The conversion of roselle calyx into a dried extract without decreasing its consistency is a challenge, given the perishability of the calyx and instability of anthocyanin, which can quickly degrade and develop colored or unwanted brown colors because of its high reactivity. The most critical factors influencing anthocyanins' stability are pH, temperature, light and post-harvest-related enzymes. Besides, the calyx suffered wound injury when removing seed from the calyx, causing stress and eventually, microbial degradation. Nonetheless, mature anthocyanins stimulate plants by responding to stress, especially drought, high salinity, excess light and injury; it is also correlated with improved stress resistance as the genes of individual plants are triggered under these conditions modulate anthocyanin biosynthesis. This work investigates the stability and potential role of roselle anthocyanin in post harvest deterioration. Anthocyanin stability can, therefore, be achieved by maintaining low pH and temperature, acylation, glycosylation, copigmentation and encapsulation. In the quest for roselle deterioration biomarkers, the detection of critical enzymes, such as Chalcone synthase CHS and FH3 Flavanone 3 hydroxylase, would offer insight into the genetic modification of anthocyanin.
Dioscorea hispida Dennst produces tuber which possess valuable medicinal properties but unsustainable harvesting has led to its reduction. The plant propagates slowly because of its low tuber sprouting rate. In average, Dioscorea hispida Dennst tubers took approximately 60 d to break dormancy and sprout. Hence, callus culture is proposed as a possible efficient type of culture for manipulation of this species. In the present study, calli were induced from stem segments to evaluate callus culture potential of Dioscorea hispida Dennst. Results indicate that the combination of 1 mgL-1 naphthaleneacetic acid (NAA), 1 mgL-1 6- benzylaminopurine (BAP) and 0.5 mgL-1 2,4-dichlorophenoxyacetic acid (2, 4-D) in Gamborg (B5) medium improved callus multiplication and differentiation in the stem culture as opposed to those in Murashige and Skoog (MS) medium. The findings from the present study provide the basis of callus culture protocol for stem explant of Dioscorea hispida Dennst with B5 being the more effective basal medium.
Aquilaria sp. belongs to Thymelaeaceae family. This genus produces a unique fragrant wood locally known as ‘gaharu’. It is well known for usages in aromatherapy while very few scientific evidence on its usage as herbal medicine have been published. The current study was therefore conducted to determine the chemical characteristics as well as antioxidant and α-glucosidase inhibition potential of carbohydrate-rich extracts (aqueous and polysaccharide extracts) of three Aquilaria species leaves (A. malaccensis, A. sinensis and A. subintegra). The isolation of polysaccharide (PS) from the aqueous extract (AE) was conducted by ethanol precipitation prior to ultrasonic-assisted extraction. The total phenolic content (TPC), proximate and Fourier Transform Infrared Spectroscopy (FTIR) analysis were carried out to investigate the chemical characteristics, while the bioactivities determined were 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and α-glucosidase inhibition. As a result, AE of A. malaccensis leaves showed the strongest α-glucosidase (IC50: 0.094 mg/mL) and DPPH (IC50: 0.094 mg/mL) inhibition while contained more TPC (61.16 mg GAE/g) compared to other two species. Furthermore, PS of A. malaccensis leaves displayed even stronger α-glucosidase inhibition (IC50: 0.014 mg/mL) compared to its respective AE and other PS. In conclusion, this study primarily revealed the scientific evidence on the bioactive potential of PS of Aquilaria sp.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.