Author: LUIS MANUEL PEÑA RODRIGUEZ

Antifungal activity of sakurasosaponin from the root extract of Jacquinia flammea

LUIS MANUEL PEÑA RODRIGUEZ (2011)

The methanolic crude extract from the roots of Jacquinia flammea showed moderate antifungal activity against dermatophytes and very strong antifungal activity against Colletotrichum gloeosporioides. The bioassay-guided purification of the extract, using a combination of vacuum-liquid chromatography and high performance liquid chromatography, allowed the identification of sakurasosaponin (1) as the main metabolite responsible for the antifungal activity.

Article

CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CIENCIAS AGRARIAS OTRAS ESPECIALIDADES AGRARIAS OTRAS

Bioactive Metabolites from Cnidoscolus souzae and Acmella pilosa

LUIS MANUEL PEÑA RODRIGUEZ (2014)

The bioassay-guided purification of the ethanol extracts of Acmella pilosa and Cnidoscolus souzae, two plants of the native flora of the Yucatan Peninsula used

in traditional medicine to treat inflammation and pain, resulted in the identification of rosmarinic acid (1) and caffeic acid (2) as the bioactive metabolites from

A. pilosa, and of 7-deoxynimbidiol (4) as the major bioactive metabolite from C. souzae. Metabolites 1, 2, and 4 proved to be responsible for the antioxidant

activity originally detected in the corresponding organic crude extracts; 7-deoxynimbidiol (4) showed good analgesic and anti-inflammatory activities,

inhibiting the pain induced by PGE2 and reducing the edema induced by carrageenan, respectively.

Article

CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA

A case of mistaken identity: Lupeol-3-(30 R)-hydroxy-stearate can be mistakenly identified as lupeol acetate when only analyzed by GC–MS

LUIS MANUEL PEÑA RODRIGUEZ (2013)

Lupeol-3-(30

R-hydroxy)-stearate, also known as procrim b (1), was isolated from the methanolic stem

extract of Pentalinon andrieuxii and initially mistaken as lupeol acetate when analyzed by GC–MS only.

The correct structure of 1 was established following a careful analysis of its NMR and MS data

Article

CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA

In vitro and in vivo trypanocidal activity of native plants from the Yucatan Peninsula

LUIS MANUEL PEÑA RODRIGUEZ (2012)

Ethanol extracts of Senna villosa, Serjania

yucatanensis, Byrsonima bucidaefolia, and Bourreria pulchra were evaluated for their in vitro activity against

epimastigotes and trypomastigotes ofTrypanosoma cruzi.

Results showed that the leaf extracts ofS. yucatanensisand

B. pulchra were the most active against epimastigotes

(IC100=100μg/mL) and trypomastigotes ofT. cruzi(95%

or more reduction in the number of parasites at 100 and

50μg/mL). However, only the leaf extract ofS. yucatanensisshowed significant trypanocidal activity when tested

in vivo, reducing 75% of the parasitemia in infected mice at

100 mg/kg. This same extract inhibited the egress of

trypomastigotes from infected cells and proved not to be

cytotoxic (IC50=318.8±2.3μg/mL).

Article

CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA

Physiological effects of the hydrophilic phytotoxins produced by Mycosphaerella fijiensis, the causal agent of black sigatoka in banana plants

LUIS MANUEL PEÑA RODRIGUEZ (2011)

Although Mycosphaerella fijiensis, the causal agent of black sigatoka disease of banana, has been known to produce numerous lipophilic host-selective (HSTs) and nonhost selective phytotoxins (non-HSTs), only recently we have reported that the pathogen also produces hydrophilic phytotoxins. Here we examined the effect of light on the toxicity of the hydrophilic phytotoxins and estimated the electrolyte leakage and H2O2 and superoxide generation in detached banana leaves to study their mode of action at the cellular level. Nonhost plant species were also tested to determine whether the toxins are HSTs or non-HSTs. Our results suggest that the hydrophilic phytotoxins are non-HSTs, that their phytotoxicity is not light dependent, and that they may act at the plasma membrane by altering permeability through oxidative damage, by inducing ROS production as part of their mechanism of action.

Article

CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CIENCIAS AGRARIAS OTRAS ESPECIALIDADES AGRARIAS OTRAS

Bioactive metabolites from the Andean flora. Antituberculosis activity of natural and semisynthetic azorellane and mulinane diterpenoids

LUIS MANUEL PEÑA RODRIGUEZ (2010)

Natural products are recognized as an

important source of new and better pharmaceuticals

for the treatment of diseases such as tuberculosis. The

azorellane and mulinane diterpenoids represent an

interesting group of bioactive metabolites produced

by Andean plants belonging to the Azorella, Mulinum,

Laretia and Bolax genus. Testing of natural and

semisynthetic azorellanes and mulinanes against two Mycobacterium tuberculosis strains showed that

while most changes in the structure of the natural

metabolites result in the loss of antituberculosis

activity, methylation of the C-20 carboxyl group

improves the biological activity of the corresponding

derivatives.

Article

CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA

Optimization of Culturing Conditions of a Strain of Phytophthora capsici Pathogenic to Habanero Pepper (Capsicum chinense)

LUIS MANUEL PEÑA RODRIGUEZ (2013)

Phytophthora capsici is an oomycete known as the causal agent of wilting

disease in Capsicum spp., which causes rotting of roots, crowns, stems,

leaves and fruits. To date, little is known about the production of phytotoxic

metabolites by P. capsici or their role in the infection process. As part

of a project directed towards the isolation and identification of phytotoxins

produced by a strain of P. capsici pathogenic to habanero pepper (Capsicum

chinense), we have evaluated the effect of factors such as aeration,

light and culture medium on the production of mycelium and phytotoxic

metabolites by P. capsici. The results showed that culturing P. capsici in

potato dextrose broth (PDB) containing habanero pepper leaf infusion, in

the dark and under still conditions, results in a high production of mycelium

and a high phytotoxicity of the culture filtrate, in the shortest period

of time.

Article

CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA

Antiprotozoal activity of Betulinic acid derivatives

LUIS MANUEL PEÑA RODRIGUEZ (2010)

Betulinic acid (1), isolated from the crude extract of the leaves of Pentalinon andrieuxii (Apocynaceae),

together with betulinic acid acetate (2), betulonic acid (3), betulinic acid methyl ester (4), and betulin

(5) were evaluated for their antiprotozoal activity. The results showed that modifying the C-3 position

increases leishmanicidal activity while modification of the C-3 and C-28 positions decreases

trypanocidal activity.

Article

CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA

Cuticular Wax Composition of Coconut Palms and their Susceptibility to Lethal Yellowing Disease

LUIS MANUEL PEÑA RODRIGUEZ (2012)

A number of metabolites isolated and identified from cuticular waxes have been used as chemotaxonomical markers and to

explain the role of the wax layer in plant-insect and plant-pathogen interactions. Chromatographic analysis of the cuticular wax from pinnae

of five coconut palm ecotypes showed that the three main components

(I, II, III) in the wax can be used as chemotaxonomical markers for

classification. The positive correlation found between the content of

metabolites I, II, and IIIin the wax from the various ecotypes and their

resistance or susceptibility to the lethal yellowing disease of coconut

palms, did not coincide with the results obtained in an antifeedant assay. The results suggest that while the individual components do not

play a significant role in the palm-insect interaction, the full composition of the cuticular wax does.

Article

CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA

Antituberculosis activity of alkylated mulinane diterpenoids

LUIS MANUEL PEÑA RODRIGUEZ (2010)

Natural azorellane and mulinane diterpenoids show antituberculosis activity, which is

increased by methylation of their free carboxyl group. We have systematically investigated

the effect of alkylation in this class of diterpenoids and found that the profile of bioactivity is

relatively unaffected by the introduction of short alkyl groups, both linear and branched. In this

investigation, three semisynthetic diterpenoids, 13 hydroxy-mulin-11-en-20-oic acid n-propyl

ester (3) and the n-propyl (19) and n-butyl (20) esters of isomulinic acid, showed the

strongest antituberculosis activity (MIC =6.25 μg/mL) against a drug-resistant strain of

Mycobacterium tuberculosis.

Article

CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA