An unusual triterpene fatty acid conjugate was isolated from the leaf resin of Dodonaea caespitosa. Its structure was formulated through spectroscopic analysis of the acetylated natural product and its hydrolysis products (p-hydroxydihydrocinnamic acid, (S)-(+)-8,16-dihydroxypalmitic acid and 30-hydroxybetulin). The stereochemistry of the hydroxyl at C8 of (S)-(+)-8,16-dihydroxypalmitic acid was determined by conversion to the known (S)-(+)-(8)-hydroxypalmitic acid using a Barton-McCombie deoxygenation reaction.

Human papillomavirus (HPV) infections are the cause of warts, lesions and cancer, with different types of HPV causing different symptoms. HPV infections are the primary cause of cervical cancer. There are over 220 different types of HPV, and only nine of these can currently be vaccinated. There is a need to treat these viral infections without just treating the symptoms of the infection, as is currently the main method. There is a wide range of small molecules that have been used to inhibit various stages of the HPV infectious cycle. This review examined 132 small molecules from 121 studies that specifically target aspects of HPV infections. HPV DNA encodes for six early genes (E1 to E7, skipping E3) and two late genes (L1 and L2). According to the results, these targets for small molecule inhibitors fall into three categories: those targeting E1 and E2, targeting E6 and E7 and, finally, targeting L1 and L2. Inhibitors of E6 and E7 are the most widely studied targets, with the majority of HPV inhibition in this area. While compounds targeting both E1/E2 and E6/E7 have made it to clinical trials, there has been no significant advancement on the topic.

Antitumour properties of some cannabinoids (CB) have been reported in the literature as early as 1970s, however there is no clear consensus to date on the exact mechanisms leading to cancer cell death. The indole-based WIN 55,212-2 and SDB-001 are both known as potent agonists at both CB1 and CB2 receptors, yet we demonstrate herein that only the former can exert in vitro antitumour effects when tested against a paediatric brain cancer cell line KNS42. In this report, we describe the synthesis of novel 3,4-fused tricyclic indoles and evaluate their functional potencies at both cannabinoid receptors, as well as their abilities to inhibit the growth or proliferation of KNS42 cells. Compared to our previously reported indole-2-carboxamides, these 3,4-fused tricyclic indoles had either completely lost activities, or, showed moderate-to-weak antagonism at both CB1 and CB2 receptors. Compound 23 displayed the most potent antitumour properties among the series. Our results further support the involvement of non-CB pathways for the observed antitumour activities of amidoalkylindole-based cannabinoids, in line with our previous findings. Transcriptomic analysis comparing cells treated or non-treated with compound 23 suggested the observed antitumour effects of 23 are likely to result mainly from disruption of the FOXM1-regulated cell cycle pathways.

Truffles usually contain a high microbial load and establishing a decontamination strategy without affecting the organoleptic features of fresh truffles before any postharvest processing is an imperative. In this study, the im-pacts of decontamination treatments including ozonated water (3 mg/L and 6 mg/L) and citric acid (5% and 10%) on the microbiological populations (total aerobic, total anaerobic, and Pseudomonas spp. counts) and organoleptic characteristics (firmness and colour) of fresh truffles were investigated. Furthermore, the effect of time of exposure (5, 10, 15, and 20 min) to each treatment was assessed. Treatment that demonstrated the most effective microbial reduction without compromising the colour and firmness of truffles was deemed preferred and its impact on the key volatile profile of truffles was assessed. Truffles treated with different concentrations and exposure times of ozonated water showed no significant changes in microbial counts, firmness, or colour compared to the control. A significant microbial reduction without compromising the colour and firmness of truffles was observed with citric acid treatments. In particular, the antimicrobial effect of citric acid against Pseudomonas spp. was improved significantly with increasing concentration and exposure time. Truffles treated with 10% citric acid treatment for 15 min promoted about 1.0 log CFU/g of reduction for the total aerobic and anaerobic microbes and the Pseudomonas spp. count was reduced from 6.18 +/- 0.19 log CFU/g (control) to < 3.48 log CFU/g. The key volatile profile of the selected treatment was not significantly different from the control. The overall finding shows that a single-step washing with citric acid could be a promising decontamination treatment for fresh truffles before any postharvest processing.

This study aimed to develop a novel technique to retain and stabilize compounds contributing to truffle aroma by encapsulation using β-cyclodextrin. Two experiments were conducted. In the first experiment, the key volatile profile and microbial population of products resulting from three different encapsulation methods, namely direct mixing method (M1), direct mixing followed by ethanol addition method (M2), and paste method (M3), were compared with untreated truffles (positive control) over a 90-day period. The M2-derived product was the least optimal for retaining key volatile compounds despite showing the lowest microbial population. There was no significant difference in the volatile profile of products derived from M1 and M3 on day 0. However, it was observed that the M3-derived product could retain its volatile profile better than the M1-derived product by day 90. M3 was compared with freeze-drying in the second experiment. Freeze-dried truffles showed an overall higher relative percentage of volatiles than the M3-derived product on day 0. However, by day 90, some volatile changes occurred in the freeze-dried truffles but not in the M3-derived product. The findings indicate that while freeze-drying could adequately conserve truffle volatiles, the encapsulation of volatile compounds in β-cyclodextrin could improve the volatile stability of truffle products and allow for longer storage times. Microbes were found in all encapsulated truffle products and freeze-dried truffles on days 0 and 90, suggesting the need to explore the possibility of incorporating a decontamination step in the process prior to either encapsulation or freeze-drying. PRACTICAL APPLICATION: A technique to capture and stabilize compounds responsible for truffle aroma by encapsulation using β-cyclodextrin was developed and compared with freeze-drying in this study. The overall finding suggests that while freeze-drying of truffle could sufficiently preserve volatiles, encapsulating truffle volatiles with β-cyclodextrin may improve its stability, extending its shelf life, which can be applied in the development of a natural truffle ingredient that can be applied in food product development.

This work investigated the effects of lemon and cinnamon oil fumigation on quality parameters and ethylene production of organic apples when kept for 100 and 180 d in a controlled atmosphere condition. Apples were fumigated with 3, 4 or 5 mu M of lemon or cinnamon oils in 60 L sealed plastic barrels for 24 h at room temperature (similar to 20 degrees C) and untreated apple fruit was considered as a control. Following 180 d storage, both lemon and cinnamon oil fumigations significantly decreased the climacteric ethylene production rates, maintained higher quality parameters and reduced superficial scald disorder in both cultivars in comparison with the control fruit. Also, fumigated apples exhibited an increased in firmness up to 26 %, titratable acidity up to 92 %, total phenol up to 130 %, ascorbic acid up to 92 % and total antioxidants up to 104 % when compared with control. Respiration climacteric peaks were reduced in both cultivars stored for 180 d as well. Therefore, through ethylene inhibition, lemon and cinnamon oils have the potential for use in organic apple production to maintain postharvest apple quality.

The cover image is based on the Original Article Methods used for extraction of plant volatiles have potential to preserve truffle aroma: A review by Ranil Coorey et al., https://doi.org/10.1111/1541-4337.12927.

Truffles are considered one of the world's most highly prized foods mainly due to their desirable organoleptic properties and rarity. However, truffles are seasonal (harvested mostly in winter from June to August in the Southern Hemisphere and from December to February in the Northern Hemisphere) and extremely perishable. Truffles deteriorate rapidly showing undesirable changes within 10 days from harvest in aroma and visual appearance after harvest. The very short postharvest shelf life (about 7-10 days) limits the potential for export and domestic consumption all year round. Several preservation methods have been studied to prolong their shelf life without the loss of aroma. However, all traditional preservation techniques have their own shortcomings and remain challenging. The extraction of natural truffle aroma volatiles for food applications could be a potential alternative to replace the existing synthetic flavoring used for processed truffle products. Four commonly used extraction methods for recovering volatile compounds from plants, namely, supercritical carbon dioxide extraction, Soxhlet extraction, distillation, and cold pressing, are critically analyzed. Up to date, existing research about the extraction of aroma volatiles from truffles is limited in the literature but based on the volatility of the key truffle volatile compounds, supercritical carbon dioxide extraction may offer the best possibility so that a natural truffle-based product that can be used in food applications throughout the year can be made available.

Black truffle ( Tuber melanosporum ) is usually available in a form of a whole, offcut pieces (sliced to remove defects or broken from larger truffles) or freeze-dried (one of the preservation methods), but there is insufficient knowledge about microbial spoilage of these products. The changes in the microbiology of whole, sliced, and freeze-dried black truffles ( Tuber melanosporum ) were determined in this study. All truffle samples were vacuum-packaged and stored at 4°C for 30 days and evaluated on day 0, 4, 8, 15, and 30. The total plate count, Pseudomonas spp. count, yeast, and mold count, as well as the presence of Listeria spp., Salmonella spp., and Bacillus spp., were examined. The main finding of this study was that the total microbial count, Pseudomonas spp. count, and yeasts count associated with the freeze-dried truffles were generally lower than that of the whole and sliced truffles. While mold, Listeria spp., and Salmonella spp. were not detected (<2.00 log CFU/g), Bacillus spp. were detected at a very low count in all sample types (<3.48 log CFU/g). Overall, the results suggest the need to establish an effective decontamination treatment before packaging and storage to delay microbial spoilage.

Fresh truffles which include black truffle (Tuber melanosporum Vittadini) deteriorate and lose aroma rapidly after harvest; therefore, postharvest processing via freeze-drying or encapsulation is an option to preserve truffle aroma for extended supply. However, the aroma profile that directly affects the truffle quality and consumer acceptance is influenced by processing and producers require processing options that balance processing feasibility with retention of a suitable aroma profile. This study aimed to determine the impact of freeze-drying and encapsulation on the profile of key volatiles, consumer discrimination, and overall sensory impression (aroma intensity, liking, and acceptability) of processed truffle products compared to the starting material (positive control). The study combined experimental-scale processing with GC-MS analysis and consumer sensory evaluation to compare and optimize postharvest processing options. Based on the results, some volatile changes were detected in the processed truffle products compared to the positive control which were aligned with the consumer discrimination (triangle test) and the aroma intensity score (consumer sensory test). Despite some chemical and sensory differences detected, the consumer panel did not have any preference for processed truffle products compared to the positive control. The overall finding indicates the potential value of processing truffles into a natural flavoring ingredient for food application via freeze-drying or encapsulation, which should be of great interest for the truffle and food industry. According to the correlation analysis, the consumer acceptance of a truffle product may be increased by retaining 1-octen-3-ol and methional, while reducing the amount of p-cresol in the product. Practical Application The postharvest process of turning truffles into a food flavoring ingredient may cause undesirable volatile changes that would directly impact the aroma quality and consumer acceptance of the processed truffle products. Hence, the impacts of freeze-drying and encapsulation on the chemical and sensory profile of truffles were evaluated in this study. Overall, the results of the concurrent instrument and sensory analysis demonstrated that both freeze-drying and encapsulation are potential options for processing.

There has been an expanding public interest towards the notion that modulation of the sophisticated endocannabinoid system can lead to various therapeutic benefits that are yet to be fully explored. In recent years, the drug discovery paradigm in this field has been largely based on the development of selective CB2 receptor agonists, avoiding the unwanted CB1 receptor-mediated psychoactive side effects. Mechanistically, target engagement studies are crucial for confirming the ligand–receptor interaction and the subsequent biological cascades that lead to the observed therapeutic effects. Concurrently, imaging techniques for visualisation of cannabinoid receptors are increasingly reported in the literature. Small molecule imaging tools ranging from phytocannabinoids such as tetrahydrocannabinol (THC) and cannabidiol (CBD) to the endocannabinoids as well as the purely synthetic cannabimimetics, have been explored to date with varying degrees of success. This Review will cover currently known photoactivatable, electrophilic, and fluorescent ligands for both the CB1 and CB2 receptors. Structural insights from techniques such as ligand-assisted protein structure (LAPS) and the discovery of novel allosteric modulators are significant additions for better understanding of the endocannabinoid system. There has also been a plethora of fluorescent conjugates that have been assessed for their binding to cannabinoid receptors as well as their potential for cellular imaging. More recently, bifunctional probes containing either fluorophores or electrophilic tags are becoming more prevalent in the literature. Collectively, these molecular tools are invaluable in demonstrating target engagement within the human endocannabinoid system.

Human African Trypanosomiasis (HAT) is a neglected tropical disease caused by the parasitic protozoan Trypanosoma brucei (T. b.), and affects communities in sub-Saharan Africa. Previously, analogues of a tetrahydroisoquinoline scaffold were reported as having in vitro activity (IC50 = 0.25-70.5 mu M) against T. b. rhodesiense. In this study the synthesis and antitrypanosomal activity of 80 compounds based around a core tetrahydroisoquinoline scaffold are reported. A detailed structure activity relationship was revealed, and five derivatives (two of which have been previously reported) with inhibition of T. b. rhodesiense growth in the sub-micromolar range were identified. Four of these (3c, 12b, 17b and 26a) were also found to have good selectivity over mammalian cells (SI > 50). Calculated logD values and preliminary ADME studies predict that these compounds are likely to have good absorption and metabolic stability, with the ability to passively permeate the blood brain barrier. This makes them excellent leads for a blood-brain barrier permeable antitrypanosomal scaffold. (C) 2021 Published by Elsevier Masson SAS.

The omnipresent threat of tuberculosis (TB) and the scant treatment options thereof necessitate the development of new antitubercular agents, preferably working via a novel mechanism of action distinct from the current drugs. Various studies identified the mycobacterial membrane protein large 3 transporter (MmpL3) as the target of several classes of compounds, including the indole-2-caboxamides. Herein, several indoleamide analogues were rationally designed, synthesised, and evaluated for their antitubercular and antitumour activities. Compound 8g displayed the highest activity (MIC = 0.32 μM) against the drug-sensitive (DS) Mycobacterium tuberculosis (M. tb) H37Rv strain. This compound also exhibited high selective activity towards M. tb over mammalian cells [IC50 (Vero cells) = 40.9 μM, SI = 128], suggesting its minimal cytotoxicity. In addition, when docked into the MmpL3 active site, 8g adopted a binding profile similar to the indoleamide ligand ICA38. A related compound 8f showed dual antitubercular (MIC = 0.62 μM) and cytotoxic activities against paediatric glioblastoma multiforme (GBM) cell line KNS42 [IC50 (viability) = 0.84 μM]. Compound 8f also showed poor cytotoxic activity against healthy Vero cells (IC50 = 39.9 μM). Compounds 9a and 15, which were inactive against M. tb, showed potent cytotoxic (IC50 = 8.25 and 5.04 μM, respectively) and antiproliferative activities (IC50 = 9.85 and 6.62 μM, respectively) against KNS42 cells. Transcriptional analysis of KNS42 cells treated with compound 15 revealed a significant downregulation in the expression of the carbonic anhydrase 9 (CA9) and the spleen tyrosine kinase (SYK) genes. The expression levels of these genes in GBM tumours were previously shown to contribute to tumour progression, suggesting their involvement in our observed antitumour activities. Compounds 9a and 15 were selected for further evaluations against three different paediatric brain tumour cell lines (BT12, BT16 and DAOY) and non-neoplastic human fibroblast cells HFF1. Compound 9a showed remarkable cytotoxic (IC50 = 0.89 and 1.81 μM, respectively) and antiproliferative activities (IC50 = 7.44 and 6.06 μM, respectively) against the two tested atypical teratoid/rhabdoid tumour (AT/RT) cells BT12 and BT16. Interestingly, compound 9a was not cytotoxic when tested against non-neoplastic HFF1 cells [IC50 (viability) = 119 μM]. This suggests that an indoleamide scaffold can be fine-tuned to confer a set of derivatives with selective antitubercular and/or antitumour activities.

Analysis of the epicuticular wax layer on the surface of plant leaves can provide a unique window into plant physiology and responses to environmental stimuli. Well‐established analytical methodologies can quantify epicuticular wax composition, yet few methods are capable of imaging wax distribution in situ or in vivo. Here, the first report of Fourier transform infrared (FTIR) reflectance spectroscopic imaging as a non‐destructive, in situ, method to investigate variation in epicuticular wax distribution at 25 µm spatial resolution is presented. The authors demonstrate in vivo imaging of alterations in epicuticular waxes during leaf development and in situ imaging during plant disease or exposure to environmental stressors. It is envisaged that this new analytical capability will enable in vivo studies of plants to provide insights into how the physiology of plants and crops respond to environmental stresses such as disease, soil contamination, drought, soil acidity, and climate change.

Several rationally designed isoniazid (INH), pyrazinamide (PZA) and ciprofloxacin (CPF) derivatives were conveniently synthesized and evaluated in vitro against H37Rv Mycobacterium tuberculosis ( M. tb ) strain. CPF derivative 16 displayed a modest activity (MIC = 16 µg/ml) and was docked into the M. tb DNA gyrase. Isoniazid‐pyrazinoic acid (INH‐POA) hybrid 21a showed the highest potency in our study (MIC = 2 µg/ml). It also retained its high activity against the other tested M. tb drug‐sensitive strain (DS) V4207 (MIC = 4 µg/ml) and demonstrated negligible cytotoxicity against Vero cells (IC 50 ≥ 64 µg/ml). Four tested drug‐resistant (DR) M. tb strains were refractory to 21a , similar to INH, whilst being sensitive to CPF. Compound 21a was also inactive against two non‐tuberculous mycobacterial (NTM) strains, suggesting its selective activity against M. tb . The noteworthy activity of 21a against DS strains and its low cytotoxicity highlight its potential to treat DS M. tb .

The treacherous nature of tuberculosis (TB) combined with the ubiquitous presence of the drug-resistant (DR) forms pose this disease as a growing public health menace. Therefore, it is imperative to develop new chemotherapeutic agents with a novel mechanism of action to circumvent the cross-resistance problems. The unique architecture of the Mycobacterium tuberculosis (M. tb) outer envelope plays a predominant role in its pathogenesis, contributing to its intrinsic resistance against available therapeutic agents. The mycobacterial membrane protein large 3 (MmpL3), which is a key player in forging the M. tb rigid cell wall, represents an emerging target for TB drug development. Several indole-2-carboxamides were previously identified in our group as potent anti-TB agents that act as inhibitor of MmpL3 transporter protein. Despite their highly potent in vitro activities, the lingering Achilles heel of these indoleamides can be ascribed to their high lipophilicity as well as low water solubility. In this study, we report our attempt to improve the aqueous solubility of these indole-2-carboxamides while maintaining an adequate lipophilicity to allow effective M. tb cell wall penetration. A more polar adamantanol moiety was incorporated into the framework of several indole-2-carboxamides, whereupon the corresponding analogues were tested for their anti-TB activity against drug-sensitive (DS) M. tb H37Rv strain. Three adamantanol derivatives 8i, 8j and 8l showed nearly 2- and 4-fold higher activity (MIC = 1.32 - 2.89 mu M) than ethambutol (MIC = 4.89 mu M). Remarkably, the most potent adamantanol analogue 8j demonstrated high selectivity towards DS and DR M. tb strains over mammalian cells [IC50 (Vero cells) >= 169 mu M], On evincing its lack of cytotoxicity. The top eight active compounds 8b, 8d, 8f, 8i, 8j, 8k, 8l and 10a retained their in vitro potency against DR M. tb strains and were docked into the MmpL3 active site. The most potent adamantanol/adamantane-based indoleamides 8j/8k displayed a two-fold surge in potency against extensively DR (XDR) M. tb strains with MIC values of 0.66 and 0.012 mu M, respectively. The adamantanol-containing indole-2-carboxamides exhibited improved water solubility both in silico and experimentally, relative to the adamantane counterparts. Overall, the observed antimycobacterial and physicochemical profiles support the notion that adamantanol moiety is a suitable replacement to the adamantane scaffold within the series of indole-2-carboxamide-based MmpL3 inhibitors.

Our group has previously reported several indolecarboxamides exhibiting potent antitubercular activity. Herein, we rationally designed several arylcarboxamides based on our previously reported homology model and the recently published crystal structure of the mycobacterial membrane protein large 3 (MmpL3). Many analogues showed considerable anti-TB activity against drug-sensitive (DS) Mycobacterium tuberculosis (M. tb) strain. Naphthamide derivatives 13c and 13d were the most active compounds in our study (MIC: 6.55, 7.11 μM, respectively), showing comparable potency to the first line anti-tuberculosis (anti-TB) drug ethambutol (MIC: 4.89 μM). In addition to the naphthamide derivatives, we also identified the quinolone-2-carboxamides and 4-arylthiazole-2-carboxamides as potential MmpL3 inhibitors in which compounds 8i and 18b had MIC values of 9.97 and 9.82 μM, respectively. All four compounds retained their high activity against multidrug-resistant (MDR) and extensively drug-resistant (XDR) M. tb strains. It is worth noting that the two most active compounds 13c and 13d also exhibited the highest selective activity towards DS, MDR and XDR M. tb strains over mammalian cells [IC50 (Vero cells) ≥ 227 μM], indicating their potential lack of cytotoxicity. The four compounds were docked into the MmpL3 active site and were studied for their drug-likeness using Lipinski's rule of five.

BACKGROUNDMycolic acids (MAs) are the characteristic, integral building blocks for the mycomembrane belonging to the insidious bacterial pathogen Mycobacterium tuberculosis (M.tb). These C60-C90 long α-alkyl-β-hydroxylated fatty acids provide protection to the tubercle bacilli against the outside threats, thus allowing its survival, virulence and resistance to the current antibacterial agents. In the post-genomic era, progress has been made towards understanding the crucial enzymatic machineries involved in the biosynthesis of MAs in M.tb. However, gaps still remain in the exact role of the phosphorylation and dephosphorylation of regulatory mechanisms within these systems. To date, a total of 11 serine-threonine protein kinases (STPKs) are found in M.tb. Most enzymes implicated in the MAs synthesis were found to be phosphorylated in vitro and/or in vivo. For instance, phosphorylation of KasA, KasB, mtFabH, InhA, MabA, and FadD32 downregulated their enzymatic activity, while phosphorylation of VirS increased its enzymatic activity. These observations suggest that the kinases and phosphatases system could play a role in M.tb adaptive responses and survival mechanisms in the human host. As the mycobacterial STPKs do not share a high sequence homology to the human's, there have been some early drug discovery efforts towards developing potent and selective inhibitors.OBJECTIVERecent updates to the kinases and phosphatases involved in the regulation of MAs biosynthesis will be presented in this mini-review, including their known small molecule inhibitors.CONCLUSIONMycobacterial kinases and phosphatases involved in the MAs regulation may serve as a useful avenue for antitubercular therapy.