F. De Simone

Screening of anti-bacterial activity of medicinal plants from Belize (Central America).

Twenty-one extracts from seven herbal drugs, Aristolochia trilobata (Aristolochiaceae) leaves and bark, Bursera simaruba (Burseraceae) bark, Guazuma ulmifolia (Sterculiaceae) bark, Hamelia patens (Rubiaceae) leaves and Syngonium podophyllum (Araceae) leaves and bark, used in traditional medicine of Belize (Central America) as deep and superficial wound healers, were evaluated for their anti-bacterial properties. Activity was tested against standard strains of Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923 and Enterococcus faecalis ATCC 29212. Almost all the extracts were able to inhibit the growth of one or more of the bacterial strains, except that of Enterococcus faecalis. For the first time an anti-microbial activity is reported for Aristolochia trilobata as well as for Syngonium podophyllum. The hexane extracts of Aristolochia trilobata leaves and bark were the most active extracts against Staphylococcus aureus (MIC=0.31 and 0.625mg/ml, respectively).

Inhibition of HIV infection by caffeoylquinic acid derivatives

The caffeoylquinic acids 3,4,5-tri-O-caffeoylquinic acid (1) and 4,5-di-O-caffeoylquinic acid (2), as well as caffeic acid (4) and synapoic acid (5) were isolated from the plant Securidaka longipedunculata (polygalaceae). 1 exhibited a greater selective inhibition of HIV replication than 2 which had an anti-HIV activity similar to that of 3,4,5-tri-O-galloylquinic acid (3), isolated from Guiera senegalensis (combretaceae); 4 and 5 were ineffective and the structurally related compound rosmarinic acid (6) had only slight anti-HIV activity. Studies of the actions of these compounds suggest that inhibition of the viral reverse transcriptase in vitro is non-specific and that they act by specific binding to gp120 which prevents its interaction with CD4 on T-lymphocytes and thus inactivates virus infectivity.

Glycolipids from Byrsonima crassifolia

Abstract From the leaves of Byrsonima crassifolia four new glycolipids, 1,2-di- O -miristoyl-3- O -(6-sulpho-α- d -quinovopyranosyl)-glycerol, 1,2-di- O -(8-hexadecenoyl)-3- O -(6-sulpho-α- d -quinovopyranosyl)-glycerol, 1,2-di- O -palmitoyl-3- O -(β- d -glucopyranosyl)- glycerol and 1,2-di- O -(8-hexadecenoyl)-3- O -(β- d -glucopyranosyl)-glycerol, have been isolated. Nine known compounds were also found. The structures of new compounds were elucidated on the basis of chemical and spectral data.

Triterpenes and quinovic acid glycosides from Uncaria tomentosa

Abstract Three new polyoxygenated triterpenes and six new quinovic acid glycosides have been isolated from Uncaria tomentosa . The triterpenes are based on ursolic or quinovic acid structures; the glycosides have a C-3, a C-3,27 or a C-27 glycosylation pattern, and the sugar moietics are made up of one to three hexopyranoses (rhamnose, glucose, quinovose, galactose). Their structures were determined by spectral methods. Copyright

Iridoids from Lippia graveolens.

An investigation of the leaves of Lippia graveolens from Guatemala provided 10 iridoid and secoiridoid glucosides as well as their ester derivatives. Minor constituents were loganin, secologanin, secoxyloganin, dimethylsecologanoside, loganic acid, 8-epi-loganic acid and caryoptoside. Major constituents were the novel iridoids caryoptosidic acid and lippioside I and II consisting of caryoptosidic acid esterified at the C-6 position of glucose with p-coumaroyl or caffeoyl residues, respectively. Their structures were mainly elucidated by NMR spectroscopy.

Anti‐HIV activity of dibenzylbutyrolactone‐type lignans from Phenax species endemic in Costa Rica

Previously, we isolated two new dibenzylbutyrolactone‐type lignans, named phenaxolactones 1 and 2, from the leaves of Phenax angustifolius Wedd. (Urticaceae). In this investigation three new dibenzylbutyrolactone lignans (phenaxolactones 3–5), together with phenaxolactone 1, and flavones vitexin (6), isovitexin (7), were isolated from Phenax rugosus Wedd. leaves collected in Santa Ana, Costa Rica. The structures were elucidated using 1D and 2D NMR spectroscopy as well as mass spectrometry. Phenaxolactones 1–5 and flavones 6 and 7 were evaluated for their inhibitory activity against HIV‐1MN in infected C8166 cells. The most promising compound was phenaxolactone 1 with an EC50 value of 3.0μM, no cytotoxicity at 112μM and a therapeutic index value of 37.3.

Furanocoumarins from the aerial parts of Dorstenia contrajerva

A new glycosylated furanocoumarin, alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranosyl-bergaptol (1), has been isolated from Dorstenia contrajerva together with three known furanocoumarins, catechin and epicatechin. Their structures were established using high field 2D NMR techniques.

Sterol constituents of Tamus communis L.

Le principal constituant sterolique des racines est le β-sitosterol; les feuilles en contiennent presque autant

Neuropharmacological effects of extracts from Sickingia williamsii

Sickingia williamsii Standl. (Rubiaceae) is used in Peruvian folk medicine for its analgesic and anti‐inflammatory activity. In this study we have examined the pharmacological profiles of petroleum ether, chloroform, chloroform‐methanol (9:1) and methanol extracts of the tree.

Flavonol glycosides from Eupatorium tinifolium

Abstract Two new flavonol glycosides, 3′-methylquercetagetin 3- O -galactoside and 3′-methylquercetagetin 3- O -glucoside, have been isolated from the ethyl acetate extract of Eupatorium tinifolium . The structure of these compounds has been established on the basis of chemical and spectral data.