Prenylated indole alkaloids from the marine-derived fungus Paecilomyces variotii

Two new prenylated indole alkaloids, namely, dihydrocarneamide A (1) and iso-notoamide B (2), were isolated from the marine-derived endophytic fungus Paecilomyces variotii EN-291. The structures of these metabolites were determined based on comprehensive spectral analysis, together with chiral HPLC analysis of the acidic hydrolysates. Unlike other prenylated indole alkaloids such as asperparalines, notoamides, and versicolamides, compounds 1 and 2 are the rare examples of C-5 prenylation, forming the fused dimethyldihydropyran ring at C-5 and C-6 of the indole ring. The cytotoxic activity of the isolated compounds was evaluated.     

Bio-Guided Fractionation of Retama raetam (Forssk.) Webb & Berthel Polar Extracts

The fractionation of the methanolic extract (MeOH-E) of Retama raetam (Forssk.) Webb & Berthel and further analysis by thin layer chromatography resulted in four fractions (F1, F2, F3 and F4) that, in parallel with the MeOH-E, were screened for antioxidant, cytotoxic, antidiabetic and antibacterial properties. In addition, chemical characterization of their bioactive molecules was performed using LC-DAD-ESI/MSⁿ. The results indicated that F3 was the most promising regarding antioxidant and cytotoxicity abilities, possibly due to its richness in flavonoids class, particularly isoflavones. In turn, F1 was characterized by the presence of the most polar compounds from MeOH-E (organic acids and piscidic acid) and showed promising abilities to inhibit α-amylase, while F4, which contained prenylated flavonoids and furanoflavonoids, was the most active against the tested bacteria. The gathered results emphasize the distinct biological potentials of purified fractions of Retama raetam.     

Two New Prenylated Xanthones from the Pericarp of Garcinia mangostana (Mangosteen)

Two new prenylated xanthones (=9H‐xanthen‐9‐ones), garcimangosxanthones D ( 1 ) and E ( 2 ), together with the six known xanthones 3 – 8 , were isolated from the pericarp of Garcinia mangostana. Their structures were determined by analysis of their spectroscopic data. All of the isolated compounds were biologically evaluated for their in vitro cytotoxic activity against A549, Hep‐G2, and MCF‐7 human‐cancer cell lines and antioxidant activity. Compound 1 exhibited moderate cytotoxicity against Hep‐G2 (IC₅₀=19.2 μM ) and weak cytotoxicity against MCF‐7 (IC₅₀=62.8 μM ) cell lines, and compound 2 showed moderate cytotoxicity against A549, Hep‐G2, and MCF‐7 cell lines with IC₅₀ values of 12.5–20.0 μM (Table 2). Both compounds 1 and 2 demonstrated a weak antioxidant activity with ferric reducing antioxidant power (FRAP) values of 41±7 and 130±4 μmol/g, respectively (Table 3).     

Enhancement of phenolic and flavonoids compounds,antioxidant and cytotoxic effects in regenerated red cabbage by application of Zeatin

Abstract

This study evaluated the roles of zeatin (2?mg/L) on direct organogenesis, phytochemical compounds, antioxidant activity, and cytotoxic activity in regenerated shoots of red cabbage. The results revealed that the extract of explant treated by 2?mg/L zeatin gives the highest content of total phenolics (5.18?mg gallic acid equivalent/g dry weight) and flavonoids (1.52?mg rutin equivalent/g dry weight). Moreover, HPLC and GC-MS analyses indicated that various bioactive compounds in red cabbage are significantly enhanced with increasing zeatin concentration. Besides that, antioxidant activity test showed that in vitro shooting culture using 2?mg/L zeatin displayed higher antioxidant activity in all assays (DPPH, FRAP and ABTS) compared to control with respective values of 68.12%, 73.28%, and 54.1%, respectively. Finally, the cytotoxic properties illustrated that the extracts of red cabbage explant treated by 2?mg/L zeatin exhibited the strongest cytotoxic effect towards cancer cells compared to control.     

Afzeliixanthones A and B, two new prenylated xanthones from Garcinia afzelii ENGL. (Guttiferae)

Two new prenylated xanthones, afzeliixanthones A (1) and B (2), together with three known xanthones (3-5) and two phytosterols, beta-sitosterol and stigmasterol, were isolated from the CH2Cl2/MeOH (1:1) extract of the stem bark of Garcinia afzelii ENGL. collected in the South West Province of Cameroon. Structures were mainly established using one and two-dimensional NMR and mass spectroscopies. The antioxidant activities of the crude extracts as well as the new compounds (1) and (2) were evaluated.     

Boesenbergia Pandurata Roxb., An Indonesian Medicinal Plant: Phytochemistry,Biological Activity,Plant Biotechnology

Boesenbergia pandurata Roxb. (Zingiberaceae), known as “temu kunci”, is one of the Indonesian medicinal plants. Its rhizome has been traditionally used in folk medicine for treatment of several diseases. Rhizome of B. pandurata contains essential oils and many flavonoid compounds that showed many interesting pharmacological activities, such as antifungal, antibacterial, antioxidant, etc. Interestingly, this plant has several prenylated flavonoid compounds, panduratins, that showed very promising of biological activities, especially as strong antifungal and antibacterial, anti-inflammatory, and anti-cancer. This paper aims to review chemical constituents of this plant and their pharmacological activities and also to give a brief view through biotechnological perspective concerning the several possibilities to produce several valuable prenylated flavonoids from this plant.     

Cytotoxic and antimalarial prenylated xanthones from Cratoxylum cochinchinense

A new prenylated xanthone, 5-O-methylcelebixanthone (1), together with six known compounds; celebixanthone (2), 1,3,7-trihydroxy-2,4-di(3-methylbut-2-enyl)xanthone (3), cochinchinone A (4), alpha-mangostin (5), beta-mangostin (6) and cochinchinone C (7) were isolated from roots of Cratoxylum cochinchinense. Their structures were elucidated by spectroscopic methods. Compounds 2 and 4-7 showed cytotoxic activity against the human lung cancer cell line (NCI-H187) with IC(50) values ranging from 0.65 to 5.2 microg/ml. Compounds 1, 2, 6 and 7 also showed antimalarial activity against Plasmodium falciparum with IC(50) values of 3.2, 4.9, 7.2 and 2.6 microg/ml, respectively.     

A New Prenylated Isoflavone and a New Flavonol Glycoside from Flemingia philippinensis

A new prenylated isoflavonoid, flemiphilippinin G ( 1 ), and a new flavonol glycoside, flemiphilippininside ( 2 ), along with eleven known isoflavonoids were obtained from the roots of Flemingia philippinensis (Merr. et Rolfe) Li . Their structures were elucidated on the basis of spectroscopic data. The in vitro cytotoxicities of compounds 1 – 13 against MCF‐7, A549, and Hep‐G2 cell lines were determined by using the MTT (=3‐(4,5‐dimethylthazol‐2‐yl)‐2,5‐diphenyl‐2H‐tetrazolium bromide) colorimetric assay, and their antioxidant activities were evaluated by ferric‐reducing antioxidant power (FRAP) method. Compound 1 exhibited significant cytotoxicity against all the tested cell lines with IC₅₀ values of 4.8–7.3 μM , and compound 2 was found to be inactive. Both compounds 1 and 2 showed weak antioxidant activities with FRAP values of 110±15 and 124±16 μmol/g, respectively.     

Total synthesis of trunkamide A, a novel thiazoline-based prenylated cyclopeptide metabolite from Lissoclinum sp.

Full details of a total synthesis of the doubly prenylated cyclic peptide trunkamide A of marine origin, and also its C45 epimer, are described.     

Indol-2-one intermediates: mechanistic evidence and synthetic utility. Total syntheses of (+/-)-flustramines A and C

A variety of 3,3-disubstituted 2-indolinones have been prepared by treatment of 3-bromo-3-alkyl-2-indolinones with dienophiles/nucleophiles in the presence of cesium carbonate. Application of this general strategy has facilitated the total syntheses of the reverse prenylated marine natural products (+/-)-flustramine A and (+/-)-flustramine C. [Structure: see text]     

Antioxidant activity and cytotoxicity study of the flavonol glycosides from Bauhinia galpinii

The antioxidant activity of the crude extract and solvent fractions obtained from the leaves of Bauhinia galpinii was evaluated in terms of capacity to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals. The crude extract and the more polar solvent fractions (ethyl acetate and butanol) showed considerable antioxidant activity. The antioxidant potential of the extracts, expressed as EC50, ranged between 28.85 +/- 1.28 microg mL(-1)and 118.16 +/- 6.41 microg mL(-1). L-Ascorbic acid was used as a standard (EC50 = 19.79 +/- 0.14 microM). Bioassay guided fractionation of the two active solvent fractions led to the isolation of three flavonoid glycosides, identified as: quercetin-3-O-galactopyranoside (1), myricetin-3-O-galactopyranoside (2), and 2'-O-rhamnosylvitexin (3). These compounds are reported for the first time from this species. The structures of the compounds were determined on the basis of spectral studies (1H NMR, 13C NMR and MS). Their antioxidant potential was evaluated using a DPPH spectrophotometric assay. Compound 2 had higher and 3 had lower antioxidant activity than L-ascorbic acid. No cytotoxic effects were displayed by compounds 1 and 3, but compound 2 was cytotoxic to Vero cells (LC50 = 74.68 microg mL(-1)) and bovine dermis cells (LC50 = 30.69 microg mL(-1)).     

Prenylated flavonoids and dihydrophenanthrenes from the leaves of Epimedium brevicornu and their cytotoxicity against HepG2 cells

Phytochemical study on the leaves of Epimedium brevicornu finally led to the isolation of four prenylated flavonoids (1–4) and three dihydrophenanthrenes (5–7), of which 1, 2, 5 and 7 were new compounds. The structures of these compounds were established mainly by spectroscopic techniques, including NMR spectroscopy and mass spectrometry. These isolates exhibited the cytotoxic activities against HepG2 cells with the IC₅₀ values of 32.8–87.3 μM.     

An Easy Synthetic Approach to Construct Some Ebselen Analogues and Benzo[b]selenophene Derivatives: Their Antioxidant and Cytotoxic Assessment

2‐(Chloroseleno)benzoyl chloride serves as a versatile building block for the synthesis of novel ebselen (2‐phenyl‐1,2‐benzisoselenazol‐3(2H)‐one) analogues and benzo[b]selenophen‐3(2H)‐one derivatives. The antioxidant activity and cytotoxic evaluation of the newly synthesized compounds were implemented. Among all the synthesized compounds, 1‐(3‐hydroxybenzo[b]selenophen‐2‐yl)ethanone oxime ( 9 ) was the most potent antioxidant and the most cytotoxic compound as well.     

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.     

Three new cytotoxic cyclic acylpeptides from marine Bacillus sp

Three new cytotoxic cyclopeptides belonging to iturin class have been isolated from marine bacterium Bacillus sp. These three compounds have the cytotoxic activities. Their structures were determined based on chemical analysis and all kinds of spectroscopic techniques.     

Antioxidant activity of diphenylpropionamide derivatives: synthesis, biological evaluation and computational analysis

We report the synthesis, antioxidant and antiproliferative activity and a QSAR analysis of synthetic diphenylpropionamide derivatives. Synthesis of these compounds was achieved by direct condensation of 2,2- and 3,3-diphenylpropionic acid and appropriate amines using 1-propylphoshonic acid cyclic anhydride (PPAA) as catalyst. Compound structures were elucidated by NMR analysis and their melting points were measured. The in vitro antioxidant activity of these compounds was tested by evaluating the amount of scavenged ABTS radical and estimating ROS and NO production in LPS stimulated J774.A1 macrophages. All compounds were tested for their effect on viability of cells and results demonstrated that they are not toxic towards the cell lines used. The cytotoxic activity of all compounds was evaluated by a Brine Shrimp Test.     

Prenylated Indole Alkaloid Derivatives from Marine Sediment‐Derived Fungus Penicillium paneum SD‐44

Three new prenylated indole alkaloids, including two β‐carbolines, penipalines A and B ( 1 and 2 , resp.), and one indole carbaldehyde derivative, penipaline C ( 3 ), as well as two known indole derived analogs, 4 and 5 , were isolated from the deep‐sea‐sediment derived fungus Penicillium paneum SD‐44 cultured in a 500‐l bioreactor. The structures of the new compounds were determined on the basis of 1D‐ and 2D‐NMR spectroscopy, as well as by high‐resolution mass spectrometry. The new compounds 2 and 3 showed potent cytotoxic activities against A‐549 and HCT‐116 cell lines.     

Haberlea rhodopensis: pharmaceutical and medical potential as a food additive

This review discusses the potential of Haberlea rhodopensis as a food additive. The following are described: plant distribution, reproduction, cultivation, propagation and resurrection properties; extraction, isolation and screening of biologically active compounds; metabolite changes during dehydration; phytotherapy-related properties such as antioxidant potential and free radical-scavenging activities, antioxidant skin effect, antibacterial activity, cytotoxic activity and cancer-modulating effect, radioprotective effect, chemoprotective effect, immunologic effect; present use in homoeopathy and cosmetics, pharmacological and economical importance; perspectives based on the ethnobotanical data for medicinal, cosmetic or ritual attributes. H. rhodopensis showed unique medical and pharmaceutical potential, related to antioxidant, antimicrobial, antimutagenic, anticancer, radioprotective, chemoprotective and immunological properties. H. rhodopensis extracts lack any cytotoxic activity and could be used in phytotherapy. The metabolic profiling of H. rhodopensis extracts revealed the presence of biologically active compounds, possessing antiradical and other physiological activities, useful for design of in vitro synthesised analogues and drugs.     

Prenylated flavonoids from the leaves of Derris malaccensis and their cytotoxicity

A new prenylated isoflavone, pomiferin-4'-O-methyl ether, and a new prenylated chalcone, 2',4'-dihydroxy-4-methoxy-3'-(2-hydroxy-3-methylbut-3-enyl)chalcone, together with four known flavonoids, were isolated from the leaves of Derris malaccensis. All isolated compounds were evaluated for their cytotoxicity.     

Isolation and identification of new prenylated acetophenone derivatives from Acronychia oligophlebia

Three new prenylated acetophenone derivatives, acronyculatin P (1), acronyculatin Q (2), and acronyculatin R (3) were isolated from the leaves of Acronychia oligophlebia. Their structures were identified by extensive analyses of spectroscopic data (IR, UV, ESI-HRMS, 1D and 2D NMR) and comparison with the literatures. In addition, the cytotoxic activity against MCF-7 cells of the compounds were evaluated by the MTT assay and the IC₅₀ values were 56.8, 40.4 and 69.1?μM, respectively.