Identification of a (+)-cubenene synthase from filamentous fungi Acremonium chrysogenum

Identification and Characterization of a Novel Multifunctional Terpene Synthase from the Pathogenic Fungus Cochliobolus heterostrophus

Sesquiterpenes, a structurally diverse class of natural products, play pivotal roles in the pharmaceutical, fragrance, and flavor industries. In this study, we first identified and functionally characterized a multifunctional sesquiterpene synthase, ChTPS6, from the plant-pathogenic fungus Cochliobolus heterostrophus. When incubated with FPP, ChTPS6 primarily catalyzed the formation of cubebol as the main product, which is widely used as a sustained cooling and refreshing agent in the food industry. Remarkably, ChTPS6 exhibited substrate promiscuity, efficiently utilizing GPP and GGPP as alternative substrates. Moreover, through protein modeling and site-directed mutagenesis, we pinpointed key amino acid residues essential for the catalytic activity of ChTPS6, and successfully re-engineered the enzyme to alter its product specificity. These findings provide novel insights into the catalytic mechanism and functional versatility of ChTPS6 while broadening its potential applications in the biosynthesis of valuable sesquiterpenes.

Bio-Inspired Synthesis of Gold Nanoparticles Using Leaf Extract of Jamun and Research on Its Biomedical Potential

Background

Bio-based synthesis of metallic nanoparticles has garnered much attention in recent times owing to their non-toxic, environmentally friendly, and cost-effective nature.

Methods

In this study, gold nanoparticles (S4-GoNPs) were synthesized by a simple and environmentally friendly technique using an aqueous extract of jamun leaves (JLE) as an effective capping, stabilizer, and reducing agent. JLE was screened for the presence of phytochemicals followed by synthesis, characterization, and evaluation of their antibacterial, antidiabetic, antioxidant, and photocatalytic degradation potentials using standard established procedures.

Results

The phytochemical profile of JLE was found to be rich in flavonoids, tannins, terpenoid phenols, anthraquinones, and cardiac glycosides. Its GC-MS analysis revealed the presence of compounds majorly of them as the (1R)-2,6,6-Trimethylbicyclo[3.1.1]hept-2-ene (5.141%), 2(10)-pinene (4.119%), α-cyclopene (5.274%) α,α-muurolene (7.525%), naphthalene, 1,2,3,4,4a,5,6,8a-octahydro-7-methyl-4-methylene-1-(1-methylethyl)-(1.alpha.,4a.beta.,8a.alpha) (8.470%), delta-cadinene (23.246), α-guajene (3.451%), and gamma-muurolene (4.379%). The visual morphology and UV-Vis spectral surface plasmon resonance at 538 nm confirmed the successful synthesis of S4-GoNPs. The average particle size was determined as 120.5 nm with Pdi = 0.152, and -27.6 mV zeta potential. Using the Scherrer equation, the average crystallite size was calculated as 35.69 nm. S4-GoNPs displayed significant antidiabetic properties, with 40.67% of α-amylase and 91.33% of α-glucosidase inhibition activity. It also exhibited promising antioxidant potential in terms of the DPPH (91.56%) ABTS (76.59%) scavenging. It displayed 31.04% tyrosinase inhibition at 0.1 mg/mL. Moreover, it also demonstrated encouraging antibacterial effects with zones of inhibition ranging from 11.02 - 14.12 mm as compared to 10.55-16.24 mm by the reference streptomycin (at 0.01 mg/disc). In addition, S4-GoNPs also showed potential for the photocatalytic degradation of the industrial dye, methylene blue.

Conclusion

In conclusion, these results suggest the promising applicability of green-synthesized S4-GoNPs in various sectors, including the biomedical, cosmetic, food, and environmental waste management industries.

Biosynthesis Progress of High-Energy-Density Liquid Fuels Derived from Terpenes

High-energy-density liquid fuels (HED fuels) are essential for volume-limited aerospace vehicles and could serve as energetic additives for conventional fuels. Terpene-derived HED biofuel is an important research field for green fuel synthesis. The direct extraction of terpenes from natural plants is environmentally unfriendly and costly. Designing efficient synthetic pathways in microorganisms to achieve high yields of terpenes shows great potential for the application of terpene-derived fuels. This review provides an overview of the current research progress of terpene-derived HED fuels, surveying terpene fuel properties and the current status of biosynthesis. Additionally, we systematically summarize the engineering strategies for biosynthesizing terpenes, including mining and engineering terpene synthases, optimizing metabolic pathways and cell-level optimization, such as the subcellular localization of terpene synthesis and adaptive evolution. This article will be helpful in providing insight into better developing terpene-derived HED fuels.