A new species of Typhonium (Araceae) from Vietnam.

Typhoniumobtusum is described as a new species endemic to Vietnam. It is unique in the genus in having an oblong-elliptic spathe limb with an obtuse apex and yellowish-greenish filiform staminodes with a down-curved acumen. The ecology, distribution and assessment of the conservation status of the new taxon, as well as a key to all known Typhonium species in Vietnam, are provided.

Chemical composition and antibacterial activities of essential oils from rhizomes and aerial parts of Homalomena cochinchinensis (Araceae).

In this study, the phytochemical composition and antibacterial activity of the essential oils isolated from the rhizomes and the aerial parts of Homalomena cochinchinensis were analysed for the first time using gas chromatography-mass spectrometry (GC-MS) and disk diffusion method. Consequently, 36 constituents were reported from H. cochinchinensis rhizomes, including linalool (57.4%), terpinen-4-ol (10.6%), α-sabinene (4.2%) as major compounds. Meanwhile, 30 compounds have been identified in the essential oil of the aerial parts of H. cochinchinensis, which myrcene (41.1%), sabinene (8.2%), D-limonene (9.1%) were the main constituents. Furthermore, the antibacterial activity of the essential oil from the rhizomes of the studied species could inhibit the growth of all six tested bacterial strains, including Bacillus cereus, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis and Salmonella typhimurium whereas the essential oil from the aerial parts was proved to be able to inhibit the growth of five bacterial strains except S. enteritidis.

An overview of the chemical composition and biological activities of essential oils from Alpinia genus (Zingiberaceae).

Alpinia Roxb. is the largest genus of the Zingiberaceae family. A large number of Alpinia species has been used as food and traditional medicines. Alpinia essential oils have been studied for their chemical profiles, in which 1,8-cineole, ß-pinene, α-pinene, ß-myrcene, camphor, γ-terpinene, p-cymene, geraniol, α-fenchyl acetate, ocimene, methyl cinnamate, and ß-caryophyllene have been found to be the major compounds. Essential oils isolated from Alpinia plants have been reported to have antimicrobial, cytotoxic, antioxidant, anti-inflammatory, anti-asthmatic, tyrosinase inhibitory, insecticidal, and larvicidal activities and slimming aromatherapy. In this review, the comprehensive information regarding the volatile components of various Alpinia plants, the bioactivities of Alpinia essential oils and their major compounds are provided.