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Biomedical subjects

R Mata

Publications and source records attributed to R Mata.

At least 37 records · Page 2Linked to original sources
PubMed1998

Purpurediolin and purpurenin, two new cytotoxic adjacent bis-tetrahydrofuran annonaceous acetogenins from the seeds of Annona purpurea.

Two novel cytotoxic acetogenins, purpurediolin (1) and purpurenin (2), were isolated from the seeds of Annona purpurea. Their structures were elucidated by a combination of chemical and spectral methods including MS and NMR measurements. In addition, six known acetogenins were obtained, namely, bullatacin, squamocin (annonin I), motrilin (squamocin C), annoglaucin, xylomatenin, and annonacin A. Compounds 1 and 2 exhibited potent cytotoxic activity in vitro against six human solid tumor cell lines.

4-Butyrolactone↗
PubMed1997

Smooth muscle relaxing flavonoids and terpenoids from Conyza filaginoides.

Activity-guided fractionation of the smooth muscle relaxing, chloroform-methanol (1:1) extract of Conyza filaginoides (D.C.) Hieron (Asteraceae) led to the isolation of three flavonoids (quercetin 3-glucoside, rutin, and pinostrobin), one sterol (alpha-spinasterol), a sesquiterpenoid (beta-caryophyllene 4,5-alpha-oxide), and two triterpenoids (erythrodiol and 3-beta-tridecanoyloxy-28-hydroxyolean-12-ene). 3-beta-Tridecanoyloxy-28-hydroxy-olean-12-ene is a new naturally occurring terpenoid. All the isolated compounds induced a concentration-dependent inhibition of the spontaneous contractions of rat ileum. The spasmolytic activity exhibited by the extract and active principles tends to support the traditional use of C filaginoides as an antispasmodic agent.

Animals↗
PubMed1997

[Invasive maxilar sinusitis by Rhizopus oryzae].

We herein present a diabetic with non Hodgkin lymphoma patient that had been treated with steroids and developed fungal invasive sinusitis. The patient had intensive facial pain that did not respond to antibiotics and on clinical inspection had a necrotic lesion on right nasal area. A smear and biopsy tissue showed broad non septate hyphae and on cultures Rhizopus oryzae was isolated. There was an unfavorable outcome, and the patient died even though liposomal Amphotericin B was administered and surgical treatment was performed.

English Abstract↗
PubMed1996

Phytogrowth-inhibitory and antifungal constituents of Helianthella quinquenervis.

Investigation on the roots of Helianthella quinquenervis (Hook.) A. Gray (Asteraceae), led to the isolation of one new benzofuran (6-methoxy-tremetone (1)) and a new prenylacetophenone (4-beta-D-(glucopyranosyloxy)-3-[3-methoxy-trans-isopenten-1 -yl] acetophenone (3)). In addition, 6-hydroxy-3-methoxytremetone (2), encecalin (6), euparin (5), demethylencecalin (4), and angelic acid were obtained. Structural assignments of the isolated compounds were based on spectroscopic and spectrometric analysis. Natural products 1-4 showed marginal cytotoxicity against three human tumor cell lines [MCF-7, A-549, and HT-29]. Compounds 4 and 6 inhibited the radicle growth of Amaranthus hypochondriacus and Echinochloa crusgalli. Furthermore, substances 4-6 exhibited antifungal activity against Trichophyton mentagrophytes.

Animals↗
PubMed1996

Smooth muscle relaxing compounds from Dodonaea viscosa.

Bioassay-directed fractionation of the chloroform-methanol (1:1) extract of Dodonaea viscosa (L.) Jacq. (Sapindaceae) resulted in the isolation of four active spasmolytic principles: sakuranetin (1), 6-hydroxykaempferyl 3,7-dimethyl ether (2) hautrivaic acid (3), and ent-15, 16-epoxy-9 alpha H-labda-13(16)14-diene-3 beta, 8 alpha-diol (4). All the isolated compounds elicited a concentration-dependent inhibition of the spontaneous and electrically-induced contractions of guinea-pig ileum. Sakuranetin and the ent-labdane inhibited ileum contractions evoked by acetylcholine (Ach), histamine, and barium chloride. In addition, both substances were capable of relaxing contractions of rat uterus induced by Ca2+ in K(+)-depolarizing solution, displacing to the right the concentration-response curves to Ca2+. These results suggest that sakuranetin and ent-15,16-epoxy-9 alpha H-labda-13(16)14-diene-3 beta, 8 alpha-diol produce an interference with calcium metabolism in smooth muscle cells. The spasmolytic activity exhibited by the active principles from D. viscosa, provides the pharmacological basis for the traditional use of the plant as an antispasmodic agent.

Animals↗
PubMed1995

Biochemically active sesquiterpene lactones from Ratibida mexicana.

Bioactivity-directed fractionation of the methanol extract of the roots of Ratibida mexicana resulted in the isolation of two bioactive sesquiterpene lactones, isoalloalantolactone and elema-1,3,11-trien-8,12-olide. Both compounds caused a significant inhibition of the radicle growth of Amaranthus hypochondriacus and Echinochloa crus-galli, exerted moderate cytotoxic activity against three different solid tumour cell lines and inhibited significantly the radial growth of three phytopathogenic fungi. Isoalloalantolactone also caused the inhibition of ATP synthesis, proton uptake and electron transport (basal, phosphorylating and uncoupled) from water to methylviologen, therefore acting as a Hill's reaction inhibitor. The lactone did not affect photosystem I but inhibited photosystem II. The site of inhibition of isoalloalantolactone is located in the span of P680 to QA redox enzymes because the uncoupled electron transport from water to silicomolybdate and, from DPC to DCIP are inhibited approximately to the same extent.

Antifungal Agents↗
PubMed1995

Vasoactive effects of aqueous extracts from five Mexican medicinal plants on isolated rat aorta.

The present investigation describes the effects of aqueous extracts from Chiranthodendron pentadactylon flowers, Galphimia glauca leaves and flowers, Ipomoea stans roots, Juglans regia leaves and Taxodium mucronatum aerial parts on isolated rat thoracic aorta precontracted by noradrenaline (NA). In all cases, the aqueous extracts (0.5-12 mg/ml) significantly inhibited, in a concentration-dependent manner, the maximal contractile response induced by NA in rat aorta. The most active extract was that of G. glauca flowers. These findings indicate that the active principle(s) present in the crude extracts can exert a vasorelaxant effect.

Animals↗
PubMed1994

[An analysis of domiciliary medical care in 7 health centers of Alicante Province].

OBJECTIVE: To know the characteristics of medical care at home done by the doctor and to what extent it is justified. DESIGN: An observational, descriptive-prospective study. Form filled out by the doctor after completing the visit. SETTING: Outpatients, 7 hospitals in area 17 of the Valencian Community. PATIENTS: 188 different patients attended in February 1993 by 15 family doctors. The statistical tests used were ji-squared test, Student's t-test and Anova. MEASUREMENTS AND MAIN RESULTS: An average of 0.4 visits/doctor/day were made. Less than 2 hours/week/doctor were needed. 80.5% of the cases were resolved using usual means available in the doctors emergency briefcase. 64.5% of the patients attended were over the age of 65.66% of the visits were considered to be justified. CONCLUSIONS: 66% of medical care at home was considered justified and did not require excessive time. Elderly patients are the ones who most require medical care at home.

Adult↗
PubMed1993

Tricolorin A, major phytogrowth inhibitor from Ipomoea tricolor.

The allelopathic potential of Ipomoea tricolor (Convolvulaceae), used in Mexican traditional agriculture as a weed controller, has been demonstrated by measuring the inhibitory activity of organic extracts on seedling growth of Amaranthus leucocarpus and Echinochloa crus-galli. Bioactivity-directed fractionation of the active CHCl3 extract led to the isolation of the allelopathic principle, which turned out to be a mixture of the so-called "resin glycosides" of convolvulaceous plants. The structure of tricolorin A, the major phytogrowth inhibitor present in the active fraction, was elucidated as (11S)-hydroxyhexadecanoic acid 11-O-alpha-L-rhamnopyranosyl-(1-->3)-O-alpha-L-[2-O-(2S-methylbutyryl)-4 -O- (2S-methylbutyryl)] rhamnopyranosyl-(1-->2)-O-beta-D-glucopyranosyl-(1-->2)-beta-D-fucopyran oside- (1,3"-lactone)[1], based on chemical methods and spectral analysis including 1H-1H COSY, 1H-13CHETCOR, long range 1H-13C COLOC, and selective INEPT experiments. Bioassays showed that radicle elongation of the two weed seedlings tested was inhibited by tricolorin A [1] with IC50 values ranging from 12 to 37 microM. Staphylococcus aureus was sensitive to compound 1 with an MIC value of 1.8 micrograms/ml. Significant cytotoxic activity against cultured P-388 and human breast cancer cells (ED50 2.2 micrograms/ml) was demonstrated for compound 1, and it also inhibited phorbol 12,13-dibutyrate binding using calf brain homogenate as a source of protein kinase C (IC50 43 microM).

Antineoplastic Agents, Phytogenic↗
PubMed1992

The effects of cholesterol oxidation products in sickle and normal red blood cell membranes.

The oxysterol content in normal and sickle red blood cell (RBC) membranes was assessed using thin-layer chromatography and capillary gas chromatography/mass spectrometry. Several more oxysterols were present in sickle RBCs compared to normal RBCs. Sickle RBC membranes had a higher concentration of 5 alpha,6 alpha-epoxycholesterol, 5 alpha-cholestane-3 beta,5,6 beta-triol, 7-ketocholesterol and 19-hydroxycholesterol than normal RBC membranes. The increased oxysterols in sickle RBC may be an effect of the increased oxidative stress which occurs in sickle RBC membranes. Physical characteristics of normal and sickle RBC membrane ghosts with and without inserted oxysterols were examined by Fourier transform infrared spectroscopy. The data are consistent with a greater sterol content in sickle cells compared to normal RBC membranes, and a possible oxysterol-cholesterol synergism.

Cholesterol↗
PubMed1992

Screening for antimicrobial activity of crude drug extracts and pure natural products from Mexican medicinal plants.

Preliminary antimicrobial screening against Candida albicans and selected Gram-positive and Gram-negative bacteria of methanol extracts prepared from eight Mexican medicinal plants, noted for their antiseptic properties, was conducted. The significant activity exhibited for extracts of Ratibida latipalearis, Teloxys graveolens, Dodonaea viscosa, Hyptis albida, H. pectinata, H. Suaveolens and H. verticillata tends to support their traditional use as anti-infective agents. Only the extract of Hintonia latiflora was inactive. The antimicrobial activities of 44 pure natural compounds and two derivatives were determined. Of these, only 23 compounds were effective in inhibiting the growth of the tested organisms (MIC less than or equal to 100 micrograms/ml).

Anti-Bacterial Agents↗
PubMed1992

Stevisalioside A, a novel bitter-tasting ent-atisene glycoside from the roots of Stevia salicifolia.

A new acetylated ent-atisene glycoside, stevisalioside A [1], has been isolated as a bitter-tasting principle from Stevia salicifolia roots. The structure was established by the interpretation of spectral data, with the nmr assignments of this compound being based on 1H-1H COSY, 1H-13C HETCOR, and selective INEPT experiments. A rearrangement product 4 of the aglycone moiety obtained by alkaline hydrolysis supported the structure of 1. This is the first report of the occurrence of an atisane-type diterpene from the genus Stevia.

Carbohydrate Sequence↗
PubMed1991

Effect of inserted oxysterols on phospholipid packing in normal and sickle red blood cell membranes.

Fourier transform infrared (FTIR) spectroscopy was used to examine the effect of oxysterol insertion into normal and sickle RBC membranes and the total lipid extracts of the membranes. Examination of the FTIR C-H stretch and fingerprint regions reveal that the insertion of 7 alpha- and 7 beta-hydroxycholesterol has the greatest effect on the fluidity of RBC membranes and lipid extracts. The results confirm the observation that sterol molecules are oriented in the membrane so that the 7 position is located in the phospholipid head group region at the lipid/water interface. The substitution of a keto for a hydroxy group at the number seven position decreases the effect of the sterol on membrane packing.

Anemia, Sickle Cell↗
PubMed1991

Pinocembrine: a bioactive flavanone from Teloxys graveolens.

Bioactivity directed fractionation of the acetone extract of Teloxys graveolens (Willd.) Weber (Chenopodiaceae), using the brine shrimp lethality test, led to the isolation of 5,7-dihydroxyflavanone (pinocembrine) (LC50 = 4.25 micrograms/ml) as the only active compound. Pinocembrine also exhibited fasciolicide, ovicide and larvicide activities on newly excysted Fasciola hepatica, on infective eggs of Ascaridi galli and on stage three larvae of Stomoxys calcitrans, respectively.

Animals↗
PubMed1991

Long-chain phenols from the bark of Amphypterygium adstringens.

The hexane extract of the stem bark of Amphypterygium adstringens at a dose of 100 mg/kg subcutaneously exhibited significant hypocholesterolemic effect on 24-h fasted rats, lowering the cholesterol levels by 31%, an effect similar to 15 mg/kg estrone given by the same route. Column chromatography of the active extract allowed the isolation of two mixtures of long chain phenols (Mixture I and Mixture II). According to GC/MS analysis, Mixture I contained five alkyl phenolic acids and Mixture II three alkyl phenolic aldehydes. Neither of the mixtures exhibited significant hypocholesterolemic activity at doses up to 15 mg/kg subcutaneously.

Animals↗
PubMed1991

Circadian variations in the superoxide production, enzyme release and neutrophil aggregation in patients with rheumatoid arthritis and controls.

Patients with rheumatoid arthritis (RA) experience fluctuations of symptoms throughout the day. These could be due to mechanical changes or modification of the inflammatory mechanisms. In the present paper we studied fluctuations of superoxide production (O2), enzyme release (beta-glucuronidase and lysozyme) and neutrophil aggregation in the peripheral blood of eight healthy volunteers and eight patients with RA. Although enzyme release was greater in patients with RA, no significant difference was found throughout the day, neither in control nor in patients. Similar results were obtained when studying neutrophil aggregation. On the contrary, the superoxide production, determined at 8:00, 14:00, and 20:00 h, was 6.3 +/- 0.5, 4.40 +/- 0.4 and 6.26 +/- 0.3, respectively, in patients with RA and 6.65 +/- 0.7, 4.7 +/- 0.7 and 7.27 +/- 0.4 in the controls. The values obtained at 14:00 h were significantly lower (alpha = 0.01). There were no differences in the curve form between patients and controls.

Arthritis, Rheumatoid↗