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Biomedical subjects

Michele D'Ambrosio

Publications and source records attributed to Michele D'Ambrosio.

6 recordsLinked to original sources
PubMed2005

Improved anti-inflammatory activity of three new terpenoids derived, by systematic chemical modifications, from the abundant triterpenes of the flowery plant Calendula officinalis.

Rings A, D and E of faradiol (1), and ring E of both arnidiol (10) and calenduladiol (4) have been subjected to various selective chemical manipulations to modify polarity, water affinity, H-bonding, sterics, and number of aromatic groups of these anti-inflammatory natural compounds. A total of 15 new and four known pentacyclic triterpenoids have been obtained in this way. Some 13 terpenoids were evaluated for their topical anti-inflammatory activities with respect to inhibition of croton oil induced ear oedema in mouse. Three derivatives of 1, the C(16) benzyl ether 15, the C(30) aldehyde 24, and the C(30) primary alcohol 25 showed significantly improved anti-inflammatory potencies, which is relevant for (future) structure-activity-relationship (SAR) studies.

Animals↗
PubMed2005

Tirucallane triterpenes from the leaf extract of Entandrophragma angolense.

From the leaves of Entandrophragma angolense, three triterpenoidal compounds were isolated and structurally elucidated by mass and NMR spectroscopy. They belong to the tirucallane group but two of them possess the rare seco-ring-A feature. The phytochemical data are discussed from a chemotaxonomic and biogenetic points of view.

Hexanes↗
PubMed2003

Parthenolide and its photochemically synthesized 1(10)Z isomer: chemical reactivity and structure-activity relationship studies in human leucocyte chemotaxis.

The present study has achieved the photochemical conversion of a germacrolide into a melampolide. The investigation on their chemical properties allowed us to evaluate the minimum interatomic distance needed for transannular bridging of C(10) ring in germacrolides and to explain the regiochemical selectivity of electrophilic cyclizations. The antiinflammatory activity of parthenolide and its semisynthetic derivatives was evaluated by in vitro chemotaxis assay with human neutrophiles. These structure-activity relationship studies have led to hypothesize a new pharmacophore and have provided useful information for computationally designed drugs.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2002

Degraded limonoids from Melia azedarach and biogenetic implications.

The roots of Melia azedarach yielded three new degraded limonoids: teracrylmelazolide A, melazolide A and teracrylmelazolide B, possessing a previously undescribed skeleton. The known pyroangolensolide, fraxinellone and its three derivatives, 30-hydroxyfraxinellone, 9 alpha- and 9 beta-hydroxyfraxinellone, were also isolated. Their stereochemisty was elucidated on the basis of spectral data and chemical reactions.

Chromatography↗
PubMedDate not supplied

Simultaneous quantitative determination of eight triterpenoid monoesters from flowers of 10 varieties of Calendula officinalis L. and characterisation of a new triterpenoid monoester.

Dichloromethane extracts of dried flowers of Calendula officinalis contain eight known bioactive triterpendiol monoesters, namely, faradiol-3-O-palmitate, faradiol-3-O-myristate, faradiol-3-O-laurate, arnidiol-3-O-palmitate, arnidiol-3-O-myristate, arnidiol-3-O-laurate, calenduladiol-3-O-palmitate and calenduladiol-3-O-myristate. These pentacyclic terpenoids have been quantified simultaneously using reversed-phase HPLC with isocratic elution and internal standardisation. Of the 10 varieties of C. officinalis investigated, Calypso Orange Florensis produced the highest amounts of the bioactive monoesters, followed by Fiesta Gitana Gelb and May Orange Florensis. The lipophilic extract from the flowers of Calypso Orange Florensis variety also contained low levels of the newly characterised calenduladiol-3-O-laurate.

Calendula↗