Plants containing bioactive substances have increasingly become the object of research studies, particularly those plants with therapeutic value. Many species of the genus Alpinia provide a variety of medicinal properties, such as, Alpinia zerumbet (Pers.) Burtt et Smith and A. purpurata (Vieill) K. Schum, which have a significant presence in Brazil. These species have been commercialized in the food and cosmetic industries. However, their greatest importance arises from the medicinal properties of their essential oils containing flavonoids, terpenoids and kavalactones which have been used in folk medicine to treat, for example, arterial hypertension and inflammatory processes. In addition, such species are also used in multidisciplinary studies, including phytochemistry, ethnobotany and biology, indicating the key pharmacological role of this genus in everyday life. Therefore, this work aims to present a bibliographic review of the genus Alpinia and its significance in therapeutic applications

Rosmarinus officinalis is known for the production of volatile compounds used in medicinal and food preparations. Leaves of R. officinalis are densely covered with capitate and peltate glandular trichomes where biosynthesis of volatiles mainly occurs. This study aims to conduct a morphological assessment to identify anatomical characteristics of both leaves and trichomes, as well as a chemical analysis of leaf volatile compounds, using histochemistry and stem distillation extraction. Specifically, anatomical and chemical constituents of the secretory structures of R. officinalis leaves were investigated using light and scanning electron microscopy, in addition to gas chromatography. One peltate and three types of capitate glandular trichomes were observed on the leaves of R. officinalis. Histochemical tests showed positive reactions to lipophilic compounds for both capitate and peltate trichomes, with only a slight detection of terpenoids with carbonyl group in peltate glands. Gas chromatography revealed camphor (23.2%) as the main volatile compound, mostly accumulating in peltate glandular trichomes. This phytochemical study of volatile compounds, together with anatomical and histochemical analyses of R. officinalis leaves, demonstrated the importance of leaves as a center of volatile production in peltate and capitate trichomes, as well as the nature of volatile composition, which is involved in species survival.

Firesh leaves of Alpinia zerumbet and A. purpurata (Zingiberaceae) were collected in Rio de Janeiro city and subjected to hydrodistillation; their chemical composition was analyzed by GC/MS. These species are used as ornamental plants and in folk medicine. Variations in the leaf oils content and composition of A. zerumbet were found between April and August 2005. In April, the main constituents identiified in leaf oil of A. zerumbet were terpinen-7-al (40.5%) and sabinene hydrate (15.4%); in August, the major components identiified were terpinen-4-ol (29.4%) and 1,8-cineole (23.1%). Leaf oil of A. purpurata was rich in P-pinene (34.7%) and α-pinene (11.8%).