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The Australian plant Acacia ligulata has a number of traditional food and medicinal uses by Australian Aboriginal people, although no bioactive compounds have previously been isolated from this species. Bioassay-guided fractionation of an ethanolic extract of the mature pods of A. ligulata led to the isolation of the two new echinocystic acid triterpenoid saponins, ligulatasides A (1) and B (2), which differ in the fine structure of their glycan substituents. Their structures were elucidated on the basis of 1D and 2D NMR, GC-MS, LC-MS/MS, and saccharide linkage analysis. These are the first isolated compounds from A. ligulata and the first fully elucidated structures of triterpenoid saponins from Acacia sensu stricto having echinocystic acid reported as the aglycone. Compounds 1 and 2 were evaluated for cytotoxic activity against a human melanoma cancer cell line (SK-MEL28) and a diploid fibroblast cell line (HFF), but showed only weak activity. Refereed/Peer-reviewed

Acacia sensu lato (Fabaceae: Mimosoideae) was recently retypified and divided into five genera worldwide: Acacia, Acaciella, Mariosousa, Senegalia and Vachellia. Acacia sensu stricto is now considered to be a large genus of predominantly Australian origin comprising seven sections: Acacia, Alatae, Botrycephalae, Juliflorae, Lycopodiifoliae, Plurinerves and Pulchellae. This review presents an overview of the current taxonomy of A. sensu stricto and the natural products isolated and identified from it. Further, the traditional uses of different species and known bioactivities of isolated natural products are summarised. The flavonoids and tannins are the best studied classes of natural products from Acacia with characteristic hydroxylation patterns of flavonoids isolated from the heartwood of species positioned in different sections of the genus. These compounds display a range of activities including antioxidant, enzyme inhibitory and antimicrobial effects. Peltogynoid compounds, differing from other flavonoids by the presence of a fourth ring, have been isolated from a small group of species, however, their biological activities remain to be defined. Only a limited number of terpenes and steroids have been identified, but complex triterpenoid saponins with various bioactivities are present across various sections. Despite their economic importance and the traditional use, only a limited number of species have been thoroughly studied for their chemical composition. Further investigation of the sections Alatae and Lycopodiifoliae would be of interest for bioactive compound research as these sections are largely unexplored. Refereed/Peer-reviewed

Acacia ligulata A.Cunn. ex Benth. (Fabaceae: Mimosoideae) is a native Australian plant used traditionally by Australian Aboriginal groups. This study was undertaken to investigate the bioactivity of A. ligulata extracts and to evaluate their chemical composition. Potential antibacterial, cytotoxic and enzyme inhibitory effects relevant to traditional medicinal and food uses of the species were examined and LC-MS/MS was performed to investigate the chemical composition. Antibacterial activity was observed for bark and leaf extracts with an MIC for the bark extract of 62.5 μg/mL against Streptococcus pyogenes. Pod extracts showed cytotoxic effects against cancer cells, with the highest activity against melanoma SK-MEL28 cells with IC50 values between 40.8 and 80.6 μg/mL. Further, the leaf and pod extracts also inhibited α-amylase EC-3.2.1.1 and α-glucosidase EC-3.2.1.20 with IC50 values between 9.7–34.8 and 12.6–64.3 μg/mL, respectively. The LC-MS/MS profiling indicated that several different saponins were present in the active extracts.

Background. Identification of the tissue of origin of a brain metastatic tumor is vital to its management. Carcinoma of unknown primary (CUP) is common in oncology, representing 3%–5% of all invasive malignancies. We aimed to validate a recently developed microRNA-based quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) test for identifying the tumor tissue of origin, first in a consecutive cohort of metastatic tumors of known origin and then in a cohort of CUP cases resected from the central nervous system (CNS). Patients and Methods. One hundred two resected CNS metastatic tumors with known origin, previously classified based on the patient's clinical history and pathological data, as well as a second cohort of resected CNS tumors from 57 patients originally diagnosed as CUP were studied. A qRT-PCR diagnostic assay that measures the expression level of 48 microRNAs was used to classify the tissue of origin of these metastatic tumors. Results. In this blinded study, the test predictions correctly identified the reference diagnosis of the samples of known origin, excluding samples from prostate origin, in 84% of cases. In the second CUP patient cohort, the test prediction was in agreement with the diagnosis that was later confirmed clinically or with pathological evaluation in 80% of cases. Conclusion. In a cohort of brain and spinal metastases, a previously developed test based on the expression of 48 microRNAs allowed accurate identification of the tumor tissue of origin in the majority of cases. The high accuracy of this test in identifying the tissue of origin of metastases of unknown primary is demonstrated for the first time and may have broad clinical application.