Molluscicidal activity of 2-hydroxy-3-alkyl-1,4-naphthoquinones and derivatives.

In the search for new molluscicidal agents we tested the activity of lapachol and other 2-hydroxy-3-alkylnaphthoquinones possessing nitrogenated alkyl chains, against the snail Biomphalaria glabrata. Lapachol, isolapachol and nor-lapachol showed strong molluscicidal activity against the adult snail (LD(90)<10 ppm) and significant toxicity against snail egg masses (LD(90)<0.2 ppm). As lapachol is easily extracted, and the derivatives can be synthesised without any difficulty, large-scale synthesis and field tests can be conducted, with a view to large-scale molluscicidal programs.

Trypanocidal activity of synthetic heterocyclic derivatives of active quinones from Tabebuia sp.

Continuing a program on the chemistry and biological activity of compounds from the Brazilian flora, the lytic activity against bloodstream forms of T. cruzi of nine new heterocyclic naphthooxazole and naphthoimidazole derivatives obtained from the reaction of naphtoquinones isolated from Tabebuia sp. (Tecoma) with amino-containing reagents has been studied. Also for the first time the biological activity of allyl derivatives of lawsone, a natural quinone from Lausonia alba inactive against T. cruzi, is reported. The introduction of an allyl group in lawsone gives rise to O-allyl-lawsone and C-allyl-lawsone that showed activity against the parasite, with ID50 values of 420.7 +/- 71.1 and 330.7 +/- 62.4 mumol/l, respectively. The trypanocidal activity of the naphtho heterocyclics synthesized from the original quinones showed no concordant behavior in relation to the parent compound. Six of nine of the synthesized compounds presented lower ID50 values than crystal violet, indicating a general trend of activity among naphthalenic heterocyclics of the oxazole/imidazole type. However, their chemical structures do not endow them with the capacity of free radical generation by biological reduction as the quinoidal moiety, nor do they have chemical reducible appendage like the nitro group of nifurtimox and benznidazole, responsible for such behaviour. As a hypothesis, the pattern of their biological actions should be focused in other aspects of their chemical structures. Because of their polycyclic planar topology, these derivatives are potential candidates for experimental tests as DNA intercalating agents.

NBS bromination reactions of dihydronaphthofuran quinones: a new fragmentation type reaction in the chemistry of quinones.

The reactions of isomeric dihydronaphthofuran-quinones of the alpha and beta type, 1 and 5, respectively, with NBS, under visible light, gave unexpected products. These reactions represent a new route to structural types represented by naphtho[1,2-b]furan and naphtho[2,3-b]furan quinones and lead to a new assessment of biosynthetic theory concerning the furan ring in plants.

[Conservative treatment of breast cancer. Experience of the Consultation Group of Breast Oncology of the Santa Maria Hospital]. / O tratamento conservador do cancro da mama. Experiência da Consulta de Grupo da Mama Oncológica do H.S.M.

Since 1983, the Oncology Breast Group Consultation of the H.S.M. has been practicing a Conservative Treatment in women with early stage breast carcinoma. So far, 61 women stages I and II, were submitted to Conservative Treatment, which consists of limited Surgery, followed by Radiotherapy. 20 patients had performed associated systemic therapy, because they presented axillary positive lymphnodes. 10 of there were pre-menopause and they had performed Chemotherapy and the other 10 were post-menopause receiving Hormonotherapy. Of the 61 patients that constitute this series, two had local failure; two had hepatic metastasis and another two had secondary neoplasms. The remaining 55 are in good condition. In 54 patients with follow-up superior to 3 month oesthetical evaluation revealed excellent results in 26 cases, good in 24, medium (fair) in 6, middling in one and bad in 4. Follow-up varies between 3 months and 6 years, and it is not possible to present results of 5 years survival because almost all patients have a follow-up of less than 2 years.

[Selection by means of KB cells of substances and extracts potentially active in cancer chemotherapy]. / Seleção por meio de células KB de substâncias e extratos potencialmente ativos em quimioterapia do câncer.

Several synthetic, semi-synthetic and natural compounds as well as plant extracts were screened for their growth inhibition activity on KB cells. The most active ones were naphthoquinones and derivatives of pyrido [4,3-b]carbazole alkaloids, with inhibition dose (ID50) less than 4 micrograms/ml. Of the crude extracts of several plants screened, Vellozia caput-ardeae showed to be the most active.