1.A New Dimeric Lignan from the Stems of Willughbeia edulis
Hai Xuan NGUYEN ; Truong Nhat VAN DO ; Tho Huu LE ; Phu Hoang DANG ; Mai Thanh THI NGUYEN ; Nhan Trung NGUYEN
Natural Product Sciences 2022;28(2):53-57
As part of our continued study on the chemical constituents of Willughbeia edulis stems, a new dimeric lignan named edulignan (1) was isolated from its EtOAc-soluble extract. Based on NMR spectroscopic interpretation, the planar structure of 1 has been suggested to have two 2-substituted 4-chromanone subunits with different stereochemical configurations. In addition, the MS/MS analysis of the products obtained by acidcatalyzed hydrolysis of 1 was supportive of its structure. Unfornatually, the new compound 1 did not show α-glucosidase inhibitory activity with an IC 50 value > 250 μM.
2.Rapid bacterial identification from clinical specimens by using the MinION™ sequencing device: A pilot study
Hoang Bach Nguyen ; Thi Thanh Mai Ho ; Rodney Lea
Malaysian Journal of Microbiology 2023;19(no.4):409-414
Aims :
DNA sequencing is a powerful tool and less time-consuming for bacterial detection and identification. The aim of this study was to compare the application of the Oxford Nanopore MinION™ sequencing device for direct DNA sequencing from clinical specimens with the routine workup.
Methodology and results :
We used conventional bacteriological-based methods to detect and identify bacterial
pathogens in 10 clinical specimens. In addition, the 16S metagenomic sequencing was performed by using a MinION™sequencing device with barcoded primers of a 16S Barcoding kit (Code N° SQK-RAB204, Oxford Nanopore Technologies, UK). The DNA was amplified by PCR using specific 16S primers (27F and 1492R) that contain barcodes and 5' tags which facilitate the ligase-free attachment of Rapid Sequencing Adapters of the 16S Barcoding kit. Data wasanalyzed with WIMP and EPI2ME to classify and identify species in real-time. Ten clinical specimens were processed for bacterial isolation. A total of 8 urine samples were subjected to culture-dependent methods, successfully identifying the
presence of pathogenic bacteria. Out of the total eight urine samples, both methods successfully identified six bacterial pathogens. Escherichia coli were identified, and the others were detected as Salmonella enterica, Veillonella parvula and Streptococcus anginosus using MinION™ sequencing. Two urine samples had different results. Escherichia coli was detected directly through MinION™ sequencing, bypassing the need for culture results.
Conclusion, significance and impact of study
MinION™ sequencing of 16S rRNA genes could accurately detect diverse bacterial pathogens in clinical specimens. Additionally, the bacterial species classification generated by analyzing 16S rRNA gene sequences can be helpful for rapid identification. The whole procedure takes less than 8 h to complete; same-day diagnosis can be completed.