Sorokiniol: a new enzymes inhibitory metabolite from fungal endophyte Bipolaris sorokiniana LK12.

BACKGROUND: Medicinal plants harboring endophytic fungi could carry significant potential for producing bioactive secondary metabolites. Endophytic fungi serve as alternate source of interesting compounds in their natural and modified synthetic forms to treat different diseases. In this regard, endophytic microflora associated with alkaloid-rich medicinal plants Rhazya stricta is least known. RESULTS: We isolated one new bioactive compound sorokiniol (1) along with two known cyclic peptides BZR-cotoxin I (2) and BZR-cotoxin IV (3) from fungal endophyte Bipolaris sorokiniana LK12. The structures of the isolated new and known compounds were elucidated through spectroscopic data, including 1D and 2D NMR ((1)H, (13)C, HSQC, HMBC, and NOESY), mass, and UV. The known peptides (2-3) were characterized by ESI-MS, MS/MS, and by comparing the NMR data with the literature. The isolated metabolites were assayed for their role against enzyme inhibition. Compound 1 was significantly inhibitory towards acetyl cholinestrase while the other compounds (2-3) had moderate anti-lipid peroxidation and urease activities. CONCLUSION: The present results suggest that the endophytic microorganism associated with indigenously important medicinal plants can offer a rich source of biologically active chemical constituents which could help in discovering enzyme inhibitory lead drugs.

Avaliação da qualidade de amostras comerciais de leite de janaguba (Himatanthus drasticus (Mart. ) Plumel) em Fortaleza – Ceará / Quality assessment of commercial samples of janaguba’s milk (Himatanthus drasticus (Mart. ) Plumel) in Fortaleza – Ceará.

RESUMO Os fitoterápicos à base de leite de janaguba (Himatanthus drasticus (Mart.) Plumel), usados para o tratamento de câncer, úlcera gástrica e outras doenças, são muito vendidos em mercados públicos de Fortaleza (CE). No entanto, registros mencionam que é comum a troca deste leite por látex de mangabeira (Hancornia speciosa Gomes). O trabalho objetivou avaliar a qualidade físico-química, química e microbiológica de amostras comerciais do leite de janaguba. Dez amostras comerciais foram adquiridas de um mercado de Fortaleza; quatro amostras autênticas de látex de janaguba foram obtidas da chapada do Araripe e uma amostra de látex de mangabeira foi obtida em Paracuru (CE). Foram determinados o aspecto geral, densidade, pH, resíduo seco, volume de sedimentação, perfil cromatográfico e qualidade microbiológica das amostras. Os resultados mostraram elevada contaminação microbiológica nas preparações comerciais e adulteração em seis destas amostras, o que aponta a urgente implantação de uma efetiva farmacovigilância dos fitoterápicos a fim de tornar seu consumo mais seguro e racional.

ABSTRACT The herbal medicines made from janaguba milk (Himatanthus drasticus (Mart.) Plumel), used to treat gastric ulcer, cancer and other diseases, and arewidely sold in the public markets of Fortaleza (CE). However, records mention that it is common to make fake copies of the milk by using mango tree latex (Hanconia speciosa Gomes). This study aimed to evaluate the chemical, physical-chemical and microbiological quality of commercial samples of janaguba milk. Ten commercial samples were purchased from a Fortaleza market; four authentic samples of janaguba latex were obtained from the Araripe plateau, and one mango tree latex sample was obtained in Paracuru (CE). We determined the general appearance, density, pH, dry residue, sedimentation volume, chromatographic profile and microbiological qualities. Results showed high microbiological contamination in the commercial preparations and evidence of tampering in six of these samples, which indicates the need for an urgent implementation of an effective pharmacovigilance strategy for herbal medicines in order to make its consumption more secure and rational.

Enzyme Inhibitory Radicinol Derivative from Endophytic fungus Bipolaris sorokiniana LK12, Associated with Rhazya stricta.

Endophytes, living inside plant tissues, play an essential role in plant growth and development, whilst producing unique bioactive secondary metabolites. In the current study, the endophytic fungus Bipolaris sorokiniana LK12 was isolated from the leaves of ethno-medicinal and alkaloidal rich Rhazya stricta. The bulk amount of ethyl acetate extract of fungus was subjected to advance column chromatographic techniques, which resulted in the isolation of a new radicinol derivative, bipolarisenol (1). It was found to be a derivative of radicinol. The structure elucidation was carried out by the combined use of 1D and 2D nuclear magnetic resonance, infrared spectroscopy, mass, and UV spectrometric analyses. The bipolarisenol was assessed for its potential role in enzyme inhibition of urease and acetyl cholinesterase (AChE). Results showed that bipolarisenol significantly inhibited the AChE activity with low IC50 (67.23 ± 5.12 µg·mL-1). Bipolarisenol inhibited urease in a dose-dependent manner with high IC50 (81.62 ± 4.61 µg·mL-1). The new compound also showed a moderate anti-lipid peroxidation potential (IC50 = 168.91 ± 4.23 µg·mL-1). In conclusion, endophytes isolated from medicinal plants possess a unique potential to be considered for future drug discovery.

Vermistatin derivatives with α-glucosidase inhibitory activity from the mangrove endophytic fungus Penicillium sp. HN29-3B1.

Three new vermistatin derivatives, 6-demethylpenisimplicissin (1), 5'-hydroxypenisimplicissin (2), and 2''-epihydroxydihydrovermistatin (3), along with five known vermistatin analogues, methoxyvermistatin (4), vermistatin (5), 6-demethylvermistatin (6), hydroxyvermistatin (7), and penisimplicissin (8), were isolated from the culture of the mangrove endophytic fungus Penicillium sp. HN29-3B1 from Cerbera manghas. Their structures were elucidated mainly by nuclear magnetic resonance spectroscopy. The absolute configurations of compounds 1 and 2 were deduced on the basis of circular dichroism data. The absolute structures of compounds 3 and 5 were confirmed by a single-crystal X-ray diffraction experiment using Cu Kα radiation. In the bioactivity assay, compounds 1 and 3 exhibited α-glucosidase inhibitory activity with IC50 values of 9.5 ± 1.2 and 8.0 ± 1.5 µM, respectively. The plausible biosynthetic pathways for all compounds are discussed.

A phytopathogenic cysteine peptidase from latex of wild rubber vine Cryptostegia grandiflora.

A 24,118 Da (MALDI-TOF) cysteine peptidase (EC 3.4.22.16) was purified from the latex extract of Cryptostegia grandiflora by two chromatographic steps involving ion exchange and Reverse-phase HPLC. The purified protein (Cg24-I) exhibits a single band profile following reduced SDS-PAGE and a unique amino terminal sequence, 1VPASIDWREKGTVL14, that is similar to other plant cysteine peptidases. Cg24-I displayed optimal proteolytic activity at pH 8.0 with 25 mM phosphate buffer. The proteolytic activity was inhibited with 0.2 mM E-64 and 1 mM iodoacetamide and was stimulated with 1 mM DTT. Cg24-I fully inhibited spore germination of phytopathogenic fungi Fusarium solani at a dose of 28.1 µg/mL. Its toxicity involves the membrane permeabilization of spores as probed by propidium iodide uptake. These results show that latex peptidases are part of the plant's defensive strategy against phytopathogens and that they most likely act synergistically with other recognized defensive proteins.

Lecythomycin, a new macrolactone glycoside from the endophytic fungus Lecythophora sp.

A new macrolactone glycoside, lecythomycin (1), 23-methyl-3-(1-O-mannosyl)-oxacyclotetracosan-1-one, was isolated from the endophytic fungus Lecythophora sp. (code 30.1), an endopyte of the Indonesian plant Alyxia reinwardtii. The structure of 1 was elucidated on the basis of NMR spectroscopic and mass spectrometric data. The isolated compound displayed antifungal activity against strains of Aspergillus fumigatus and Candida kruzei at minimal inhibitory concentrations (MIC) of 62.5-125 microg/mL.

Bacterial community associated with the trunk latex of Hancornia speciosa Gomes (Apocynaceae) grown in the northeast of Brazil.

Prevention or cure of different illnesses through the use of plant latex is a worldwide known concept. The antifungal activity of Hancornia speciosa latex has been observed against Candida albicans. However, H. speciosa latex is not a sterile plant exudate and secondary metabolites produced by bacteria could be involved in fungal inhibition. In the present study, the bacterial communities of the latex from three H. speciosa trees were characterized using traditional plating and molecular methods. Twelve strains isolated from the latex samples were clustered into four groups by amplified ribosomal DNA restriction analysis (ARDRA). One representative of each group was sequenced and they were identified as belonging to the genera Bacillus, Klebsiella, Enterobacter and Escherichia. None of the 12 isolates showed antifungal activity against C. albicans. A lack of a microbial origin for the antifungal properties of latex was noted. DGGE profiles generated from each of the three latex samples showed unique patterns. Sequencing of the DGGE bands demonstrated the affiliation with the genera Klebsiella, Pantoea, Enterobacter and Burkholderia. In addition, clone libraries were generated and the phylogenetic distribution of the 50 analyzed clones was similar to that obtained using DGGE. The presence of some potential pathogens should be considered before using H. speciosa latex in folk medicine.

Chemical constituents of the endophytic fungus Lecythophora sp. isolated from Alyxia reinwardtii.

Seven compounds, (2R)-3-(2-hydroxypropyl)-benzene-1,2-diol (1), kojic acid (2), 7-O-acetyl-kojic acid (3), p-hydroxybenzoic acid (4), emodine (5), 7-chloroemodine (6), and ergosterol-5,8-peroxide (7) were isolated from the endophytic fungus Lecythophora sp. (specimen codes 30.1 and 30.5), which were isolated from Alyxia reinwardtii (Apocynaceae).

Genetic transformation and hairy root induction in Holostemma ada-kodien K. Schum--a vulnerable medicinal plant.

Hairy roots were induced from shoot buds and seedling hypocotyls of Holostemma by infection with agropine type Agrobacterium rhizogenes strains. Type of explant, Agrobacterium rhizogenes strain used for infection, co-culture time and photoperiod influenced the transformation frequencies. Hairy roots were induced from seedling hypocotyls and shoot bud explants upon infection with agropine type Agrobacterium rhizogenes strains. The hairy roots were thin, whitish in colour and showed negatively geotropic growth. The transformed nature of hairy roots was confirmed by opine analysis.