The seminal discovery of paclitaxel from endophytic fungus Taxomyces andreanae was a milestone in recognizing the immense potential of endophytic fungi as prolific producers of bioactive secondary metabolites of use in medicine, agriculture, and food industries. Following the discovery of paclitaxel, the research community has intensified efforts to harness endophytic fungi as putative producers of lead molecules with anticancer, anti-inflammatory, antimicrobial, antioxidant, cardio-protective, and immunomodulatory properties. Endophytic fungi have been a valuable source of bioactive compounds over the last three decades. Compounds such as taxol, podophyllotoxin, huperzine, camptothecin, and resveratrol have been effectively isolated and characterized after extraction from endophytic fungi. These findings have expanded the applications of endophytic fungi in medicine and related fields. In the present review, we systematically compile and analyze several important compounds derived from endophytic fungi, encompassing the period from 2011 to 2022. Our systematic approach focuses on elucidating the origins of endophytic fungi, exploring the structural diversity and biological activities exhibited by these compounds, and giving special emphasis to the pharmacological activities and mechanism of action of certain compounds. We highlight the tremendous potential of endophytic fungi as alternate sources of bioactive metabolites, with implications for combating major global diseases. This underscores the significant role that fungi can play in the discovery and development of novel therapeutic agents that address the challenges posed by prevalent diseases worldwide.

Nitrogen is an essential nutrient utilized by living organisms to produce a number of organic molecules such as nucleic acid, amino acid and protein. A special class of microorganisms known as diazotrophs that are able to fix atmospheric nitrogen into biological form of nitrogen which is directly utilized by plants. Moreover, they stimulate plant growth by decreasing or preventing deleterious effects of pathogens through synthesis of antibiotics, competition for nutrients through production of siderophores. Along with terrestrial diazotrophs, various marine bacterial species are well known which involves in biological nitrogen fixation process. In an open oligotrophic ocean, pelagic and sympagic nitrogen fixation has been shown a significant source of biological nitrogen for survival of oceanic living organisms. A different range of diazotroph have been reported at low temperature ice sea environment. The community of nitrogen fixing bacteria under deep anoxic bottom water is gradually increase. It may be possible that due to genetic variation population of nitrogen fixing bacteria increases under sea water. In this review article, authors have focused on nature of diazotrophs in terrestrial as well as in aquatic conditions. Moreover, the bacterial habitat and their classification, latest approaches and future prospects is also included in the manuscript. Thus, the study would be helpful for understanding the mode of action, their behavior and survival rate in different environment and beneficial for improvement in agricultural sustainability.

β-Ionone is a naturally occurring C13-norisoprenoid apocarotenoid which is mainly derived from carotenoid cleavage and has gained significant attention due to its potential anticancer activity. Experimental investigations have shown that β-ionone has the ability to arrest the proliferation of cancer cells and to induce programmed cell death by several mechanisms depending on the type of tumors and experimental conditions. Mitochondrial apoptosis, such as Bax/Bcl-2 balance, cytochrome c release, activation of caspases, and p53-associated signaling, is the most consistently supported evidence for β-Ionone. Other mechanisms include modulation of the PI3K/Akt and MAPK/ERK signaling pathways, regulation of cell-cycle progression, generation of oxidative stress, and increased sensitivity to death-receptor-mediated apoptosis. Moreover, recent experimental studies have provided further support for the role of β-ionone in ferroptosis, as it was found to modulate the ferroptosis-associated proteins and Wnt/β-catenin signaling in gastric cancer models. By contrast, other mechanisms such as autophagy and the JAK/STAT3 signaling pathway are proposed mechanisms that need to be directly tested. Most importantly, evidence collected using β-ionone derivatives (such as esters and endoperoxides) differs from that collected from the parent. While promising preclinical results have been observed, translation is hampered by the lack of human pharmacokinetic data, uncertainties in bioavailability, and a lack of toxicity data and clinical trials. Target validation, characterization of the PHPD profile, safety assessment, formulation optimization, and clinically relevant in vivo validation should thus be given special attention in future studies.

Muskmelon (Cucumis melo) is a widely cultivated and economically important fruit crop that is severely affected by Fusarium wilt caused by Fusarium oxysporum f. sp. melonis (race 1.2) (Fom). Conventional management practices have shown limited effectiveness and pose environmental and health risks; therefore, sustainable and eco-friendly alternatives are required to manage this disease. In the present study, 23 endophytic fungal isolates belonging to eight genera were isolated from Ecballium elaterium and screened to determine antifungal potential against Fom using an in vitro antagonistic assay. Two endophytic isolates (Fusarium sp. EeR4 and Fusarium clavum EeR24) exhibited an inhibitory effect against Fom on quarter-strength PDA plates. In growth chamber experiments, F. clavum EeR24-colonized melon seedlings and significantly protected plants from wilting compared to non-colonized pathogen-challenged seedlings. Under greenhouse conditions, F. clavum EeR24 significantly improved morphological and physiological traits, including plant height, weight, number of leaves, membrane stability, photosynthesis, stomatal conductance, and transpiration, in Cucumis melo. Endophytic colonization improved catalase (56%), guaiacol peroxide (47%), and superoxide dismutase activity (25%), and increased flavonoid and phenolic content by 11–59% compared to non-colonized Fom-challenged plants. Lipid peroxidation significantly decreased by 37% and proline accumulation increased by 70% in colonized plants compared to non-colonized plants. Histochemical analysis also indicated that endophytic colonization considerably reduced the levels of H₂O₂, O₂⁻, malondialdehyde, and cell mortality in Fom-challenged plants. In addition, the culture filtrate and organic residues of F. clavum EeR24 inhibited the mycelial growth of Fom by 52–58%, respectively. Furthermore, a study on spatial colonization of the endophyte and the pathogen using GFP and RFP tagging indicated that both the endophyte and the pathogen simultaneously colonized the root tissues of C. melo; however, the endophyte significantly reduced the pathogenicity of Fom. These results suggest that endophytic F. clavum EeR24 may be developed as an effective biocontrol agent for the management of Fusarium wilt in melon plants under field conditions.