ABSTRACT
The development of new antibiotics and inexpensive antifungals is an important field of research. Based on the privileged pharmacophore of lawsone, a series of phenolic ether derivatives of 1,4-naphthoquinone were synthesized easily in one step in reasonable yields. All the new compounds were characterized and tested as potential antifungal and antibacterial agents against Candida albicans, Escherichia coli and Staphylococcus aureus. Compound 55 has significant antibacterial action (as good as or better than the controls) against E. coli and S. aureus. Against C. albicans, compounds 38, 46, 47 and 60 were the best candidates as antifungals. Using a qualitative structure-activity analysis, a correlation between molar mass and antimicrobial activity was identified, regardless of the substituent group on the phenolic moiety, except for 55 and 63, where electronic effects seem more important. An in silico evaluation of the absorption, distribution, metabolism and excretion (ADME) for 37, 50, 55 and 63 was made, indicating that the classic Lipinski's rule of five applies in all cases.
ABSTRACT
The present work describes the evaluation of the antidepressant-like activity of the extract, fractions, and compounds obtained from the aerial parts of Solanum capsicoides. The methanolic extract (MESC) obtained by conventional maceration was partitioned with solvents of increasing polarities yielding the respective fractions of hexane (HE), dichloromethane (DCM), and ethyl acetate (EA). The dichloromethane and ethyl acetate fractions were submitted to chromatographic and spectroscopic techniques, leading to the isolation and identification of cilistadiol (1), astragalin (2), and cilistol A (3). In relation to the antidepressant activity, the extract was active against the forced swimming test (FST) at a concentration of 300 mg/kg an ED50 (deffective dose that reduces 50% of immobility time) of 120.3 (117.3-123.4) mg/kg. Similar values were observed when evaluated in the tail suspension test (TST). In addition, the results showed no influence on motor behavior when evaluated in the open field test (OFT). Based on the observed profile of the MESC, dichloromethane fraction presenting the best profile, in both FST and TST test. Likewise, the fraction also did not present motor impairment when evaluated by the OFT test. Considering that the dichloromethane fraction was more effective, the isolated compounds cilistadiol and cilistol A were evaluated in the same experimental models. In FST, both compounds had a significant antidepressant-like effect, with ED50 values of 0.22 (0.16-0.28) and 1.03 (0.89-1.18) µmol/kg, respectively. When evaluated in the TST, showed ED50 values of 0.30 (0.18-0.52) and 1.49 (1.27-1.73) µmol/kg, respectively. The isolated compounds also did not present significant differences in the motor behavior when evaluated on OFT test in comparison with the control group. No toxicological parameters were observed until the highest dose of MESC (2000 mg/kg), demonstrating safety in the use of this plant.
Subject(s)
Antidepressive Agents/pharmacology , Antidepressive Agents/toxicity , Plant Components, Aerial/chemistry , Plant Extracts/pharmacology , Plant Extracts/toxicity , Solanum/chemistry , Withanolides/pharmacology , Withanolides/toxicity , Animals , Behavior, Animal/drug effects , Dose-Response Relationship, Drug , Female , Hindlimb Suspension , Methylene Chloride , Mice , Motor Activity/drug effects , Solvents , Swimming/psychologyABSTRACT
CONTEXT: Pimenta dioica (L.) Merr. (Myrtaceae) is used in Costa Rican traditional medicine for women's health. Our previous work showed that P. dioica extracts were oestrogenic. OBJECTIVES: This work identifies phytochemicals from P. dioica that are responsible for the plant's oestrogen-like activities. MATERIALS AND METHODS: P. dioica leaves were collected in Costa Rica in 2005. Fractions resulting from chromatographic separation of a methanol extract were tested at 50 µg/mL in a competitive oestrogen receptor-binding assay. Active compounds were isolated by HPLC and identified by NMR and MS. Pure compounds were tested at 1 µM in the oestrogen-responsive SEAP reporter gene assay. The effects on cell viability, cytotoxicity and apoptosis were investigated in breast cancer (MCF-7 and SK-BR3) and gastric cancer (AGS and NCI-N87) cell lines using the ApoTox-Glo and Caspase-Glo assays and qPCR. RESULTS: Quercitrin and three new chromones, including a 2-phenoxychromone, 6,8-di-C-methylcapillarisin (1) were isolated and identified. Compound 1 caused a 6.2-fold increase in SEAP expression at 1 µM (p < 0.05). This activity was blocked by the ER antagonist ICI 182,780. Compound 2 caused a 6.0-fold increase in SEAP, inhibited the growth of MCF-7, AGS and NCI-N87 cells (IC50 54.27, 38.13 and 51.22 µg/mL, respectively), and induced apoptosis via caspase 8 and increased the Bax/Bcl-2 mRNA ratio in MCF-7 cells. Compound 3 was anti-oestrogenic in MCF-7 cells. DISCUSSION AND CONCLUSIONS: Compounds from P. dioica have oestrogenic, anti-oestrogenic and cytotoxic effects that may explain the ethnomedical use of this plant.
Subject(s)
Antineoplastic Agents, Phytogenic/pharmacology , Chromones/pharmacology , Estrogen Receptor Modulators/pharmacology , Neoplasms/drug therapy , Phytoestrogens/pharmacology , Pimenta , Plant Extracts/pharmacology , Antineoplastic Agents, Phytogenic/isolation & purification , Antineoplastic Agents, Phytogenic/metabolism , Apoptosis/drug effects , Apoptosis Regulatory Proteins/genetics , Apoptosis Regulatory Proteins/metabolism , Binding, Competitive , Cell Proliferation/drug effects , Chromones/isolation & purification , Chromones/metabolism , Dose-Response Relationship, Drug , Estrogen Receptor Modulators/isolation & purification , Estrogen Receptor Modulators/metabolism , Female , Humans , Inhibitory Concentration 50 , MCF-7 Cells , Neoplasms/genetics , Neoplasms/metabolism , Neoplasms/pathology , Phytoestrogens/isolation & purification , Phytoestrogens/metabolism , Phytotherapy , Pimenta/chemistry , Plant Extracts/isolation & purification , Plant Extracts/metabolism , Plant Leaves , Plants, Medicinal , Receptors, Estrogen/drug effects , Receptors, Estrogen/metabolismABSTRACT
This work deals with the synthesis and evaluation of new compounds designed by combination of 1,4-naphthoquinone and ferrocene fragments in a 3-ferrocenylmethyl-2-hydroxy-1,4-naphthoquinone arrangement. A practical coupling reaction between 2-hydroxy-1,4-naphthoquinone and ferrocenemethanol derivatives has been developed. This procedure can be carried out "on-water", at moderate temperatures and without auxiliaries or catalysts, with moderate to high yields. The synthesized derivatives have shown significant in vitro antiplasmodial activity against chloroquine-sensitive and resistant Plasmodium falciparum strains and it has been shown that this activity is not related to the inhibition of biomineralization of ferriprotoporphyrin IX. Binding energy calculations and docking of these compounds to cytochrome b in comparison with atovaquone have been performed.