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Oral squamous cell carcinoma (OSCC) is a worldwide public health problem, with high morbidity and mortality rates. The development of new drugs to treat OSCC is paramount. Piper plant species have shown many biological activities. In the present study, we show that dichloromethane partition of Piper cernuum (PCLd) is nontoxic in chronic treatment in mice, reduces the amount of atypia in tongues of chemically induced OSCC, and significantly increases animal survival. To identify the main active compounds, chromatographic purification of PCLd was performed, where fractions 09.07 and 14.05 were the most active and selective. These fractions promoted cell death by apoptosis characterized by phosphatidyl serine exposition, DNA fragmentation, and activation of effector caspase-3/7 and were nonhemolytic. LC-DAD-MS/MS analysis did not propose matching spectra for the 09.07 fraction, suggesting compounds not yet known. However, aporphine alkaloids were annotated in fraction 14.05, which are being described for the first time in P. cernuum and corroborate the observed cytotoxic activity. Putative molecular targets were determined for these alkaloids, in silico, where the androgen receptor (AR), CHK1, CK2, DYRK1A, EHMT2, LXRβ, and VEGFR2 were the most relevant. The results obtained from P. cernuum fractions point to promising compounds as new preclinical anticancer candidates.

The extensive marine biodiversity has proved to be a promising source of substances with biomedical potential. In this study, the cytotoxicity of the Brazilian octocoral Phyllogorgia dilatata (Gorgoniidae) was evaluated against two tumor cell lines and three bacterial strains. The methanol/dichloromethane crude extract presented no antibacterial activity up to the highest concentration tested (512 µg/mL), however it revealed a noteworthy antiproliferative effect against HCT-116 (80%) and MCF-7 (54%) cell lines at 50 μg/mL. Therefore, guided by the cytotoxic activity, a multistep chemical fractionation of the extract provided the subfraction 5 (PDPH2-5) with IC50 values of 3.18 and 17.80 μg/mL against HCT-116 and MCF-7, respectively. The LC-HRMS/MS analysis of PDPH2-5 showed ions of m/z 219.1742 and 219.1743, characterized as (E,E) and (Z,E) germacrone, after a LC-DAD-SPE/NMR analysis of the hexanic fraction and comparisons of NMR data with the literature. Previously reported assessments to the cytotoxic activity of the (E,E)-diastereoisomer disclosed higher IC50 values than that obtained for the PDPH2-5 fraction, suggesting, herein, a potentiated effect of the diastereoisomeric mixture. Such remark encourage further bioactivity studies with stereoisomer mixtures and reduce the urge for compound isolation.

Marine sponges from the Plakinidae family are well known for hosting cytotoxic secondary metabolites and the Brazilian Atlantic coast and its oceanic islands have been considered as a hotspot for the discovery of new Plakinidae species. Herein, we report the chemical profile among cytotoxic extracts obtained from four species of Plakinidae, collected in Fernando de Noronha Archipelago (PE, Northeastern Brazil). Crude organic extracts of Plakinastrella microspiculifera, Plakortis angulospiculatus, Plakortis insularis, and Plakortis petrupaulensis showed strong antiproliferative effects against two different cancer cell lines (HCT-116: 86.7-100%; MCF-7: 74.9-89.5%) at 50 μg/mL, by the MTT assay. However, at a lower concentration (5 μg/mL), high variability in inhibition of cell growth was observed (HCT-116: 17.3-68.7%; MCF-7: 0.00-55.5%), even within two samples of Plakortis insularis which were collected in the west and east sides of the Archipelago. To discriminate the chemical profile, the samples were investigated by UHPLC-HRMS under positive ionization mode. The produced data was uploaded to the Global Natural Products Social Molecular Networking and organized based on spectral similarities for purposes of comparison and annotation. Compounds such as dipeptides, nucleosides and derivatives, polyketides, and thiazine alkaloids were annotated and metabolomic differences were perceived among the species. To the best of our knowledge, this is the first assessment for cytotoxic activity and chemical profiling for Plakinastrella microspiculifera, Plakortis insularis and Plakortis petrupaulensis, revealing other biotechnologically relevant members of the Plakinidae family.

Quinoline and its derivatives comprise an important group of heterocyclic compounds that exhibits a wide range of pharmacological properties such as antibacterial, antiviral, anticancer, antiparasitic, anti-Alzheimer and anticholesterol. The quinoline nucleus is found in the structure of many drugs and rational design in medicinal chemistry for the discovery of novel bioactive molecules. Persistent efforts have been made over the years to develop novel congeners with superior biological activities and minimal potential for undesirable side effects. This review highlights some discoveries on the development of quinoline-based compounds in recent years (2013-2019), focusing on their biological activities, including anticancer, antitubercular, antimalarial, anti-ZIKV, anti-DENV, anti- Leishmania and anti-Alzheimer's disease., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Background: Oral squamous cell carcinoma (OSCC) is one of the ten most common types of cancer worldwide. Plants of the genusPiper are used in traditional medicine to treat cancer, and they have a vast diversity of phytochemicals with cytotoxic potential. Purpose and Study Design: In this work, we analyzed the cytotoxic and selective potential of extracts and semipurified fractions of Piper mollicomum (PM), Piper truncatum (PT), Piper cernuum (PC), Piper arboreum (PA), and Piper cabralanum (PCa) using three different OSCC cell lines (SCC4, SCC9 and SCC25), and we measured their in vivo toxicities and conducted chemical analyses of their active fractions., Results: The dichloromethane fractions of the crude methanolic extracts of the leaves of PM(-L-D), PC(-L-D) and PCa(-L-D) exhibited notable IC 50 values of 94.2, 47.2 and 47.5 μg/mL, respectively, and all three of these extracts were more active than carboplatin (172.3 μg/mL). The most selective fraction was PC-L-D, which exhibited SI > 4.5; less than 5% hemolysis; and no significant alterations in in vivo acute toxicology. The major constituents in active fractions were lignans (PC-L-D and PCa-L-D) and chromenes (PM-L-D)., Conclusion: PC-L-D demonstrated great potential for further development as an anticancer drug and could be the key to developing more effective and less toxic therapies against oral cancer., (Copyright © 2018 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

The Aedes aegypti mosquito is one of the major vectors of arboviruses. These diseases have re-emerged and the insecticides used nowadays are toxic to mammals and environment and have only been effective in the short-term. In this context, natural products are an alternative. The genus Piper has many active compounds against arthropods, including neolignans. The present study evaluated the larvicidal potential of the n-hexanic extract of Piper solmsianum and eupomatenoid-6, identified by GC-MS and NMR techniques, from this extract against Ae. aegypti. The crude extract (100 μg/mL) killed 80% and 98.3% of larvae in the first and third day, respectively. Eupomatenoid-6 exhibited LD 50 of 19.33 μM and LD 90 of 28.68 μM and was then assayed in human fibroblast cells (MRC5), showing an IC 50 of 39.30 μM with estimated LD 50 of 42.26 mmol/kg. Our results indicate eupomatenoid-6 as a potent insecticide with relatively low toxicity for mammals.

Chemo-resistance has been reported as a relevant barrier for the efficiency of gastric cancer treatment. Therefore, the development of effective and safe drugs for cancer chemotherapy is still a challenge. The purpose of this study was to evaluate the anticancer potential of (E)-2-(((2-(benzo[d]thiazo-2-yl)hydrazono)methyl)-4-nitrophenol) (AFN01) against gastric cancer cell lines. Our results showed promising anticancer activity against gastric cancer cells ACP-02 (IC 50  = 1.0 μM) and mild activity against other cell lines including non-malignant gastric cell MNP-01 (IC 50  = 3.4 μM). This compound significantly induced S phase cell cycle arrest, prevented cell migration and triggered apoptosis in a concentration-dependent manner. Moreover, AFN01 was significantly more genotoxic against tumoral cell ACP-02, when compared to non-malignant cells, such as MNP-01 and healthy peripheral mononuclear blood cells. AFN01 also synergistically interacts with doxorubicin suppressing cell proliferation and c-MYC gene expression in gastric cancer cell line model, with remarkable c-MYC overexpression. Although further pre-clinical and clinical studies are required to explore its safety and efficiency, AFN01 may represent a promising lead anticancer agent for the treatment of gastric cancer., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Malignant melanoma is an important type of cancer worldwide due to its aggressiveness and poor survival rate. Significant efforts to understand the biology of melanoma and approaches to treat the advanced disease are focused on targeted gene inhibitors. Frequently mutated genes, such as NRAS, B-RAF and TP53, significantly exceed the frequency of mutations of other genes, emphasizing their importance for future targeted therapies. Considering the antitumor activity of benzothiazolic derivatives, this study aimed to demonstrate the action of benzothiazolic (E)-2-((2-(benzo[d]thiazol-2-yl)hydrazono)methyl)-4-nitrophenol (AFN01) against three established human melanoma cell lines that recapitulate the molecular landscape of the disease in terms of its genetic alterations and mutations, such as the TP53, NRAS and B-RAF genes. The results presented here indicate that AFN01, as a significant cytostatic and cytotoxic drug due to its induction of DNA fragmentation, causes single and double DNA strand breaks, consequently inhibiting cell proliferation, migration and invasion by promoting apoptosis. Our data suggest that AFN01 might be considered as a future therapeutic option for managing melanoma., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The crystal structures of 6-meth-oxy-1,3-benzoxa-thiol-2-one, C 9 H 8 O 3 S, (I), and 2-oxo-1,3-benzoxa-thiol-6-yl acetate, C 9 H 6 O 4 S, (II), are described. Compound (I) is almost planar (r.m.s. deviation for the non-H atoms = 0.011 Å), whereas (II) shows a substantial twist between the fused-ring system and the acetate substituent [dihedral angle = 74.42 (3)°]. For both structures, the bond distances in the heterocyclic ring suggest that little if any conjugation occurs. In the crystal of (I), C-H⋯O hydrogen bonds link the mol-ecules into [1-11] chains incorporating alternating R 2 2 (8) and R 2 2 (12) inversion dimers. The extended structure of (II) features C (7) [201] chains linked by C-H⋯O hydrogen bonds, with further C-H⋯O bonds and weak π-π stacking inter-actions connecting the chains into a three-dimensional network. Hirshfeld fingerprint analyses for (I) and (II) are presented and discussed.

Background: Over the last few years, fungal infections have emerged as a worrisome global public health problem. Candidiasis is a disease caused by Candida species and has been a problem worldwide mainly for immunosuppressed patients. Lately, the resistant strains and side effects have been reported as important issues for treating Candidiasis, which have to be solved by identifying new drugs., Objective: The goal of this work was to synthesize a series of 1,3-benzoxathiol-2-one derivatives, XYbenzo[ d][1,3]oxathiol-2-ones, and evaluate their antifungal activity against five Candida species., Methods: In vitro antifungal screening test and minimum inhibitory concentration determination were performed according to CLSI protocols using ketoconazole as the reference drug. The cytotoxicity of the most active compounds was evaluated by hemolysis and MTT (Vero cells) assays., Results: Compounds 2 (XY = 6-hydroxy-5-nitro, MIC = 4-32 µg/mL) and 7 (XY = 6-acetoxy-5-nitro, MIC =16-64 µg/mL) showed good results when compared with current antifungals in CLSI values (MIC = 0.04-250 µg/mL). These compounds exhibited a safer cytotoxicity as well as a lower hemolytic profile than ketoconazole., Conclusion: Overall, the in vitro results pointed to the potential of compounds 2 and 7 as new antifungal prototypes to be further explored., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

Background: The genus Piper L. has the shikimic acid pathway predominantly expressed, biosynthesizing many cinnamic acid derivatives (CAD)., Objective: Neolignans comprise an important class of CAD that exhibit a wide range of pharmacological properties such as antibacterial, antitumor, insecticidal, anti-inflammatory, antioxidant, smooth muscle relaxant, neuroprotective, antiprotozoal and against platelet aggregation factor. These substances have been extracted and isolated from Piper species using different technics., Results: The present review aims to summarize extraction and isolation methods and biological activities of the different types of neolignans covering the period from 1968 to January 2016., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)