of the aggregate is directly proportional to the AIEE intensity. And the ultraviolet electroluminescence (UV‐EL) fabricated by Compd. 3 as emitting layer is first reported. [ABSTRACT FROM AUTHOR]

Four new phenanthrene derivatives, gastrobellinols A-D (1–4), were isolated from the methanolic extract of Gastrochilus bellinus (Rchb.f.) Kuntze, along with eleven known phenolic compounds including agrostophyllin (5), agrostophyllidin (6), coniferyl aldehyde (7), 4-hydroxybenzaldehyde (8), agrostophyllone (9), gigantol (10), 4-(methoxylmethyl)phenol (11), syringaldehyde (12), 1-(4′-hydroxybenzyl)-imbricartin (13), 6-methoxycoelonin (14), and imbricatin (15). Their structures were determined by spectroscopic methods. Each isolate was evaluated for α-glucosidase inhibitory activity. Compounds 1, 2, 3, 7, 9, 13, and 15 showed higher activity than the drug acarbose. Gastrobellinol C (3) exhibited the strongest α-glucosidase inhibition with an IC50 value of 45.92 μM. A kinetic study of 3 showed competitive inhibition on the α-glucosidase enzyme. This is the first report on the phytochemical constituents and α-glucosidase inhibitory activity of G. bellinus.