José Paz Parente

Biologically active flavonoids and kava pyrones from the aqueous extract of Alpinia zerumbet

From the aqueous extract of Alpinia zerumbet (Pers) B. L. Burttet Smith. (= Alpinia speciosa K. Schum.) flavonoids and kava pyrones were obtained. The flavonoids identified as rutin (1), kaempferol‐3‐O‐rutinoside (2), kaempferol‐3‐O‐glucuronide (3), (+)‐catechin (4) and (−)‐epicatechin (5) are well known substances that can contribute to the hypotensive, diuretic and antiulcerogenic activity of the aqueous extract of the plant, while the kava pyrones dihydro‐5,6‐dehydrokawain (6) and 5,6‐dehydrokawain (7) have been described as antiulcerogenic and antithrombotic. The compounds were identified from their UV, 1H‐ and/or 13C‐NMR, hydrolytic and co‐TLC data. The well known activity of these compounds, which have not been previously isolated from the leaves of Alpinia zerumbet, may explain the use of the plant in the treatment of hypertension.

An anti-inflammatory and immunomodulatory polysaccharide from Orbignya phalerata.

A polysaccharide, a glucan with mean M(r) of 1.0 x 10(6) (MP1), was isolated from the mesocarp of fruits of Orbignya phalerata. Chemical and spectroscopic studies indicated that MP1 has a highly branched glucan type structure composed of alpha-(1-->4) linked D-glucopyranose residues with (3-->4), (4-->6), and with (3-->6) branching points. MP1 enhanced phagocytosis in vivo and exhibited anti-inflammatory activity.

Flavonol glycosides from Costus spicatus.

Two flavonol diglycosides, tamarixetin 3-O-neohesperidoside, kaempferide 3-O-neohesperidoside and the known quercetin 3-O-neohesperidoside, together with six other known flavonoids were isolated from the leaves of Costus spicatus and their structures were elucidated by a combination of spectroscopic and chemical methods. The flavonol diglycosides were evaluated for inhibitory activity of nitric oxide production by activated macrophages (Fig. 1).

Alkamides from Cissampelos glaberrima

Two alkamides, deca-2E,4E-dienoic acid isobutylamide (1) and octa-2E,4E-dienoic acid isobutylamide (2), were isolated from the roots of Cissampelos glaberrima (Menispermaceae). Their structures were established by spectral and physical methods. Traces of two new alkamides, decen-2-oic acid isobutylamide (3) and decanoic acid isobutylamide (4), were identified by mass spectrometry.

Furocoumarins from the rhizomes of Dorstenia brasiliensis

Abstract A monoterpenoid substituted furocoumarin, 5-[3-(4,5-dihydro-5,5-dimethyl-4-oxo-2-furanyl)butoxy]-7H-furo[3-2-g][1]benzopyran-7-one, was isolated from the rhizomes of Dorstenia brasiliensis Lam. along with psoralen, bergapten, sitosterol, stigmasterol, 3- O -β-glucosylsitosterol and sucrose. Traces of a new unsaturated analogue, 5-[[3-(4,5-dihydro-5,5-dimethyl-4-oxo-2-furanyl-2-butenyl-] oxy]-7H-furo[3-2-g][1]benzopyran-7-one, were identified by mass spectrometry.

Anti-inflammatory and immunologically active polysaccharides of Periandra mediterranea.

Three polysaccharides, glucans with mean M(r)s of 1.5 x 10(5), 3.6 x 10(4) and 2.1 x 10(4), were isolated from dried roots of Periandra mediterranea by fractionation on Sephacryl S-300 HR and Sephadex G-25. Chemical and spectroscopic studies indicated that they have a highly branched glucan type structure composed of alpha-(1-->4) linked D-glucopyranose residues with both (3-->4) and (4-->6) branching points. The polysaccharides enhance phagocytosis in vivo, and exhibit anti-inflammatory activity.

A new steroidal saponin with antiinflammatory and antiulcerogenic properties from the bulbs of Allium ampeloprasum var. porrum.

A new steroidal saponin was isolated from the bulbs of Allium ampeloprasum var. porrumL. On the basis of chemical evidence, comprehensive spectroscopic analyses and comparison of known compounds, its structure was established as (3β,5α,6β,25R)-6-[(β-D-glucopyranosyl)oxy]-spirostan-3-yl O-β-D-glucopyranosyl-(1→2)-O-[β-D-glucopyranosyl-(1→3)]-β-D-galactopyranoside. Results of the present study indicated that the steroidal saponin showed haemolytic effects in the in vitro assays and demonstrated antiinflammatory activity and gastroprotective property using in vivo models.

Bioactive polysaccharides from Costus spicatus

Abstract Three polysaccharides, glucans with mean M r s of 7.50×10 5 , 4.25×10 5 and 2.15×10 5 , were isolated from fresh stems of Costus spicatus by fractionation on Sephacryl S-300 HR and Sephadex G-25. Chemical and spectroscopic studies indicated that they have a highly branched glucan type structure composed of α-(1→4) linked d -glucopyranose residues with (1→3), (1→6) branching points, and a small amount of (1→6) branching to α-(1→3) linked d -glucopyranose residues. The polysaccharides inhibit capillary permeability and demonstrate phagocytosis stimulating properties.

Odoratin 7-O-β-D-glucopyranoside from Bowdichia virgilioides

An isoflavonoid glucoside, odoratin 7-O-β-D-glucopyranoside, was isolated from the roots of Bowdichia virgilioides and its structure was established by spectroscopic and chemical methods. In vitro tests showed that this compound inhibited both T-lymphocyte and B-lymphocyte proliferation.

A furostanol glycoside from rhizomes of Costus spicatus

A new furostanol glycoside was isolated from the rhizomes of Costus spicatus. Its structure was established as (3 beta,22 alpha,25R)-26-(beta -D-glucopyranosyloxy)-22-methoxyfurost-5-en-3-yl O-D-apio-beta-D-furanosyl-(1-->2)-O-[6-deoxy-alpha-L-mannopyranosy l-(1-->4)]- beta-D-glucopyranoside. The structural identification was performed using detailed analysis of 1H and 13C NMR spectra including 2D NMR spectroscopic techniques (COSY, HETCOR and COLOC) and chemical conversions.