Mosquito Larvicidal Activity of the Essential Oil of Zingiber collinsii against Aedes albopictus and Culex quinquefasciatus.

The chemical composition and larvicidal activity of essential oils from the leaves and rhizomes of Zingiber collinsii Mood & Theilade (Zingiberaceae) were reported. The main compounds in the leaf oil were α-pinene (25.6%), ß-caryophyllene (16.8%), ß-pinene (16.1%) and bicyclogermacrene (6.9%) while the rhizome oil consist mainly of camphene (22.5%), ß-pinene (16.3%), α-pinene (9.0%) and humulene oxide II (9.0%). The rhizome oil demonstrated larvicidal effects towards fourth instant larvae of mosquito vectors. The highest mortality (100%) was observed at 24 h exposure against Aedes albopictus (concentration 100 µg/mL) and 48 h (concentration of 50 and 100 µg/mL), while the highest mortality (100%) was observed for Culex quinquefasciatus at 24 h and 48 h at concentration of 100 µg/mL. The 24 h mosquito larvicidal activity of the rhizome oil against Ae. albopictus were LC50 = 25.51 µg/mL; LC90 = 40.22 µg/mL and towards Cx. quinquefasciatus with LC50 = 50.11 µg/mL and LC90 = 71.53 µg/mL). However, the 48 h larvicidal activity were LC50 = 20.03 µg/mL and LC90 = 24.51 µg/mL (Ae. albopictus), as well as LC50 = 36.18 µg/mL and LC90 = 55.11 µg/mL (Cx. quinquefasciatus). On the other hand, no appreciable mortality and larvicidal activity was observed for the leaf oil. The larvicidal activity of the essential oils of Z. collinsii was being reported for the first time.

Chemical composition and larvicidal activity of essential oils from Zingiber montanum (J. Koenig) Link ex. A. Dietr. against three mosquito vectors / Composición química y actividad larvicida de aceites esenciales de Zingiber montanum (J. Koenig) Link ex. A. Dietr. contra tres vectores de mosquitos

The chemical composition and larvicidal activity of essential oils derived from the leaves and rhizomes of Zingiber montanum (J. Koenig) Link ex. A. Dietr. were reported. The main compounds in the leaf oil were ß-pinene (13.8%), ß-phellandrene (11.3%) and α-pinene (7.3%) while the rhizome oil was dominated by sabinene (41.1%), terpinen-4-ol (22.7%) and (E)-nerolidol (14.3%). The minimum lethal concentration (larvicidal activity) LC50of the rhizome oil at 24 h against Aedes albopictus was 35.17 µg/mL, while LC50 values of 32.20 µg/mL and 31.12 µg/mL were obtained against Aedes aegypti and Culex quinquefasciatus respectively. At 48 h the oil displayed larvicidal action with LC50 values of 23.18 µg/mL, 25.58 µg/mL and 18.99 µg/mL respectively towards Ae. albopictus, Ae. Aegyptiand Cx. quinquefasciatus. The leaf oil did not exhibit significant mortality and larvicidal action. The results indicate the potential of rhizome essential oil of Z. montanumas a source of larvicidal agent.

En el presente trabajo se reportan la composición química y actividad larvicida de los aceites esenciales obtenidos de hojas y rizomas de Zingiber montanum (J. Koenig) Link ex. A. Dietr. Los principales compuestos en el aceite de hojas fueron ß-pineno (13.8%), ß-felandrene (11.3%) y α-pineno (7.3%); mientras que los más abundantes en el aceite de rizomas fueron sabineno (41.1%), terpinen-4-ol (22.7%) y (E)-nerolidol (14.3%). La concentración letal mínima (actividad larvicida) LC50 del aceite de riomas ante Aedes albopictus fue 35.17 µg/mL, mientras que los valores de LC50 de 32.20 µg/mL y 31.12 µg/mL fueron obtenidos ante Aedes aegyptiy Culex quinquefasciatus respectivamente. A las 48 horas, el aceite mostró acción larvicida con valores de LC50 de 23.18 µg/mL, 25.58 µg/mL y 18.99 µg/mL respectivamente, ante Ae. albopictus, Ae. Aegyptiand Cx. quinquefasciatus. El aceite de hojas no mostró mortalidad ni acción larvicida significativa. Los resultados indican el potencial del aceite esencial de rizomas de Z. montanum como una fuente de agentes larvicidas.

Cyclic Steroid Glycosides from the Starfish Echinaster luzonicus: Structures and Immunomodulatory Activities.

Five new steroid glycosides, luzonicosides B-E (2-5), belonging to a rare structure group of marine glycosides, containing carbohydrate moieties incorporated into a macrocycle, and a related open carbohydrate chain steroid glycoside, luzonicoside F (6), were isolated from the starfish Echinaster luzonicus along with the previously known cyclic steroid glycoside luzonicoside A (1). The structures of compounds 2-6 were established by extensive NMR and ESIMS techniques as well as chemical transformations. Luzonicoside A (1) at concentrations of 0.01-0.1 µM was shown to be potent in lysosomal activity stimulation, intracellular ROS level elevation, and NO synthesis up-regulation in RAW 264.7 murine macrophages. Luzonicoside D (4) was less active in these biotests.

Two new asterosaponins, archasterosides A and B, from the Vietnamese starfish Archaster typicus and their anticancer properties.

New asterosaponins archasterosides A (1), B (2), and the known regularoside A (3) were isolated from the Vietnamese starfish Archaster typicus and structurally elucidated by extensive NMR techniques and chemical transformations. Compounds 1-3 showed moderate cytotoxic activities against HeLa and mouse JB6 P(+) Cl41 cell lines. The most active, 2, induced basal AP-1- and p53-, but not NF-kappaB-transcriptional activations in JB6 Cl41 cells.