Biomedical subjects

René Torres

Publications and source records attributed to René Torres.

7 recordsLinked to original sources

PubMed2006

Synthesis of 3H-spiro[benzofuran-2,1'-cyclohexane] derivatives from naturally occurring filifolinol and their classical complement pathway inhibitory activity.

Six 3H-spiro[benzofuran-2,1'-cyclohexane] derivatives were synthesized from naturally occurring filifolinol, and their classical complement pathway inhibitory activity was determined. IC(50) values of the most potent compounds were comparable to the activity of the natural complement inhibitor K76-COOH and some synthetic tricyclic analogs of it.

Animals↗

PubMed2006

Antioxidant activity of coumarins and flavonols from the resinous exudate of Haplopappus multifolius.

The antioxidant activity of eight coumarins and two flavonols isolated from Haplopappus multifolius was studied with the DPPH radical method. Results show that a high concentration of phenolic coumarins and the presence of quercetin and rhamnetin in the exudates could account for the protection of the plant against oxidative stress. Structures for the coumarins 6-hydroxy-7-[(E,E)-3',7'-dimethyl-2',4',7'-octatrienyloxy] coumarin and 7-[(E)-3'-methyl-4'-hydroxy-2'-butenyloxy] coumarin are proposed on the basis of spectroscopic evidence.

Antioxidants↗

PubMed2005

Structure-antioxidant activity relationships of flavonoids isolated from the resinous exudate of Heliotropium sinuatum.

Relationships between the structural characteristics of flavonoids isolated from the resinous exudate of Heliotropium sinuatum and their antioxidant activity were studied. Radical formation energies, DeltaH of dehydrogenation and spin densities were calculated using DFT methods (B3LYP/6-31G*). Results show that studied flavonoids can be divided into two sets according to their activity. It has been found that antioxidant activity depends both on substitution pattern of hydroxyl groups of the flavonoid skeleton and the presence of an unsaturation at the C2-C3 bond. A good tendency between DeltaH of dehydrogenation and antioxidant activity was established.

Antioxidants↗

PubMed2004

Two new O-geranyl coumarins from the resinous exudate of Haplopappus multifolius.

From the resinous exudate of leaves of Haplopappus multifolius two new coumarins were isolated and assigned the structures 6-hydroxy-7-(5'-hydroxy-3',7'-dimethylocta-2',6'-dien)-oxycoumarin (1) and 6-hydroxy-7-(7'-hydroxy-3',7'-dimethylocta-2',5'-dien)-oxy coumarin (2).

Coumarins↗

PubMed2003

Antibacterial new clerodane diterpenes from the surface of Haplopappus foliosus.

A biologically monitored fractionation of the resinous exudate extract of Haplopappus foliosus DC. is reported. Purification of the two active fractions yielded 2-alpha-hydroxy- cis-cleroda-3,13(Z),8(17)-trien-15-oic acid (1) and 2-alpha-acetoxy- cis-cleroda-3,13(Z),8(17)-trien-15-oic acid (2), two new clerodane diterpenes.

Anti-Infective Agents↗

PubMed2003

Antioxidant capacity of flavonoids and a new arylphenol of the resinous exudate from Heliotropium sinuatum.

From the resinous exudate of Heliotropium sinuatum (family Boraginaceae), a new compound: 4-(3',5'-dihydroxynonadecyl)phenol 1, together with eight previously described flavonoids, were isolated and their antioxidant activities were assessed by quenching measurements with ABTS and DPPH cation radicals.

Antioxidants↗

PubMed2002

Labdane diterpenes from Haplopappus illinitus.

A chemical study of aerial parts of Haplopappus illinitus afforded five labdane diterpenoids whose structures were elucidated by high field NMR spectroscopy and 2D techniques. Four of them are dicarboxylic acids previously reported as the corresponding dimethyl ester derivatives and the fifth is a new compound.

Chile↗