Endophytic fungi are ubiquitous organisms found in the plants, residing intercellular or intracellular, at least for a portion of their lives without causing apparent symptoms of infection. Almost all plants are known to harbor endophytes. The choice of the plant to be used for exploring endophytes for bioactives is important. Therefore, medicinal plants which are known to be used since centuries as an alternative source of medicine, are a valuable source for bioprospecting endophytes. Nevertheless, due to many reasons there is a dire need for novel resources for novel drugs which can be an answer to many deadly diseases. It is in this context that the present review was envisaged. The review reveals the importance of endophytic fungi from medicinal plants as a source of bioactive and chemically novel compounds. The bioactive metabolites produced by endophytic fungi originate from different biosynthetic pathways and belong to diverse structural groups such as terpenoids, steroids, quinones, phenols, coumarins etc. Endophytes therefore, represent a chemical reservoir for new compounds such as, anticancer, immunomodulatory, antioxidant, antiparasitic, antiviral, antitubercular, insecticidal etc. for use in the pharmaceutical and agrochemical industries. Although, efforts have been made to accommodate as many examples as possible but the depth of the subject is so vast that it cannot be covered in one single review. This in itself speaks of the fact that endophytic fungi from medicinal plants is indeed a treasure worth searching. In the present review only some selected examples have been covered.

Endophytic fungi from medicinal plants: a treasure hunt for bioactive metabolites

A copper-catalyzed amino lactonization of unsaturated carboxylic acids has been achieved as well as the analogous intermolecular three-component amino oxygenation of olefins. The transformation features mild conditions and a remarkably broad substrate scope, offering a novel and efficient approach to construct a wide range of amino lactones as well as 1,2-amino alcohol derivatives. Mechanistic studies suggest that the reaction proceeds via a distinctive O-benzoylhydroxylamine-promoted electrophilic amination of alkenes.

Copper-Catalyzed Amino Lactonization and Amino Oxygenation of Alkenes Using O-Benzoylhydroxylamines.

Iridoid glycosides are natural products occurring widely in many herbal plants. Geniposide (C17H24O10) is a well-known one, present in nearly 40 species belonging to various families, especially the Rubiaceae. Along with this herbal component, dozens of its natural derivatives have also been isolated and characterized by researchers. Furthermore, a large body of pharmacological evidence has proved the various biological activities of geniposide, such as anti-inflammatory, anti-oxidative, anti-diabetic, neuroprotective, hepatoprotective, cholagogic effects and so on. However, there have been some research articles on its toxicity in recent years. Therefore, this review paper aims to provide the researchers with a comprehensive profile of geniposide on its phytochemistry, pharmacology, pharmacokinetics and toxicology in order to highlight some present issues and future perspectives as well as to help us develop and utilize this iridoid glycoside more efficiently and safely.

A Review on the Phytochemistry, Pharmacology, Pharmacokinetics and Toxicology of Geniposide, a Natural Product

Antioxidant compounds from microbial sources: A review

Ethnobotanical study of Loloh: Traditional herbal drinks from Bali (Indonesia)

Bioassay-guided fractionation of metabolites from the fungus Cephalosporium sp.AL031 isolated from Sinarundinaria nitida led to the discovery of a new isobenzofuranone derivative, 4,6-dihydroxy-5-methoxy-7-methylphthalide (1), together with three known compounds: 4,5,6-trihydroxy-7-methyl-1,3-dihydroisobenzofuran (2), 4,6-dihydroxy-5-methoxy-7-methyl-1,3-dihydroisobenzofuran (3) and 4,5,6-trihydroxy-7-methylphthalide (4). The structure of the new compound 1 was determined based on MS, 1D and 2D NMR spectral data. Compounds 1-4 showed potent antioxidant activity with EC₅₀ values of 10, 7, 22 and 5 μM by 1,1-diphenyl-2-picryhydrazyl (DPPH) radical-scavenging assay.

https://www.mdpi.com/1420-3049/17/4/4219/pdf

A Novel Antioxidant Isobenzofuranone Derivative from Fungus Cephalosporium sp.AL031

Two new sphingolipids, pipercerebrosides A (1) and B (2), were isolated from the leaves of Piper betle L. Their structures, including absolute configurations, were determined by spectroscopic analysis and chemical degradation. These two compounds did not show significant cytotoxic activity against the cancer cell lines K562 and HL-60 in a MTT assay.

https://www.mdpi.com/1420-3049/18/9/11241/pdf

Two new sphingolipids from the leaves of Piper betle L.

A novel lignan glycoside with antioxidant activity from Tinospora sagittata var. yunnanensis

Cytotoxic flavanes from Uraria clarkei.

OBJECTIVE To study the chemical constituents from the stems of Piper betle. METHODS Various chromatographic techniques were used to isolate and purify the constituents. The structures of these compounds were elucidated on the basis of spectral analysis. RESULTS Nine compounds were isolated from the petroleum ester and ethyl acetate soluble fractions of the 70% acetone extract and their structures were identified as 6beta-hydroxystigmast-4-en-3-one (1), beta-sitosterol (2), stigmasterol (3), oleanolic acid (4), 23-hydroxyursan-12-en-28-oic acid (5), beta-sitosterol-3-O-beta-D-glucoside-6'-O-palmitate (6), beta-daucosterol (7), (2S) -4'-hydroxy- 2,3-dihydroflavonone-7-O-beta-D-glucoside (8) and alpha-ethyl glucoside (9). CONCLUSION Among these compounds, 1, 3 -9 are isolated from this plant for the first time.

Xiang-Zhong Huang

Papers

A Novel Antioxidant Isobenzofuranone Derivative from Fungus Cephalosporium sp.AL031

Two new sphingolipids from the leaves of Piper betle L.

A novel lignan glycoside with antioxidant activity from Tinospora sagittata var. yunnanensis

Cytotoxic flavanes from Uraria clarkei.

Studies on the chemical constituents of the stems of Piper betle