Hamidun Bunawan

Analysis of the Chemical Composition of the Essential Oil of Polygonum minus Huds. Using Two-Dimensional Gas Chromatography-Time-of-Flight Mass Spectrometry (GC-TOF MS)

The essential oil in leaves of Polygonum minus Huds., a local aromatic plant, were identified by a pipeline of gas chromatography (GC) techniques coupled with mass-spectrometry (MS), flame ionization detector (FID) and two dimensional gas chromatography time of flight mass spectrometry (GC×GC–TOF MS). A total of 48 compounds with a good match and high probability values were identified using this technique. Meanwhile, 42 compounds were successfully identified in this study using GC-MS, a significantly larger number than in previous studies. GC-FID was used in determining the retention indices of chemical components in P. minus essential oil. The result also showed the efficiency and reliability were greatly improved when chemometric methods and retention indices were used in identification and quantification of chemical components in plant essential oil.

Ficus deltoidea Jack: A Review on Its Phytochemical and Pharmacological Importance

Ficus deltoidea Jack (Moraceae) has had a long history of use in traditional medicine among the Malays to alleviate and heal ailments such as sores, wounds, and rheumatism and as an after-birth tonic and an antidiabetic drug. Modern pharmacological studies demonstrated that this plant has a wide variety of beneficial attributes for human health. Despite its importance, a review of this species has not been published in the scientific literature to date. Here, we review and summarize the historic and current literature concerning the botany, traditional uses, phytochemistry, pharmacological effects, and toxicity of this wonder plant. This summary could be beneficial for future research aiming to exploit the therapeutic potential of this useful, medicinal species.

Volatile Profiling of Aromatic Traditional Medicinal Plant, Polygonum minus in Different Tissues and Its Biological Activities

The aim of this research was to identify the volatile metabolites produced in different organs (leaves, stem and roots) of Polygonum minus, an important essential oil producing crop in Malaysia. Two methods of extraction have been applied: Solid Phase Microextraction (SPME) and hydrodistillation coupled with Gas Chromatography-Mass Spectrometry (GC-MS). Approximately, 77 metabolites have been identified and aliphatic compounds contribute significantly towards the aroma and flavour of this plant. Two main aliphatic compounds: decanal and dodecanal were found to be the major contributor. Terpenoid metabolites were identified abundantly in leaves but not in the stem and root of this plant. Further studies on antioxidant, total phenolic content, anticholinesterase and antimicrobial activities were determined in the essential oil and five different extracts. The plant showed the highest DPPH radical scavenging activity in polar (ethanol) extract for all the tissues tested. For anti-acetylcholinesterase activity, leaf in aqueous extract and methanol extract showed the best acetylcholinesterase inhibitory activities. However, in microbial activity, the non-polar extracts (n-hexane) showed high antimicrobial activity against Methicillin-resistant Staphylococcus aureus (MRSA) compared to polar extracts. This study could provide the first step in the phytochemical profiles of volatile compounds and explore the additional value of pharmacology properties of this essential oil producing crop Polygonum minus.

Erwinia mallotivora sp., a New Pathogen of Papaya (Carica papaya) in Peninsular Malaysia

Erwinia mallotivora was isolated from papaya infected with dieback disease showing the typical symptoms of greasy, water-soaked lesions and spots on leaves. Phylogenetic analysis of 16S rRNA gene sequences showed that the strain belonged to the genus Erwinia and was united in a monophyletic group with E. mallotivora DSM 4565 (AJ233414). Earlier studies had indicated that the causal agent for this disease was E. papayae. However, our current studies, through Koch’s postulate, have confirmed that papaya dieback disease is caused by E. mallotivora. To our knowledge, this is the first new discovery of E. mallotivora as a causal agent of papaya dieback disease in Peninsular Malaysia. Previous reports have suggested that E. mallotivora causes leaf spot in Mallotus japonicus. However, this research confirms it also to be pathogenic to Carica papaya.

Molecular Systematics of Polygonum minus Huds. Based on ITS Sequences

Plastid trnL-trnF and nuclear ribosomal ITS sequences were obtained from selected wild-type individuals of Polygonum minus Huds. in Peninsular Malaysia. The 380 bp trnL-trnF sequences of the Polygonum minus accessions were identical. Therefore, the trnL-trnF failed to distinguish between the Polygonum minus accessions. However, the divergence of ITS sequences (650 bp) among the Polygonum minus accessions was 1%, indicating that these accessions could be distinguished by the ITS sequences. A phylogenetic relationship based on the ITS sequences was inferred using neighbor-joining, maximum parsimony and Bayesian inference. All of the tree topologies indicated that Polygonum minus from Peninsular Malaysia is unique and different from the synonymous Persicaria minor (Huds.) Opiz and Polygonum kawagoeanum Makino.

Sauropus androgynus (L.) Merr. Induced Bronchiolitis Obliterans: From Botanical Studies to Toxicology.

Sauropus androgynus L. Merr. is one of the most popular herbs in South Asia, Southeast Asia, and China where it was known as a slimming agent until two outbreaks of pulmonary dysfunction were reported in Taiwan and Japan in 1995 and 2005, respectively. Several studies described that the excessive consumption of Sauropus androgynus could cause drowsiness, constipation, and bronchiolitis obliterans and may lead to respiratory failure. Interestingly, this herb has been used in Malaysia and Indonesia in cooking and is commonly called the “multigreen” or “multivitamin” plant due to its high nutritive value and inexpensive source of dietary protein. The plant is widely used in traditional medicine for wound healing, inducing lactation, relief of urinary disorders, as an antidiabetic cure and also fever reduction. Besides these medicinal uses, the plant can also be used as colouring agent in food. This review will explore and compile the fragmented knowledge available on the botany, ethnobotany, chemical constitutes, pharmacological properties, and toxicological aspects of this plant. This comprehensive review will give readers the fundamental, comprehensive, and current knowledge regarding Sauropus androgynus L. Merr.

Homogeneous nature of Malaysian Marine fish Epinephelus fuscoguttatus (Perciformes; Serranidae): Evidence based on molecular markers, morphology and fourier transform infrared analysis

Taxonomic confusion exists within the genus Epinephelus due to the lack of morphological specializations and the overwhelming number of species reported in several studies. The homogenous nature of the morphology has created confusion in the Malaysian Marine fish species Epinephelus fuscoguttatus and Epinephelus hexagonatus. In this study, the partial DNA sequence of the 16S gene and mitochondrial nucleotide sequences of two gene regions, Cytochrome Oxidase Subunit I and III were used to investigate the phylogenetic relationship between them. In the phylogenetic trees, E. fuscoguttatus was monophyletic with E. hexagonatus species and morphology examination shows that no significant differences were found in the morphometric features between these two taxa. This suggests that E. fuscoguttatus is not distinguishable from E. hexagonatus species, and that E. fuscoguttatus have been identified to be E. hexagonatus species is likely attributed to differences in environment and ability to camouflage themselves under certain conditions. Interestingly, this finding was also supported by Principal Component Analysis on Attenuated Total Reflectance–Fourier-transform Infrared (ATR-FTIR) data analysis. Molecular, morphological and meristic characteristics were combined with ATR-FTIR analysis used in this study offer new perspectives in fish species identification. To our knowledge, this is the first report of an extensive genetic population study of E. fuscoguttatus in Malaysia and this understanding will play an important role in informing genetic stock-specific strategies for the management and conservation of this highly valued fish.

Papaya Dieback in Malaysia: A StepTowards A New Insight of Disease Resistance

A draft genome of Erwinia mallotivora BT-Mardi (1), the causal pathogen of papaya dieback infection in Peninsular Malaysia, has significant potential to overcome and reduce the effect of this vulnerable crop (2). The authors found that the draft genome sequence is approximately 4824 Kbp and the G+C content of the genome was 52-54%, which is very similar to the reference genomes of other Erwinia species. They concluded that the draft genome would be useful for understanding host-pathogen interaction and determining the mechanism of infection of the disease. In addition to this, we believe that there are some further directions that should be considered in the future. Firstly, the comprehensive analysis of pathogenicity genes in E. mallotivora, which would enable the comparison of genes important in pathogenicity between species in the genus Erwinia, and highlight any differences. These include the most important and well-studied pathogenicity system in gram negative bacteria: the Type III Secretion (TTSS). Investigation of genes important in the pathogenesis of E. mallotivora will decipher the function of these genes and unravel the complex interaction of the bacteria and host, and this will enable the understanding of their capabilities to enter plant cells, overcome host resistance and induce disease. This in-depth understanding will potentially allow the identification and application of new sources of biocontrol for this disease. Secondly, the elucidation and identification of the potential pathogen-inducible and defence-related genes in papaya. The papaya genome is available onlineto enable the identification of the putative immunity related genes (IRG) and it will be greatly useful for revealing the blueprint of host genes under pathogen stress. Wee et al. (3) reported the expression analysis for four possible defence related genes in the E. mallotivara host (zinc finger protein, leucine rich protein, aquaporin and peroxidase), in order to understand the defence mechanisms in papaya. This information will be valuable for strategies in generating host resistance and understanding host-pathogen interaction. Thirdly, the discovery of papaya microRNAs (miRNAs) is also important. Previous studies have shown that miRNAs could act in wide range of biological processes as well as in the plant’s defence system towards biotic and abiotic stresses. Therefore, profiling and functional analysis of miRNAs would be important to generate novel possibilities in improving resistance to dieback. The high potential application of miRNAs in the host defence mechanism indicates that they should be used or manipulated to confer pathogen resistance in papaya. Finally, the development of resistant plants using a genetic engineering approach is also an important tool in the control of papaya dieback disease. Currently, there is no chemical control treatment available and no resistant papaya varieties offered in order to overcome this severe disease, and generating resistant plants using a biotechnology approach could be the solution. The strategy of disruption of bacterial virulence factors, improvement of plant defence responses and the expression of antimicrobial proteins of non-plant origin could be applied in papaya to confer resistance. The draft genome of E. mallotivora BT Mardi is the first step and the initial key to the understanding of the host-microbe interaction and mechanism of infection of this severe disease. This could be fundamental for