2021, Vol. 6, No. 4
Unique plants and their properties, once considered synonymous to medicine, remain a potent source for new compounds in modern science. Plant polyphenols and natural products continue to be investigated for effective treatments for the most persistent of human ailments. In this review, fifty novel plant phenolic compounds have been compiled and briefly described from the previous five years. Select compounds and notable plant species from genus Morinda and Sophora are further expanded on. Traditional medicine plants often contain rich and diverse mixtures of flavonoids, from which rare compounds should receive attention. The bioactivity of crude plant extracts, purified compounds and mixtures can differ greatly, requiring that these interactions and mechanisms of action be investigated in greater detail. Novel applications of uncommon natural products, namely mimosine and juglone, are explored within this review. The 2019 coronavirus pandemic has resulted in abrupt spike of related scientific publications: speculation is made regarding plant natural products and future of antiviral drug discovery.
There is an increased global demand for activated carbon (AC) in application of water treatment and purification. Water pollutants that have exhibited a greater removal efficiency by AC included but not limited to heavy metals, pharmaceuticals, pesticides, natural organic matter, disinfection by-products, and microplastics. Granular activated carbon (GAC) is mostly used in aqueous solutions and adsorption columns for water treatment. Commercial AC is not only costly, but also obtained from non-renewable sources. This has prompted the search for alternative renewable materials for AC production. Biomass wastes present a great potential of such materials because of their availability and carbonaceous nature. This in turn can reduce on the adverse environmental effects caused by poor disposal of these wastes. The challenges associated with biomass waste based GAC are their low strength and attrition resistance which make them easily disintegrate under aqueous phase. This paper provides a comprehensive review on recent advances in production of biomass waste based GAC for water treatment and highlights future research directions. Production parameters such as granulation conditions, use of binders, carbonization, activation methods, and their effect on textural properties are discussed. Factors influencing the adsorption capacities of the derived GACs, adsorption models, adsorption mechanisms, and their regeneration potentials are reviewed. The literature reveals that biomass waste materials can produce GAC for use in water treatment with possibilities of being regenerated. Nonetheless, there is a need to explore 1) the effect of preparation pathways on the adsorptive properties of biomass derived GAC, 2) sustainable production of biomass derived GAC based on life cycle assessment and techno-economic analysis, and 3) adsorption mechanisms of GAC for removal of contaminants of emerging concerns such as microplastics and unregulated disinfection by-products.
According to the National Company of Supplying (CONAB) in 2017 alone, the national production of acai pulp reached 219 855 t, equating to 180 million dollar (USD). Almost 85% of the weight of fruit is constituted by residual biomass, even though researches have highlighted important applications for this biomass, most of it is discarded as organic waste. Thus, it is relevant to envisage in-depth studies about how to use these residues, particularly regarding the environmental impact of its target destination. Nanocrystalline cellulose (CNC) and lignin are organic derivatives obtained through the physical-chemical treatment of lignocellulosic biomass. Both are abundant and currently considered as biopolymers because of their structural characteristics and their diverse applications in food and the medical field. This work presents the mass yields achieved and the physical-chemical characteristics of the lignocellulosic derivatives extracted from the fiber of the acai berry. A statistical design was used to define the influence of process variables as temperature, reaction time and fiber size on the yield of these byproducts. A maximum yield close to 64% of type I CNC, with 45% of crystallinity degree was achieved at the minimum condition of temperature and fiber size. Additionally, through rheological analysis, it was possible to predict the nanocrystal aspect ratios, ranging from 71 to 125. The extracted lignin was rich in methoxy groups, p-coumaryl alcohol and p-coumaric acid, and its structural unit's low state of aggregation can be an indication of low molecular weight, which envisions an appropriate use for this lignin to produce commodity chemicals.
The Pleurotus florida is recognized as a medicinal and edible mushroom and the present study intends to reveal the active isomeric molecules from this mushroom. The P. florida was cultivated using different nutrient supplements: groundnut husk, maize powder, horse gram powder and coconut oil-cake powder. Horse gram supplement showed the higher mushroom yield and henceit was used for the cultivation of P. florida. Methanolic extract of P. florida was found to be efficient in antioxidant activity among ethanol, aqueous, ethyl acetate and hexane extracts. The bioactive fraction 3-methoxy-4-hydroxy cinnamic acid (PF5) was isolated and purified from the methanolic extract of P. florida by column chromatography, thin layer chromatography (TLC) and gas chromatography-mass spectrum (GC-MS) and further it was characterized by Nuclear magnetic resonance (NMR). The PF5 was tested for its DPPH and reducing power assays, and the IC50 values were found to be 21.7 µg/mL and 105 µg/mL, respectively. We found that the cytotoxic effect of 3-methoxy-4-hydroxy cinnamic acid was tested against the lung cancer cell line using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT), sulphorodamine B (SRB) and trypan blue assays which exhibited a higher cytotoxic effect (CTC50, 645 µg/mL). These results suggested that 3-methoxy-4-hydroxy cinnamic acid from P. florida could be explored as a novel and potent natural antioxidant and cancer preventive agent, alternative to existing synthetic molecules.
Significance increase in dengue cases have been recorded worldwide every year and South East Asian countries have been badly affected. Currently, antiviral drug to treat dengue is still not available but papaya leaves extract (PLE) have been successfully used in treating dengue patients. Carpaine in PLE is the major active compounds that contributes to the anti-thrombocytopenic activity (raising platelet count in patient's blood). The PLE also contains polyphenols that contribute to antioxidant properties. Studies were carried out to extract and quantify carpaine from young leaves, old leaves and stalks of papaya plant. Carpaine crystalline powders were successfully purified and confirmed by 1H and 13C NMR (Nuclear Magnetic Resonance). Young papaya leaves recorded significantly higher amount of carpaine (P < 0.05) as compared with old leaves and stalks. Blending treatment showed significant effect (P < 0.05) on the amount of carpaine extracted from the young and old leaves and blended young leaves showed significantly much higher amount of carpaine as compared with the unblended samples (P < 0.05). In terms of total polyphenols content (TPC), young leaves (both unblended and blended samples) contained significantly higher amount of TPC (P < 0.05) followed by the old leaves and stalks. Results also showed relationship between the TPC and the 1, 1-diphenyl-2-picrylhydrazyl (DPPH) assay scavenging activities namely IC50 (R2 = 0.9743) and acid equivalent antioxidant capacity (AEAC) (R2 = 0.9581). Both young and old leaves also showed significantly higher (P < 0.05) DPPH scavenging activities as compared with the stalks in both unblended and blended samples. Young papaya leaves were recommended as source of material to extract carpaine for future development of drug in dengue treatment.
Proanthocyanin (PA) dimers isolated from Acacia mearnsii bark were enzymatically acylated with palmitic acid as the acyl donor by immobilized Candida antarctica lipase on acrylic resin (Novozym 435). The acylation reaction conditions were optimized by comparing the amount of enzyme, the temperature, the reaction solvents, initial water content, substrate molar ratios and reaction time. The highest acylation conversion of 96.53% was achieved under the follow conditions: PA dimers/palmitic acid at a molar ratio of 1꞉10 in tert-amyl alcohol; initial water content of 5% at 60 ℃ for 12 h with 30 g/L enzyme dosage. Introducing palmitic acid into PA dimers significantly improved both the lipophilicity and antioxidant properties. The 1-octanol/water partition coefficient of the PA dimers and their derivatives showed that the lipophilicity of the derivatives were 2.4 times higher than that of the PA dimers. The derivatives exhibited strong antioxidant scavenging capacities, approximately 1.6 times greater than the original dimers. This work is of great significance to expand the application of natural PA dimers in cosmetic and food industries and also lay a foundation for the high value-added utilization of A. mearnsii.
In the present study, myofibrillar proteins were extracted from the meat proteins of beef, lamb, chicken, tuna and emperor fish using non-denaturation method, and their physico-chemical and rheological properties were assessed. The myofibrillar proteins of beef, emperor and lamb samples had higher percentage of protein extractability than tuna and chicken samples. The tuna sample showed significantly higher bound bromophenol blue (BPB) value while lamb samples showed lower value (P < 0.05). The myofibrillar protein of chicken sample was found to have more ionic and hydrogen bonds than all other myofibrillar samples. The disulphide bonds in tuna and lamb myofibrillar protein samples were significantly higher than other three samples (P < 0.05). The myofibrillar protein samples showed major bands myosin heavy chain, α-actinin, desimin, actin, troponin, tropomyosin and myosin light chain with wider molecular weight distribution in the range of 20–200 ku. The myofibrillar proteins exhibited Newtonian and shear thickening nature behaviour at lower protein concentration (1 mg/mL) as revealed by flow profile and visco-elastic analysis using rheometer.
The essential oil from Melaleuca leucadendra L. leaves has been widely used as a perfume and traditional remedy, cosmetics and pharmaceutical products ingredient since many years ago. The common technology to recover the oil is hydro-distillation and steam-distillation. However, all oil can not be fully extracted from the leaves by this method due to the recalcitrant structure of leaves that hindrance the access of the solvent. Adding a submerged fermentation as a pre-treatment step prior to the extraction process helped to loosen the lignocellulose structure and enhance oil release in the extraction process. In this study, the raw materials were collected from the natural forest in Buru Island, Maluku, Indonesia. The biological agents applied in these processes were Phanerochaete chrysosporium ITBCC136 and Trichoderma viride ITBCC143. The oil extraction process was conducted by method of steam-distillation, the oil was analysed using gas chromatography-mass spectroscopy (GC-MS), and the lignocellulose content in the biomass was measured by the fractionation method. The treatment using T.viride provided the highest increase in yield percentage up to 3.47% as compared with control of 1.45%, with the lowest percentages of the remained cellulose, while the fermentation with the presence of P.chrysosporium did not affect the oil yield even the lignin content was decrease as much as 21%. The percentages of 1, 8-cineole in the oil were almost unchanged, which was about 20% of the oil.