Martha Lydia Macías-Rubalcava

• National Autonomous University of Mexico

Aims This study aimed to assess the mode of action of fusaric and 9,10-dehydrofusaric acids on cell respiration by measuring the hyphal oxygen consumption rate, and the effects on cell membrane integrity by determining the electrical conductivity of the mycelium. Methods and results Bioactivity-directed fractionation of the active culture medium a...

From the aerial parts of Salvia carranzae Zamudio and Bedolla, three new icetexane-type diterpenoids were isolated. Their structures were established through spectroscopic methods and named the following: salvicarranzanolide (1), 19-deoxo-salvicarranzanolide (2) and 19-deoxo-20-deoxy-salvicarranzanolide (3). In addition, the known icetexane-type di...

Terpenes and terpenoids are a group of isoprene-derived molecules that constitute the largest group of natural products and secondary metabolites produced by living things, with more than 25,000 compounds reported. These compounds are synthesized by enzymes called terpene synthases, which include several families of cyclases and enzymes. These are...

The Embleya genus is a new member of the Streptomycetaceae family formed by only two species isolated from soil (Embleya scabrispora and Embleya hyalina). Strain NF3 is an endophytic actinobacterium obtained from the medicinal tree Amphipterygium adstringens. By 16S rRNA gene analysis, NF3 strain was identified as Embleya sp., closely related to E....

Weeds represent one of the most challenging biotic factors for the agricultural sector, responsible for causing significant losses in important agricultural crops. Traditional herbicides have managed to keep weeds at bay, but overuse has resulted in negative environmental and toxicological impacts, including the increase of herbicide-resistant spec...

An extract from a PDB static culture of Malbranchea dendritica exhibited α-glucosidase and PTP-1B inhibitory activities. Fractionation of the active extract led to the isolation of gymnoascolide A (1), a γ-butenolide, and xanthones sydowinin A (2), sydowinin B (3), and AGI-B4 (4), as well as orcinol (5). Compound 1 exhibited important inhibitory ac...

A decoction prepared from the aerial parts of Melampodium divaricatum showed antinociceptive and antihyperalgesic responses when tested in the formalin model in mice. From the CH2Cl2 fraction of the decoction, two non‐previously reported secondary metabolites, 3‐O‐β‐D‐glucopyranosyl‐16α‐hydroxy‐ent‐kaurane (1) and melampodiamide (2) [(2′R*,4′Z)‐2′‐...

Bioassay-guided fractionation of the organic extracts of the endophyte Daldinia eschscholtzii strain GsE13 led to the isolation of several phytotoxic compounds, including two chromenone and two chromanone derivatives: 5-hydroxy-8-methoxy-2-methyl-4H-chromen-4-one, 1; 5-hydroxy-2-methyl-4H-chromen-4-one, 2; 5-methoxy-2-methyl-chroman-4-one, 3; and 5...

RESUMEN Silva-Valenzuela, M., R. I. Rojas-Martínez, R. H. Manzanilla-López, M. L. Macías-Ruvalcaba, S. Aranda-Ocampo, y E. Zavaleta-Mejía. 2020. Hongos endófitos: Una alternativa biológica para el manejo de nematodos fitoparásitos. Nematropica 50:101-117. Las pérdidas en la producción agrícola mundial ocasionadas por los nematodos fitoparásitos se...

Hypoxylon species are distributed worldwide and have been isolated from different habitats. The endophyte Hypoxylon anthochroum strain Gseg1 was isolated from healthy leaves of Gliricidia sepium. A chemical study of the culture medium and mycelium organic extracts of the endophytic fungus H. anthochroum Gseg1 led to the isolation of three known iso...

During a search for new α-glucosidase and protein tyrosine phosphatase 1B inhibitors from fungal sources, eight new secondary metabolites, including two anthranilic acid-derived peptides (1 and 2), four glycosylated anthraquinones (3-6), 4-isoprenylravenelin (7), and a dimer of 5,8-dihydroxy-4-methoxy-α-tetralone (8), along with four known compound...

Bioinformatic mining of the Streptomyces thermocarboxydus K155 genome predicted the presence of four synthases for the production of geosmin, hopene, albaflavenone, and a type B-type A diterpenoid system like that described for labdane-related diterpenoids (LRD). The lrd cluster was comprised by an operon of four genes (lrdABDC). This cluster seeme...

Previously non-isolated compounds (scopoletin and β-D-Glucopyranoside, (1R)-O-isopropyl 6-O-(2,3,4-tri-O-acetyl-β-D-xylopyranosyl)-2,3,4-triacetate) were isolated from an organic extract of the Cnidoscolus chayamansa stem. Also, lupeol acetate (main compound, 49.7 mg/g of dry extract) and scopoletin (0.19 mg/g of dry extract) were quantified by HPL...

Previous report described that CHCl 3 :MeOH extract of C. chayamansa leaves and pure compounds (moretenol, moretenyl acetate, kaempferol-3,7-dimethyl ether, and 5-hydroxy-7-3′,4′-trimethoxyflavanone) showed important topical and systemic anti-inflammatory activity in acute model, as well as in vitro antimycobacterial and antiprotozoal activities. I...

Fungi have consistently been one of the richest sources of natural products, with unprecedented chemical scaffolds and potent biological activities. During the last 20 years, pharmacognosy researchers in Mexico, in collaboration with mycologists, have discovered many novel bioactive fungi natural products and new fungal species. To date, more than...

To assess their potential as biopesticides, the effect on the growth of phytopathogen Fusarium oxysporum of six volatile organic compounds from endophytic fungi was studied in vivo and in vitro; compounds were used both as a mixture and individually. In vivo studies were performed inoculating the pathogen into cherry tomatoes, while the in vitro an...

Aim: To understand the allelopathy among different taxonomic levels of freshwater photoautotrophs, the effect of aqueous extracts of Phragmites australis and Schoenoplectus californicus on monocultures of Microcystis aeruginosa and Scenedesmus acutus was investigated. In addition, the cell extract and filtered medium of each phytoplankton species w...

The nucleophilic addition of bis(trimethylsilyl)ketene acetals to 1H-imidazo[4,5-b]pyridine in the presence of triflic anhydride has been examined. The reaction proceeds in a highly regioselective fashion and affords carboxylic acid 7-substituted 1,7-dihydroimidazo[4,5-b]pyridines exclusively. Subsequent reaction of these acids can be efficiently t...

A forest plantation, product of the reforestation of pine trees, represented a pool of biological resources for the implementation of a solid state fermentation process. The trees were identified as Pinus pseudostrobus Lindl from which lignocellulosic material in the form of pine needles was collected. Soil fungi, responsible for plant litter decom...

Fungal endophytes are important sources of bioactive secondary metabolites. The genus Xylaria Hill (ex Schrank, 1789, Xylariaceae) comprises various endophytic species associated to both vascular and non vascular plants. The secondary metabolites produced by Xylaria species include a variety of volatile and non-volatile compounds. Examples of the f...

We investigated the mechanism of action on the photosynthesis light reactions of three major secondary metabolites produced by the endophytic fungus Xylaria feejeensis strain SM3e-1b, isolated from Sapium macrocarpum; and four novel derivatives of coriloxine, a major compound produced by X. feejeensis. The natural phytotoxins include one epoxycyclo...

A direct method for the synthesis of highly functionalized bicyclic-γ-lactones with three consecutive stereocenters has been developed from the reaction of the easily available 2,3-epoxycyclohexanone and different bis-(trimethylsilyl)ketene acetals in the presence of TiCl4. During reaction, a chlorine atom transfer from TiCl4 occurs as confirmed by...

Bioactivity-directed fractionation of the combined culture medium and mycelium extract of the endophytic fungus Xylaria feejeensis strain SM3e-1b, isolated from Sapium macrocarpum, led to the isolation of three known natural products: (4S,5S,6S)-4-hydroxy-3-methoxy-5-methyl-5,6-epoxycyclohex-2-enone, or coriloxine, 1, 2-hydroxy-5-methoxy-3-methylcy...

Aims: To evaluate the phytotoxic, antifungal and antioomycete activity; and, determine the chemical composition of the volatile organic compounds (VOCs) and semi-volatile metabolites produce by the endophyte Hypoxylon anthochroum strain Blaci isolated from Bursera lancifolia. Methods and results: Based on its macro and micro-morphological featur...

An interesting endophytic fungus was isolated from the leaves of Bursera simaruba, a tree in the semi-deciduous dry tropical forest at El Eden Ecological Reserve. The cultured strain developed the morphology characteristic of the genus Acremonium—tapered phialides and small aseptate conidia clustered in slimy heads. A detailed morphological examina...

Aims: To determine the antifungal, antioomycete and phytotoxic activity; and, chemical composition of the volatile organic compounds (VOCs) produced by endophytic fungus Xylaria sp. PB3f3 isolated from Haematoxylon brasiletto Karst. Methods and results: Bioactivity and chemical composition of the VOCs from Xylaria sp. PB3f3 were established by u...

This study demonstrates volatile organic compounds (VOCs) production as one of the defense mechanisms of the antagonistic endophyte Nodulisporium sp. GS4d2II1a, and the volatile changes in two times of the fungal growth; and, as result of its intra and interspecific interactions with the plant pathogen Pythium aphanidermatum. The antifungal activit...

Species of the genus Hypericum have elicited great interest in pharmacological research, therefore their propagation is necessary. However, only a low germination percentage has been achieved to date. A population of Hypericum philonotis (Cham. & Schlecht.) grows every 2 or 5 years in the Parque Ecológico de la Ciudad de México (PECM). To understan...

Bioactivity-directed fractionation of the organic mycelium extract of the endophytic fungus Acremonium camptosporum W. Gams (Clavicipitaceae), isolated from the leaves of Bursera simaruba (Burseraceae), led to the isolation of six major heterodimeric polyketides, including one not previously characterized acremoxanthone derivative. In addition, the...

Plants express chitinase and chitinase‐like proteins ( CLP s) belonging to the glycosyl hydrolases of the GH 18 and GH 19 families, which exhibit varied functions. CLP s in the GH 18 family have been structurally and functionally characterized; however, there are no structures available for any member of the GH 19 family. In this study, two CLP s o...

Endophytic fungi are capable of producing an array of antibiotic volatile organic compounds (VOCs). A fungus VOC profile may be altered qualitatively and/or quantitatively during inter- and intra-specific interactions. The purpose of this study is to determine the changes in VOCs production during antagonic interaction between the endophyte Nodulis...

om the fermentation mycelium of the endophytic fungus Edenia gomezpompae several phytotoxic compounds including two new members of the naphthoquinone spiroketals family, namely palmarumycin EG1, 1, and preussomerin EG4, 4. In addition, preussomerins EG1‒EG3, 7‒9, and palmarumycins CP19, 2, CP17, 3, and CP2, 6, as well as the ergosta-4,6,8(14),22-te...

Endophytic fungi are microorganisms that live inside plant tissues without causing disease symptoms. In most cases, their relationship with the host plant is considered beneficial because the endophyte is able to produce bioactive metabolites that the host can use as defense mechanisms, and this allows survival of both organisms. Recent studies hav...

A greenhouse experiment was performed to test whether competition, and possibly allelopathy, were involved in Rottboellia cochinchinensis-maize interactions in two soil conditions: fertilized and unfertilized. Changes in morphological and physiological growth parameters for each species were determined by classical plant growth analysis. The dry we...

From the organic extract of the culture media of Aspergillus stromatoides, emodin (1), ω-hydroxyemodin (2), citrinin (3), methyl 8-hydroxy-6-methyl-9-oxo-9H-xanthene-1-carboxylate (4), and coniochaetone A (5) were isolated. All the compounds were tested for their abilities to quench the fluorescence of the calmodulin (CaM) biosensor hCaM M124C-mBBr...

An organic extract was prepared from the culture medium and mycelia of the marine fungus Aspergillus stromatoides Raper & Fennell. The extract was fractionated via column chromatography, and the resulting fractions were tested for their abilities to quench the fluorescence of the calmodulin (CaM) biosensor hCaM M124C-mBBr. From the active fraction,...

Muscodor yucatanensis, an endophytic fungus, was isolated from the leaves of Bursera simaruba (Burseraceae) in a dry, semideciduous tropical forest in the Ecological Reserve El Eden, Quintana Roo, Mexico. We tested the mixture of volatile organic compounds (VOCs) produced by M. yucatanensis for allelochemical effects against other endophytic fungi,...

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During a study on the fungal endophytic associations with some trees of the secondary forest of El Eden Ecological Reserve located in the northeastern Yucatan Peninsula of Mexico, a new fungal species was isolated as an endophyte of a tree named chakah, chachah, or hukup (Bursera simaruba) by indigenous Mayas. This fungus is characterized by produc...

Chemical investigation of the mycelium of Edenia gomezpompae, a newly discovered endophytic fungus isolated from the leaves of Callicarpa acuminata (Verbenaceae) collected from the ecological reserve El Eden, Quintana Roo, Mexico, resulted in the isolation of four naphthoquinone spiroketals, including three new compounds and palmarumycin CP2 (4). W...

We analysed the production of phytotoxic glycosidic resins and tricolorin A in seeds and seven early development stages of Ipomoea tricolor (Convolvulaceae). We performed in vitro bioassays to test (i). the bioactivity of I. tricolor aqueous leachates (15%) (1% for whole and ground seeds) and organic extracts (100 μg ml-1) from fresh cotyledons, tr...

During a preliminary survey to report the biodiversity of endophytic fungi associated with leaves of some woody plants from El Eden Ecological Reserve in Mexico, a new fungus was isolated from Callicarpa acuminata leaves. Cultures of this fungus on PDA form a white floccose colony with a reddish-brown reverse and a mycelium that develops by 90° ang...

Six known pentacyclic triterpenes possessing oleanane, lupane, or taraxerane-type skeletons were isolated from the leaves of Sebastiania adenophora (Euphorbiaceae) and are reported for the first time in this species. These compounds include 3-epi-beta-amyrin, beta-amyrinone, 3-epi-lupeol, lupenone, taraxerol, and taraxerone. Structures were elucida...

Aqueous leachates and a CHCl3-MeOH (1:1) extract of roots of Stauranthus perforatus showed a significant phytotoxic effect on Amaranthus hypochondriacus and Echinochloa crus-galli. Bioassay-directed fractionation of the active organic extract led to the isolation and characterization of ten secondary metabolites, which included two pyranocoumarins...

Bioassay-directed fractionation of a CH(2)Cl(2)-MeOH (1:1) extract of the aerial parts of Flourensia cernua led to the isolation of three phytotoxic compounds, namely, dehydroflourensic acid (1), flourensadiol (2) and methyl orsellinate (3). Dehydroflourensic acid is a new natural product whose structure was established by spectral means. In additi...

The effect of a series of phytotoxins isolated from the fungus Guanomyces polytrix on calmodulin (CaM)-dependent nicotinamide adenine dinucleotide kinase (NADK) and CaM-dependent cyclic nucleotide phosphodiesterase (PDE) activities was investigated. The results indicated that (2S,3S)-5-hydroxy-6,8-dimethoxy-2,3-dimethyl-4H-2,3-dihydronaphtho[2,3-b]...

Reinvestigation of the fermentation broth and mycelium of the fungus Phoma herbarum led to the isolation of a new phytotoxic nonenolide, namely, (7R,9R)-7-hydroxy-9-propyl-5-nonen-9-olide, which was designated with the trivial name herbarumin III (3). The known compounds herbarumins I (1) and II (2) were also obtained. The structure of 3 was elucid...

Activity-directed fractionation of a CH(2)Cl(2)-MeOH (1:1) extract of Leucophyllum ambiguum led to the isolation of two new lignans designated with the trivial names of 2'-methoxykobusin (1) and 2'-methoxy-4' '-hydroxydemethoxykobusin (2). In addition, the known compounds kobusin (3), 2',2' '-dimethoxysesamin (4), trans-cinnamic acid, apigenin, and...

Reinvestigation of the fermentation broth and mycelium of the coprophilous fungus Guanomyces polythrix, grown in static conditions, led to the isolation of several phytotoxic compounds, including two new naphthopyranone derivatives, namely (2S, 3R)-5-hydroxy-6,8-dimethoxy-2,3-dimethyl-2,3-dihydro-4H-naphtho[2,3-b]-pyran-4-one and (2S, 3R)-5-hydroxy...

Bioactivity-directed fractionation of the fermentation broth and mycelium of the coprophilous fungus Guanomyces polythrix led to the isolation of several phytotoxic compounds, including five new naphthopyranone derivatives (1-5). In addition, rubrofusarin B, emodin, citrinin, and 4-hydroxybenzoic acid methyl ester were obtained. The structures of t...

Xanthyletin (1), 3-(1',1'-dimethylallyl)xanthyletin (2), and chalepensin (3), the major coumarins isolated from Stauranthus perforatus, inhibit ATP synthesis from water to methylviologen in spinach thylakoids in a concentration-dependent manner. At low concentration chalepensin (3) inhibits basal and phosphorylating electron flow from water to K(3)...

A new triterpenoid, namely, lanost-25-en-3-beta-ol, and two known flavonoids (kaempferol-3,6-dimethyl ether and kaempferol 7- O-glucoside) were isolated from the aerial parts of Chamaesyce prostrate (Euphorbiaceae). The structure of the new compound was established based on spectral evidences.

Investigation of the aerial parts of Esenbeckia yaxhoob Lundell (Rutaceae) led to the isolation of a new dammarane-type of triterpene which was characterized by spectral means as (24S)-24-methyl-dammara-20,25-diene-3β-yl-acetate. In addition, 2-tridecanone, asarinin, imperatorin, lupeol and hesperidin were obtained. (24S)-24-Methyl-dammara-20,25-di...

Investigation of the aerial parts of Esenbeckia yaxhoob Lundell (Rutaceae) led to the isolation of a new dammarane-type of triterpene which was characterized by spectral means as (24S)-24-methyl-dammara-20,25-diene-3β-yl-acetate. In addition, 2-tridecanone, asarinin, imperatorin, lupeol and hesperidin were obtained. (24S)-24-Methyl-dammara-20,25-di...