Janne Rojas

Latazienone, a new lathyrane-type diterpenoid from Euphorbia latazi Kunth.

A new lathyrane-type diterpene 8α,15β-diacetoxy-7β-benzoyloxy-3β-(2-methylpropanoyloxy)-4αH,9αH, 11αH-lathyra-5E,12E-dien-14-one (latazienone) has been isolated from the latex of Euphorbia latazi Kunth. The structure of the new diterpene was determined by a combination of 1D- and 2D-NMR techniques.

Jatropha curcas leaves analysis, reveals it as mineral source for low sodium diets.

Jatropha curcas is a perennial herb, belonging to the family Euphorbiaceae, found in countries such as India, Mexico and Venezuela. In the present study, proximate composition and mineral content on the leaves of J. curcas was analysed and compared to spinach (Spinacia oleracea L.) using a ICP-AES. The bromatologic test (dry material) results for ashes, proteins, lipids and carbohydrates revealed 23.4%, 28.0%, 3.2% and 45.4% for J. curcas; whereas for S. oleracea values were 28.9%, 20.8%, 0.5% and 49.9%. Furthermore, minerals found in both species ashes were: calcium, potassium, magnesium, iron and phosphorus, resulting that leaves of J. curcas are composed by three times the iron and calcium amount comparing to spinach; while sodium was absent from the former species. In this study Cu and Zn were found only in spinach, while Pb and As were not detected in any of the studied species. These results indicate that J. curcas leaves might be considered as mineral source suitable for animal and human consumption, especially for people who requires a low sodium diet.

Comparative Study of the Chemical Composition of the Essential Oil of Vismia baccifera var. dealbata (Guttiferae) Collected in two Different Locations in Merida-Venezuala

Abstract The essential oil from leaves of Vismia baccifera var. dealbata collected from Chiguará (1250 m) and La Hechicera (1800 m) were analyzed by GC and GC-MS. Several differences are clearly observed in both collections. Germacrene-D (15.8 %), α-cadinol (14.5 %), epi-α-cadinol (11.9 %), β-caryophyllene (10.1 %) and δ-cadinene (7.5 %) were the major constituents in the Chiguará sample while β-caryophyllene (45.7 %), valencene (12.3 %), β-elemene (10.7 %), α-humulene (8.9 %) and germacrene-D (6.3 %) were observed as major components in the La Hechicera sample.

Insecticide Activity of Ageratina jahnii and Ageratina pichinchensis (Asteraceae) against Lutzomyia migonei (Diptera: Psychodidae)

Background: Insects are mostly pathogens transmitters, thus the necessity of finding effective bioinsecticides to combat them. In the present investigation, the insecticide activity of Ageratina jahnii and Ageratina pichinchensis (Asteraceae) essential oils, methanol, and aqueous extracts was evaluated against Lutzomyia migonei (Diptera: Psychodidae) females, Leishmania transmitters, a wide distributed parasitosis in Latin America. Materials and Methods: All extracts were prepared by maceration at room temperature, and essential oils were obtained by hydrodistillation process. Females of L. migonei were used in the bioassays using the adulticide test in pots. Results: Essential oils from both assayed plant species showed 100% of L. migonei mortality at 48 h of exposure at the concentration of 10 mg/ml. A. jahnii essential oil exhibited the following values, LD50 = 0.39 mg/ml, LD90 = 1.57 mg/ml, LD95 = 2.31 mg/ml, and LD99 = 4.80 mg/ml while for A. pichinchensis essential oil values were LD50 = 0.31 mg/ml, LD90 = 0.99 mg/ml, LD95 = 1.38 mg/ml, and LD99 = 2.55 mg/ml. Conclusion: Higher toxicity was observed with A. pichinchensis essential oil against L. migonei, comparing to A. jahnii oil. Two new plant species are being reported, showing bioactive properties against common tropical disease vectors such as L. migonei, hence, opening possibilities to a more environmental friendly control.

Chemical Composition of the Essential Oil of Croton huberi Steyerm. (Euphorbiaceae) Collected from Tachira-Venezuela

Abstract GC and GC-MS analyses of Croton huberi essential oil showed the presence of fourteen compounds, with the major ones being β-caryophyllene (18.3 %) and germacrene-D (16.1 %) while valencene (8.3 %), caryophyllene oxide (7.3 %), bicycle-germacrene (7.1 %) and τ-muurolol (6.1 %) were observed in lower amounts. The oil was characterized by a high percentage of sesquiterpene hydrocarbons 65 %, whereas oxygenated sesquiterpenes represented 21 % and oxygenated monterpenes and diterpenes only 14 % of the total oil.