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A R Araújo

Publications and source records attributed to A R Araújo.

11 recordsLinked to original sources
PubMed2000

nor-Lignans from the leaves of Styrax ferrugineus (Styracaceae) with antibacterial and antifungal activity.

Chemical examination of the leaves of Styrax ferrugineus yielded 5-[3''-(beta-D-glucopyranosyloxy)propyl]-7-methoxy-2-(3',4'-dimethoxyphenyl) benzofuran, along with the known nor-lignans 5-(3''-hydroxypropyl)-7-methoxy-2-(3',4'-methylenedioxyphenyl) benzofuran, 5-(3''-hydroxypropyl)-7-methoxy-2-(3',4'-dimethoxyphenyl)benzofuran, 5-[3''-(beta-D-glucopyranosyloxy)propyl]-7-methoxy-2-(3',4'-methylenedioxyphenyl)benzofuran and the lignan, dihydrodehydrodiconiferyl alcohol. All arylpropanoids isolated showed antibacterial and antifungal activities. The structures of the isolates were established by spectroscopic analysis.

Anti-Bacterial Agents↗
PubMed2000

Biosynthesis of friedelane and quinonemethide triterpenoids is compartmentalized in Maytenus aquifolium and Salacia campestris.

Maytenus aquifolium (Celastraceae) and Salacia campestris (Hippocrateaceae) species accumulate friedelane and quinonemethide triterpenoids in their leaves and root bark, respectively. Enzymatic extracts obtained from leaves displayed cyclase activity with conversion of the substrate oxidosqualene to the triterpenes, 3beta-friedelanol and friedelin. In addition, administration of (+/-)5-(3)H mevalonolactone in leaves of M. aquifolium seedlings produced radio labelled friedelin in the leaves, twigs and stems, while the root bark accumulated labelled maytenin and pristimerin. These experiments indicated that the triterpenes once biosynthesized in the leaves are translocated to the root bark and further transformed to the antitumoral quinonemethide triterpenoids.

Chromatography, High Pressure Liquid↗
PubMed1999

Search for antifungal and anticancer compounds from native plant species of Cerrado and Atlantic Forest.

Bioactivity-guided fractionation of several bioactive extracts obtained from Cerrado and Atlantic Forest plant species led to the isolation of potent DNA-damaging piperidine 1-5 and guanidine alkaloids 6-9 from Cassia leptophylla and Pterogyne nitens respectively, two common Leguminosae from Atlantic Forest. By means of biotechnological approach on Maytenus aquifolium, a species from Cerrado, moderate DNA-damaging sesquiterpene pyridine alkaloid 10-11 was isolated. Bioassay-guided fractionation on Casearia sylvestris, a medicinal plant species found in Cerrado and Atlantic Forest, led to the isolation of clerodane diterpenes 12-13 which showed effect on DNA. In addition, we have reported several interesting potent antifungal iridoids: 1 beta-hydroxy-dihydrocornin (14), 1 alpha-hydroxy-dihydrocornin (15), alpha-gardiol (16), beta-gardiol (17), plumericin (18), isoplumericin (19), 11-O-trans-caffeoylteucrein (20); ester derivative: 2-methyl-4-hydroxy-butyl-caffeoate (21), amide N-[7-(3',4'-methylenedioxyphenyl)-2Z, 4Z-heptadienoyl] pyrrolidine (22) and triterpene viburgenin (23).

Antifungal Agents↗
PubMed1998

The blood bank and hepatitis G.

HGV can be transmitted by transfusion and is capable of inducing persistent infection. Thus far it appears to have no discernable disease association. We determined the infection rate of HGV in volunteer blood donors and patient with risk factors for viral transmission through the blood. The association between HGV infection and exposure to labile blood products could be a problem for blood banks in the future.

Blood Banks↗
PubMed1998

Triterpenes and saponins from Rudgea viburnioides.

A novel triterpene, viburgenin (1), has been isolated from an extract of the ripe fruit rinds of Rudgea viburnioides, together with the known saponins, arjunglucoside I and trachelosperosides B-1 and E-1, and the triterpenes trachelosperogenin B (2) and arjungenin. Compound 2 was previously obtained as a product from enzymatic hydrolysis, and it is reported for the first time as a natural product. The structure of compound 1 was determined as 2alpha,3beta, 19alpha,23,24-pentahydroxyurs-12-ene by extensive use of 1D and 2D NMR spectroscopic methods. Compound 1 exhibited moderate antifungal activity against Cladosporium cladosporioides.

Antifungal Agents↗
PubMedDate not supplied

[Parvovirus B19 infection].

In 1975, during blood screening for hepatitis B, Cossart et al. discovered the human parvovirus B19 (B19). It is a small, single strand DNA virus of the Parvoviridae family. This virus is widespread with 40-80% of adults showing evidence of infection. It is found in the respiratory secretions of viraemic patients and direct contact has been suggested as the most likely mode of transmission. Parenteral transmission is common during treatment with clotting-factor concentrates, but rarely occurs during transfusion with single donor products. Although B19 usually causes a self-limited illness, complications of infection can be severe and at times life threatening. In pregnant women, infection can lead to spontaneous abortions and hydrops fetalis and, in patients with haemolytic anaemias or in immunocompromised individuals, can induce aplastic crisis and chronic anaemias. The diagnosis can be made by indirect (testing for B19 antibodies) or direct methods (detecting B19 viremia). There are no vaccines or specific therapy currently available. Contact isolation is recommended for hospitalized patients.

Erythema Infectiosum↗