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Ten Amaryllidaceae alkaloids (AAs) were isolated for the first time from Pancratium maritimum collected in Calabria region, Italy. They belong to different subgroups of this family and were identified as lycorine, which is the main alkaloid, 9-O-demethyllycorine, haemanthidine, haemanthamine, 11-hydroxyvittatine, homolycorine, pancracine, obliquine, tazettine and vittatine. Haemanthidine was isolated as a scalar mixture of two 6-epimers, as already known also for other 6-hydroxycrinine alkaloids, but for the first time they were separated as 6,11-O,O′-di-p-bromobenzoyl esters. The evaluation of the cytotoxic and antiviral potentials of all isolated compounds was undertaken. Lycorine and haemanthidine showed cytotoxic activity on Hacat cells and A431 and AGS cancer cells while, pancracine exhibited selective cytotoxicity against A431 cells. We uncovered that in addition to lycorine and haemanthidine, haemanthamine and pancracine also possess antiretroviral abilities, inhibiting pseudotyped human immunodeficiency virus (HIV)−1 with EC50 of 25.3 µM and 18.5 µM respectively. Strikingly, all the AAs isolated from P. maritimum were able to impede dengue virus (DENV) replication (EC50 ranged from 0.34–73.59 µM) at low to non-cytotoxic concentrations (CC50 ranged from 6.25 µM to >100 µM). Haemanthamine (EC50 = 337 nM), pancracine (EC50 = 357 nM) and haemanthidine (EC50 = 476 nM) were the most potent anti-DENV inhibitors. Thus, this study uncovered new antiviral properties of P. maritimum isolated alkaloids, a significant finding that could lead to the development of new therapeutic strategies to fight viral infectious diseases. [ABSTRACT FROM AUTHOR]

Grapevine trunk diseases (GTDs) are one of the most serious biotic stresses affecting this important crop. Among them a range of diseases were identified and associated to a plethora of phytopathogenic fungi, including species of Diaporthe. Diaporthe eres was recently identified as one of the species involved in cane blight of grapevine. The ability of a strain of this fungus isolated from infected grapevine plant in Italy to produce in vitro phytotoxic metabolites was investigated. Five phytotoxic metabolites were identified by their physical and spectroscopic properties as 4-hydroxybenzaldehyde, 4-hydroxybenzoic acid, nectriapyrone, p-cresol and tyrosol. When tested on grapevine leaf disks and by leaf absorption, 4-hydroxybenzoic acid induced symptoms on both disks and leaves, 4-hydroxybenzaldehyde and p-cresol showed, respectively, phytotoxicity on leaf disks and on the leaf absorption bioassay. [ABSTRACT FROM AUTHOR]

In this study the production of secondary metabolites by a virulent strain of Sardiniella urbana, a recently described pathogen originally found on declining European hackberry trees in Italy, was investigated for the first time. Chemical analysis of the culture filtrate extracts led to the isolation of three well known compounds as R-(−)-mellein and (3R,4R)-and (3R,4S)-4-hydroxy melleins which were identified by spectroscopic methods (essentially NMR and ESIMS). The isolated compounds were tested for their phytotoxic, antifungal and zootoxic activities. Among them, only R-(−)-mellein was found to be active. [ABSTRACT FROM AUTHOR]

In this paper, the first phytochemical analysis of the ethanolic extract of Daphne sericea Vahl flowering aerial parts collected in Italy and its biological activities were reported. Eleven compounds were identified i.e., α-linolenic acid (1), tri-linoleoyl-sn-glycerol (2), pheophorbide a ethyl ester (3), pilloin (4), sinensetin (5), yuanhuanin (6), rutamontine (7), syringin (8), p-coumaric acid (9), p-anisic acid (10) and caffeic acid (11). To the best of our knowledge, compounds (1-4, 7-8 and 10) were isolated from D. sericea for the first time during this work, whereas sinensetin (5) represents a newly identified component of the entire Thymelaeaceae family. The extract was found to possess radical scavenging against both DPPH• and 2,2′-azino-bis(3-thylbenzothiazoline-6-sulfonic acid (ABTS•+) radicals, with at least a 40-fold higher potency against the latter. Moreover, chelating abilities against both ferrous and ferric ions have been highlighted, thus suggesting a possible indirect antioxidant power of the extract. Although the precise bioactive compounds remain to be discovered, the polyphenolic constituents, including phenolic acids, tannins and flavonoids, seem to contribute to the antioxidant power of the phytocomplex. In addition, the extract produced cytotoxic effects in MDA-MB-231 and U87-MG cancer cell lines, especially at the concentration of 625 μg/mL and after 48–72 h. Further studies are required to clarify the contribution of the identified compounds in the bioactivities of the extract and to support possible future applications. [ABSTRACT FROM AUTHOR]

Lampedusa, the largest island of the Pelagie archipelago, Sicily, Italy, has proven to be a rich source of plants and shrubs used in folk medicine. These plants, often native to the island, have been very poorly investigated for their phytochemical composition and biological potential to be translated into pharmacological applications. To start achieving this purpose, a specimen of Limonium lopadusanum , a plant native to Lampedusa, was investigated for the first time. This manuscript reports the results of a preliminary biological assay, focused on antimicrobial activity, carried out using the plant organic extracts, and the isolation and chemical and biological characterization of the secondary metabolites obtained. Thus 3-hydroxy-4-methoxybenzoic acid methyl ester ( syn : methyl isovanillate, ( 1 ), methyl syringate ( 2 ), pinoresinol ( 3 ), erythrinassinate C ( 4 ) and tyrosol palmitate ( 5 ) were isolated. Their antimicrobial activity was tested on several strains and compound 4 showed promising antibacterial activity against Enterococcus faecalis . Thus, this metabolite has antibiotic potential against the drug-resistant opportunistic pathogen E. faecalis.

Grapevine trunk diseases (GTDs) are one of the most serious biotic stresses affecting this important crop. Among them a range of diseases were identified and associated to a plethora of phytopathogenic fungi, including species of Diaporthe . Diaporthe eres was recently identified as one of the species involved in cane blight of grapevine. The ability of a strain of this fungus isolated from infected grapevine plant in Italy to produce in vitro phytotoxic metabolites was investigated. Five phytotoxic metabolites were identified by their physical and spectroscopic properties as 4-hydroxybenzaldehyde, 4-hydroxybenzoic acid, nectriapyrone, p -cresol and tyrosol. When tested on grapevine leaf disks and by leaf absorption, 4-hydroxybenzoic acid induced symptoms on both disks and leaves, 4-hydroxybenzaldehyde and p -cresol showed, respectively, phytotoxicity on leaf disks and on the leaf absorption bioassay.

Fungi are among the biotic agents that can cause deterioration of building stones and cultural heritage. The most common methods used to control fungal spread and growth are based on chemical pesticides. However, the massive use of these synthetic chemicals produces heavy environmental pollution and risk to human and animal health. Furthermore, their use is time dependent and relies on the repetition of treatments, which increases the possibility of altering building stones and culture heritage through environmental contamination. One alternative is the use of natural products with high antifungal activity, which can result in reduced toxicity and deterioration of archeological remains. Recently, three fungal strains, namely Aspergillus niger, Alternaria alternata and Fusarium oxysporum, were isolated as damaging agents from the external tuff wall of the Roman remains "Villa of Poppea" in Oplontis, Naples, Italy. In this manuscript, three selected fungal metabolites, namely cyclopaldic acid, cavoxin and epi -epoformin, produced by fungi pathogenic for forest plants, were evaluated as potential antifungal compounds against the above fungi. Cavoxin and epi -epoformin showed antifungal activity against Asperigillus niger and Fusarium oxysporum , while cyclopaldic acid showed no activity when tested on the three fungi. The same antifungal activity was observed in vitro experiments on infected stones of the Neapolitan yellow tuff (NYT), a volcanic lithotype widely diffused in the archeological sites of Campania, Italy. This study represents a first step in the use of these two fungal metabolites to allow better preservation of artworks and to guarantee the conditions suitable for their conservation.

Two new 5'-monosubstituted tetrahydro-2H-bifuranyl-5-ones, named diplobifuranylones A and B (1 and 2), were isolated from the culture filtrates of Diplodia corticola, the causal agent of a canker of cork oak (Quercus suber). The same fungus also produced eight known metabolites, namely, the diplopyrone, (3S,4R)-trans- and (3R,4R)-cis-4-hydroxymellein, sapinofuranone B and its (S,S)-enantiomer, and sphaeropsidins A-C. Diplobifuranylones A and B (1 and 2) were characterized, using spectroscopic and chemical methods, as two diastereomeric 5'-(1-hydroxyethyl)-3,4,2',5'-tetrahydro-2H-[2,2']bifuranyl-5-ones. While the relative stereochemistry of the two metabolites (1 and 2) was deduced by NOESY and ROESY experiments, the absolute stereochemistry of the chiral carbon of the hydroxyethyl side chain at C-5', determined by application of Mosher's method, proved to be S and R in 1 and 2, respectively. Assayed on a nonhost plant, diplobifuranylones A and B did not show phytotoxic activity. In an Artemia salina larvae lethality bioassay neither 1 nor 2 was toxic at the highest concentration tested (300 microg/mL).

A new phytotoxic hexasubstituted pyranopyran, biscopyran (3), was isolated together with phenylacetic acid (2) and previously isolated 5-methylmellein (1) from the liquid culture filtrates of Biscogniauxiamediterranea, a major fungal pathogen involved in oak decline in Sardinia. Biscopyran was characterized by spectroscopic methods as a new (Z)-2-methoxy-1-[7-((Z)-2-methoxybut-2-enoyl)-3,4,5,6-tetramethyl-2H,7H-pyrano[2,3-b]pyran-2-yl]but-2-en-1-one. Biscopyran assayed at 0.26-0.026 mM concentration range caused epinasty on cork oak cuttings. On a nonhost plant, tomato, biscopyran caused wilting. Phenylacetic acid, assayed at the same concentration, was toxic to Q. suber, while on tomato cuttings it induced internal tissue collapse on the stem.

Cytochalasins Z4, Z5, and Z6, three new cytochalasans, were isolated from the wheat culture of Phoma exigua var. heteromorpha together with the known cytochalasins A, B, F, T, Z2, and Z3, 7-O-acetylcytochalasin B, and deoxaphomin. Z2 and Z3, together with Z1, have recently been described as new 24-oxa[14]cytochalasans produced by Pyrenophora semeniperda, a fungus proposed for biological control of grass weeds. All three new cytochalasins were characterized as 24-oxa[14]cytochalasans by extensive use of NMR and MS techniques. Cytochalasins Z4 and Z5 proved to be structurally related to cytochalasin B, whereas Z6 was related to cytochalasin F. When assayed on tomato seedlings at 10(-4) M, Z6 caused a very low inhibition of rootlet elongation (30%), whereas Z4 and Z5 were almost inactive. On brine shrimp, at the same concentration, only Z5 had a minor effect, with 20% mortality, whereas the other two metabolites proved to be inactive.

A new phytotoxic monosubstituted tetrahydropyranpyran-2-one, named diplopyrone (1), was isolated from the liquid culture filtrates of Diplodia mutila, a plant pathogenic fungus causing a form of canker disease of cork oak (Quercus suber). Diplopyrone was characterized, using spectroscopic and chemical methods, as 6-[(1S)-1-hydroxyethyl]-2,4a,6,8a-tetrahydropyran[3,2-b]pyran-2-one. The absolute stereochemistry of the chiral secondary hydroxylated carbon (C-9), determined by application of Mosher's method, proved to be S. Diplopyrone assayed at a 0.01-0.1 mg/mL concentration range caused necrosis and wilting on cork oak cuttings. On a nonhost plant, tomato, diplopyrone caused brown discoloration or stewing on the stem.