Biotransformation of plant secondary metabolite decursin by Mycobacterium sp. PYR1001

Chemistry, Pharmacology and Therapeutic Potential of Decursin: A Promising Natural Lead for New Drug Discovery and Development

Decursin is a pyranocoumarin compounds which are rare secondary metabolic plant products, isolated from the roots of Angelica gigas (A. gigas). The native Korean species Angelica gigas Nakai (AGN) is widely used as a remedy for a variety of medical conditions including hematopoiesis, improving women's circulation, as sedatives, analgesics and tonic. It is unique because of the presence of substantial amounts of pyranocoumarins including decursin, decursinol, and decursinol angelate. In this review, we provide a comprehensive insight into the distribution, morphology, and chemical composition of A. gigas. A detailed discussion regarding the biological applications of decursin based on the literature retrieved from PubMed, ScienceDirect, Scopus, and Google Scholar from 2000 to the present has been discussed. Both in vitro and in vivo studies have demonstrated that decursin has potential neuroprotective, anti-inflammatory, anti-melanogenic, anti-angiogenic, antioxidant, and anti-visceral properties. Mechanistic findings establish its significance in regulating important signalling pathways, triggering apoptosis, and preventing metastasis in different cancer types. The review additionally addressed the isolation methods, biosynthesis, physiochemical characteristics, toxicity and pharmacokinetic profile of decursin. The present state of clinical studies including A. gigas is investigated, emphasizing its advancements and possibilities in the field of translational medicine.

Probing the Biotransformation Process of Sclareol by Resting Cells of Hyphozyma roseonigra

Sclareol glycol is a key starting material with significant market interest for synthesizing high-value ambroxide, a sustainable substitute for ambergris in high-end fragrances. Sclareol glycol can be obtained by biotransformation of sclareol, a labdane-type diterpene, using Hyphozyma roseonigra. However, the pathway and mechanism of sclareol glycol biosynthesis remain unclear. In this study, the dynamic time course of sclareol biotransformation was explored by resting cell assays and several intermediates produced during biotransformation were detected. The results show that (1) sclareol glycol and sclareolide are not interconverted and are potentially synthesized via different metabolic pathways and (2) several putative intermediates resulting from biotransformation are featured with a labdane carbon backbone, including isomerized and oxidized analogues. A plausible transformation pathway of sclareol in H. roseonigra was proposed based on detected metabolites. This study sheds light on the biosynthetic mechanism of sclareol glycol and paves a way for the future biotechnological production of this promising compound.

Inositol Derivatives and Phenolic Compounds from the Roots of Taraxacum coreanum

In this study, the characterization of chemical constituents and biological activity of the roots of Taraxacum coreanum (Asteraceae) was attempted. Phytochemical investigation of the roots of T. coreanum led to the isolation of two new inositol derivatives, taraxinositols A (1) and B (2), and a new phenolic compound, taraxinol (16), together with twenty known compounds including four inositol derivatives, neo-inositol-1,4-bis (4-hydroxybenzeneacetate) (3), chiro-inositol-1,5-bis(4- hydroxybenzeneacetate) (4), chiro-inositol-2,3-bis (4-hydroxybenzeneacetate) (5) and chiro-inositol- 1,2,3-tris (4-hydroxybenzeneacetate) (6), nine phenolic compounds: p-hydroxybenzaldehyde (7), vanillin (8), syringaldehyde (9), vanillic acid (10), 4-methoxyphenylacetic acid (11), 4-hydroxy- phenylacetic acid methyl ester (12), optivanin (13), isoferulic acid (14) and dihydroconiferyl alcohol (15), four coumarins: nodakenetin (17), decursinol (18), prangol (19) and isobyakangelicin (20), and three lignans: syringaresinol-4′-O-β-d-glucoside (21), syringaresinol (22), and pinoresinol (23). The structures of isolated compounds were determined on the basis of spectroscopic analysis. Among the isolated compounds, vanillic acid, isoferulic acid and syringaresinol showed radical scavenging activity with IC₅₀ values ranging from 30.4 to 75.2 μM.

Natural products against Alzheimer's disease: Pharmaco-therapeutics and biotechnological interventions

Alzheimer's disease (AD) is a severe, chronic and progressive neurodegenerative disease associated with memory and cognition impairment ultimately leading to death. It is the commonest reason of dementia in elderly populations mostly affecting beyond the age of 65. The pathogenesis is indicated by accumulation of the amyloid-beta (Aβ) plaques and neurofibrillary tangles (NFT) in brain tissues and hyperphosphorylation of tau protein in neurons. The main cause is considered to be the formation of reactive oxygen species (ROS) due to oxidative stress. The current treatment provides only symptomatic relief by offering temporary palliative therapy which declines the rate of cognitive impairment associated with AD. Inhibition of the enzyme acetylcholinesterase (AChE) is considered as one of the major therapeutic strategies offering only symptomatic relief and moderate disease-modifying effect. Other non-cholinergic therapeutic approaches include antioxidant and vitamin therapy, stem cell therapy, hormonal therapy, use of antihypertensive or lipid-lowering medications and selective phosphodiesterase (PDE) inhibitors, inhibition of β-secretase and γ-secretase and Aβ aggregation, inhibition of tau hyperphosphorylation and intracellular NFT, use of nonsteroidal anti-inflammatory drugs (NSAIDs), transition metal chelators, insulin resistance drugs, etanercept, brain-derived neurotrophic factor (BDNF) etc. Medicinal plants have been reported for possible anti-AD activity in a number of preclinical and clinical trials. Ethnobotany, being popular in China and in the Far East and possibly less emphasized in Europe, plays a substantial role in the discovery of anti-AD agents from botanicals. Chinese Material Medica (CMM) involving Chinese medicinal plants has been used traditionally in China in the treatment of AD. Ayurveda has already provided numerous lead compounds in drug discovery and many of these are also undergoing clinical investigations. A number of medicinal plants either in their crude forms or as isolated compounds have exhibited to reduce the pathological features associated with AD. In this present review, an attempt has been made to elucidate the molecular mode of action of various plant extracts, phytochemicals and traditional herbal formulations investigated against AD as reported in various preclinical and clinical tests. Herbal synergism often found in polyherbal formulations were found effective to combat disease heterogeneity as found in complex pathogenesis of AD. Finally a note has been added to describe biotechnological improvement, genetic and genomic resources and mathematical and statistical techniques for empirical model building associated with anti-AD plant secondary metabolites and their source botanicals.