Natural-product-inspired design and synthesis of two series of compounds active against Trypanosoma cruzi: Insights into structure-activity relationship, toxicity, and mechanism of action.

Chemical scaffolds of natural products have historically been sources of inspiration for the development of novel molecules of biological relevance, including hit and lead compounds. To identify new compounds active against Trypanosoma cruzi, we designed and synthesized 46 synthetic derivatives based on the structure of two classes of natural products: tetrahydrofuran lignans (Series 1) and oxazole alkaloids (Series 2). Compounds were screened in vitro using a cellular model of T. cruzi infection. In the first series of compounds, 11 derivatives of hit compound 5 (EC50 = 1.1 µM) were found to be active; the most potent (7, 8, and 13) had EC50 values of 5.1-34.2 µM. In the second series, 17 analogs were found active at 50 µM; the most potent compounds (47, 49, 59, and 63) showed EC50 values of 24.2-49.1 µM. Active compounds were assessed for selectivity, hemocompatibility, synergistic potential, effects on mitochondrial membrane potential, and inhibitory effect on trypanothione reductase. All active compounds showed low toxicity against uninfected THP-1 cells and human erythrocytes. The potency of compounds 5 and 8 increased steadily in combination with benznidazole, indicating a synergistic effect. Furthermore, compounds 8, 47, 49, 59, and 63 inhibited parasitic mitochondria in a dose-dependent manner. Although increased reactive oxygen species levels might lead to mitochondrial effects, the results indicate that the mechanism of action of the compounds is not dependent on trypanothione reductase inhibition. In silico calculation of chemical descriptors and principal component analysis showed that the active compounds share common chemical features with other trypanocidal molecules and are predicted to have a good ADMET profile. Overall, the results suggest that the compounds are important candidates to be further studied for their potential against T. cruzi.

Chemical Constituents and Pharmacology properties of Aristolochia triangularis: a south brazilian highly-consumed botanical with multiple bioactivities.

Aristolochia triangularis Cham., is one of the most frequently used medicinal plant in Southern Brazil. Preparations containing the leaves and/or stems are traditionally used as anti-inflammatory, diuretic, as well as antidote against snakebites. This study screened A. triangularis extracts, fractions and isolated compounds for different bioactivities. A weak antiproliferative activity against human lung cancer cell line (A549) was observed only for chloroform fraction obtained from stems (CFstems - CC50: 2.93 µg/mL). Also, a moderate antimicrobial activity against Staphylococcus aureus was detected just for chloroform fraction obtained from leaves (CFleaves -13-16 mm inhibition zone). Additionally, two semi-purified fractions (CFstems-4 and CFleaves-4) selectively inhibited HSV-1 replication (IC50 values of 0.40 and 2.61 µg/mL, respectively), while only CFleaves showed promising results against Leishmania amazonensis. Fractionation of extracts resulted in the isolation of one neolignan (-) cubebin and one lignan (+) galbacin. However, these compounds are not responsible for the in vitro bioactivities herein detected. The presence of aristolochic acid I and aristolochic acid II in the crude ethanol extract of stems (CEEstems) and leaves (CEEleaves) was also investigated. The HPLC analysis of these extracts did not display any peak with retention time or UV spectra comparable to aristolochic acids I and II.

Clerodane Diterpenes from the Marine Sponge Raspailia bouryesnaultae Collected in South Brazil.

The marine sponge Raspailia bouryesnaultae, collected in South Brazil, was selected for detailed investigation considering the results of a screening that pointed to an in vitro antiproliferative effect against non-small cells of human lung cancer (A549) and anti-herpes activity against Herpes Simplex virus type 1 (KOS and 29R strains) of ethanolic extracts. The fractionation and chemical investigation of the sponge's hexanic fraction led to the isolation and structural elucidation of six clerodane diterpenes. The main component was identified as the already-reported raspailol (1), isolated from a sponge of the same genus collected in New Zealand. The structure of a new diterpene (2) with a rearranged skeleton was established by high-resolution mass spectrometry (HRMS) and 1D and 2D Nuclear magnetic resonance spectroscopy (NMR) experiments, and named here as raspadiene. Furthermore, four diterpenes were elucidated as isomers of clerodane diterpenes previously obtained from plants, namely kerlinic acid (3), kerlinic acid methyl ester (4), annonene (5), and 6-hydroxyannonene (6). They differ in their stereochemistry, since these diterpenes are characterized by a trans ring fusion at the decalin moiety and the relative configuration of the two methyl groups at C-8 and C-9 in a cis relationship (type trans/cis). The Raspailia diterpenes have a cis ring fusion at the decalin moiety, and the two methyl groups at C-8 and C-9 are in a trans relationship (type cis/trans). The isolated compounds were evaluated for their potential antiproliferative effects on human cancer cell line A549, and it was observed that the diterpenes bearing a hydroxyl group at C-6 exhibited moderate cytotoxic activity, with 50% inhibitory concentration (IC50) values lower than 25 µM. The evaluation of the potential anti-herpes activity against Herpes Simplex Virus type 1 (HSV-1, KOS and 29R strains) showed that the more promising results were observed for the new compound 2, since it inhibited HSV-1 (KOS and 29R strains) replication by 83% and 74%, respectively.

TSH fraction from Petromica citrina: A potential marine natural product for the treatment of sepsis by Methicillin-resistant Staphylococcus aureus (MRSA).

BACKGROUND AND PURPOSE: Antibiotic resistance is now a worldwide public health problem. A potential alternative source in the search for new antibiotics is the bioactive molecules obtained from marine products, as the halistanol trisulfate, obtained from Petromica citrina, and herein investigated from its antimicrobial and anti-inflammatory properties. EXPERIMENTAL APPROACH: The antimicrobial activity of the fractionation products (TSH fraction, halistanol sulfate (HS) and halistanol sulfate C (HS-C)) of the marine sponge Petromica citrina was evaluated against twenty bacteria and two fungi strains by the disk diffusion and microdilution methods. After initial in vitro tests, an in vivo assay was proposed, to evaluate survival and inflammatory parameters in an animal model of peritonitis mediated by MRSA. The animals are treated with TSH fraction (1, 2.5 and 5 mg kg-1) or Vancomycin (30 mg kg-1) twice (6 and 18 h after induction) until organ removal for evaluation of the inflammatory profile, or for 3 days, 12 h each (6 h, 18 h, 30 h, 42 h, 54 h and 66 h after induction) in animals which were followed-up for by five days, for the evaluation of survival. KEY RESULTS: The BF fraction, TSH fraction, HS and HS-Cinhibited, in vitro, the Enterococcus faecalis, Staphylococcus aureus and Candida albicans growth. Moreover, these samples were effective against S. aureus (MSSA), MRSA and Vancomycin-Resistence Enterococcus (VRE). The in vivo results demonstrated that TSH fraction reduced mortality when compared to the saline group. To evaluate the role of inflammation in outcomes of peritonitis, cytokines (IL-1ß, IL-6, TNF-α) and MPO activity were measured. In general, anti-inflammatory activity was detected in animals treated with TSH in different doses. CONCLUSION AND IMPLICATIONS: These data suggest that TSH may be an interesting alternative for the treatment infections by Gram-positive resistant bacteria, due to its antimicrobial profile associated with its anti-inflammatory properties.

Synthesis and biological evaluation of isoxazolyl-sulfonamides: A non-cytotoxic scaffold active against Trypanosoma cruzi, Leishmania amazonensis and Herpes Simplex Virus.

In this study we report the synthesis, characterization, biological evaluation, and druglikeness assessment of a series of 20 novel isoxazolyl-sulfonamides, obtained by a four-step synthetic route. The compounds had their activity against Trypanosoma cruzi, Leishmania amazonensis, Herpes Simplex Virus type 1 and cytotoxicity evaluated in phenotypic assays. All compounds have drug-like properties, showed low cytotoxicity and were promising regarding all other biological activities reported herein, especially the inhibitory activity against T. cruzi. The compounds 8 and 16 showed significant potency and selectivity against T. cruzi (GI50 = 14.3 µM, SI > 34.8 and GI50 = 11.6 µM, SI = 29.1, respectively). These values, close to the values of the reference drug benznidazole (GI50 = 10.2 µM), suggest that compounds 8 and 16 represent promising candidates for further pre-clinical development targeting Chagas disease.

Synthesis and SAR of new isoxazole-triazole bis-heterocyclic compounds as analogues of natural lignans with antiparasitic activity.

Despite the impressive scientific and technological advances of recent decades, no effective treatment is currently available for Chagas disease. Our research group has been studying the design and synthesis of analogues of natural lignans aiming to identify compounds with antiparasitic activity. This article reports the synthesis of 42 novel bis-heterocyclic derivatives and the structure-activity relationship study conducted based on results of biological assays against Trypanosoma cruzi amastigotes. Thirty-seven compounds were active, and eight of them had GI50 values lower than 100 µM (GI50 88.4-12.2 µM). A qualitative structure activity relationship study using three dimensional descriptors was carried out and showed a correlation between growth inhibitory potency and the presence of bulky hydrophobic groups located at rings A and D of the compounds. Compound 3-(3,4-dimethoxyphenyl)-5-((4-(4-pentylphenyl)-1H-1,2,3-triazol-1-yl)methyl)isoxazole (31) was the most active in the series (GI50 12.2 µM), showing, in vitro, low toxicity and potency similar to benznidazole (GI50 10.2 µM). These results suggest that this compound can be a promising scaffold for the design of new trypanocidal compounds.

The sedative activity of flavonoids from Passiflora quadrangularis is mediated through the GABAergic pathway.

The aim of this study was to investigate the sedative activity of the aqueous leaf extract of Passiflora quadrangularis, a species that is widely cultivated and consumed in South America, and to identify its main constituents and elucidate the involvement of the GABAergic pathway in its mechanism of action. The bioguided fractionation of the crude extract showed a positive relationship between the sedative activity of the extract and its flavonoids. The methods employed to identify and isolate its main flavonoids resulted in the identification of vitexin-2''-O-xyloside, vitexin-2''-O-glucoside, orientin-2''-O-xyloside and orientin-2''-O-glucoside. Vitexin-2"-O-xyloside, the major flavonoid of the extract, showed sedative activity after oral administration in mice.

Antitumor effectiveness of a combined therapy with a new cucurbitacin B derivative and paclitaxel on a human lung cancer xenograft model.

Non-small cell lung cancer (NSCLC) is one of the most common malignant tumors, with a high mortality rate due to the elevated risk of resistance. Natural cucurbitacins and their derivatives are recognized as promising antitumor compounds for several types of cancer, including NSCLC. In a recent study published by our research group, DACE (2-deoxy-2-amine-cucurbitacin E), which is a semisynthetic derivative of cucurbitacin B, showed potential in vitro synergistic antiproliferative effects combined with paclitaxel (PTX) in A549 cells. In sequence, the purpose of this study was to evaluate the in vivo antitumor efficacy of this combined therapy as well as with these drugs individually, using a human NSCLC xenograft model. Some indicators of sub chronic toxicity that could be affected by treatments were also assessed. The results obtained in vivo with the combined treatment (1mg/kg+PTX 10mg/kg) showed the most effective reduction of the relative tumor volume and the highest inhibition of tumor growth and proliferation, when compared with those of the single treatments. Furthermore, scintigraphic images, obtained before and after the treatments, showed that the most effective protocol able to reduce the residual viable tumor mass was the combined treatment. All treatment regimens were well tolerated without significant changes in body weight and no histological and functional damage to liver and kidney tissues. These results corroborate our previous in vitro synergistic effects published. Taken together, these insights are novel and highlight the therapeutic potential of DACE and PTX combination scheme for NSCLC.

Design and synthesis of a new series of 3,5-disubstituted isoxazoles active against Trypanosoma cruzi and Leishmania amazonensis.

Chagas disease and leishmaniasis are neglected tropical diseases (NTDs) endemic in developing countries. Although there are drugs available for their treatment, efforts on finding new efficacious therapies are continuous. The natural lignans grandisin (1) and veraguensin (2) show activity against trypomastigote T. cruzi and their scaffold has been used as inspiration to design new derivatives with improved potency and chemical properties. We describe here the planning and microwave-irradiated synthesis of 26 isoxazole derivatives based on the structure of the lignans 1 and 2. In addition, the in vitro evaluation against culture trypomastigotes and intracellular amastigotes of T. cruzi and intracellular amastigotes of L. amazonensis and L. infantum is reported. Among the synthesized derivatives, compounds 17 (IC50 = 5.26 µM for T. cruzi), 29 (IC50 = 1.74 µM for T. cruzi) and 31 (IC50 = 1.13 µM for T. cruzi and IC50 = 5.08 µM for L. amazonensis) were the most active and were also evaluated against recombinant trypanothione reductase of T. cruzi in a preliminary study of their mechanism of action.

Chemical profiles of traditional preparations of four South American Passiflora species by chromatographic and capillary electrophoretic techniques

ABSTRACT Several species of the genus Passiflora are distributed all over South America, and many of these species are used in popular medicine, mainly as sedatives and tranquilizers. This study analyzes the chemical profile of extracts of four Passiflora species used in folk medicine, focusing on the flavonoids, alkaloids and saponins. We employed simple and fast fingerprint analysis methods by high performance liquid chromatography, ultra performance liquid chromatography and capillary electrophoresis techniques. The analysis led to the detection and identification of C-glycosylflavonoids in all the plant extracts, these being the main constituents in P. tripartita var. mollissima and P. bogotensis. Saponins were observed only in P. alata and P. quadrangularis, while harmane alkaloids were not detected in any of the analyzed extracts in concentrations higher than 0.0187 ppm, the detection limit determined for the UPLC method.

Cytotoxic effects of natural and semisynthetic cucurbitacins on lung cancer cell line A549.

Cucurbitacins and their derivatives are triterpenoids that are found in various plant families, and are known for their pharmacological and biological activities, including anti-cancer effects. Lung cancer represents a major public health problem, with non-small-cell lung cancer (NSCLC) being the most frequent and aggressive type of lung cancer. The objective of this work was to evaluate four cucurbitacins (CUCs) for their cytotoxic activity, effects on apoptosis induction, cell cycle progression, anti-migratory, and anti-invasive effects on the human NSCLC cell line (A549 cells). Our findings showed that these CUCs could suppress human NSCLC cell growth in vitro through their effects on the PI3Kinase and MAPK pathways, which lead to programmed cell death induction, as well as inhibition of cell migration and cell invasion. Additionally, these effects culminate in apoptosis induction and G2/M cell cycle arrest by modulating cyclin B1 expression, and in the mitigation of strategic steps of lung cancer metastasis, including migration and invasion of A549 cells. These results suggest that two natural (DDCB and CB) and two novel semisynthetic derivatives of cucurbitacin B (ACB and DBCB) could be considered as promising compounds with antitumor potential.

Feasibility study with 99mTc-HYNIC-ßAla-Bombesin(7-14) as an agent to early visualization of lung tumour cells in nude mice.

AIM: More sensitive and accurate imaging approaches for early detection and therapy monitoring of lung tumours are needed to ameliorate prognosis and outcome. Lung tumours are known to overexpress receptors for bombesin-like peptides. However, thus far, no study has demonstrated the potential role of bombesin-like peptides in identifying A549 lung tumour cells in xenograft animal models. Thus, we evaluate the feasibility of Tc-HYNIC-ßAla-Bombesin(7-14) as an imaging probe in lung cancer. METHODS AND RESULTS: Xenograft lung tumours were implanted in nude mice and evaluated by histopathological analysis. Tumours were easily visualized by Tc-HYNIC-ßAla-Bombesin(7-14) within 30 days after inoculation of the A549 cell line into mice. Scintigraphic images showed high tumour-to-background ratio. DISCUSSION: The data obtained in this study indicate that Tc-HYNIC-ßAla-Bombesin(7-14) may be useful as an imaging probe to detect A549 lung cancer cells. To our knowledge, this is the first time that this specific radiocompound has been used to visualize non-small-cell lung cancer A549 in mice. Further translational research in humans is required to establish the potential role of this radiocompound in clinical practice.

Ilex paraguariensis Pellets from a Spray-Dried Extract: Development, Characterization, and Stability.

Several studies have shown the potential use of Ilex paraguariensis in developing products with the aim to protect biological systems against oxidative stress-mediated damages. In the same way, technological studies have demonstrated the feasibility of obtaining dry products, by spray-drying process, from aqueous extracts of I. paraguariensis in laboratory. The present work was designed to develop pellets by extrusion/spheronization process, from an I. paraguariensis spray-dried powder. The pellets were characterized with respect to their chemical, physical, and technological properties, and the thermal and the photostability of the main polyphenol constituents were investigated. The pellets exhibited adequate size, shape, and high process yield (78.7%), as well as a good recovery of the total polyphenols (>95%) and a good dissolution in water (89.44 to 100.05%). The polyphenols were stable against light when conditioned in amber glass bottles; unstable against heat when the samples were conditioned either in open glass bottles or in hermetically sealed glass bottles and demonstrated to be hygroscopic and sensible to the temperature, especially when stored in permeable flasks. These findings pointed to the relevance of reducing the residual moisture content of pellets as well as of conditioning them in opaque humidity tight packages under low temperatures. The feasibility of obtaining pellets from an I. paraguariensis spray-dried powder using extrusion/spheronization technique was, for the first time, demonstrated. This finding represents a novelty for the herbal products in both pharmaceutical and food fields.

Comparative central effects of the aqueous leaf extract of two populations of Passiflora edulis

ABSTRACTPassiflora edulis Sims, Passifloraceae, has been used in Brazilian traditional folk medicine to the treatment of anxiety and insomnia. P. edulis is commonly known for its economic interests in Brazil. This species exhibits significant variability in the fruit rind color, then two subpopulations has been described (P. edulis fo. flavicarpa O. Deg. (PEF); P. edulis fo. edulis (PEE)). This study compared phytochemical profile and biological actions of aqueous leaf extract of PEE and PEF. HPLC analysis showed marked distinct chromatograms to the P. edulisvarieties. However, in both extracts the major compounds observed were flavonoids C-glycosides. Behavioral studies showed that PEE (300 mg/kg, p.o.) and PEF (100 and 300 mg/kg, p.o.) reduced anxiety in the elevated plus maze test. PEE (300 and 1000 mg/kg, p.o.) and PEF (1000 mg/kg, p.o.) also induced antidepressant-like actions in the forced swimming test. PEE 1000 mg/kg significantly reduced distance moved, thus suggesting sedation. No alterations in sleeping time were observed with PEE and PEF extracts. In conclusion, despite the similarities between the biological actions observed for both P. edulis varieties, quite different phytochemical profile was herein reported. These data suggest that the anxiolytic and antidepressant actions are not due to a specific phytochemical component.

Synergistic Antiproliferative Effects of a New Cucurbitacin B Derivative and Chemotherapy Drugs on Lung Cancer Cell Line A549.

Nonsmall cell lung cancer (NSCLC) represents an important cause of mortality worldwide due to its aggressiveness and growing resistance to currently available therapy. Cucurbitacins have emerged as novel potential anticancer agents showing strong antiproliferative effects and can be promising candidates for combined treatments with clinically used anticancer agents. This study investigates the synergistic antiproliferative effects of a new semisynthetic derivative of cucurbitacin B (DACE) with three chemotherapy drugs: cisplatin (CIS), irinotecan (IRI), and paclitaxel (PAC) on A549 cells. The most effective combinations were selected for studies of the mechanism of action. Using an in silico tool, DACE seems to act by a different mechanism of action when compared with that of different classes of drugs already used in clinical settings. DACE also showed potent synergic effects with drugs, and the most potent combinations induced G2/M cell cycle arrest by modulating survivin and p53 expression, disruption of F-actin cytoskeleton, and cell death by apoptosis. These treatments completely inhibited the clonogenic potential and did not reduce the proliferation of nontumoral lung cells (MRC-5). DACE also showed relevant antimigratory and anti-invasive effects, and combined treatments modulated cell migration signaling pathways evolved with metastasis progression. The effects of DACE associated with drugs was potentiated by the oxidant agent l-buthionine-sulfoximine (BSO), and attenuated by N-acetilcysteine (NAC), an antioxidant agent. The antiproliferative effects induced by combined treatments were attenuated by a pan-caspase inhibitor, indicating that the effects of these treatments are dependent on caspase activity. Our data highlight the therapeutic potential of DACE used in combination with known chemotherapy drugs and offer important insights for the development of more effective and selective therapies against lung cancer.

Isolation of C-glycosylflavonoids with α-glucosidase inhibitory activity from Passiflora bogotensis Benth by gradient high-speed counter-current chromatography.

In this study, we applied a gradient High-Speed Counter-Current Chromatography (HSCCC) method that allowed, by direct injection of an aqueous crude extract of the leaves of Passiflora bogotensis, the successful isolation of six flavonoids in a single run, with purity of each compound higher than 81%. This separation enabled the isolation of two new flavonoid glycosides, apigenin-6-C-α-l-rhamnopyranosyl-(1→2)-(6″-O-acetyl)-ß-d-glucopyranoside (2) and luteolin-6-C-α-l-rhamnopyranosyl-(1→2)-(6″-O-acetyl)-ß-d-glucopyranoside (4), and four known ones, isovitexin (1), isoorientin (3), isovitexin-2″-O-rhamnoside (5) and isoorientin-2″-O-rhamnoside (6). The structures of the isolated compounds were identified by HPLC-DAD, LC-MS, (1)H and (13)C NMR and comparison with literature data. The inhibitory activities of all of these compounds were evaluated in vitro on α-glucosidase from S. cerevisiae, and the IC50 was determinate. This is the first study concerning the chemical composition and biological activity of Passiflora bogotensis.

Involvement of GABAergic pathway in the sedative activity of apigenin, the main flavonoid from Passiflora quadrangularis pericarp

Abstract In the current study we showed that oral administration of an aqueous extract of Passiflora quadrangularis L., Passifloraceae, pericarp results in a significant prolongation of the sleep duration in mice evaluated in the ethyl ether-induced hypnosis test which indicates sedative effects. Apigenin, the main flavonoid of the extract, induced a similar sedative response when applied alone, at a dose equivalent to that found in the extract, suggesting that apigenin is mediating the sedative effects of P. quadrangularis extract. In addition, the sedative effect of apigenin was blocked by pretreatment with the benzodiazepine antagonist flumazenil (1 mg/kg), suggesting an interaction of apigenin with gamma-aminobutyric acid type A (GABAA) receptors. However, apigenin at concentrations 0.1–50 µM failed to enhance GABA-induced currents through GABAA receptors (α1β2γ2S) expressed in Xenopus oocytes. Nevertheless, based on our results, we suggest that the in vivo sedative effect of the P. quadrangularis extract and its main flavonoid apigenin maybe be due to an enhancement of the GABAergic system.

In vitro and in vivo antitumor activity of a novel semisynthetic derivative of cucurbitacin B.

Lung cancer is the most deadly type of cancer in humans, with non-small-cell lung cancer (NSCLC) being the most frequent and aggressive type of lung cancer showing high resistance to radiation and chemotherapy. Despite the outstanding progress made in anti-tumor therapy, discovering effective anti-tumor drugs is still a challenging task. Here we describe a new semisynthetic derivative of cucurbitacin B (DACE) as a potent inhibitor of NSCLC cell proliferation. DACE arrested the cell cycle of lung epithelial cells at the G2/M phase and induced cell apoptosis by interfering with EGFR activation and its downstream signaling, including AKT, ERK, and STAT3. Consistent with our in vitro studies, intraperitoneal application of DACE significantly suppressed the growth of mouse NSCLC that arises from type II alveolar pneumocytes due to constitutive expression of a human oncogenic c-RAF kinase (c-RAF-1-BxB) transgene in these cells. Taken together, these findings suggest that DACE is a promising lead compound for the development of an anti-lung-cancer drug.

The influence of leaf age on methylxanthines, total phenolic content, and free radical scavenging capacity of Ilex paraguariensis aqueous extracts

Yerba-mate (Ilex paraguariensis A. St. Hil., Aquifoliaceae) is a South American native species that is widely used for its industrial potential in the preparation of drinks, teas and cosmetics. Its properties are directly related to the presence of its chemical constituents, such as saponins, methylxanthines and phenolic compounds. This study aimed to investigate the influence of leaf age on methylxanthine and total phenolic contents by High Performance Liquid Chromatography and Ultraviolet Spectroscopy, as well as on free radical scavenging capacity, of aqueous extracts of I. paraguariensis leaves. The results showed great variability in all the metabolites measured. Leaf ageing significantly increased the methylxanthine content and total phenolic content of the extracts. Free radical scavenging capacity was also significantly affected (p < 0.05) by leaf age. A positive correlation was observed, between the antioxidant activity and total phenolic content.

Polyoxygenated steroids from the octocoral Leptogorgia punicea and in vitro evaluation of their cytotoxic activity.

Five new polyoxygenated marine steroids-punicinols A-E (1-5)-were isolated from the gorgonian Leptogorgia punicea and characterized by spectroscopic methods (IR, MS, 1H, 13C and 2-D NMR). The five compounds induced in vitro cytotoxic effects against lung cancer A549 cells, while punicinols A and B were the most active, with IC50 values of 9.7 µM and 9.6 µM, respectively. The synergistic effects of these compounds with paclitaxel, as well as their effects on cell cycle distribution and their performance in the clonogenic assay, were also evaluated. Both compounds demonstrated significant synergistic effects with paclitaxel.