Cytotoxicity, antinociceptive and gastroproiltective potential of the Abuta selloana Eichler: a fruit plant from Catarinense flora, Brazil.

This study evaluated some biological activities of extracts from Abuta selloana. The gastroprotective potential was determined against ethanol/HCl- and indomethacin-induced gastric ulcers, whereas the antinociceptive effect was evaluated by acetic acid-induced abdominal contortions in mice. The cytotoxicity activity was measured against human cancer cell lines: U251 (glioma), MCF-7 (breast cancer) and NCI-H460 (lung cancer). The radical scavenger potential was verified; and preliminary phytochemical analyses were performed. The phytochemical screening revealed higher levels of phenolic compounds in all extracts. Moreover, the methanolic extract from pulp fruit (MEPu), peel fruit (MEPe), branches (MEB) and leaves (MEL) scavenged the DPPH radical at 100 µg/mL. Besides, only MEL presented GI50 < 30 µg/mL in all tested cells. Besides, MEPu, MEPe, MEB or MEL at 10 mg/kg (i.p) reduced the abdominal contortions at 47.22%, 63.31%, 84.59% and 37.76%, respectively. The MEPu, MEPe, MEB and MEL reduced the ethanol/HCl- and indomethacin- induced ulcer at 250 mg/kg (p.o). In conclusion, A. selloana had interesting biological activities; presenting the leaves as a promising source for compounds with cytotoxic potential, however, further studies should be performed to confirm its antitumoral activity. Besides, the whole plant can be an important source of bioactive compounds associated with gastroprotective and antinociceptive properties.

Ultrastructural changes induced by açaí (Euterpe oleracea Mart) in MCF-7 breast cancer cell line.

Açaí (Euterpe oleracea Mart) is an Amazon plant with many biological properties. Previous report of this group evidenced autophagy induction after treatment with açaí seed extract in MCF-7 breast cancer cell lines by acridine orange assay. The aim of this study was to evaluate the ultrastructural changes induced by açaí seed extract in MCF-7 breast cancer cell lines. First, MCF- 7 breast cancer cell line viability was evaluated by MTT assay. Acridine orange assay showed increase in the acidic compartments, suggesting autophagolysosome formation. These cells were treated with 25 µg/ml for 24 h and evaluated by transmission electron microscopy (MET). This analysis showed that açaí seed extract induced autophagy, confirmed by autophagolysosome formation. Furthermore, açaí seed extract increased the number of mitochondria, suggesting the enrollment of reactive oxygen species in autophagy.

Evaluation of non-clinical toxicity of extract and vouacapans from fruits of Pterodon pubescens Benth.

Pterodon pubescens Benth. is widely used in folk medicine for the treatment of inflammatory conditions, with the activity attributed to the compounds with a vouacapan moiety, however, few studies report the toxicological evaluation of the extract and safety issues related to the species. Herein the non-clinical toxicity, in in vivo and in vitro tests, of dichloromethane crude extract of Pterodon pubescens fruits (PPE) and vouacapan diterpene furan isomer´s mixture (1:1) 6α-hydroxy-7ß-acetoxy-vouacapan-17ß-oate methyl ester and 6α-acetoxy-7ß-hydroxy-vouacapan-17ß-oate methyl ester isomers (VDFI mixture) is reported. Toxicological evaluation of 110-day repeated dose oral toxicity study, as hematological, biochemical, and histopathological parameters demonstrated that animals (male and female Wistar rats) treated with PPE presented no signs of toxicity, nevertheless daily high dose administration (500 mg/Kg) altered the metabolic homeostasis of animals that manifested microgoticular hepatic steatosis. Biochemical and histopathological results of animals (female Swiss mice) treated daily with VDFI mixture, at the highest dose (300 mg/Kg), indicated liver toxicity in one animal causing acute hepatotoxicity. Alkaline Comet assay demonstrated that PPE and VDFI mixture increased the percentage of DNA fragmentation without interfering with the tail moment parameter, but only VDFI mixture (30 µg/mL) presented statistical difference. In the micronucleus induction test, PPE and VDFI mixture did not demonstrate mutagenic potential. Our data provide evidence for the safety use of PPE and VDFI mixture in lower doses enabling further clinical studies and the development of herbal medicine.

Açai (Euterpe oleracea Mart.) Seed Extract Induces ROS Production and Cell Death in MCF-7 Breast Cancer Cell Line.

Euterpe oleracea Mart. (açai) is a native palm from the Amazon region. There are various chemical constituents of açai with bioactive properties. This study aimed to evaluate the chemical composition and cytotoxic effects of açai seed extract on breast cancer cell line (MCF-7). Global Natural Products Social Molecular Networking (GNPS) was applied to identify chemical compounds present in açai seed extract. LC-MS/MS and molecular networking were employed to detect the phenolic compounds of açai. The antioxidant activity of açai seed extract was measured by DPPH assay. MCF-7 breast cancer cell line viability was evaluated by MTT assay. Cell death was evaluated by flow cytometry and time-lapse microscopy. Autophagy was evaluated by orange acridin immunofluorescence assay. Reactive oxygen species (ROS) production was evaluated by DAF assay. From the molecular networking, fifteen compounds were identified, mainly phenolic compounds. The açai seed extract showed cytotoxic effects against MCF-7, induced morphologic changes in the cell line by autophagy and increased the ROS production pathway. The present study suggests that açai seed extract has a high cytotoxic capacity and may induce autophagy by increasing ROS production in breast cancer. Apart from its antioxidant activity, flavonoids with high radical scavenging activity present in açai also generated NO (nitric oxide), contributing to its cytotoxic effect and autophagy induction.

Antiangiogenic therapy with Nintedanib affects hypoxia, angiogenesis and apoptosis in the ventral prostate of TRAMP animals.

The antiangiogenic therapy for prostate cancer with Nintedanib, a potent inhibitor of important growth factor receptors, has been proven to delay tumor progression and arrest tumor growth; thus, the aim herein is to evaluate Nintedanib effects on tumor cells, besides angiogenesis and apoptosis processes, metalloproteinases and hypoxia factor in an animal model. Nintedanib promoted growth inhibition and cell death in a dose-dependent manner, showing no tumor selectivity. Transgenic Adenocarcinoma of the Mouse Prostate (TRAMP) were treated with Nintedanib (10 mg/kg/day) in different stages of tumor development and the ventral prostate was examined for protein levels by means of immunohistochemistry and Western blotting and apoptosis evaluation. In vitro antiproliferative activity of Nintedanib was also assessed in nine human tumor cell lines. Early Nintedanib treatment has shown decreased levels of FGF-2, VEGFR-1, MMP-9 and HIF-1α and a significantly increased apoptosis of epithelial cells. Furthermore, late Nintedanib treatment decreased FGF-2, VEGFR-1 and FGFR-3 levels. Importantly, even after treatment discontinuation, treated animals displayed a significant decrease in VEGFR-1 as well as MMP-9. Although Nintedanib treatment in late stages of tumor growth has shown some good results, it is noteworthy that the drug presents the best tissue response when administered in the early stages of disease development. Nintedanib treatment has shown to be a promising approach for prostate cancer therapy, especially in the early stages of the disease, interfering in different carcinogenesis progression pathways.

Yellow-colored extract from cashew byproduct - Nonclinical safety assessment.

Natural and synthetic dyes are widely used in foodstuff, medicines and cosmetics industries to enhance and/or restore the color of the final products. This study aimed to evaluate the safety of oral consumption of one carotenoids and anacardic acids-enriched extract (CAE), obtained by green extraction from cashew apple residue fibers, a byproduct of the cashew juice industry. Presenting intense yellow color, CAE could be proposed as a new natural dye. Single and repeated-dose oral toxicity (30 days) were evaluated in female Swiss mice at doses ranging from 50 to 1000 mg/kg, while (anti)mutagenic effects were evaluated in CHO-K1 cells (in vitro Cytokinesis-Block Micronucleus assay - CBMN) and in erythrocytes collected from murine bone marrow (in vivo). CAE did not induce toxic or mutagenic effects in female mice even after 30 days of treatment, regardless of the dose used. Considering cyclophosphamide (CPA)-challenged animals treated with CAE, neither antimutagenic effect was observed nor CAE increased CPA-mutagenic effects although in vitro CBMN results indicated that CAE might increase methyl methanesulfonate-induced micronuclei (MN) frequency besides promoting reduction on CPA-induced MN frequency. The obtained results suggest that CAE may be a safe source of carotenoids with potential use as industrial dye.

Anti-Estrogenic Activity of Guajadial Fraction, from Guava Leaves (Psidium guajava L.).

The research of natural products has allowed for the discovery of biologically relevant compounds inspired by plant secondary metabolites, which contributes to the development of many chemotherapeutic drugs used in cancer treatment. Psidium guajava leaves present a diverse phytochemical composition including flavonoids, phenolics, meroterpenoids, and triterpenes as the major bioactive constituents. Guajadial, a caryophyllene-based meroterpenoid, has been studied for potential anticancer effects tested in tumor cells and animal experimental models. Moreover, guajadial has been reported to have a mechanism of action similar to tamoxifen, suggesting this compound as a promisor phytoestrogen-based therapeutic agent. Herein, the anti-estrogenic action and anti-proliferative activity of guajadial is reported. The enriched guajadial fraction was obtained by sequential chromatographic techniques from the crude P. guajava dichloromethane extract showing promising anti-proliferative activity in vitro with selectivity for human breast cancer cell lines MCF-7 and MCF-7 BUS (Total Growth Inhibition = 5.59 and 2.27 µg·mL-1, respectively). Furthermore, evaluation of anti-estrogenic activity in vivo was performed demonstrating that guajadial enriched fraction inhibited the proliferative effect of estradiol on the uterus of pre-pubescent rats. These results suggest a relationship between anti-proliferative and anti-estrogenic activity of guajadial, which possibly acts in tumor inhibition through estrogen receptors due to the compounds structural similarity to tamoxifen.

Spilanthol, the Principal Alkylamide from Acmella oleracea, Attenuates 5-Fluorouracil-Induced Intestinal Mucositis in Mice.

Mucositis is one of the commonest side effects in cancer patients undergoing treatment with radiotherapy and/or chemotherapy, and it currently lacks appropriate and effective treatment. Acmella oleracea, a species of flowering herb from South America, contains spilanthol, an alkylamide that has several pharmacological properties, including anesthetic, analgesic, and anti-inflammatory activities. Therefore, the purpose of this work was to evaluate the effect of spilanthol in intestinal mucositis in Swiss mice induced by 5-fluorouracil (5-FU), an antineoplastic agent administered systemically for the treatment of many different cancers. The repeated administration of 5-FU resulted in intestinal mucositis and consequent decreased food intake, together with weight loss, in all the animals. Daily administration of spilanthol significantly lowered the severity of intestinal mucositis, reducing histopathological changes and increasing the villus height in the animals treated with spilanthol at a dosage of 30 mg/kg (p < 0.0044) compared to a group exposed only to 5-FU. A decrease of myeloperoxidase activity was also observed in the animals treated with 30 mg/kg of spilanthol (p < 0.05), although several pro-inflammatory cytokines were not quantifiable in any group. In conclusion, the data demonstrated that spilanthol effectively reduced inflammation in a mouse model of intestinal mucositis induced by 5-FU, and that the compound might be a promising therapeutic candidate for the prevention and treatment of this condition.

Anti-inflammatory natural product goniothalamin reduces colitis-associated and sporadic colorectal tumorigenesis.

The tumor microenvironment offers multiple targets for cancer therapy, including pro-tumorigenic inflammation. Natural compounds represent an enormous source of new anti-inflammatory and anticancer agents. We previously showed that the styryl lactone goniothalamin (GTN) has promising antiproliferative and anti-inflammatory activities. Because inflammation is a major driver of colorectal cancer (CRC), we therefore evaluated the therapeutic and preventive potentials of GTN in colitis, colitis-associated cancer (CAC) and spontaneous CRC. First, in a simplistic model of inflammation in vitro, GTN was able to inhibit cytokine production in bone marrow-derived macrophages induced by lipopolysaccharide. Next, in dextran sulfate sodium (DSS) induced-colitis model, mice treated with GTN displayed restored tissue architecture, increased cell proliferation in the colonic crypts and reduced epithelial damage. Moreover, colon tissue from GTN-treated mice had significantly less expression of the inflammatory genes interleukin 1ß (IL-1ß), tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), S100A9, interleukin 23A (IL-23A), IL-22 and IL-17A In the azoxymethane/DSS model of CAC, GTN reduced tumor multiplicity, load and size. Additionally, GTN suppressed production of IL-6, IL-17 and TNF-α in tumor tissue, as well as abrogated stromal immune cell activation and nuclear translocation of NF-κB. Finally, in a tamoxifen inducible model of sporadic CRC, GTN-treated mice had significantly fewer tumors and decreased levels of IL-17A, IL-6, S100A9 and TNF-α protein within the tumors. These results suggest that GTN possesses anti-inflammatory and antitumor activities and represents a preventive and therapeutic agent modulating the inflammatory environment in the colon during colitis as well as CAC and CRC development.

Goniothalamin prevents the development of chemically induced and spontaneous colitis in rodents and induces apoptosis in the HT-29 human colon tumor cell line.

Colon cancer is the third most incident type of cancer worldwide. One of the most important risk factors for colon cancer development are inflammatory bowel diseases (IBD), thus therapies focusing on IBD treatment have great potential to be used in cancer prevention. Nature has been a source of new therapeutic and preventive agents and the racemic form of the styryl-lactone goniothalamin (GTN) has been shown to be a promising antiproliferative agent, with gastroprotective, antinociceptive and anti-inflammatory effects. As inflammation is a well-known tumor promoter, the major goal of this study was to evaluate the therapeutic and preventive potentials of GTN on chemically induced and spontaneous colitis, as well as the cytotoxic effects of GTN on a human colon tumor cell line (HT-29). GTN treatments inhibited TNBS-induced acute and chronic colitis development in Wistar rats, reducing myeloperoxidase levels and inflammatory cells infiltration in the mucosa. In spontaneous-colitis using IL-10 deficient mice (C57BL/6 background), GTN prevented colitis development through downregulation of TNF-α, upregulation of SIRT-1 and inhibition of proliferation (PCNA index), without signs of toxicity after three months of treatment. In HT-29 cells, treatment with 10µM of GTN induced apoptosis by increasing BAX/BCL2, p-JNK1/JNK1, p-P38/P38 ratios as well as through ROS generation. Caspase 8, 9 and 3 activation also occurred, suggesting caspase-dependent apoptotic pathway, culminating in PARP-1 cleavage. Together with previous data, these results show the importance of GTN as a pro-apoptotic, preventive and therapeutic agent for IBD and highlight its potential as a chemopreventive agent for colon cancer.

7,7-Dimethylaporphine and Other Alkaloids from the Bark of Guatteria friesiana.

Phytochemical investigation of the bark of Guatteria friesiana afforded 12 new aporphines (1-12), along with nine known alkaloids (13-21). The structures of the new alkaloids were determined on the basis of spectroscopic data interpretation. The cytotoxic activity of the isolated compounds against a small panel of tumor cell lines was assessed using the Alamar blue assay.

Eugenia aurata and Eugenia punicifolia HBK inhibit inflammatory response by reducing neutrophil adhesion, degranulation and NET release.

BACKGROUND: Eugenia spp. are used in popular medicine in the treatment of pain, diabetes, intestinal disorders and cough. The aim of the work is to evaluate, ex vivo and in vivo, the anti-inflammatory activity of the hydroethanolic extracts of the leaves of Eugenia aurata (EA) and Eugenia punicifolia HBK (EP) upon neutrophils. METHODS: Ex vivo, isolated human neutrophils were sensitized by Eugenia extracts (0.1-1000 µg/mL) and stimulated by PMA. In these conditions, different neutrophil activities related to inflammatory process were measured: adhesion, degranulation and NET release. Neutrophil viability and tumor line cells were monitored. In vivo, neutrophil influx was evaluated by peritonitis model performed in mice pretreated with different concentrations of Eugenia extracts. Phytochemical profile was assessed by mass spectrometry. RESULTS: Ex vivo, EA and EP (1000 µg/mL) reduced cell adhesion and degranulation, respectively. NET release was inhibited by EA and EP. Anti-inflammatory activities occurred in the absence of cytotoxicity. In vivo, both EA as EP inhibited neutrophil migration. The phytochemical profile revealed that EA contains myricitrin, rutin, quinic acid and quercetin derivatives. EP presents gallic acid, quercetin derivatives, syringic acid, ellagic acid, monogalloyl-glucose, glycosyringic acid, mudanoside B, HHDP glucose isomer and digalloylglucose isomer. EA and EP inhibit neutrophil migration by different pathways. CONCLUSION: Different chemical compositions may explain the anti-inflammatory effects described herein for EA and EP. Both extracts inhibit NET release but only EA reduces cell adhesion whereas EP decreases elastase secretion. This work contributes to the elucidation of cellular mechanisms related to the anti-inflammatory activity for leaves of E. aurata and E. punicifolia HBK.

Antiproliferative Effect of Synadenium grantii Hook f. stems (Euphorbiaceae) and a Rare Phorbol Diterpene Ester.

Synadenium grantii is frequently used for the treatment of various diseases such as allergies, gastric disorders, and especially cancer. The aim of this study was to evaluate the possible antiproliferative potential of the methanol extract, fractions, and pure compounds from the stems of S grantii Phytochemical analysis was carried out by conventional chromatographic techniques, and the antiproliferative activity was analyzed using the sulforhodamine B assay and an MTT-based assay. Nonpolar fraction and its subfractions from the stems of S grantii exhibited promising cytostatic effect against several human tumor cell lines (glioma, breast, kidney, and lung), with total grown inhibition values ranging from 0.37 to 2.9 µg/mL. One of the active principles of this plant was identified as a rare phorbol diterpene ester, denoted as 3,4,12,13-tetraacetylphorbol-20-phenylacetate. This compound demonstrated antiproliferative activity against glioma, kidney, lung, and triple-negative breast cancer cell lines. These results demonstrate that S grantii stems produce active principles with relevant antiproliferative potential.

In vitro antiproliferative activity of uncommon xanthones from branches of Garcinia achachairu.

Context Garcinia achachairu Rusby (Clusiaceae) popularly known as 'achachairu' is used in folk medicine to treat rheumatism, inflammation, pain and gastric disorder. Objective The present study investigated the chemical profile and antiproliferative effects of the methanolic extract, fractions and two xanthones, against some carcinoma cell lines in vitro. Materials and methods The compounds were isolated and identified by chromatographic and spectroscopic methods. The extract, fractions and compounds were tested human tumour cell lines of U-251 (glioma), MCF-7 (breast), NCI/ADR-RES (ovary expressing multi-drug resistance phenotype), 786-0 (kidney), NCI-H460 (lung, non-small cells), PC-3 (prostate) and HT-29 (colon), non-tumour cell line HaCat (human keratinocytes) in doses of 0.25-250 µg mL (-) (1) for 48 h. The antiproliferative activity was determined by spectrophotometric quantification (at 540 nm) of the cellular protein content using sulphorhodamine B assay. The prediction of parameters involved in the molecular bioavailability was executed directly by ChemDoodle (version 5.0.1) software (iChemLabs, LLC, Somerset, NJ). Results 3-Demethyl-2-geranyl-4-prenylbellidypholine (1) and 1,5,8-trihydroxy-4',5'-dimethyl-2H-pyrane (2,3:3,2)-4-(3-methylbut-2-enyl) xanthone (2), gartanin (3) and stigmasterol (4) were identified on the basis of spectroscopic techniques. Compounds 1 and 2 exhibited cytocidal activity, especially against breast, prostate and kidney cell lines, with TGI values of 15.8, 4.9, 9.1 and 39.4, 44.7, 40.9 µg/mL, respectively. Discussion and conclusion The presence of two sets of hydrophobic and hydrophilic groups in separate domains in each molecule might play a role in the mediation of tumour-specific action. Our data show that G. achachairu have potent antiproliferative action and should be considered an important source of potent anticancer compounds.

Essential oil from fruit of Xylopia langsdorffiana: antitumour activity and toxicity.

CONTEXT: The genus Xylopia L. (Annonaceae) includes aromatic plants that have both nutritional and medicinal uses. Essential oils of Xylopia species have antitumour effects. However, the efficacy of the essential oil from the fruit of Xylopia langsdorffiana St. Hil & Tul. (EOX) has not been examined. OBJECTIVE: EOX was evaluated to determine its chemical composition, antitumour activity and toxicity. MATERIALS AND METHODS: EOX was obtained from fresh fruits of X. langsdorffiana subjected to hydrodistillation, and gas chromatography-mass spectrometry was used to characterize the chemical composition of EOX. The toxicity of EOX was evaluated using haemolysis, acute toxicity and micronucleus assays. The in vitro antitumour activity of EOX was investigated using the sulforhodamine B assay. The sarcoma 180 murine tumour model was used to evaluate the in vivo antitumour activity and toxicity of EOX (50 and 100 mg/kg) after 7 d of treatment. RESULTS: The major components of EOX were α-pinene (34.57%) and limonene (31.75%). The HC50 (concentration producing 50% haemolysis) was 293.6 µg/ml. EOX showed greater selectivity for the leukaemia cell line K562, with total growth inhibition (TGI) (concentration producing TGI) of 1.8 µg/ml, and for multidrug-resistant ovarian tumour cell line NCI/ADR-RES (TGI of 45.4 µg/ml). The LD50 was approximately 351.09 mg/kg. At doses of 50 and 100 mg/kg, EOX inhibited the in vivo growth of sarcoma 180 by 38.67 and 54.32%, respectively. EOX displayed minor hepatic alterations characteristic of acute hepatitis and induced no genotoxicity. CONCLUSION: EOX showed in vitro and in vivo antitumour activity and low toxicity, which warrants further pharmacological studies.

Xanthenones: calixarenes-catalyzed syntheses, anticancer activity and QSAR studies.

An efficient method is proposed for obtaining tetrahydrobenzo[a]xanthene-11-ones and tetrahydro-[1,3]-dioxolo[4,5-b]xanthen-9-ones. The method is based on the use of p-sulfonic acid calix[n]arenes as catalysts under solvent-free conditions. The antiproliferative activity of fifty-nine xanthenones against six human cancer cells was studied. The capacity of all compounds to inhibit cancer cell growth was dependent on the histological origin of the cells. QSAR studies indicate that among compounds derived from ß-naphthol the most efficient compounds against glioma (U251) and renal (NCI-H460) cancer cells are those having higher hydrogen bonding donor ability.

Antiproliferative activity of synthetic fatty acid amides from renewable resources.

In the work, the in vitro antiproliferative activity of a series of synthetic fatty acid amides were investigated in seven cancer cell lines. The study revealed that most of the compounds showed antiproliferative activity against tested tumor cell lines, mainly on human glioma cells (U251) and human ovarian cancer cells with a multiple drug-resistant phenotype (NCI-ADR/RES). In addition, the fatty methyl benzylamide derived from ricinoleic acid (with the fatty acid obtained from castor oil, a renewable resource) showed a high selectivity with potent growth inhibition and cell death for the glioma cell line-the most aggressive CNS cancer.

Synthesis, DNA Binding, and Antiproliferative Activity of Novel Acridine-Thiosemicarbazone Derivatives.

In this work, the acridine nucleus was used as a lead-compound for structural modification by adding different substituted thiosemicarbazide moieties. Eight new (Z)-2-(acridin-9-ylmethylene)-N-phenylhydrazinecarbothioamide derivatives (3a-h) were synthesized, their antiproliferative activities were evaluated, and DNA binding properties were performed with calf thymus DNA (ctDNA) by electronic absorption and fluorescence spectroscopies. Both hyperchromic and hypochromic effects, as well as red or blue shifts were demonstrated by addition of ctDNA to the derivatives. The calculated binding constants ranged from 1.74 × 10(4) to 1.0 × 10(6) M(-1) and quenching constants from -0.2 × 10(4) to 2.18 × 10(4) M(-1) indicating high affinity to ctDNA base pairs. The most efficient compound in binding to ctDNA in vitro was (Z)-2-(acridin-9-ylmethylene)-N- (4-chlorophenyl) hydrazinecarbothioamide (3f), while the most active compound in antiproliferative assay was (Z)-2-(acridin-9-ylmethylene)-N-phenylhydrazinecarbothioamide (3a). There was no correlation between DNA-binding and in vitro antiproliferative activity, but the results suggest that DNA binding can be involved in the biological activity mechanism. This study may guide the choice of the size and shape of the intercalating part of the ligand and the strategic selection of substituents that increase DNA-binding or antiproliferative properties.

Synthesis, antiproliferative activity and molecular properties predictions of galloyl derivatives.

The present study was designed to investigate the in vitro antiproliferative activity against ten human cancer cell lines of a series of galloyl derivatives bearing substituted-1,3,4-oxadiazole and carbohydrazide moieties. The compounds were also assessed in an in silico study of the absorption, distribution, metabolism and excretion (ADME) in the human body using Lipinski's parameters, the topological polar surface area (TPSA) and percentage of absorption (%ABS). In general, the introduction of N'-(substituted)-arylidene galloyl hydrazides 4-8 showed a moderate antitumor activity, while the 2-methylthio- and 2-thioxo-1,3,4-oxadiazol-5-yl derivatives 9 and 10 led to increased inhibition of cancer cell proliferation. The precursor compound methyl gallate 2 and the intermediary galloyl hydrazide 3 showed greater antiproliferative activity with GI50 values < 5.54 µM against all human tumor cell lines tested. A higher inhibition effect against ovarian cancer (OVCAR-3) (GI50 = 0.05-5.98 µM) was also shown, with compounds 2, 3, 9 and 10 with GI50 ≤ 0.89 µM standing out in this respect. The in silico study revealed that the compounds showed good intestinal absorption.

Seven-membered rings through metal-free rearrangement mediated by hypervalent iodine.

A versatile and metal-free approach for the synthesis of carbocycles and of heterocycles bearing seven- and eight-membered rings is described. The strategy is based on ring expansion of 1-vinylcycloalkanols (or the corresponding silyl or methyl ether) mediated by the hypervalent iodine reagent HTIB (PhI(OH)OTs). Reaction conditions can be easily adjusted to give ring expansion products bearing different functional groups. A route to medium-ring lactones was also developed.