Antonio Morales

Hypochaerin: a new sesquiterpene lactone from Hypochaeris setosus

Abstract Hypochaeris setosus contains desacetoxymatricarin, achillin, 1-hydroxy-6β,7α,11β-H-eudesm-4-en-6,12 olide, jacquinelin and hypochaerin, a new guaianolide, established as 3-oxo-4β,5α,6β,7α,11β-H-guai-1(2)-en-6,12 olide.

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.

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.

Andesgenin, a new steroid sapogenin from Solanum hypomalacophyllum☆

Abstract The structure of andesgenin, a new steroid sapogenin isolated from Solanum hypomalacophyllum, was determined on the basis of spectral data and synt

Chemical Composition of Hypericum laricifolium Juss. Essential Oil Collected from merida-Venezuela

Hypericum is one of nine genera forming the family Hypericaceae distributed mainly in temperate regions and tropical mountains. Fresh aerial parts of H. laricifolium Juss. collected by the Pinango road, Merida state, at 3900 m above sea level, yielded 1.2 mL (0.24% w/v) of essential oil by hydrodistillation. GC and CG/MS analysis showed the presence of 21 components being α-pinene (20.2%), verticiol (13.4%), 3-methyl-nonane (12.3%), 2-methyl-octane (9.6%) and nonane (7.6%) in major proportions. To the best of our knowledge, this is the first report on the chemical composition of the Hypericum laricifolium essential oil.

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.

Ramalina africana in Venezuela

Ramalina africana (B. Stein) Dodge, previously known only from eastern Africa, is reported new to the New World from Peninsula de Paraguand, Edo. Falc6n, and Chiguard, Edo. MWrida, Venezuela.