Hermógenes de Freitas Leitão Filho

Floração, frutificação e síndromes de dispersão de uma comunidade de floresta de brejo na região de Campinas (SP)

Flowering and fruiting phenophase data of species from a wet forest community were analyzed. The data were collected monthly during the floristic study. Habit, the presence or absence of flowers and/or fruits, and the color and texture of fruits were registered. Fruiting data were grouped in relation to dehiscence type and texture. When dry and dehiscent the fruits were discriminated by the presence of an aril or arillode or by the explosive dehiscence. By these analyses the species were classified according to their dispersal syndromes. In the community flowering and fruiting occurred during all the year with a peak of activity in June. When species are grouped by habit, differences in the peaks of flowering and fruiting during the year were observed. Zoochory was the most frequent syndrome (57% of species), followed by anemochory (27%) and autochory (16%). For arborescents and shrubs, zoochory was the most frequent (75% and 57% of the species, respectively), and anemochory was most common in climbers species (63%).

Floristic Composition and Community Structure in an Area of Cerrado in SE Brazil

Summary Cerrado is the generic name for the savanna-like vegetation which occupies the vast area of the central Brazilian plateau and also extends into peripheral, fragmented islands within the Surrounding moist forests. Cerrado occurs as a complex of intergrading structural sub-types which range from more or less closed forest to open grassland with scattercd shrubs, and it also shows phytogeographical shifts in floristic composition although these are as yet poorly studied. This investigation presents for the first time a full list of the woody species from one of the peripheral islands of cerrado in Sao Paulo state. In addition, a principal components analysis of the data from 60 quadrats of 10 × 25 m indicates that the two community subtypes present in this area, cerrado and campo cerrado , distinguished by Goodland on the basis of physiognomic characteristics, can also be defined in terms of species composition. The possible causes for these floristic and physiognomic sub-communities are examined but no single controlling factor can be established.

Coumarins from Pterocaulon balansae and P. lanatum

Abstract Analysis of the petrol-diethyl ether extracts of Pterocaulon balansae and P. lanatum aerial parts afforded, besides puberulin, scopoletin-[2′

The seed bank of a gallery forest in Southeastern Brazil

The soil seed bank was studied in a gallery forest in Southeastern Brazil. Samples were collected from edge to edge along transects perpendicular to the river during the wet (December, 1990) and dry (August, 1991) seasons. The number of seeds found in the seed bank samples was greater in the dry season than in the wet season indicating that there was important variation in the seed stocks in these two periods. The similarity values between the seed bank and the community composition were low. The high density of weed species might be reflecting forest fragmentation and indicating a degree of perturbation.

Cinnamoylgrandifloric acid from Mikania oblongifolia.

Abstract Isolation of the cinnamate of grandifloric acid from Mikania oblongifolia is reported.

Indole alkaloids from Aspidosperma ramiflorum

Two new bis-indole alkaloids, ramiflorines A and B, were isolated, together with the known compounds, β-yohimbine and 10-methoxygeissoschizol, from the bark and seeds of Aspidosperma ramiflorum. 2D-NMR analysis, together with CD measurements, established the absolute configuration of both stereogenic centres in the ramiflorines.

13C NMR analysis of alkaloids from Peschiera fuchsiaefolia

Abstract Fractionation of an ethereal extract of Peschiera fuchsiaefolia resulted in the isolation of decarbomethoxyvoacamine, demethylvoacamine, voacamidine, perivine, 16-epiaffinine and voacanginehydroxyindolenine, together with the previously reported alkaloids voacamine, voacangine, voachalotine and affinisine. Analysis of the 13 C NMR spectra of the bisindole alkaloids and of 16-epiaffinine is reported.

Eudesmanolides and 15-deoxygoyazensolide from Lychnophora pseudovillosissima

Abstract Extraction of the aerial of Lychnophora pseudovillosissima gave 15-deoxygoyazensolide as the major sesquiterpene lactone constituent and a group of six closely related eudesmanolides.

Polyacetylenes from pterocaulon species

Abstract Analysis of ethereal extracts from the roots of Pterocaulon allopecuroides , P. balansae , P. lanatum and P. rugosum ; gave two pentynes, of which one was new (tridec-1,2-dimethoxy-3,5,7,9,11-pentyne), and six yne-thiophenediyne derivatives.

Polyacetylenes of Brazilian species of Didymopanax (Araliaceae)

Analysis of ethereal extracts of the roots of Didymopanax macrocarpus and D. vinosus gave falcarinol, dehydrofalcarinol, falcarinone, dehydrofalcarinone and octa-9(Z); 17-diene-12,14-diyne-1,16-diol. The presence of these dehydro compounds in the Araliaceae is very unusual and may constitute an index for chemotaxonomic characterization of the genus.