Abstract Dermatitis is defined as a set of inflammatory diseases that affect the skin, with varied causes. Among the different types of dermatitis, contact dermatitis is the most prevalent. Although the current therapy is often effective, it is associated with adverse effects and the possibility of drug tolerance. N-Methyl-(2S, 4R)-trans-4-hydroxy-L-proline is a L-proline amino acid derivative found in the leaves of Sideroxylon obtusifolium, a species traditionally used to treat inflammatory diseases. The aim of this study was to investigate the topical anti-inflammatory effect of N-methyl-(2S, 4R)-trans-4-hydroxy-L-proline (NMP) in 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced irritant contact dermatitis in mice. Topically administered NMP, at doses of 0.03 − 0.50 mg/ear, reduced TPA-induced ear edema and neutrophil migration, as evidenced by low tissue myeloperoxidase activity and verified by histological examination. In addition, NMP (0.06 mg/ear) reduced tissue levels of pro-inflammatory cytokines (TNF-α, IL-6, IL-1β, INF-γ and MCP-1) and of the anti-inflammatory cytokine IL-10, and reduced gene expression of TNF-α, IL-6 and IL-1β increased by TPA. The data suggest that N-methyl-(2S, 4R)-trans-4-hydroxy-L-proline acts as a topical anti-inflammatory agent that decreases the expression of inflammatory cytokines, making it useful for the treatment of skin inflammation. Further investigations are necessary for its development as a therapeutic agent.

The phytochemical reinvestigation from the heartwood of the extracts of Cordia glazioviana led to the isolation of four still undescribed hydroquinones derivatives designated as cordiaquinol D (1), cordiaquinol E (2), (10R)-10,11-dihydrofuran-1,4-dihydroxy-globiferin (3) and 2-[(1’E,6’E)-3’,8’- dihydroxy-3’,7’-dimethylocta-1’,6’-dienyl]-benzene-1,4-diol (4), along with the naphthoquinone 6-[(2’R)-2’-hydroxy-3’,6’-dihydro-2H-pyran-5’-yl]-2-methoxy-7-methylnaphthalene-1,4-dione (5). Additionally, six previously known compounds were also isolated: rel-1,4-dihydroxy-8(,11(;9(,11(-diepoxy-2-methoxy-8a(-methyl-5,6,7,8,8a,9,10,10a-octahydro-10-antracenone (6), didehydroconicol (7), 1(,6(-dihydroxy-7-epi-eudesm-3-ene (8), 1(,6(-dihydroxy-7-epi-eudesm-4(15)-ene (9), 10,11-dihydroxybisabolol (10), and hamanasal-A (11). The structures of the new compounds were assigned by high-resolution mass spectrometry (HRMS) and nuclear magnetic resonance (NMR) analyses. The relative stereochemistry of 3, 4, and 5 was improved by quantum mechanical calculations. Eight, out of the eleven isolated compounds (2-9), were tested through cellular viability and lipopolysaccharide (LPS)-induced inflammation assays against RAW 264.7 macrophage-like cells. Compounds 3-5 exhibited a stronger effect on LPS-induced NO production (half-maximal inhibitory concentration (IC50) 50.34, 105.83, and 66.73 µM, respectively).

A Streptomyces sp. (BRA-384) was selected among nine strains of bacteria isolated from the zoanthids Palythoa caribaeorum due to the high cytotoxic activity presented by its EtOAc extract (inhibitory concentration mean (IC50) of 2 ng mL-1) against colon cancer cell line. From the EtOAc extract of BRA-384 three new chemical entities (A6, A7 and A8) and one dextrorotatory chromomycin (A5), a promising class of anticancer compounds, were identified. The cytotoxicity of chromomycins A5 to A8 was tested against five tumor cell lines (HCT 116 (human colon adenocarcinoma), MCF-7 (human breast carcinoma), PC-3M (human metastatic prostate cancer), 501-mel (human metastatic melanoma) and MM200 (metastatic melanoma)). All chromomycins were highly potent showing IC50 values from 0.2 to 133 nM. Chromomycin A5 was consistently the most potent over all tested cells (IC50 values from 0.2 in MM200 to 7.9 nM in PC-3M), inclusive when compared to the standard chemotherapeutic agent doxorubicin, that presented IC50 values ranging from 147 to 568 nM against MM200 and MCF-7, respectively.

Orbitides are a class of small naturally occurring cyclic peptides with structural and functional diversities. Their chemical properties make this class feasible to be obtained by solid phase peptide synthesis (SPPS). Therefore, this synthetic accessibility enables useful application and facilitates the identification of analogues, bioactivity studies, and thus, enables them to be applied to obtain peptide libraries. The aim of this work was to investigate the effects of orbitides and their linear synthetic analogues on the migration of neonatal human foreskin fibroblasts. The screening of linear peptide analogues, originally designed from natural orbitides isolated from Jatropha species, demonstrated that some molecules (linear pohlianin B and linear ribifolin) have the potential to induce fibroblast migration and collagen deposition and may thus contribute to accelerating the processes of wound healing and tissue repair. These results also demonstrate the significance of using peptides as an important tool for the discovery of simple and novel drug scaffolds.

Myracrodruon urundeuva (Anacardiaceae) is the scientific designation of “aroeira-do-sertão”, a tree well dispersed at the northeastern Brazil. The medicinal use of this plant is widespread throughout the rural population and the inner trunk bark decoction is used to treat cutaneous affections, urinary and respiratory diseases, and gynecological problems. “Aroeira-do-sertão” has been included in the list of native species under extinction threat. In order to find a sustainable source of the plant, seedlings have been cultivated. The purpose of this work was to investigate the chemical composition of the decoction from leaves of cultivated plants (aqueous extract from Myracrodruon urundeuva (AEMU)) and its anti-inflammatory activity on human neutrophils. The addition of AEMU on cells suspension inhibited significantly its activation/degranulation induced by phorbol myristate acetate. AEMU since at 50 µg mL-1 showed better pattern of inhibitions when related to indomethacin, non-selective cyclooxygenase inhibitor used as reference anti-inflammatory. The decoction fractionation was performed by high-speed counter-current chromatography (HSCCC) and semi-preparative high-performance liquid chromatography (HPLC) using a phenyl column as the stationary phase, allowing the isolation of 24 compounds. These results showed how the AEMU is rich in bioactive metabolites, which probably contribute for the anti-inflammatory effects of this plant extract, modulating the degranulation of human neutrophils, one of the pro-inflammatory mechanism of these cells.

Two new polyunsaturated 3,4-epoxy-heneicosane derivatives named as epoxy-lobophorene A and epoxy-lobophorene B were isolated from the brown alga Lobophora variegata, in addition to nine known compounds. The structures of the new compounds were elucidated using a combination of 1D/2D nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectrometry (HRMS). The isolated compounds were submitted to antiproliferative assays against the human colon cancer cell line HCT-116, human metastatic prostate cancer PC-3M, murine metastatic melanoma B16-F10 and murine fibroblast cell line L929 and also tested as antibacterial. Both 3,4-epoxy lobophorene A and 3,4-epoxy lobophorene B depicted moderate antiproliferative effect against cell lines. None of them showed antibacterial activity.

Five new withanolides, designated as 15-oxo-nicaphysalin B, 6β,7α-dihydroxynicandrenone 10, 24α,25β-dihydroxy-nicandrenone-2 and a mixture of the epimers 17-(1α/1β-methylpropanone)-nicandrenone, in addition to six known others, were isolated from the leaf acetone extract from Nicandra physalodes. The complete structures of the five new withanolides, particularly their relative stereochemistries, were established by extensive spectroscopic analyses, including 1D and 2D nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectrometry (HRESIMS). The main isolated withanolides were evaluated for their antibacterial, antifungal and larvicidal properties, but, except nicandrenone, which showed marginal larvicidal activity, none of them was active.

Five new diterpenes derivatives named as ornatin A, B, C, D and E, in addition to six known related diterpenes were isolated from the aerial parts of cultivated specimens of Plectranthus ornatus. The structures were elucidated using a combination of 1D/2D nuclear magnetic resonance (NMR) spectroscopy, high-resolution electrospray ionization mass spectrometry (HRESIMS) and comparison with published NMR data of analogous compounds. All isolated compounds were assayed against four human cancer cell lines, and Gram-positive and Gram-negative bacteria strains. None of them showed any cytotoxic activity, but ornatin C, D, E and three related diterpenes displayed marginal bactericidal or bacteriostatic effects against the Gram-positive strains.

Two unreported ergostane-type sterols 24(R)-7α-hydroperoxy-ergost-5-en-3β-ol and 6β-carboxyl-24(R)-(8→6)-abeo-ergostan-3β,5β-diol, along with seven known ones were isolated from the hexane and alcohol extracts from the zoanthids Palythoa caribaeorum and Palythoa variabilis. The structures of the new compounds were determined using spectroscopic techniques, including 1D and 2D nuclear magnetic resonance (NMR), high-resolution electrospray ionization mass spectrometry (HRESIMS), and comparison with data previously published. 6β-Carboxyl-24(R)-(8→6)-abeo-ergostan-3β,5β-diol showed moderate cytotoxicity against colon cancer cells (HCT-116) as previously described for others abeo-sterol derivatives.

The actinomycete strain BRA 177 was recovered from sediment samples collected at the St. Peter and St. Paul Archipelago, Brazil. This work accessed the ability of this strain, identified as Actinomadura sp., to produce bioactive metabolites by exploring the genome and characterizing chemistry and cytotoxicity of isolated compounds. From the crude ethyl acetate extract, the pigments nonylprodigiosin, cyclononylprodigiosin and methylcyclooctilprodigiosin were isolated and displayed cytotoxicity against human tumor and non-tumor cell lines. Sequencing, assembling and prospection of BRA 177 draft genome led to identification of two contigs encoding enzymes with high homology to those from prodiginine biosynthetic gene clusters (BGC) in actinomycetes. Further, Actinomadura sp. BGC presented unique putatives RedJ thioesterase and RedL-like type I PKS, involved on selection of prodiginine biosynthetic fatty acyl precursor, and RedG-like Rieske oxygenase, key for cyclization of the prodiginines, suggesting that cyclononilprodigiosin and methylcyclooctylprodigiosin could actually be considered chemical signatures of Actinomadura spp.

Four new epimeric spirostanol and furostanol-type steroidal saponins, (25R,S)-5α-spirostan-2α,3β-diol 3-O-β-D-glucopyranosyl-(1→4)-β-D-galactopyranosyl-(1→4)-β-D-galactopyranoside, (25R,S)-5α-spirostan-2α,3β-diol 3-O-β-D-glucopyranosyl-(1→2)-α-L-rhamnopyranosyl-(1→4)-β-D-galactopyranoside, 26-O-β-D-glucopyranosyl-(25R,S)-5α-furost-20-ene,2α,3β-diol 3-O-β-D-galactopyranoside and 26-O-β-D-glucopyranosyl-(25R,S)-5α-furost-20-ene,2α,3β-diol 3-O-β-D-galactopyranosyl-(1→4)-β-D-galactopyranoside, in addition to the known (25R,S)-5α-spirostan-2α,3β-diol 3-O-β-D-galactopyranoside, were isolated from Cestrum laevigatum. Compounds were submitted to cytotoxic activity assays using colorectal adenocarcinoma (HCT-116), human promyelocytic leukemia (HL-60), ovarian carcinoma (OVCAR-8), glioma (SF-295) human cancer cell lines, and the antimicrobial activity was evaluated against Candida parapsilosis, C. albicans, C. krusei, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis.

Two new meroterpenoid hydroquinones,rel-(4bE,6Z,8E,9aS,10S)-1,4-dihydroxy-9a,10-dihydro-10,12-epoxy-5-methylbenzo[a]azulen-12-one andrel-(4bZ,6Z,8E,9aS,10S)-1-hydroxy-9a,10-dihydro-4,11:10,12-diepoxy-benzo[a]azulen-11,12-dione, along with the known peptide derivative (S)-N-benzoylphenylalanine-(S)-2-benzamide-3-phenylpropyl ester, were isolated from the roots of Cordia globosa. Their structures were determined by 1D and 2D nuclear magnetic resonance (NMR) spectrometry, Fourier transform infrared (FTIR) spectroscopy and high resolution atmospheric pressure chemical ionization mass spectrometry (HRAPCIMS) data analysis. The new compounds were tested against three human cancer cell lines (colon adenocarcinoma, ovarian carcinoma and glioblastoma), but none of them exhibited any activity.

One new alkaloid, 2α-10bα-dihydroxy-9-O-demethylhomolycorine, in addition to seven others known alkaloids, and 5-(hydroxymethyl)furfural, piscidic acid and eucomic acid, were isolated from the bulbs of Hippeastrum solandriflorum. The structures of all compounds were determined using nuclear magnetic resonance (NMR) spectroscopic techniques: 1H NMR and 13C NMR, heteronuclear single quantum coherence (HSQC), heteronuclear multiple bond correlation (HMBC), nuclear Overhauser effect spectroscopy (NOESY), and also the high-resolution electrospray ionization mass spectrometry (EI-HRMS). The cytotoxic activity of all alkaloids was evaluated against three human cancer cell lines (HCT-116, HL-60, OVCAR8 and SF-295) showing IC50 values ranging from 0.01 to 35.7 µM.

<p>An asymmetrical dimer of kaurane diterpene and monoterpene and four novel diterpenes were isolated from the roots of <italic>Croton limae</italic>, along with kaempferol-3-<italic>O</italic>-glucoside, ombuin- 3-O-rutinoside and acetyl aleuritolic acid. The cytotoxic activity of the kaurane diterpene was evaluated against colorectal adenocarcinoma (HCT-116), ovarian carcinoma (OVCAR-8) and glioma (SF-295) cell lines, exhibiting IC₅₀ values of 7.14, 8.19 and > 10 µg mL⁻¹, respectively.</p>

Two new alkaloids containing Nb-methyl-triptamine units linked to bis-quinoline moieties, N-8”-formyl-calycosidine and N-8”-methyl-N-1’-demethyl-iso-calycosidine, were isolated from the aerial part of Margaritopsis carrascoana, along with known calycosidine and hodgkinsine. The cytotoxicity of the isolated alkaloids has been evaluated against cancer cell lines. The first two compounds showed only weak activity against HL-60 cell line, while hodgkinsine was the most active compound against HCT-116, OVCAR-8, HL-60 and SF-295 cancer cell lines. The structures of the isolated compounds were established by spectroscopic and molecular mechanical methods.