Advances on the microbial synthesis of plant-derived diterpenoids / 生物工程学报

Natural plant-derived diterpenoids are a class of compounds with diverse structures and functions. These compounds are widely used in pharmaceuticals, cosmetics and food additives industries because of their pharmacological properties such as anticancer, anti-inflammatory and antibacterial activities. In recent years, with the gradual discovery of functional genes in the biosynthetic pathway of plant-derived diterpenoids and the development of synthetic biotechnology, great efforts have been made to construct a variety of diterpenoid microbial cell factories through metabolic engineering and synthetic biology, resulting in gram-level production of many compounds. This article summarizes the construction of plant-derived diterpenoid microbial cell factories through synthetic biotechnology, followed by introducing the metabolic engineering strategies applied to improve plant-derived diterpenoids production, with the aim to provide a reference for the construction of high-yield plant-derived diterpenoid microbial cell factories and the industrial production of diterpenoids.

Actividad antibacteriana del extracto etanólico de Plantago major frente a Streptococcus mutans / Antibacterial activity of Plantago major ethanolic extract against Streptococcus mutans

Introducción: Las propiedades antibacterianas de Plantago major frente a microorganismos orales no se ha estudiado ampliamente. Objetivo: Identificar los metabolitos secundarios presentes en el extracto etanólico de Plantago major y determinar su actividad antibacteriana frente a Streptococcus mutans. Métodos: Se prepararon concentraciones del 25 por ciento, 50 por ciento, 75 por ciento y 100 por ciento de extracto etanólico (EE) de Plantago major. Se cargaron seis discos de papel con 10 µL, 15 µL, 20 µL y 25 µL de cada concentración, haciendo un total de 96 discos. Los discos fueron colocados en placas Petri con agar cerebro-corazón inoculadas con Streptococcus mutans, se empleó clorhexidina al 0,12 por ciento como control positivo. Se calcularon seis repeticiones para cada concentración. Las placas fueron incubadas a 37 °C por 48 horas. La medición de los halos de inhibición se realizó con un compás digital. El análisis estadístico se realizó mediante la prueba ANOVA de un factor seguido por la prueba post hoc de Tukey. Resultados: El análisis químico del extracto etanólico de Plantago major identificó la presencia de terpenos, diterpenos, saponinas, terpenoidales y aceites esenciales. Las concentraciones del 25 por ciento y 50 por ciento no mostraron efecto antibacteriano, los volúmenes mayores de 20 µL de la concentración del 75 por ciento y todas los del 100 por ciento fueron efectivos para inhibir el crecimiento de Streptococcus mutans con halos de inhibición de 8,36 mm a 14,64 mm. La clorhexidina al 0,12 por ciento inhibió el crecimiento de Streptococcus mutans con halos de inhibición de 17,77 mm en promedio, presentando diferencias significativas con todas las concentraciones del extracto etanólico de Plantago major (P < 0,05). Conclusiones: El extracto etanólico de Plantago major presentó derivados de los terpenos y saponinas, y mostró actividad antibacteriana frente a Streptococcus mutans en volúmenes y concentraciones mayores a 20 µL/75 por ciento(AU)

Introduction: The antibacterial properties of Plantago major against oral microorganisms have not been widely studied. Objective: Identify the secondary metabolites present in an ethanolic extract of Plantago major and determine their antibacterial activity against Streptococcus mutans. Methods: The Plantago major ethanolic extract (EE) was prepared at concentrations of 25 percent, 50 percent, 75 percent and 100 percent. Six paper discs were loaded with 10 µl, 15 µl, 20 µl and 25 µl of each concentration, for a total 96 discs, which were then placed on Petri plates with brain heart agar inoculated with Streptococcus mutans. The positive control was 0.12 percent chlorhexidine. Six replicates were estimated for each concentration. The plates were incubated at 37ºC for 48 hours. Inhibition haloes were measured with a digital caliper. Statistical analysis was based on one-factor ANOVA testing followed by Tukey's post hoc test. Results: Chemical analysis of the Plantago major ethanolic extract identified the presence of terpenes, diterpenes, saponins, terpenoids and essential oils. The 25 percent and 50 percent concentrations did not display an antibacterial effect, whereas volumes above 20 µl of the 75 percent concentration and all 100 percent volumes were effective to inhibit Streptococcus mutans growth with inhibition haloes of 8.36 mm to 14.64 mm. 0.12 percent chlorhexidine inhibited Streptococcus mutans with inhibition haloes of 17.77 mm on average, presenting significant differences with all the concentrations of the Plantago major ethanolic extract (p < 0.05). Conclusions: The Plantago major ethanolic extract was found to contain terpene and saponin derivatives, and displayed antibacterial activity against Streptococcus mutans at volumes and concentrations above 20 µl / 75 percent(AU)

Comparative proteomic analyses of Hyphozyma roseonigra ATCC 20624 in response to sclareol

Abstract Sclareol is an important intermediate for ambroxide synthesis industries. Hyphozyma roseonigra ATCC 20624 was the only reported strain capable of degrading sclareol to the main product of sclareol glycol, which is the precursor of ambroxide. To date, knowledge is lacking about the effects of sclareol on cells and the proteins involved in sclareol metabolism. Comparative proteomic analyses were conducted on the strain H. roseonigra ATCC 20624 by using sclareol or glucose as the sole carbon source. A total of 79 up-regulated protein spots with a >2.0-fold difference in abundance on 2-D gels under sclareol stress conditions were collected for further identification. Seventy spots were successfully identified and finally integrated into 30 proteins. The up-regulated proteins under sclareol stress are involved in carbon metabolism; and nitrogen metabolism; and replication, transcription, and translation processes. Eighteen up-regulated spots were identified as aldehyde dehydrogenases, which indicating that aldehyde dehydrogenases might play an important role in sclareol metabolism. Overall, this study may lay the fundamentals for further cell engineering to improve sclareol glycol production.

A New Acetylcholinesterase Inhibitor from Green Glycosylation of Trachyloban-19-oic Acid by Mucor plumbeus

ABSTRACT The in vitro metabolism of a widespread natural product, trachyloban-19-oic acid (1), by the fungal species Mucor plumbeus was studied in a sucrose-yeast liquid medium. Two products were isolated, and their structures were determined by spectroscopic means as 7β-hydroxytrachyloban-19-oic acid (5) and trachyloban-19-O-β-D-glucopyranosyl ester (6). To the best of our knowledge, compound 6 is herein reported by the first time in the literature. These compounds were assayed for acetylcholinesterase inhibition along with some related compounds. Compound 6 showed the highest acetylcholinesterase inhibitory activity at 10000 µg/mL among the tested compounds, a result (92.89%) comparable to the activity of the positive control, galanthamine (94.21%). Therefore, biotransformation of the natural product 1 by M. plumbeus produced a novel compound with potential as a new lead to develop anti-Alzheimer medicines.

O consumo de café e sua relação com a hiperhomocisteinemia: revisão / Coffee intake and the relation with hyperhomocisteinemia: a review

Coffee is one of the most worldwide consumed beverages, and Brazil is its major source. Coffee plants belong to the Rubiacea e family, and there are many species, although only C. arabica and C. canephora (Robusta) have commercial value. The chemical composition of green coffee depends on the species, climatic conditions, processing and storage. Recently, coffee intake has been related to increased plasma homocysteine levels ­ this non-proteica minoacid is one of the risk factors for occlusive cardiovascular diseases,one of the main causes of death in industrialized countries. This finding points out to the relevance of analysis of coffee constituents involved inincreased homocysteine plasma levels. Caffeine, chlorogenic acid and diterpenes (caffestol and caveol) are important substances present in coffee,which exert physiological effects

El café es una de las bebidas mas consumidas en el mundo, siendo Brasil el mayor produto rmundial. El café pertenece a la família Rubiáceas, y existen numerosas especies, pero solamente la C. arabica y la C. canéfora (Robusta) tienen valor comercial. La composición química del café verde depende dela especie, condiciones climáticas, de procesamiento y de almacenamiento. Recientemente, el consumo de café ha sido relacionado al aumento de los niveles de homocisteína plasmática ­ este aminoácido no proteico es uno de los factores de riesgo para las enfermedades cardiovasculares oclusivas, las cuales responden por las principales causas de muerte en países industrializados ­ esto es relevante para la investigación que busca los componentes del café, responsables por el aumento de los niveles de homocisteínaplasmática. La cafeína, el acido clorogénico, diterpenos (cafestol y cahweol) son importantes substancias presentes en el café que ejercen efectos fisiológicos en el organismo

A bebida de café é uma das bebidas mais consumidas no mundo, sendo o Brasil o seu maior produtor. As plantas de café pertencem à família Rubiaceae, e possuem inúmeras espécies, mas somente a C. arábica e C. canéfora (Robusta) têm valor comercial. A composição química do café verde depende da espécie, condições climáticas, processamento e estocagem. Recentemente, o consumo de café tem sido relacionado ao aumento dos níveis de homocisteína plasmática - esse aminoácido não protéico é um dos fatores de risco para a ocorrência de doenças cardiovasculares oclusivas, uma das principais causas de morte em países industrializados - tal fato torna relevante a investigação sobre os componentes do café, envolvidos no incremento dos níveis de homocisteína plasmática. A cafeína, o ácido clorogênico e os diterpenos (cafestol e caveol) são importantes substâncias presentes no café, exercendo efeitos fisiológicos no organismo

Lack of mutagenicity of stevioside and steviol in Salmonella typhimurium TA 98 and TA 100.

Stevioside, a sweet-tasting diterpene glycoside derived from Stevia rebaudiana, and steviol, a product from enzymatic hydrolysis of stevioside, were tested for mutagenic activity by the in vitro Ames test, a preincubation method, using Salmonella typhimurium TA 98 and TA 100 as the tester strains, either in the presence or absence of metabolic activating system derived from the sodium phenobarbital and 5,6-benzoflavone pretreated liver S9 fractions from various animal species including rat, mouse, hamster and guinea pig. Stevioside and steviol at the concentrations up to 50 mg and 2 mg per plate, respectively showed no mutagenic effect on both tester strains either in the presence or absence of metabolic activating system. However, at the high concentration both stevioside and steviol showed some toxic effects on both tester strains. The toxic effect was decreased in the presence of the metabolic activating system.