RESUMO
Alzheimer's diseases (AD) and other infectious diseases caused by drug-resistance bacteria have posed a serious threat to human lives and global health. With the aim to search for human acetylcholinesterase (hAChE) inhibitors and antibacterial agents from medicinal plants, 16 phloroglucinol oligomers, including two new phloroglucinol monomers (1a and 1b), four new phloroglucinol dimers (3a, 3b, 4b, and 5a), six new phloroglucinol trimers (6a, 6b, 7a, 7b, 8a, and 8b), and two naturally occurring phloroglucinol monomers (2a and 2b), along with two known congeners (4a and 5b), were purified from the leaves of tropic Rhodomyrtus tomentosa. The structures and absolute configurations of these new isolates were unequivocally established by comprehensive analyses of their spectroscopic data (NMR and HRESIMS), ECD calculation, and single crystal X-ray diffraction. Structurally, 3a/3b shared a rare C-5' formyl group, whereas 6a/6b possessed a unique C-7' aromatic ring. In addition, 7a/7b and 8a/8b were rare phloroglucinol trimers with a bis-furan and a C-6' hemiketal group. Pharmacologically, the mixture of 3a and 3b showed the most potent human acetylcholinesterase (hAChE) inhibitory activity with an IC50 value of 1.21 ± 0.16 µM. The molecular docking studies of 3a and 3b in the hAChE binding sites were performed, displaying good agreement with the in vitro inhibitory effects. In addition, the mixture of 3a and 3b displayed the most significant anti-MRSA (methicillin-resistant Staphylococcus aureus) with MIC and MBC values of both 0.50 µg/mL, and scanning electron microscope (SEM) studies revealed that they could destroy the biofilm structures of MRSA. The findings provide potential candidates for the further development of anti-AD and anti-bacterial agents.
Assuntos
Antibacterianos , Inibidores da Colinesterase , Staphylococcus aureus Resistente à Meticilina , Floroglucinol , Humanos , Acetilcolinesterase , Antibacterianos/farmacologia , Simulação de Acoplamento Molecular , Estrutura Molecular , Floroglucinol/análogos & derivados , Floroglucinol/química , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Extratos Vegetais/químicaRESUMO
Alzheimer's disease (AD) diagnoses are greatly increasing in frequency as the global population ages, highlighting an urgent need for new anti-AD strategies. With the aim to search for human acetylcholinesterase (hAChE) inhibitors from the species of Myrtaceae family, ten acylphloroglucinol trimers (APTs), including eight new APTs, callistemontrimers A-H (1a, 1b, 2a, 2b, 3a, 3b, 4b, and 5b), and two naturally occurring ones (4a and 5a), along with one reported triketone-acylphloroglucinol-monoterpene adduct (6), were obtained and structurally characterized from the hAChE inhibitory acetone extract of Callistemon salignus seeds. The structures and their absolute configurations for new APTs were unequivocally established via the detailed interpretation of extensive spectroscopic data (HRESIMS and NMR), ECD calculations, and single crystal X-ray diffraction, whereas the absolute configurations of known APTs were determined by further chiral separation, and calculated ECD calculations. The results of hAChE inhibitory assay revealed that an enantiomeric mixture of 2a/2b, 2a, and 2b are good hAChE inhibitors with IC50 values of 1.22⯱â¯0.23, 2.28⯱â¯0.19, and 4.96⯱â¯0.39⯵M, respectively. Molecular docking was used to uncover the modes of interactions for bioactive compounds with the active site of hAChE. In addition, 2 and 6 displayed moderate neurite outgrowth-promoting effects with differentiation rates of 6.16% and 6.19% at a concentration of 1.0⯵M, respectively.
Assuntos
Inibidores da Colinesterase/farmacologia , Floroglucinol/farmacologia , Acetilcolinesterase/metabolismo , Inibidores da Colinesterase/química , Inibidores da Colinesterase/isolamento & purificação , Humanos , Simulação de Acoplamento Molecular , Myrtaceae/química , Floroglucinol/análogos & derivados , Floroglucinol/isolamento & purificação , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
Twelve new diterpenoids based on two rare skeletal types, namely, paralianones A-D (1-4) and pepluanols A-H (5-12), along with five known compounds, were isolated from an acetone extract of Euphorbia peplus. Their structures were proposed based on 1D and 2D NMR spectroscopic data analysis. These diterpenoids were evaluated for potential anti-inflammatory activity in a lipopolysaccharide-stimulated mouse macrophage cellular model. Compounds 3, 4, 11, 13, and 16 displayed moderate inhibitory effects on NO inhibition, with IC50 values ranging from 29.9 to 38.3 µM.
Assuntos
Anti-Inflamatórios/isolamento & purificação , Anti-Inflamatórios/farmacologia , Diterpenos/isolamento & purificação , Diterpenos/farmacologia , Medicamentos de Ervas Chinesas/isolamento & purificação , Medicamentos de Ervas Chinesas/farmacologia , Euphorbia/química , Animais , Anti-Inflamatórios/química , Antineoplásicos Fitogênicos/química , Diterpenos/química , Medicamentos de Ervas Chinesas/química , Concentração Inibidora 50 , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , Camundongos , Estrutura Molecular , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico/biossíntese , Raízes de Plantas/químicaRESUMO
Three new triterpenoid alkaloids, namely buxmicrophyllines P-R (1-3), were isolated from the twigs and leaves of Buxus microphylla. Their structures were elucidated on the basis of NMR and MS spectroscopic analyses. Structurally, compounds 1-3 belong to the 9,10-cycloartane type alkaloids. In addition, compound 3 exhibited moderate cytotoxic activities in vitro against HL-60, SMMC-7221, A-549, MCF-7, and SW480 cell lines (with IC50 values ranging from 4.51 to 15.58 µM).
Assuntos
Alcaloides , Antineoplásicos Fitogênicos , Buxus/química , Citotoxinas , Triterpenos , Células A549 , Alcaloides/química , Alcaloides/isolamento & purificação , Alcaloides/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Citotoxinas/química , Citotoxinas/isolamento & purificação , Citotoxinas/farmacologia , Células HL-60 , Humanos , Células MCF-7 , Triterpenos/química , Triterpenos/isolamento & purificação , Triterpenos/farmacologiaRESUMO
Four previously undescribed phloroglucinols, including three pairs of enantiomers, (±)-rhodotomentodimer F, (±)-rhodotomentodimer G, and (±)-rhodotomentomonomer E, and one phloroglucinol-sesquiterpene meroterpenoid, rhodotomentodione E, together with one previously reported congener, (±)-rhodomyrtosone A, were obtained from the leaves of Rhodomyrtus tomentosa. The structures including absolute configurations of previously undescribed isolates were elucidated by extensive spectroscopic analysis (HRESIMS and NMR), ECD calculations, and single-crystal X-ray diffraction. (±)-Rhodotomentodimer F is a rare phloroglucinol derivative conjugated by a ß-triketone moiety and an unprecedented resorcinol unit via the formation of a rare bis-furan ring system, whereas (±)-rhodotomentomonomer E shares a rearranged pentacyclic scaffold. Pharmacologically, (±)-rhodotomentomonomer E showed the strongest human acetylcholinesterase (hAChE) inhibitory effect with an IC50 value of 1.04 ± 0.05 µM. Molecular formula studies revealed that hydrogen bonds formed between hAChE residues Glu202, Ser203, Ala204, Gly121, Gly122, Tyr337, and His447 and (±)-rhodotomentomonomer E played crucial roles in its observed activity. These findings indicated that the leaves of Rhodomyrtus tomentosa can supply a rich source of hAChE inhibitors. These inhibitors might potentially be utilized in the therapeutic strategy for Alzheimer's disease, offering promising candidates for further research and development.
RESUMO
Six pairs of previously undescribed enantiomeric phytocannabinoid-like meroterpenoids, (±)-spinulinoids AâF, and two naturally occurring compounds, (+)-rhododaurichromanic acid A and (E)-4-((3,7-dimethylocta-2,6-dien-1-yl)oxy)benzoic acid, together with one known congener, (-)-rhododaurichromanic acid A, were obtained from the twigs and leaves of Rhododendron spinuliferum. Their structures were established by their extensive spectral data (NMR and HRESIMS), ECD calculations, and single-crystal X-ray diffraction data. Spinulinoids A and B are unprecedented phytocannabinoid-like meroterpenoids constructed by the resorcinol moiety and a ß-bisabolene unit, whereas spinulinoid C represents a rare adduct of quinone and ß-bisabolene with a tricyclic 6/6/6 ring system.
RESUMO
Four undescribed phloroglucinol meroterpenoids, rhodotomentodiones A-D, and one undescribed phloroglucinol dimer, rhodotomentodimer A, were obtained and structurally established from tropic Rhodomyrtus tomentosa leaves. Their structures were unambiguously elucidated based on the comprehensive analyses of the NMR and MS spectroscopic data, electronic circular dichroism (ECD) calculation, and single-crystal X-ray diffraction. In particular, rhodotomentodiones A and B represent the first examples of phloroglucinol meroterpenoids featuring a unique γ-pyranoid moiety. More importantly, rhodotomentodimer A exhibited the most potential human acetylcholinesterase (hAChE) and α-glucosidase inhibitory effects with IC50 values of 7.5 µM and 5.6 µM, respectively. The possible interaction sites of the above potential hAChE and α-glucosidase inhibitor were achieved by molecular docking studies. These findings greatly enrich the diversity of natural products from Myrtaceae species, and provide potential candidates for the further development of anti-Alzheimer and antidiabetic diseases.
Assuntos
Produtos Biológicos , Myrtaceae , Acetilcolinesterase , Inibidores de Glicosídeo Hidrolases/farmacologia , Humanos , Simulação de Acoplamento Molecular , Estrutura Molecular , Myrtaceae/química , Floroglucinol/química , Floroglucinol/farmacologia , alfa-GlucosidasesRESUMO
Twenty withanolides, including previously unknown nicanlodes A-M, were isolated from aerial parts of Nicandra physalodes. Their structural elucidations were unambiguously achieved through interpretation of extensive spectroscopic data (NMR and HRMS) and by comparison with literature data. Nicanlodes A and B have an unusual aromatic amine moiety. The isolated compounds were evaluated for their cytotoxicity against five human cancer cell lines.
Assuntos
Solanaceae/química , Vitanolídeos/química , Linhagem Celular Tumoral , Humanos , Estrutura Molecular , Componentes Aéreos da Planta/química , Extratos Vegetais/química , Vitanolídeos/isolamento & purificaçãoRESUMO
Five new ent-kaurane diterpenoids, named mascaroside III-V (1-3), and 20-nor-cofaryloside I-II (4-5), together with seven known diterpenoids, were isolated from methanol extracts of the green coffee beans of Yunnan Arabica Coffee. Their chemical structures were elucidated by extensive spectroscopic analyses. Meanwhile, cytotoxicity assay against HL-60, A-549, SMMC-7721, MCF-7 and SW480 cell lines showed that they have not evident inhibition of cytotoxicity.
RESUMO
(±)-Ganoapplanin (1), a pair of novel meroterpenoid enantiomers featuring an unprecedented dioxaspirocyclic skeleton constructed from a 6/6/6/6 tetracyclic system and an unusual tricyclo[4.3.3.03',7']dodecane motif, were isolated from Ganoderma applanatum. Its structure and absolute configurations were determined by spectroscopic analyses, X-ray crystallography, and ECD (electronic circular dichroism calculations). A plausible biogenetic pathway, involving a key Gomberg-Bachmann reaction, was also proposed for (±)-1. Biological studies showed that (±)-1 and its enantiomers exhibited different inhibitory activities on T-type voltage-gated calcium channels.
Assuntos
Bloqueadores dos Canais de Cálcio/farmacologia , Canais de Cálcio Tipo T/metabolismo , Ganoderma/química , Terpenos/farmacocinética , Bloqueadores dos Canais de Cálcio/química , Bloqueadores dos Canais de Cálcio/isolamento & purificação , Cristalografia por Raios X , Células HEK293 , Humanos , Modelos Moleculares , Estrutura Molecular , Estereoisomerismo , Terpenos/química , Terpenos/isolamento & purificaçãoRESUMO
Phytochemical investigation of the stems and leaves of Paris polyphylla var. yunnanensis led to isolation of 12 steroidal saponins, chonglouosides SL-9-SL-20, which had not been described previously, along with 13 known compounds. Their structures were established on the basis of extensive spectroscopic analysis and chemical methods. Four of the twelve steroidal saponins possessed three steroidal aglycones which have not been reported in nature. Steroidal saponins were also evaluated for their cytotoxicities against two human cancer cell lines (HepG2 and HEK293) and anti-HCV effects. One known steroidal saponin was the most cytotoxic compound overall with IC50 values of 2.9 ± 0.5 µM and 5.0 ± 0.6 µM against HepG2 and HEK293 cell lines, respectively, while none showed anti-HCV activity at a concentration of 20 µM.
Assuntos
Antivirais/isolamento & purificação , Medicamentos de Ervas Chinesas/isolamento & purificação , Liliaceae/química , Saponinas/isolamento & purificação , Esteroides/isolamento & purificação , Antivirais/química , Antivirais/farmacologia , Relação Dose-Resposta a Droga , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/farmacologia , Células HEK293 , Células Hep G2 , Hepacivirus/efeitos dos fármacos , Humanos , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Folhas de Planta/química , Caules de Planta/química , Saponinas/química , Saponinas/farmacologia , Esteroides/química , Esteroides/farmacologiaRESUMO
Three new meroterpenoids, guajavadials A-C (1-3), were isolated from Psidium guajava cultivated in temperate zone. Their structures were established by extensive spectroscopic evidence and electronic circular dichroism (ECD) calculations. Guajavadial A (1) represents a novel skeleton of the 3,5-diformylbenzyl phloroglucinol-coupled monoterpenoid, while guajavadials B (2) and C (3) are new adducts of the 3,5-diformylbenzyl phloroglucinol and a sesquiterpene with different coupling models. The plausible biosynthetic pathways as well as antimicrobial and cytotoxic activities of these meroterpenoids are also discussed. All these isolates exhibited moderate cytotoxicities against five human cancer cell lines, with 3 being most effective with an IC50 value of 3.54 µM toward SMMC-7721 cell lines.
Assuntos
Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Compostos Fitoquímicos/química , Compostos Fitoquímicos/isolamento & purificação , Psidium/química , Terpenos/química , Terpenos/isolamento & purificação , Anti-Infecciosos/química , Anti-Infecciosos/isolamento & purificação , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Dicroísmo Circular , Humanos , Concentração Inibidora 50 , Análise EspectralRESUMO
Medulloblastoma (MB) is a form of malignant brain tumor that predominantly arises in infants and children, of which approximately 25 % is due to upregulation of canonical Wnt pathway with mainly mutations in CTNNB1. Therefore, Wnt inhibitors could offer rational therapeutic strategies and chemoprevention for this malignant cancer. In our present study, we undertook a screening for antagonists of Wnt signaling from 600 natural compounds, and identified Ginkgetin, a biflavone isolated from Cephalotaxus fortunei var. alpina. Ginkgetin inhibited Wnt pathway with an IC50 value around 5.92 µM and structure-activity relationship analysis suggested the methoxy group in Ginkgetin as a functional group. Biflavone Ginkgetin showed obvious cytotoxicity in Daoy and D283 MB cells. Cell cycle analysis by flow cytometry showed that Ginkgetin induced efficiently G2/M phase arrest in Daoy cells. Further mechanism studies showed that Ginkgetin reduced the expression of Wnt target genes, including Axin2, cyclinD1 and survivin in MB cells. The phosphorylation level of ß-catenin also decreased in a time- and concentration-dependent manner. Collectively, our data suggest that Ginkgetin is a novel inhibitor of Wnt signaling, and as such warrants further exploration as a promising anti-medulloblastoma candidate.