A review on the nutritional, medicinal, molecular and genome attributes of Durian (Durio zibethinus L.), the King of fruits in Malaysia

Upgraded durian genome reveals the role of chromosome reshuffling during ancestral karyotype evolution, lignin biosynthesis regulation, and stress tolerance

Durian (Durio zibethinus) is a tropical fruit that has a unique flavor and aroma. It occupies a significant phylogenetic position within the Malvaceae family. Extant core-eudicot plants are reported to share seven ancestral karyotypes that have undergone reshuffling, resulting in an abundant genomic diversity. However, the ancestral karyotypes of the Malvaceae family, as well as the evolution trajectory leading to the 28 chromosomes in durian, remain poorly understood. Here, we report the high-quality assembly of the durian genome with comprehensive comparative genomic analyses. By analyzing the collinear blocks between cacao and durian, we inferred 11 Malvaceae ancestral karyotypes. These blocks were present in a single-copy form in cacao and mainly in triplicates in durian, possibly resulting from a recent whole genome triplication (WGT) event that led to hexaploidization of the durian genome around 20 (17-24) million years ago. A large proportion of the duplicated genes in durian, such as those involved in the lignin biosynthesis module for phenylpropane biosynthesis, are derived directly from whole genome duplication, which makes it an important force in reshaping its genomic architecture. Transcriptome studies have revealed that genes involved in feruloyl-CoA formations were highly preferentially expressed in fruit peels, indicating that the thorns produced on durian fruit may comprise guaiacyl and syringyl lignins. Among all the analyzed transcription factors (TFs), members of the heat shock factor family (HSF) were the most significantly upregulated under heat stress. All subfamilies of genes encoding heat shock proteins (HSPs) in the durian genome appear to have undergone expansion. The potential interactions between HSF Dzi05.397 and HSPs were examined and experimentally verified. Our study provides a high-quality durian genome and reveals the reshuffling mechanism of ancestral Malvaceae chromosomes to produce the durian genome. We also provide insights into the mechanism underlying lignin biosynthesis and heat stress tolerance.

Changes and correlation analysis of volatile flavor compounds, amino acids, and soluble sugars in durian during different drying processes

Durian contains rich flavor components that undergo complex changes during drying. In this study, durian was subjected to integrated freeze-drying (IFD), conventional freeze-drying (CFD), and hot air drying (AD). Compared with the fresh samples, those dried by IFD, CFD, and AD lost 11, 9, and 7 original volatile compounds, respectively, and generated 7, 6, and 8 new volatile compounds, respectively, and showed a rapid and then slow decreasing trend in the total content during drying. However, the types of amino acids and soluble sugars remained unchanged during each of the drying methods. Furthermore, volatile compounds showed a significant negative correlation with the majority of amino acids and a significant positive correlation with soluble sugars. The IFD samples had the highest content of volatile compounds, amino acids, and soluble sugars. Therefore, IFD is recommended as a preferable drying method for durian.

Development of Gene-Based InDel Markers on Putative Drought Stress-Responsive Genes and Genetic Diversity of Durian (Durio zibethinus)

Insertion-deletion (InDel) markers are co-dominant, relatively abundant and practical for agarose gel genotyping. InDel polymorphism usually affects gene functions. Nucleotide sequences of durian (Durio zibethinus) are available, but InDel makers have not been well established. This study aimed to develop drought-related gene-based InDel markers for durian through bioinformatic analysis of RNA-Seq datasets. The polymorphism of the markers was verified in 24 durian genotypes local to Thailand. Bioinformatic analysis indicated 496 InDel loci having lengths more than 9 bp. To evaluate these InDel markers, 15 InDel loci were selected. Nine markers were successfully amplified a clear polymorphic band pattern on 2% agarose gel. The polymorphic information content (PIC) of these nine markers ranged from 0.1103 to 0.5808. The genetic distance between the 24 genotypes ranged from 0.222 to 0.889. The phylogeny based on the nine InDel loci distinguished the 24 genotypes and divided samples into four groups. This set of gene-based InDel markers on putative drought-responsive genes will be useful for genetic studies.

Transcriptome analysis during fruit developmental stages in durian (Durio zibethinus Murr.) var. D24

Durian (Durio zibethinus Murr.) fruits are famous for their unique aroma. This study analysed the Durian fruit transcriptome to discover the expression patterns of genes and to understand their regulation. Three developmental stages of Durian fruit, namely, early [90 days post-anthesis (DPA)], mature (120 DPA), and ripen (127 DPA), were studied. The Illumina HiSeq platform was used for sequencing. The sequence data were analysed using four different mapping aligners and statistical methods: CLC Genomic Workbench, HISAT2+DESeq2, Tophat+Cufflinks, and HISAT2+edgeR. The analyses showed that over 110 million clean reads were mapped to the Durian genome, yielding 19,976, 11,394, 17,833, and 24,351 differentially expressed genes during 90-127 days post-anthesis. Many identified differentially expressed genes were linked to the fruit ripening processes. The data analysis suggests that most genes with increased expression at the ripening stage were primarily involved in the metabolism of cofactors and vitamins, nucleotide metabolism, and carbohydrate metabolism. Significantly expressed genes from the young to mature stage were mainly associated with carbohydrate metabolism, amino acid metabolism, and cofactor and vitamin metabolism. The transcriptome data will serve as a foundation for understanding Durian fruit development-specific genes and could be helpful in fruit's trait improvement.

A Whiff of Sulfur: One Wind a Day Keeps the Doctor Away

Reactive Sulfur Species (RSS), such as allicin from garlic or sulforaphane from broccoli, are fre-quently associated with biological activities and possible health benefits in animals and humans. Among these Organic Sulfur Compounds (OSCs) found in many plants and fungi, the Volatile Sulfur Compounds (VSCs) feature prominently, not only because of their often-pungent smell, but also because they are able to access places which solids and solutions cannot reach that easily. Indeed, inorganic RSS such as hydrogen sulfide (H₂S) and sulfur dioxide (SO₂) can be used to lit-erally fumigate entire rooms and areas. Similarly, metabolites of garlic, such as allyl methyl sulfide (AMS), are formed metabolically in humans in lower concentrations and reach the airways from inside the body as part of one’s breath. Curiously, H₂S is also formed in the gastrointestinal tract by gut bacteria, and the question of if and for which purpose this gas then crosses the barriers and enters the body is indeed a delicate matter for equally delicate studies. In any case, nature is surprisingly rich in such VSCs, as fruits (for instance, the infamous durian) demonstrate, and therefore these VSCs represent a promising group of compounds for further studies.

The Effectiveness Antimicrobial of Polysaccharide Gel from Durian Peel Ethanol Extract and Chitosan Gel

BACKGROUND: Research on galenic bioactive compounds as antimicrobial agents needs to be developed. Durian peel ethanol extract is a polar polysaccharide consisting of D-galacturonic acid with -1,4 glycosidic bonds and can form a polysaccharide gel. Chitosan can be synthesized through the deacetylation of chitin as a compound (1.4)-2 amino-2deoxy D-glucopyranose and can form a gel in 1.5–2% acetic acid. The properties of chitosan are biodegradable, non-toxic, polycationic antimicrobial, and biocompatible. AIM: The study aimed to determine the effectiveness of the ethanolic extract of PG durian peel and CG as antimicrobial agents. METHODS: The research design was an experimental study and conducted at the Microbiology Laboratory, Faculty of Health, Setia Budi University, Surakarta, in August–December 2020. The research stages were the extraction of durian skin polysaccharides, bioformulation of PG durian peel extract and CG, and antimicrobial activity testing using the diffusion method. RESULTS: The results showed PG durian peel ethanolic extract concentration (100%, 50%, 25%, 12.5%, 1.5%, and CG 1.5% %) or a combination of durian peel extract PG (1.5%) and CG (1.5%) 1:1 ratio; 1:2; 2:1 was antimicrobial against Staphylococcus aureus ATCC 25923, Bacillus subtilis ATCC 6633, Escherichia coli ATCC 25922, Salmonella typhi ATCC 13311, Pseudomonas aeruginosa ATCC 27853, and Candida albicans ATCC 10231. PG durian peel ethanolic extract concentration of 100%, 50%, 25%, 12.5%, 1.5%, and CG 1.5% or a combination of durian peels ethanolic extract PG (1.5%) and CG (1.5%) ratio 1:1; 1:2; and 2:1 as an antimicrobial in vitro. CONCLUSION: PG durian peels ethanolic extract concentration 100% showed optimum effectiveness as an antimicrobial against B. subtilis ATCC 6633. Chitosan 1.5% showed optimal effectiveness as an antimicrobial against P. aeruginosa ATCC 27853. The effectiveness of the mixture of PG 1.5% and CG 1.5% ratio 1:2 showed optimum effectiveness against all test cultures.

Minor tropical fruits as a potential source of bioactive and functional foods

Tropical fruits are defined as fruits that are grown in hot and humid regions within the Tropic of Cancer and Tropic of Capricorn, covering most of the tropical and subtropical areas of Asia, Africa, Central America, South America, the Caribbean and Oceania. Depending on the cultivation area covered, economic value and popularity these tropical fruits are divided into major and minor tropical fruits. There is an annual increment of 3.8% in terms of commercialization of the tropical fruits. In total 26 minor tropical fruits (Kiwifruit, Lutqua, Carambola, Tree Tomato, Elephant apple, Rambutan, Bay berry, Mangosteen, Bhawa, Loquat, Silver berry, Durian, Persimon, Longan, Passion fruit, Water apple, Pulasan, Indian gooseberry, Guava, Lychee, Annona, Pitaya, Sapodilla, Pepino, Jaboticaba, Jackfruit) have been covered in this work. The nutritional composition, phytochemical composition, health benefits, traditional use of these minor tropical fruits and their role in food fortification have been portrayed.

Antioxidant and anti-inflammatory activities of durian (Durio zibethinus Murr.) pulp, seed and peel flour

The unripe pulp, inner peel and seed of durian were used in this study. These are generally not considered edible and must be disposed of as waste. However, they are good sources of bioactive compounds. Flour extracts from the unripe pulp, inner peel, and seed of two durian (Durio zibethinus Murr.) varieties, namely, Monthong and Chanee, were analyzed chemically to determine their total phenolic content (TPC), antioxidant, and anti-inflammatory capacities. Chanee pulp (CPu) contained a higher TPC (5285.37 ± 517.65 mg GAE/g) than Monthong pulp (MPu), Monthong peel (MP), Monthong seed (MS), Chanee peel (CP) and Chanee seed (CS) (p = 0.0027, 0.0042, 0.0229, 0.0069 and 0.36), respectively. The antioxidant activity of each durian extract was determined against ABTS, nitric oxide, superoxide, hydroxyl, and metal ions. The results indicated that the pulp, inner peel and seed of these durian varieties had antioxidant capacities. Murine Raw 264.7 macrophages were used to determine the cytotoxicity of the flour extracts. The extract of CS flour had the lowest cytotoxicity followed by MP, CPu, CP, MPu and MS (p = 0.5926, 0.44, 0.3191, 0.1471 and 0.0014), respectively. The anti-inflammatory activity was tested by anti-nitric oxide (NO) production in lipopolysaccharide (LPS) stimulated cells by co-treating the Raw 264.7 cells with each durian flour extract and LPS. The extract of MP flour had the lowest IC50 against NO production, indicating the highest anti-NO production activity followed by CS, CPu, MPu, CP and MS (p = 0.7473, 0.0104, < 0.0001, 0.0002 and < 0.0001, respectively). The information obtained in this study is useful for researchers to explore more durian varieties in Southeast Asia to find bioactive compounds that might be novel nutraceuticals for antioxidant, anti-inflammation and therapeutic functional food.

The Antimicrobial Effectiveness of Chitosan and Polysaccharide of Durian Peel Extract against Mycobacterium tuberculosis Isolates

BACKGROUND: Tuberculosis (TB) disease is an infection caused by Mycobacterium tuberculosis and is transmitted through sputum droplets of sufferers or suspect TB in the air. Chitosan as an antimicrobial agent can be used in the biomedical field because it has a number of hydroxyl groups (OH) and amine groups (NH2). The chemical substance of durian peel extract (Durio zibethinus L.) contains pectin which is multifunctional and can be used in the pharmaceutical field. Chemically, pectin is a polysaccharide polymer of D-galacturonic acid linked by -1,4 glycosidic bonds which can dissolve in water to form colloidal solutions or gels. AIM: This study was to determine the antimicrobial effectiveness of chitosan and polysaccharides from durian peel extract (D. zibethinus L.) against M. tuberculosis isolates in vitro. METHODS: The research method is based on an experimental study in vitro. M. tuberculosis isolates in this research from sputum samples of patients suspected of TB in Surakarta Regional General Hospital. The stages of the research were performed that preparation chitosan gel (CG), bioformulation of CG, and polysaccharide gel (PG) durian peel extract are 5%, 10%, 15%, 20%, and 25%, and drug susceptibility testing against M. tuberculosis isolates. RESULTS: CG 10% was effective as an antimicrobial against M. tuberculosis isolates but PG durian peel extract (5%; 10%; 15%; 20%; and 25%) was not effective as an antimicrobial against M. tuberculosis isolates. The types of anti-tuberculosis drug (ATD) that was effective against M. tuberculosis isolates were ethambutol 80% and streptomycin 40%, while isoniazid and rifampicin were not effective as ATD against M. tuberculosis isolates. CONCLUSION: CG 10% was effective as an antimicrobial against M. tuberculosis isolates, while PG 25% durian peel extract was not effective as an antimicrobial against M. tuberculosis isolates. CG has the potential as an ATD based on natural bioactive ingredients for TB therapy.

Fruit Volatile Fingerprints Characterized among Four Commercial Cultivars of Thai Durian (Durio zibethinus)

Ripe durian fruits produce unique volatiles of pungent odor comprising esters, alcohols, ketones, and sulfur-containing compounds. Recently, “Chanthaburi 1” hybrid bred from 2 famous commercial cultivars of “Chanee” and “Monthong” claimed to be less fragrant during ripening, but there was no report. The present study compared the volatile profiles from 3 Thai commercial cultivars of “Kanyao,” “Chanee,” and “Monthong” compared to “Chanthaburi 1”, and the relationships of the cultivars were organized using the volatile fingerprints. Out of 41 volatile compounds detected by SPME/GC-MS in ripe durian flesh, 33 compounds were esters, but only 14 esters were found in “Chanthaburi 1.” Ripe flesh of most durian cultivars contains ethyl-2-methyl butanoate and ethyl hexanoate as the active volatiles. “Chanthaburi 1” contained fewer components with low odor activity value (OAV) of the volatiles. “Chanee” ripe flesh exhibited the strongest durian smell among the four varieties, whereas “Monthong” exhibited a strong apple-like fruity odor and “Kanyao” was more green fruity. Diethyl disulfide and 3, 5 dimethyl-1, 2, 4-trithiolane contributing pungent smells of garlic or onion were found only in “Chanthaburi 1” and “Monthong.” In terms of detected volatiles, “Kanyao” and “Chanee” were highly close when “Monthong” was apart. PCA analysis revealed that “Chanthaburi 1” contained ester compounds ancestrally related to the parents, “Chanee” in the component I and “Monthong” in the component II. These data could be beneficial for managing the status of Thai durians in global markets.

Anti-cholinesterase potential of diverse botanical families from Malaysia: Evaluation of crude extracts and fractions from liquid-liquid extraction and acid-base fractionation

ETHNOPHARMACOLOGICAL RELEVANCE

Enhancement of cholinergic functions in the brain via acetylcholinesterase inhibition is one of the main therapeutic strategies to improve symptoms associated with Alzheimer's or related cognitive deficits. There is a pathophysiological correlation between Alzheimer's and Diabetes Mellitus, as well as inflammation and oxidative stress that may cause cognitive decline.

AIM OF THE STUDY

The present study was intended to evaluate anti-cholinesterase potential of 177 Malaysian plant extracts from 148 species known to have related ethnomedicinal uses such as anti-inflammatory, anti-oxidant, anti-diabetic, epilepsy, headache, memory enhancement and anti-aging.

MATERIALS AND METHODS

Anti-cholinesterase screening against both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes was performed on the basis of in-vitro colorimetric 96-well microplate-based assay method. Potent active plant extracts were subjected to liquid-liquid extraction and acid-base fractionation for further analysis.

RESULTS

Fifty-seven plant extracts exhibited potent anti-cholinesterase activities (50-100% inhibition) at 200 μg/ml. Majority of the active plants originated from Fabaceae family. Coccoloba uvifera (L.) L. stem extract manifested the lowest IC₅₀ of 3.78 μg/ml for AChE and 5.94 μg/ml for BChE. A few native species including Tetracera indica (Christm. & Panz.) Merr., Cyrtostachys renda Blume and Ixora javanica (Blume) DC. showed cholinesterase inhibition despite limited local medical applications. Further anti-AChE evaluation (50 μg/ml) of 18 potent plant extracts harbored active polar components in butanol and water fractions, except Senna pendula (Willd.) H.S.Irwin & Barneby (leaves and stems), Acacia auriculiformis Benth. (leaves), Artocarpus altilis (Parkinson ex F.A.Zorn) Fosberg (leaves), and Macaranga tanarius (L.) Mull.Arg. (leaves) that showed inhibitory activity in less polar fractions. The acidic extraction of these four plant species improved their inhibition level against AChE.

CONCLUSION

This study rendered a preliminary overview of anti-cholinesterase activity from diverse Malaysian botanical families in which provided the medical relevance toward these native plant species, especially ones with limited ethnobotanical record or practice.

Bioactive Compounds, Nutritional Value, and Potential Health Benefits of Indigenous Durian (Durio Zibethinus Murr.): A Review

Durian (Durio zibethinus Murr.) is an energy-dense seasonal tropical fruit grown in Southeast Asia. It is one of the most expensive fruits in the region. It has a creamy texture and a sweet-bitter taste. The unique durian flavour is attributable to the presence of fat, sugar, and volatile compounds such as esters and sulphur-containing compounds such as thioacetals, thioesters, and thiolanes, as well as alcohols. This review shows that durian is also rich in flavonoids (i.e., flavanols, anthocyanins), ascorbic acid, and carotenoids. However, limited studies exist regarding the variation in bioactive and volatile components of different durian varieties from Malaysia, Thailand, and Indonesia. Experimental animal models have shown that durian beneficially reduces blood glucose and cholesterol levels. Durian extract possesses anti-proliferative and probiotics effects in in vitro models. These effects warrant further investigation in human interventional studies for the development of functional food.