Quillaic Acid–Containing Saponin-Based Immunoadjuvants Trigger Early Immune Responses

Saponins of Selected Triterpenoids as Potential Therapeutic Agents: A Review

Saponins represent important natural derivatives of plant triterpenoids that are secondary plant metabolites. Saponins, also named glycoconjugates, are available both as natural and synthetic products. This review is focused on saponins of the oleanane, ursane, and lupane types of triterpenoids that include several plant triterpenoids displaying various important pharmacological effects. Additional convenient structural modifications of naturally-occurring plant products often result in enhancing the pharmacological effects of the parent natural structures. This is an important objective for all semisynthetic modifications of the reviewed plant products, and it is included in this review paper as well. The period covered by this review (2019–2022) is relatively short, mainly due to the existence of previously published review papers in recent years.

Vaccine development for bacterial pathogens: Advances, challenges and prospects

The advent and use of antimicrobials have played a key role in treating potentially life-threatening infectious diseases, improving health, and saving the lives of millions of people worldwide. However, the emergence of multidrug resistant (MDR) pathogens has been a significant health challenge that has compromised the ability to prevent and treat a wide range of infectious diseases that were once treatable. Vaccines offer potential as a promising alternative to fight against antimicrobial resistance (AMR) infectious diseases. Vaccine technologies include reverse vaccinology, structural biology methods, nucleic acid (DNA and mRNA) vaccines, generalised modules for membrane antigens, bioconjugates/glycoconjugates, nanomaterials and several other emerging technological advances that are offering a potential breakthrough in the development of efficient vaccines against pathogens. This review covers the opportunities and advancements in vaccine discovery and development targeting bacterial pathogens. We reflect on the impact of the already-developed vaccines targeting bacterial pathogens and the potential of those currently under different stages of preclinical and clinical trials. More importantly, we critically and comprehensively analyse the challenges while highlighting the key indices for future vaccine prospects. Finally, the issues and concerns of AMR for low-income countries (sub-Saharan Africa) and the challenges with vaccine integration, discovery and development in this region are critically evaluated.

Soapbark Triterpenes: Quillaja brasiliensis Cell Culture Sapogenin and Free Sterol Analysis by GCMS

Triterpene saponins of the genus Quillaja (Quillajaceae) are known for their immunoadjuvant, hypocholesterolemic, and anti-inflammatory activity. Plant cell cultures are useful for the study of saponin metabolism and industrial production of these bioactive compounds. While structurally related phytosterols are primary metabolites essential to growth and development, saponins are responsive to pathogen and abiotic stress, fulfilling roles in plant specialized metabolism. For cell culture production of saponins, phytosterols may be considered a competing pathway which relies on a common pool of cytosolic isoprenoid precursors.Understanding the metabolic allocation of resources between these two related pathways is key to maximizing saponin production in in vitro production systems. Sterols and saponins naturally occur in multiple conjugated forms, which complicate separation and quantification. The acid hydrolysis of conjugated sterols and saponins to their free forms is a useful technique to simplify their analysis by gas chromatography. Here we provide the workflow for the quantification of free sterols and sapogenins in cell cultures of Quillaja brasiliensis .