Isolation, identification and characterisation of antibacterial compounds from Carissa lancelota R.Br.Root

Carissa lanceolata (conkerberry) is a perennial woody shrub used in traditional medicine by indigenous communities in Western Australia, the Northern Territory and Queensland for various medical conditions such as toothache, respiratory infections and the cleaning of sores, which all strongly indicate an antibacterial activity. A literature review revealed that the wood of this plant possesses significant antibacterial activity, which was found to be related to the presence of eudesmane type sesquiterpenes. C. edulis and C. carandus are frequently used in other traditional systems of medicine in different parts of the world, and thus have also been investigated for bioactive compounds and pharmacological properties. Some of these were found to be in line with the main findings of this work. Carissa lanceolata root was shown to exhibit significant antibacterial activity against both Gram negative and Gram positive organisms. A micro-broth dilution assay was performed on 96-well plates using resazurin as an indicator for microbial growth of Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus. Bioassays carried out in this work showed that crude extracts of root bark and wood, particularly their polar constituents were more active against the four strains of bacteria tested.Chemical investigation of the root bark revealed that it contains a volatile oil, which was isolated by steam distillation as well as solid phase micro extraction. It was found to consist of a single compound, which was identified as 2'-hydroxy acetophenone. The identity of this compound was confirmed by GC/MS and 1H NMR spectroscopy. Furthermore, the eudesmane-type sesquiterpene, carissone, was isolated from the root bark DCM and root wood hexane extracts. Its chemical identity was confirmed by IR, 1 [superscript] H and 13 [superscript] C NMR spectroscopy. The lignan, carinol, on the other hand, was isolated from the moderately polar fractions of the root wood MeOH extract. The obtained IR and 1 [superscript] H NMR data as well as Rf values all correspond to the literature. Two other yet unidentified compounds were isolated, but further studies into their chemistry and antibacterial activity were not possible in this current study. The antibacterial activity of the isolated compounds was considerable, with 2'-hydroxy acetophenone exhibiting the strongest effect, followed by carinol and then carissone

Pharmaceutical evaluation of Western Australian sandalwood seed oil

This study evaluated Western Australian sandalwood (Santalum spicatum) seed oil and chemically defined it for cosmetic and pharmaceutical use. Parameters for the selection of suitable raw material sources were established. A novel supercritical carbon dioxide extraction method was developed to isolate the seed oil and its stability established. Isolated triximenynin and its pharmacological activities were studied. Sandalwood seed oil was non-toxic and non-irritant from in-vitro studies

Effect of ximenynic acid on cell cycle arrest and apoptosis and COX-1 in HepG2 cells

Ximenynic acid is a conjugated enyne fatty acid, which is currently of interest due to its anti-inflammatory activity. Due to the association between inflammation and cancer, the present study was designed to investigate the anti-cancer activity of ximenynic acid in the HepG2 human hepatoma cell line and the underlying mechanisms. The current study demonstrated the anti-proliferation and pro-apoptosis activities of ximenynic acid by cell viability assay and flow cytometry analysis. The expression of anti-apoptosis protein silent information regulator T1 (SIRT1) was significantly suppressed by ximenynic acid. Furthermore, ximenynic acid blocked G1/S phase transition by inhibiting the protein expression of the cell cycle-associated protein general control of amino acid synthesis yeast homolog like 2 (GCN5L2), and the mRNA expression of cyclin D3 and cyclin E1. Furthermore, ximenynic acid suppressed the expression of angiogenesis-associated genes, including vascular endothelial growth factor (VEGF)-B and VEGF-C. Finally, ximenynic acid significantly inhibited the expression of cyclooxygenase-1 (COX-1) mRNA and protein, however COX-2 expression was not reduced. The results of the present study suggested that ximenynic acid may inhibit growth of HepG2 cells by selective inhibition of COX-1 expression, which leads to cell cycle arrest, and alters the apoptosis pathway and expression of angiogenic factors. The current study aimed to investigate whether ximenynic acid might be developed as novel anticancer agent

Assessment of Western Australian sandalwood seeds for seed oil production

The Western Australian sandalwood (Santalum spicatum R.Br.) industry is transforming into an agro-forestry industry in which the seeds are being considered as a valuable secondary income generating product. Oil extracted from the seeds has a potential use in the cosmetic industry. This study aimed to identify the quality parameters for seeds to obtain oil of better and consistent quality, and the effect of seed source, seed size and storage time. Different seed samples varied in oil content, moisture content and fatty acid profile. Larger seeds from plantation trees in the wheatbelt region of Western Australia are the most suitable source of seed oil thus far evaluated. The seed grading system currently used by the sandalwood industry was suitable for selecting seeds from plantations (but not from natural stands in arid regions – ‘wild wood’) for seed oil production. Basic parameters for the selection of seeds for oil extraction were identified

Safeguarding sandalwood: A review of current and emerging tools to support sustainable and legal forestry

Societal Impact Statement: Sandalwood and other high value tree species are under significant threat from illegal harvest. Illegal logging is an increasing problem contributing to deforestation, biodiversity loss, human rights abuses and funding transnational crime. Successful prosecution of illegal logging is hindered by a lack of methods to provide evidence of the origin of timber. New analytical techniques have been developed to trace timber back to its source. These methods, together with the establishment of sustainable sources of forest resources, can help protect vulnerable species by providing evidence to prosecute illegal harvest and ensure that commercially available forest products come from sustainable sources. Summary: Sandalwood is highly valued for its fragrant oil and has a long history of cultural and economic importance in many regions of the world. Historical overharvest and poor management have depleted natural populations of sandalwood, which are slow to regenerate. The increasing establishment of plantation sandalwood creates an alternative resource for the sandalwood industry while potentially relieving harvesting pressure on natural stands. Due to the high demand for sandalwood, remaining wild populations are still under threat from illegal logging and methods to identify the source of harvested sandalwood are needed. Laws and regulations aimed at preventing illegal harvest and possession of sandalwood have been put in place but cannot be enforced without the forensic tools to independently verify claimed origin or product quality. The high value of sandalwood combined with the difficulties in enforcing illegal logging laws makes these species particularly vulnerable to poaching. There is an immediate need to develop tools that can identify illegally sourced and adulterated sandalwood products. This paper reviews the current and developing scientific tools that can help identify and control illegal activity in sandalwood supply chains and provides recommendations for future research. Topics include isotope and DNA analysis for tracing illegally harvested sandalwood, chemical profiling for quality control of sandalwood oils, network and policy development to establish a framework for future regulation of the sandalwood trade

Agarwood resin production and resin quality of Gyrinops walla Gaertn

Agarwood is a resin produced by certain species of family Thymalaeaceae due to a self-defence mechanism. Most species of Aquilaria and a few species of Gyrinops, Aetoxylon and Gonystylus are capable of producing agarwood. Gyrinops walla, a member of the family Thymalaeceae is recorded only in the wet zone of Sri Lanka and very rarely in southwest India, has not been previously studied to identify its ability of producing agarwood. Therefore the present study was the first ever to conduct and identify the production of agarwood in G. walla and the quality of its resins. Six G. walla trees growing in two distinctive areas of the wet zone of Sri Lanka were used for the present study. All six trees had natural wounds occurred sometime before the sample collection due to abrasions or fallen branches. The dark coloured tissues of the affected areas were carefully collected without cutting the trees and resins were extracted by solvent extraction method. The extracted resins were analysed using gas chromatography to identify the different compounds. Finally these compounds were compared with that of selected Aquilaria species. The results revealed a strong similarity of resin compounds of G. walla with that of Aquilaria species which are commercially used to collect agarwood. Further studies should be conducted to identify the effects of artificial resin induction methods on G. walla that are already used on Aquilaria species

Antibacterial compounds from the root of the indigenous Australian medicinal plant Carissa lanceolata R.Br.

The conkerberry, Carissa lanceolata R.Br. (Apocynaceae), is commonly used by many indigenous Australian communities across Northern Australia for the treatment of a variety of conditions such as chest pain, toothache, colds and flu. Indigenous uses of this plant strongly argue for an antibacterial bioactivity. The aim is to identify antibacterial compounds from root material of C. lanceolata, therefore confirming the indigenous use of the plant. Antibacterial activity was examined against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Bacillus subtilis using a micro broth dilution technique. Three compounds demonstrating considerable activity were isolated. The volatile phenolic compound 2′-hydroxyacetophenone and the lignan carinol both were reported for the first time from C. lanceolata, whereas this is the second account of the occurrence of carissone. All three compounds showed activity, with 2′-hydroxyacetophenone and carinol having a minimum inhibitory concentration of <1.25 mg mL−1 against all four bacteria. Extracts and compounds isolated from C. lanceolata roots were found to possess a significant antibacterial activity, confirming the indigenous use of this plant

Essential oil content and composition of Indian Sandalwood (Santalaum album) in Sri Lanka

Santalum album (Indian Sandalwood) is found in the mountainous regions of the intermediate zone of Sri Lanka. Few studies have been conducted on sandalwood ecology in this region, and ours is the first recorded study of essential oil content and chemical composition of heartwood. We harvested two trees with State permission and took cross-sections for analysis. We demonstrated a difference in the heartwood formation and oil yield of the trees. The composition of the oil was found to be consistent between trees and along the trunk of the tree. Main aromatic compounds were santalols and other compounds are recorded in lesser quantities. Results of this study comply with the other published work on sandalwood elsewhere. This initial study on S. album in Sri Lanka provided promising results for the future of sandalwood agroforestry

Western Australian sandalwood seed oil: new opportunities

Western Australian Sandalwood (Santalum spicatum R.Br.) is an economically important timber crop. Sandalwood seeds have been identified as a potential secondary source of income prior to harvesting the tree. Chemical and toxicological studies of the seed have found that the kernels contain nearly 50% of a drying oil. This oil is comprised mainly of unsaturated fatty acids. The presence of an unusual acetylenic fatty acid has been confirmed. The oil was found to cause no pathological abnormalities in mice but reduced fat deposition. Acetylenic fatty acids are known to inhibit eicosanoids and stimulate certain enzymes, even though dietary consumption is yet to be trialled. The oil has potential uses in cosmetic and external pharmaceutical applications. Vegetable oils used in pharmaceutical and cosmetic formulations require high oxidation stability and antioxidant activity and benefit from the presence of other compounds such as sterols and tocopherols. This article summarises the research conducted over a half a century on sandalwood seeds and considers suitable uses and the future research needed to commercialise this oil

Contents of Fatty Acids, Selected Lipids and Physicochemical Properties of Western Australian Sandalwood Seed Oil

The study was designed to characterise two extracts of Western Australian sandalwood (Santalum spicatum) seed oils for their physicochemical and lipid characteristics. Sandalwood plantation’s surplus seeds could be used for their oil content, to improve the commercial viability of this industry. The seed oils were obtained by solvent extraction and supercritical carbon dioxide extraction respectively. Important physicochemical parameters were compared with other oils commonly used in pharmaceutical and cosmetic products. Acid values were found to be higher (6.0–7.5 mg KOH/1 g oil) while peroxide values (6.7–9.0 mequiv/Kg) were lower than reported for other oils. Tocopherols were found to be lower than those usually reported for nut oils (α-tocopherol 1–3 mg/100 g; δ-tocopherol 2.2–5.7 mg/100 g), squalenes and phytosterols were found in considerable quantities. The fatty acid content consisted largely of ximenynic acid (35 %) and oleic acid (52 %). No oxidative derivatives of fatty acids were observed. Although there were statistically significant differences in some properties, the magnitude of these were insufficient to conclude there were any notable differences in the two oil extracts