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Biomedical subjects

Maurizio Bruno

Publications and source records attributed to Maurizio Bruno.

16 recordsLinked to original sources

Antibacterial activity of flavonoids and phenylpropanoids from Marrubium globosum ssp. libanoticum.

Marrubium globosum Montbr. et Auch. ex Benth. ssp. libanoticum Boiss. (Lamiaceae) is a medicinal plant used for the treatment of inflammatory diseases, asthma, coughs and other pulmonary and urinary problems. The goal of our study was to assess the biological activity of M. globosum testing the methanol extract of aerial parts for its antibacterial activity against bacteria known to cause respiratory, gastrointestinal, skin and urinary disorders; the extract showed antibacterial effects against all the strains of bacteria used. A purification of this active extract showed the presence, as main constituents, of verbascoside, isorhamnetin 3-O-beta-D-rutinoside, quercetin 3-O-beta-D-rutinoside, naringenin 7-O-beta-D-glucoside, kaempferol 3-O-beta-D-rutinoside, isorhamnetin 3-O-beta-D-glucoside, quercetin 3-O-beta-D-glucoside, apigenin 7-O-(3''-p-coumaryl)-glucoside, p-methoxy-cinnamic acid, kaempferol 3-O-beta-D-glucoside and apigenin 7-O-beta-D-glucoside. The pure compounds were tested for their antibacterial activity; quercetin 3-O-beta-D-rutinoside, verbascoside and naringenin 7-O-beta-D-glucoside showed the greatest activity.

Anti-Infective Agents↗

Antibacterial and anticoagulant activities of coumarins isolated from the flowers of Magydaris tomentosa.

The phytochemical investigation of the acetone and methanol extracts of the flowers of Magydaris tomentosa (Desf.) DC afforded six known coumarins as well as (+)-meranzin hydrate (7), not previously reported as a natural product. The antibacterial activity of umbelliprenin (1), osthol (2), imperatorin (3), citropten (4) and (+)-meranzin hydrate (7) was tested against Gram-positive and Gram-negative bacteria. All coumarins (1-7) isolated in this study inhibited growth of all bacterial strains tested (MIC between 16 and 256 microg/mL), the most active being imperatorin (3) (MICs between 32 and 128 microg/mL) and citropten (4) (MICs between 16 and 256 microg/mL). The anticoagulant activity of compounds 1-4 and 7 was also evaluated.

Animals↗

Antibacterial and antioxidant activities in Sideritis italica (Miller) Greuter et Burdet essential oils.

Sideritis italica (Miller) Greuter et Burdet is a widespread Lamiacea in the Mediterranean region used in traditional medicine. Essential oils were antibacterial against nine ATCC and as many clinically isolated Gram-positive and Gram-negative bacterial strains. Antibacterial activity was also found against Helicobacter pylori: a dose-dependant inhibition was shown between 5 and 25 microg/ml. The antibacterial activity of the oils was expressed as MICs (minimum inhibitory concentrations) and MBCs (minimum bactericidal concentrations). At a concentration between 3.9 and 250 microg/ml the oils showed a significant antibacterial effect against both Gram-negative and Gram-positive bacteria. In particular the ATCC strains Pseudomonas aeruginosa (MIC=3.9 microg/ml and 7.8 for flowerheads and leaves, respectively), Proteus mirabilis (MIC=15.6 and 7.8 microg/ml), Salmonella typhi (MIC=7.8 microg/ml) and Proteus vulgaris (MIC=15.6 microg/ml) were the most inhibited. Only Pseudomonas aeruginosa showed MBC at a concentration between 62.6 and 125 microg/ml. The antioxidant activity of the essential oils was evaluated by two cell free colorimetric methods: ABTS and DMPD; leaf oil is more active (4.29 +/- 0.02 trolox equivalents and 4.53 +/- 0.67 ascorbic acid equivalents by ABTS and DMPD, respectively). Finally the antioxidant activity of the essential oils was also evaluated by their effects on human whole blood leukocytes (WB) and on isolated polymorphonucleate (PMN) chemiluminescence. Comparing the effects of the oils from leaves and flowerheads on both PMN and WB chemiluminescence emission, we found no significant differences. Essential oils showed a dose-dependent and linear inhibitory activity on isolated PMN as well as on WB CL emission when PMA-stimulated. On the contrary, the inhibitory activity on resting cells was nonlinear. Our data represent an answer to the continual demand for new antibiotics and antioxidants for the continuous emergence of antibiotic-resistant strains and the growing interest in the substitution of synthetic antioxidants with natural ones. Furthermore, our finding of antibacterial and antioxidant activities in the essential oils from Sideritis italica flowerheads and leaves validated the use of the plant for medical purposes.

Anti-Bacterial Agents↗

Labdane Diterpenoids from Marrubium globosum ssp. libanoticum.

From the aerial parts of Marrubium globosum ssp. libanoticum, seven labdane diterpenoids were isolated. Three of them are new natural products [(13R)-9alpha,13alpha-epoxylabda-6beta(19),16(15)-diol dilactone (2), deacetylvitexilactone (7), marrulanic acid (8)], whereas the other four, namely, (13S)-9alpha,13alpha-epoxylabda-6beta(19),16(15)-diol dilactone (1), cyllenin A (3), 15-epi-cyllenin A (4), and marrulibanoside, are previously known compounds. The structures of 2, 7, and 8 were determined by spectroscopic and chemical methods.

Diterpenes↗

Phytochemical and pharmacological studies on the acetonic extract of Marrubium globosum ssp. libanoticum.

A new natural labdane diterpene, marrulibanoside, was isolated from the acetonic extract of aerial parts of M. globosum Montbr. et Auch. ex Benth. ssp. libanoticum Boiss. (Lamiaceae). Its structure was determined by spectroscopic methods such as 1D and 2D NMR and mass spectrometry. Pharmacological studies have shown that the extract of M. globosum exerts anti-inflammatory effects in the rat paw oedema induced by carrageenin resulting in reduced paw swelling. This activity, which seems due to marrulibanoside, is a consequence of iNOS and COX-2 activities inhibition.

Animals↗

Cytotoxic activity of some natural and synthetic guaianolides.

Several natural guaianolides and synthetic derivatives of repin (1) were tested and found to be active against tumor cell replication. Repin (1) and both mono- and di-halohydrin analogues (2, 7-9, 11, 12) showed significant antitumor potency. A more effective compound (17) was obtained by esterificating repin with the paclitaxel side chain.

Antineoplastic Agents, Phytogenic↗

Cytotoxic activity of some natural and synthetic sesquiterpene lactones.

Several natural and synthetic sesquiterpene lactones with different skeletons were tested and found to be active against nine cancer cell lines. Elemane, heliangolane and their hydroxy analogues 9 and 10, all containing an alpha,beta-unsaturated aldehyde substituent, were the most potent compounds.

Antineoplastic Agents, Phytogenic↗

Extremely potent antifeedant neo-clerodane derivatives of scutecyprol A.

Two known neo-clerodane diterpenoids, scutecyprol A (1) and scutalbin C (2), have been isolated from the acetone extract of the aerial parts of Scutellaria sieberi. The antifeedant activity of scutecyprol A (1), of its 15-oxo derivative (3), and of several halohydrins (4-9), synthesized starting from compounds 1 and 3, against Spodoptera littoralis have been determined and structure-antifeedant relationships are discussed.

Animals↗

Neoclerodanes from Teucrium orientale.

Two new neoclerodane diterpenoids, 6-deacetyl-teucrolivin A (5) and 8beta-hydroxy-teucrolivin B (6), were isolated from the aerial parts of Teucrium orientale, along with four already known neoclerodane diterpenoids, teucrolivin A (1), teucrolivin B (2), teucrolivin C (3) and teucrolivin H (4), previously isolated from Teucrium oliverianum. Their structures were elucidated on the basis of spectroscopic evidence and chemical transformations. Compounds 1-3 were assayed for antifeedant activity against Spodoptera littoralis, S. frugiperda and Heliocoverpa armigera. Teucrolivin A was the most potent of the three compounds tested.

Animals↗

Chemical composition and antibacterial activity of essential oils from Thymus spinulosus Ten. (Lamiaceae).

The chemical composition of essential oils from aerial parts of Thymus spinulosus Ten. (Lamiaceae) is reported. Four oils from plants growing in different environmental conditions were characterized by GC and GC-MS methods; the oils seem to indicate a new chemotype in the genus Thymus. Influences of soil and altitude characteristics on the essential oil composition are discussed. The oils showed antibacterial activity against Gram-positive (Staphylococcus aureus, Streptococcus faecalis, Bacillus subtilis, and Bacillus cereus) and Gram-negative (Proteus mirabilis, Escherichia coli, Salmonella typhimuium Ty2, and Pseudomonas aeruginosa) bacteria.

Anti-Bacterial Agents↗

Antibacterial evaluation of cnicin and some natural and semisynthetic analogues.

Some ester derivatives of salonitenolide have been prepared from cnicin, a germacranolide sesquiterpenoid. The compounds were tested for their antibacterial activity. The 8,15-diesters showed a good activity, comparable with that of cnicin. The 15-monoester compounds were not very active showing that esterification at the C-8 position is an important structural feature for antibacterial properties.

Anti-Bacterial Agents↗

Neoclerodane diterpenoids from Teucrium montbretii subsp. libanoticum and their absolute configuration.

From the aerial parts of Teucrium montbretii subsp. libanoticum 10 neoclerodane diterpenoids were isolated. Three of them are new [3beta-hydroxyteubutilin A (1), 12-epi-montanin G (2), 20-epi-3,20-di-O-deacetylteupyreinidin (3)], whereas the other seven, namely, 6-ketoteuscordin (4), teuscordinon (5), 6beta-hydroxyteuscordin (6), montanin D (7), 3,20-di-O-deacetylteupyreinidin (8), montanin G (9), and 3-O-deacetylteugracilin A (10), are previously known structures. The structures of 1-3 were determined by spectral and chemical methods.

Chromatography, Thin Layer↗

Anti-HIV agents derived from the ent-kaurane diterpenoid linearol.

Twenty-six semisynthetic ent-kaurane derivatives of linearol (1) have been investigated for their anti-HIV effects. Five compounds (4, 7, 11, 25, and 26) showed significant activity against HIV replication in H9 lymphocyte cells with EC(50) values in the range <0.1-3.11 microg/mL. With TI values of 163 and 184, compounds 4 and 25 are especially promising for further development as potential anti-HIV agents.

Anti-HIV Agents↗