Sunil Kumar Deshmukh

Anti-inflammatory and anticancer activity of ergoflavin isolated from an endophytic fungus.

Biodiversity is a major resource for identification of new molecules with specific therapeutic activities. To identify such an active resource, high throughput screening (HTS) of the extracts prepared from such diversity are examined on specific functional assays. Based on such HTS studies and bioactivity-based fractionation, we have isolated ergoflavin, a pigment from an endophytic fungus, growing on the leaves of an Indian medicinal plant Mimosops elengi (bakul). We report here the isolation, structure elucidation, and biological properties of this compound, which showed good anti-inflammatory and anticancer activities.

Endophytic fungi: a reservoir of antibacterials

Multidrug drug resistant bacteria are becoming increasingly problematic particularly in the under developed countries of the world. The most important microorganisms that have seen a geometric rise in numbers are Methicillin resistant Staphylococcus aureus, Vancomycin resistant Enterococcus faecium, Penicillin resistant Streptococcus pneumonia and multiple drug resistant tubercule bacteria to name a just few. New drug scaffolds are essential to tackle this every increasing problem. These scaffolds can be sourced from nature itself. Endophytic fungi are an important reservoir of therapeutically active compounds. This review attempts to present some data relevant to the problem. New, very specific and effective antibiotics are needed but also at an affordable price! A Herculean task for researchers all over the world! In the Asian subcontinent indigenous therapeutics that has been practiced over the centuries such as Ayurveda have been effective as “handed down data” in family generations. May need a second, third and more “in-depth investigations?”

Anticancer activity of Ophiobolin A, isolated from the endophytic fungus Bipolaris setariae.

Abstract The present work describes the anticancer activity of Ophiobolin A isolated from the endophytic fungus Bipolaris setariae. Ophiobolin A was isolated using preparative HPLC and its structure was confirmed by HRMS, 1H NMR, 13C NMR, COSY, DEPT, HSQC and HMBC. It inhibited solid and haematological cancer cell proliferation with IC50 of 0.4–4.3 μM. In comparison, IC50 against normal cells was 20.9 μM. It was found to inhibit the phosphorylation of S6 (IC50 = 1.9 ± 0.2 μM), ERK (IC50 = 0.28 ± 0.02 μM) and RB (IC50 = 1.42 ± 0.1 μM), the effector proteins of PI3K/mTOR, Ras/Raf/ERK and CDK/RB pathways, respectively. It induced apoptosis and inhibited cell cycle progression in MDA-MB-231 cancer cells with concomitant inhibition of signalling proteins. Thus, this study reveals that anticancer activity of Ophiobolin A is associated with simultaneous inhibition of multiple oncogenic signalling pathways namely PI3K/mTOR, Ras/Raf/ERK and CDK/RB. Graphical abstract

Incidence of keratinophilic fungi from the soils of Vedanthangal Water Bird Sanctuary (India)

Fifty‐three soil samples were collected from various sites in the vicinity of Vedanthangal Water Bird Sanctuary and screened for the presence of keratinophilic fungi using the hair baiting techniques for isolation. Twenty‐eight isolates were recovered and identified by recognition of their macro‐ and micromorphological features. Seven species related to five genera were recorded viz. Auxarthron conjugatum (1.89%), Chrysosporium fluviale (3.77%), Chrysosporium indicum (20.75%), Chrysosporium tropicum (7.55%), Chrysosporium state of Ctenomyces serratus (5.66%), Gymnoascus petalosporus (1.89%) and Microsporum gypseum complex (11.32%). The study shows that migratory birds harbour a variety of keratinophiles and may be a potential source of transfer of these fungi from one location to another.

Anticancer activity of new depsipeptide compound isolated from an endophytic fungus

A novel depsipeptide (PM181110) was purified from an endophytic fungus Phomopsis glabrae isolated from the leaves of Pongamia pinnata (family Fabaceae). The chemical structure of PM181110 was elucidated using physiochemical properties, 2D NMR and other spectroscopic methods. PM181110 is very close in structure to FE399. The compound exhibited in vitro anticancer activity against 40 human cancer cell lines with a mean IC50 value of 0.089 μM and ex vivo efficacy towards 24 human tumor xenografts (mean IC50=0.245 μM).

Anticancer activity of koningic acid and semisynthetic derivatives

A screening program aimed at discovering novel anticancer agents based on natural products led to the selection of koningic acid (KA), known as a potent inhibitor of glycolysis. A method was set up to produce this fungal sesquiterpene lactone in large quantities by fermentation, thus allowing (i) an extensive analysis of its anticancer potential in vitro and in vivo and (ii) the semi-synthesis of analogues to delineate structure-activity relationships. KA was characterized as a potent, but non-selective cytotoxic agent, active under both normoxic and hypoxic conditions and inactive in the A549 lung cancer xenograft model. According to our SAR, the acidic group could be replaced to keep bioactivity but an intact epoxide is essential.

Antiproliferative Activity of Hamigerone and Radicinol Isolated from Bipolaris papendorfii

Secondary metabolites from fungi organisms have extensive past and present use in the treatment of many diseases and serve as compounds of interest both in their natural form and as templates for synthetic modification. Through high throughput screening (HTS) and bioassay-guided isolation, we isolated two bioactive compounds hamigerone (1) and radicinol (2). These compounds were isolated from fungus Bipolaris papendorfii, isolated from the rice fields of Dera, Himachal Pradesh, India. The structures of the compounds were established on the basis of spectroscopic data, namely, NMR (1H, 13C, mass, and UV). Both compounds were found to be antiproliferative against different cancer cells. Furthermore we have also noted that both compounds showed increase in apoptosis by favorably modulating both tumor suppressor protein (p53) and antiapoptic protein (BCL-2), and in turn increase caspase-3 expression in cancer cells. This is the first report of these compounds from fungus Bipolaris papendorfii and their anticancer activity.

Incidence of Keratinophilic Fungi from Selected Soils of Vidarbha Region of Maharashtra State, India

One hundred and fifty samples were collected from eleven districts of Vidarbha region of Maharashtra state and screened for the presence of keratinophilic fungi using hair baiting technique for isolation. Seventy-one isolates were recovered and identified. The cultures were identified using macro- and micromorphological features. Their identification was also confirmed by the BLAST search of sequences of the ITS1-5.8S-ITS2 rDNA region against the NCBI/Genbank data and compared with deposited sequences for identification purpose. Thirteen species of eight genera were isolated, namely, Auxarthron conjugatum (2.00%), Chrysosporium indicum (14.00%), Chrysosporium evolceanui (2.66%), Chrysosporium tropicum (4.66%), Chrysosporium zonatum (1.33%), Chrysosporium state of Ctenomyces serratus (3.33%), Gymnascella dankaliensis (1.33%), Gymnascella hyalinospora (0.66%), Gymnoascoideus petalosporus (0.66%), Microsporum gypseum complex (9.33%), Trichophyton mentagrophytes (2.00%), T. terrestre (3.33%), and Uncinocarpus queenslandicus (2.00%). This study indicates that the soils of Vidarbha region of Maharashtra may be significant reservoirs of certain keratinophilic fungi.

Molecular, Physiological and Phenotypic Characterization of Paracoccus denitrificans ATCC 19367 Mutant Strain P-87 Producing Improved Coenzyme Q10.

Coenzyme Q10 (CoQ10) is a blockbuster nutraceutical molecule which is often used as an oral supplement in the supportive therapy for cardiovascular diseases, cancer and neurodegenerative diseases. It is commercially produced by fermentation process, hence constructing the high yielding CoQ10 producing strains is a pre-requisite for cost effective production. Paracoccus denitrificans ATCC 19367, a biochemically versatile organism was selected to carry out the studies on CoQ10 yield improvement. The wild type strain was subjected to iterative rounds of mutagenesis using gamma rays and NTG, followed by selection on various inhibitors like CoQ10 structural analogues and antibiotics. The screening of mutants were carried out using cane molasses based optimized medium with feeding strategies at shake flask level. In the course of study, the mutant P-87 having marked resistance to gentamicin showed 1.25-fold improvements in specific CoQ10 content which was highest among all tested mutant strains. P-87 was phenotypically differentiated from the wild type strain on the basis of carbohydrate assimilation and FAME profile. Molecular differentiation technique based on AFLP profile showed intra specific polymorphism between wild type strain and P-87. This study demonstrated the beneficial outcome of induced mutations leading to gentamicin resistance for improvement of CoQ10 production in P. denitrificans mutant strain P-87. To investigate the cause of gentamicin resistance, rpIF gene from P-87 and wild type was sequenced. No mutations were detected on the rpIF partial sequence of P-87; hence gentamicin resistance in P-87 could not be conferred with rpIF gene. However, detecting the mutations responsible for gentamicin resistance in P-87 and correlating its role in CoQ10 overproduction is essential. Although only 1.25-fold improvement in specific CoQ10 content was achieved through mutant P-87, this mutant showed very interesting characteristic, differentiating it from its wild type parent strain P. denitrificans ATCC 19367, which are presented in this paper.

Optimization of Fermentation Process Conditions for the Production of CoQ10 using Paracoccus denitrificans ATCC 19367 Fusant Strain PF-P1

The process for the production of Coenzyme Q10 (CoQ10) from a novel fusant strain PF-P1 has been scaled up to 2 L laboratory fermenter level. At laboratory fermenter level, the strain PF-P1 produced 113.68 mg/L of CoQ10 at 96 h using fed batch [intermittent dosing of para Hydroxy Benzoic Acid (pHBA) at a concentration of 25 mg/L (final concentration) at 24 h followed by 30% of sucrose solution at 48 h and 72 h respectively] fermentation with optimized production medium containing carbon source as cane molasses and showed specific CoQ10 content of 2.4448 mg/g of dry cell weight (DCW). Optimized process resulted in significant improvement in biomass, CoQ10 titer and specific CoQ10 content than shake flask fermentation with PF-P1 strain. Keywords— Fusant PF-P1; Specific CoQ10 Content; Process Optimization.