scholarly journals Pyrrolizidine Alkaloids: Biosynthesis, Biological Activities and Occurrence in Crop Plants

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 498 ◽  
Author(s):  
Sebastian Schramm ◽  
Nikolai Köhler ◽  
Wilfried Rozhon

Pyrrolizidine alkaloids (PAs) are heterocyclic secondary metabolites with a typical pyrrolizidine motif predominantly produced by plants as defense chemicals against herbivores. They display a wide structural diversity and occur in a vast number of species with novel structures and occurrences continuously being discovered. These alkaloids exhibit strong hepatotoxic, genotoxic, cytotoxic, tumorigenic, and neurotoxic activities, and thereby pose a serious threat to the health of humans since they are known contaminants of foods including grain, milk, honey, and eggs, as well as plant derived pharmaceuticals and food supplements. Livestock and fodder can be affected due to PA-containing plants on pastures and fields. Despite their importance as toxic contaminants of agricultural products, there is limited knowledge about their biosynthesis. While the intermediates were well defined by feeding experiments, only one enzyme involved in PA biosynthesis has been characterized so far, the homospermidine synthase catalyzing the first committed step in PA biosynthesis. This review gives an overview about structural diversity of PAs, biosynthetic pathways of necine base, and necic acid formation and how PA accumulation is regulated. Furthermore, we discuss their role in plant ecology and their modes of toxicity towards humans and animals. Finally, several examples of PA-producing crop plants are discussed.

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.


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.


Planta Medica ◽  
2021 ◽  
Author(s):  
Jerald Nair ◽  
Johannes Van Staden

The Amaryllidaceae features prominently amongst bulbous flowering plant families. Accommodating about a third of its species, South Africa affords a sound basis for Amaryllidaceae plant research. Boophone, Nerine, Crossyne, Clivia, Cryptostephanus, Haemanthus and Scadoxus have been well-represented in such endeavors. The account herein summarizes the studies undertaken between 2013-2020 on these genera in regards to their chemical and biological characteristics. A total of 136 compounds comprising 63 alkaloids and 73 non-alkaloid entities were described during this period from eighteen members of the title genera. The alkaloids were reflective of the structural diversity found in eight isoquinoline alkaloid groups of the Amaryllidaceae. Of these, the crinane (29 compounds), lycorane and homolycorine (11 compounds each) groups were the most-represented. The non-alkaloid substances were embracive of the same number of unrelated groups including, acids, phenolics, flavonoids and triterpenoids. A wide variety of assays were engaged to ascertain the biological activities of the isolated compounds, notably in regards to cancer and motorneuron-related diseases. There were also attempts made to determine the antimicrobial, anti-inflammatory and antioxidant effects of some of the substances. New information has also emerged on the herbicidal, insecticidal and plant growth regulatory effects of selected alkaloid principles. Coupled to the biological screening measures were in instances probes made to establish the molecular basis to some of the activities, particularly in relation to cancer and Parkinsonʹs disease.


2021 ◽  
Vol 18 ◽  
Author(s):  
Meenu Devi ◽  
Shivangi Jaiswal ◽  
Sonika Jain ◽  
Navjeet Kaur ◽  
Jaya Dwivedi

: Nitrogen-containing heterocycles attract the attention of chemists due to their multifarious activities. Amongst all, pyrimidine plays a central role and exhibits a broad spectrum of biological activities. Literature is replete with the various aspects of synthetic development in pyrimidine chemistry for a wide array of applications. It aroused our interest to compile various novel and efficient synthetic approaches towards the synthesis of pyrimidine and its derivatives. Pyrimidine derivatives are broadly useful as therapeutic agents, owing to their high degree of structural diversity. They have been recorded to possess a diverse range of therapeutic activities, viz. anticancer, anti-inflammatory, anti-HIV etc.


Molecules ◽  
2022 ◽  
Vol 27 (1) ◽  
pp. 305
Author(s):  
Willy Cely-Veloza ◽  
Diego Quiroga ◽  
Ericsson Coy-Barrera

Fusarium oxysporum is an aggressive phytopathogen that affects various plant species, resulting in extensive local and global economic losses. Therefore, the search for competent alternatives is a constant pursuit. Quinolizidine alkaloids (QA) are naturally occurring compounds with diverse biological activities. The structural diversity of quinolizidines is mainly contributed by species of the family Fabaceae, particularly the genus Lupinus. This quinolizidine-based chemo diversity can be explored to find antifungals and even mixtures to address concomitant effects on F. oxysporum. Thus, the antifungal activity of quinolizidine-rich extracts (QREs) from the leaves of eight greenhouse-propagated Lupinus species was evaluated to outline promising QA mixtures against F. oxysporum. Thirteen main compounds were identified and quantified using an external standard. Quantitative analysis revealed different contents per quinolizidine depending on the Lupinus plant, ranging from 0.003 to 32.8 mg/g fresh leaves. Bioautography showed that all extracts were active at the maximum concentration (5 µg/µL). They also exhibited >50% mycelium growth inhibition. All QREs were fungistatic except for the fungicidal QRE of L. polyphyllus Lindl. Angustifoline, matrine, 13α-hydroxylupanine, and 17-oxolupanine were ranked to act jointly against the phytopathogen. Our findings constitute reference information to better understand the antifungal activity of naturally afforded QA mixtures from these globally important plants.


Author(s):  
Е.Ю. Лебедева ◽  
А.Ю. Сергеев

В статье представлены результаты археоботанических исследований в Московском Кремле и обсуждается проблема использования растений жителями города с особым акцентом на потреблении зерновой продукции. Материалы рассматриваются по двум хронологическим выборкам (XII - перв. пол. XIII в. и втор. пол. XIII - XV в.), что позволяет проследить динамику изменения археоботанических спектров. Выделяются три специфические черты, характеризующие коллекцию зерновых в Москве. Во-первых, высокая насыщенность зерном культурного слоя во-вторых, стабильно высокий показатель доли ржи на протяжении столетий (ок. 70 ) и, в-третьих, остающийся непонятным факт сокращения на 10 доли овса в поздней выборке. Последнее, по мнению авторов, противоречит логике развития города, требующей увеличения фуражных запасов для лошадей - основного транспортного средства средневековья. Авторы приходят к выводу, что при отсутствии или скудости находок экзотических растений, выступающих маркерами элитного питания в европейских городах, в средневековой Руси в этом качестве могут интерпретироваться обычные зерновые культуры, в частности - мягкая пшеница. The paper presents the results of archaeobotanical studies in the Moscow Kremlin and discusses the use of plants by the city residents with a focus on consumption of crops. The analysis is based on two chronological selections (the 12th - first half of the 13th centuries and the first half of the 13th - 15th centuries) it gives an insight into the changes over time of archaeobotanical spectra. Three specific features characterizing the crop grains in Moscow are singled out. Firstly, abundance of crop plants in the occupation layers secondly, consistently high values of the rye share in total crops throughout centuries (around 70 ) and, thirdly, the reduction in the share of oats by 10 in the later sample for some inexplicable reasons. In the view of the authors, the latter fact contradicts the logical development of the city that required increase in forage reserves for horses which was the main animal for transportation in the medieval times. The authors come to the conclusion that in the absence or scarcity of exotic plant finds used as markers of luxury food in European cities, common grain crops such as bread wheat can be used as elite food indicator in Medieval Russia.


Author(s):  
Shaoquan Lin ◽  
Han Liu ◽  
Esben B. Svenningsen ◽  
Christine Pedersen ◽  
Peter Nørby ◽  
...  

The polyether ionophores are complex natural products capable of transporting cations across biological membranes. Many family members possess highly potent antimicrobial activity and a few selected compounds have ability to target particularly aggressive cancer cells. Despite these interesting perspectives, a detailed understanding of the cellular mode-of-action of polyether ionophores is generally lacking. In principle, broad mapping of structure-activity relationships across several biological activities could provide mechanistic insights as well as identification of lead structures but access to structural diversity within the overall class is synthetically very challenging. In this manuscript, we demonstrate that novel polyether ionophores can be constructed by recycling components of highly abundant polyethers. We provide the first examples of synthetically incorporating halogen-functionalized tetronic acids as cation-binding groups into polyether ionophores and we identify analogs with strong anti-bacterial activity and minimal effects on mammalian cells.


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