scholarly journals Bioactive Molecules from Extreme Environments

Marine Drugs ◽  
2020 ◽  
Vol 18 (12) ◽  
pp. 640
Author(s):  
Daniela Giordano

Marine organisms inhabiting extreme habitats are a promising reservoir of bioactive compounds for drug discovery. Extreme environments, i.e., polar and hot regions, deep sea, hydrothermal vents, marine areas of high pressure or high salinity, experience conditions close to the limit of life. In these marine ecosystems, “hot spots” of biodiversity, organisms have adopted a huge variety of strategies to cope with such harsh conditions, such as the production of bioactive molecules potentially valuable for biotechnological applications and for pharmaceutical, nutraceutical and cosmeceutical sectors. Many enzymes isolated from extreme environments may be of great interest in the detergent, textile, paper and food industries. Marine natural products produced by organisms evolved under hostile conditions exhibit a wide structural diversity and biological activities. In fact, they exert antimicrobial, anticancer, antioxidant and anti-inflammatory activities. The aim of this Special Issue “Bioactive Molecules from Extreme Environments” was to provide the most recent findings on bioactive molecules as well as enzymes isolated from extreme environments, to be used in biotechnological discovery pipelines and pharmaceutical applications, in an effort to encourage further research in these extreme habitats.

Marine Drugs ◽  
2019 ◽  
Vol 18 (1) ◽  
pp. 9 ◽  
Author(s):  
Muhammad Zain ul Arifeen ◽  
Yu-Nan Ma ◽  
Ya-Rong Xue ◽  
Chang-Hong Liu

Growing microbial resistance to existing drugs and the search for new natural products of pharmaceutical importance have forced researchers to investigate unexplored environments, such as extreme ecosystems. The deep-sea (>1000 m below water surface) has a variety of extreme environments, such as deep-sea sediments, hydrothermal vents, and deep-sea cold region, which are considered to be new arsenals of natural products. Organisms living in the extreme environments of the deep-sea encounter harsh conditions, such as high salinity, extreme pH, absence of sun light, low temperature and oxygen, high hydrostatic pressure, and low availability of growth nutrients. The production of secondary metabolites is one of the strategies these organisms use to survive in such harsh conditions. Fungi growing in such extreme environments produce unique secondary metabolites for defense and communication, some of which also have clinical significance. Despite being the producer of many important bioactive molecules, deep-sea fungi have not been explored thoroughly. Here, we made a brief review of the structure, biological activity, and distribution of secondary metabolites produced by deep-sea fungi in the last five years.


Toxins ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 322
Author(s):  
Georg Gӓrtner ◽  
Maya Stoyneva-Gӓrtner ◽  
Blagoy Uzunov

The review summarizes the available knowledge on toxins and their producers from rather disparate algal assemblages of aeroterrestrial, airborne and other versatile extreme environments (hot springs, deserts, ice, snow, caves, etc.) and on phycotoxins as contaminants of emergent concern in soil and plants. There is a growing body of evidence that algal toxins and their producers occur in all general types of extreme habitats, and cyanobacteria/cyanoprokaryotes dominate in most of them. Altogether, 55 toxigenic algal genera (47 cyanoprokaryotes) were enlisted, and our analysis showed that besides the “standard” toxins, routinely known from different waterbodies (microcystins, nodularins, anatoxins, saxitoxins, cylindrospermopsins, BMAA, etc.), they can produce some specific toxic compounds. Whether the toxic biomolecules are related with the harsh conditions on which algae have to thrive and what is their functional role may be answered by future studies. Therefore, we outline the gaps in knowledge and provide ideas for further research, considering, from one side, the health risk from phycotoxins on the background of the global warming and eutrophication and, from the other side, the current surge of interest which phycotoxins provoke due to their potential as novel compounds in medicine, pharmacy, cosmetics, bioremediation, agriculture and all aspects of biotechnological implications in human life.


2021 ◽  
Vol 8 ◽  
Author(s):  
Alicia M. Reigel ◽  
David A. Paz-García ◽  
Michael E. Hellberg

Most tropical reef corals live at temperatures near 27°C and pH values near 8. Conditions outside of these can stress corals and lead to bleaching, disease, and death. However, some corals can survive in marginal or extreme habitats outside of these ranges. To date there is a paucity of knowledge about the role that associated microbes may play in the acclimation of corals to such extreme habitats. Here, we explore differences in the compositional and functional profile of the microbiomes of the scleractinian coral Porites panamensis living both on and off potentially stressful shallow-water hydrothermal vents. The environment near the vents is extreme, with temperatures exceeding 80°C and pH values below 6. Coral microbiomes under stress often exhibit increased diversity, increased abundance of pathogenic bacteria, and functional profiles that shift toward pathways associated with pathogenic taxa. Samples from along a transect that crossed an arc of hydrothermal vents were sequenced for the 16S rRNA gene (V4 region). On-vent coral microbiomes were distinct from those of off-vent corals, but did not have increased alpha or beta diversity. On-vent samples had a higher relative abundance of the beneficial endosymbiont, Endozoicomonas. On- and off-vent microbiomes did not differ in overall abundance of the endolithic green alga Ostreobium, however, a single ASV, close to O. quekettii was more abundant in on-vent corals. Ostreobium can provide many of the same benefits to corals as zooxanthellae and their symbiosis is better maintained under thermal stress. Surprisingly, on-vent coral microbiomes had fewer microbial taxa that are known to be pathogenic or associated with stress than did off-vent corals. The predicted functional profiles of on-vent microbiomes revealed enrichment of pathways related to aerobic respiration, fermentation and amino acid biosynthesis, but not of virulence-related pathways. Our results suggest that P. panamensis microbiomes have acclimated to the extreme environment of the hydrothermal vent habitat rather than showing signs of stress. These results exemplify the need to focus efforts on examining the mechanisms of resilience, including symbioses with microbiota, in corals living in extreme environments in an effort to design better management strategies for reef-building corals under thermal and pH stress.


Marine Drugs ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 54 ◽  
Author(s):  
Xu ◽  
Yuan ◽  
Li ◽  
Li

Nitrogen heterocycles have drawn considerable attention due to of their significant biological activities. The marine fungi residing in extreme environments are among the richest sources of these basic nitrogen-containing secondary metabolites. As one of the most well-known universal groups of filamentous fungi, marine-derived Aspergillus species produce a large number of structurally unique heterocyclic alkaloids. This review attempts to provide a comprehensive summary of the structural diversity and biological activities of heterocyclic alkaloids that are produced by marine-derived Aspergillus species. Herein, a total of 130 such structures that were reported from the beginning of 2014 through the end of 2018 are included, and 75 references are cited in this review, which will benefit future drug development and innovation.


2019 ◽  
Vol 16 (2) ◽  
pp. 258-275 ◽  
Author(s):  
Navjeet Kaur

Background:A wide variety of biological activities are exhibited by N, O and S containing heterocycles and recently, many reports appeared for the synthesis of these heterocycles. The synthesis of heterocycles with the help of metal and non-metal catalyst has become a highly rewarding and important method in organic synthesis. This review article concentrated on the synthesis of S-heterocylces in the presence of metal and non-metal catalyst. The synthesis of five-membered S-heterocycles is described here.Objective:There is a need for the development of rapid, efficient and versatile strategy for the synthesis of heterocyclic rings. Metal, non-metal and organocatalysis involving methods have gained prominence because traditional conditions have disadvantages such as long reaction times, harsh conditions and limited substrate scope.Conclusion:The metal-, non-metal-, and organocatalyst assisted organic synthesis is a highly dynamic research field. For ßthe chemoselective and efficient synthesis of heterocyclic molecules, this protocol has emerged as a powerful route. Various methodologies in the past few years have been pointed out to pursue more sustainable, efficient and environmentally benign procedures and products. Among these processes, the development of new protocols (catalysis), which avoided the use of toxic reagents, are the focus of intense research.


2020 ◽  
Vol 17 (9) ◽  
pp. 1102-1116
Author(s):  
Sudip Kumar Mandal ◽  
Utsab Debnath ◽  
Amresh Kumar ◽  
Sabu Thomas ◽  
Subhash Chandra Mandal ◽  
...  

Background and Introduction: Sesquiterpene lactones are a class of secondary metabolite that contains sesquiterpenoids and lactone ring as pharmacophore moiety. A large group of bioactive secondary metabolites such as phytopharmaceuticals belong to this category. From the Asteraceae family-based medicinal plants, more than 5,000 sesquiterpene lactones have been reported so far. Sesquiterpene lactone-based pharmacophore moieties hold promise for broad-spectrum biological activities against cancer, inflammation, parasitic, bacterial, fungal, viral infection and other functional disorders. Moreover, these moiety based phytocompounds have been highlighted with a new dimension in the natural drug discovery program worldwide after the 2015 Medicine Nobel Prize achieved by the Artemisinin researchers. Objective: These bitter substances often contain an α, β-unsaturated-γ-lactone as a major structural backbone, which in recent studies has been explored to be associated with anti-tumor, cytotoxic, and anti-inflammatory action. Recently, the use of sesquiterpene lactones as phytomedicine has been increased. This study will review the prospect of sesquiterpene lactones against inflammation and cancer. Methods: Hence, we emphasized on the different features of this moiety by incorporating its structural diversity on biological activities to explore structure-activity relationships (SAR) against inflammation and cancer. Results: How the dual mode of action such as anti-inflammatory and anti-cancer has been exhibitedby these phytopharmaceuticals will be forecasted in this study. Furthermore, the correlation of anti-inflammatory and anti-cancer activity executed by the sesquiterpene lactones for fruitful phytotherapy will also be revealed in the present review in the milieu of pharmacophore activity relation and pharmacodynamics study as well. Conclusion: So, these metabolites are paramount in phytopharmacological aspects. The present discussion on the future prospect of this moiety based on the reported literature could be a guide for anti-inflammatory and anti-cancer drug discovery programs for the upcoming researchers.


2020 ◽  
Vol 20 (8) ◽  
pp. 970-981
Author(s):  
Hamed A. Ghramh ◽  
Essam H. Ibrahim ◽  
Mona Kilnay

Background: Juniperus procera and Majra honey are well-known as a folk medicine in many countries. Objectives: This work aimed to study the immunomodulatory effects after mixing Majra honey, J. procera water leaves extract and silver Nanoparticles (AgNPs) on immune or cancer cells. Methods: Juniperus procera water leaves extract and 20% Majra honey were prepared. Both the extract and honey were used separately to synthesize AgNPs. AgNPs were characterized using UV/Vis spectrophotometry and electron microscopy. Bioactive molecules in honey and the extract were explored using Fourier Transform Infrared (FT-IR) spectroscopy. Protein profile of honey was explored using Sodium Dodecyl Sulfate- Polyacrylamide Gel Electrophoresis (SDS-PAGE) and honey sugar content was determined using High- Performance Liquid Chromatography (HPLC). Biological activities of honey and the extract were tested. Results: The results demonstrated the ability of the extract/honey to produce AgNPs in a spherical shape. The extract/honey contained many functional groups. SDS-PAGE of Majra honey showed many protein bands. HPLC revealed honey is of good quality and no external additives are added to it. The extract and extract+ AgNPs inhibited the growth of normal rat splenic cells while honey stimulated it. The extract+honey turned stimulatory to the splenic cells’ growth and significantly diminished the inhibitory potential of the extract containing AgNPs. Both the extract and honey have antimicrobial activities, this potential increased in the presence of AgNPs. Honey and Honey+AgNPs inhibited HepG2 cancer cell proliferation while Hela cell growth inhibited only with honey+AgNPs. Conclusion: Both honey and the extract have antibacterial and immunomodulatory potentials as well as the power to produce AgNPs. Majra honey alone showed anticancer activity against HepGe2 cells, but not against Hela cells, and when contained AgNPs had anticancer activity on both cell lines. Mixing of Majra honey with J. procera extract showed characterized immunomodulatory potentials that can be described as immunostimulant.


2021 ◽  
Vol 22 (1) ◽  
pp. 403
Author(s):  
Fanni Tóth ◽  
Edina Katalin Cseh ◽  
László Vécsei

The incidence of neurodegenerative diseases has increased greatly worldwide due to the rise in life expectancy. In spite of notable development in the understanding of these disorders, there has been limited success in the development of neuroprotective agents that can slow the progression of the disease and prevent neuronal death. Some natural products and molecules are very promising neuroprotective agents because of their structural diversity and wide variety of biological activities. In addition to their neuroprotective effect, they are known for their antioxidant, anti-inflammatory and antiapoptotic effects and often serve as a starting point for drug discovery. In this review, the following natural molecules are discussed: firstly, kynurenic acid, the main neuroprotective agent formed via the kynurenine pathway of tryptophan metabolism, as it is known mainly for its role in glutamate excitotoxicity, secondly, the dietary supplement pantethine, that is many sided, well tolerated and safe, and the third molecule, α-lipoic acid is a universal antioxidant. As a conclusion, because of their beneficial properties, these molecules are potential candidates for neuroprotective therapies suitable in managing neurodegenerative diseases.


2021 ◽  
Vol 7 (7) ◽  
pp. 541
Author(s):  
Lúcia P. S. Pimenta ◽  
Dhionne C. Gomes ◽  
Patrícia G. Cardoso ◽  
Jacqueline A. Takahashi

Filamentous fungi are known to biosynthesize an extraordinary range of azaphilones pigments with structural diversity and advantages over vegetal-derived colored natural products such agile and simple cultivation in the lab, acceptance of low-cost substrates, speed yield improvement, and ease of downstream processing. Modern genetic engineering allows industrial production, providing pigments with higher thermostability, water-solubility, and promising bioactivities combined with ecological functions. This review, covering the literature from 2020 onwards, focuses on the state-of-the-art of azaphilone dyes, the global market scenario, new compounds isolated in the period with respective biological activities, and biosynthetic pathways. Furthermore, we discussed the innovations of azaphilone cultivation and extraction techniques, as well as in yield improvement and scale-up. Potential applications in the food, cosmetic, pharmaceutical, and textile industries were also explored.


Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1898
Author(s):  
Fauzia Izzati ◽  
Mega Ferdina Warsito ◽  
Asep Bayu ◽  
Anggia Prasetyoputri ◽  
Akhirta Atikana ◽  
...  

Marine invertebrates have been reported to be an excellent resource of many novel bioactive compounds. Studies reported that Indonesia has remarkable yet underexplored marine natural products, with a high chemical diversity and a broad spectrum of biological activities. This review discusses recent updates on the exploration of marine natural products from Indonesian marine invertebrates (i.e., sponges, tunicates, and soft corals) throughout 2007–2020. This paper summarizes the structural diversity and biological function of the bioactive compounds isolated from Indonesian marine invertebrates as antimicrobial, antifungal, anticancer, and antiviral, while also presenting the opportunity for further investigation of novel compounds derived from Indonesian marine invertebrates.


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