Anti-inflammatory lignanamides and monoindoles from Alocasia macrorrhiza

Antiproliferative piperidine alkaloids from the leaves of Alocasia macrorrhiza

Seventeen piperidine alkaloids, including 15 previously undescribed 2-substituted-6-(9-phenylnonyl)-piperidine-3,4-diol alkaloids and a previously undescribed 2-substituted-6-(9-phenylnonyl)-piperidine-3-ol alkaloid, were isolated from the leaves of Alocasia macrorrhiza (L.) Schott. Their planar structures and configurations were elucidated based on HR-ESI-MS, 1D and 2D NMR, Snatzke's method, modified Mosher method, single-crystal X-ray crystallography, as well as quantum chemical calculation. It was found that ΔδH5b-H5a can be used to elucidate the relative configuration of 2,3,4,6-tetrasubstituted piperidine, by analyzing the NMR data of 2-substituted-6-(9-phenylnonyl)-piperidine-3,4-diol. Antiproliferative activity was evaluated for all of the alkaloids, and compounds 6-8 showed considerable inhibitory activity against K562 cell line, with the IC50 values of 17.24 ± 1.62, 19.31 ± 0.9 and 18.77 ± 1.09μM, respectively. Furthermore, compounds 6 and 7 exerted an antiproliferative effect by inducing apoptosis.

Aromatic glycosides and lignans glycosides with their acetylcholinesterase inhibitory activities from the leaves of Picrasma quassioides

In this study, eight new natural products were isolated from the leaves of Picrasma quassioides. Spectroscopic techniques were used for the elucidation of their planar structures. Their absolute configurations were elucidated on the basis of electron circular dichroism (ECD) techniques combined with the P/M helicity rule for the 2,3-dihydrobenzofuran chromophore, and saccharide hydrolysis. Cholinesterase inhibitors are often used as Alzheimer's disease inhibitors.Thus, acetylcholinesterase and butyrylcholinesterase inhibitory activity of these eight compounds were tested, and results showed that only compound 6 showed weakly acetylcholinesterase inhibitory activity. In particular, molecular docking was used to illustrate the bindings between compound 6 and the active sites of AChE.

Metabolic profiling by LC-DAD-MS, FTIR, NMR and CE-UV of polyphenols with potential against skin pigmentation disorder

In traditional Brazilian medicine, tubers extracts from Alocasia macrorrhizos are widely used in the treatment of skin pigmentation disorder. However, studies that evaluate its benefits in the treatment of this disorder are non-existent. Thus, this work aims to investigate the bioactivity of A. macrorrhizos extracts in cell culture and murine model of Vitiligo and correlating with its phenolic profile. The metabolic profiling from the bioactive extracts was obtained by LC-DAD-MS, FTIR, NMR, and CE-UV. The murine model of Vitiligo was induced with 5% hydroquinone in C57BL/6 male mice, which were treated or not with 100 mg/kg of roasted tuber aqueous extract. In Vitiligo model assay was observed hair follicle repigmentation and reduction of the epidermal layer thickness at the histopathological level, in the animals treated with aqueous extract of roasted tubers. The present study provides new molecular insight and scientific evidence on the potential utility of the extract of A. macrorrhizos against Vitiligo.

Lignanamides from the stems of Piper hancei maxim. and their anti-inflammatory and cytotoxic activities

Four new lignanamides, hancamides A - D (1-4), together with four known analogs (5-8), were isolated from the stems of Piper hancei Maxim. Their structures were determined based on 1D and 2D NMR, IR, UV, and HR-ESIMS spectroscopic analysis as well as by comparison with the reported data. All the isolates exhibited potential inhibitory effects on NO production in LPS-induced BV-2 microglial cells, with IC₅₀ values of 4.26-40.68 μM. Moreover, compounds 2 and 8 displayed moderate cytotoxic activities against MGC-803, HepG2, SKOV-3, T24, and HeLa cells, with IC₅₀ values ranging from 13.57 to 34.20 μM, respectively.

Traditional Uses, Phytochemistry and Biological Activities of Alocasia Species: A Systematic Review

The genus Alocasia (Schott) G. Don consists of 113 species distributed across Asia, Southeast Asia, and Australia. Alocasia plants grow in tropical and subtropical forests with humid lowlands. Featuring their large green heart-shaped or arrow-shaped ear leaves and occasionally red-orange fruit, they are very popular ornamental plants and are widely used as traditional medicines to treat various diseases such as jaundice, snake bite, boils, and diabetes. This manuscript critically analysed the distribution, traditional uses, and phytochemical contents of 96 species of Alocasia. The numerous biological activities of Alocasia species were also presented, which include anti-cancer, antidiabetic and antihyperglycaemic, antioxidant, antidiarrhoea, antimicrobial and antifungal, antiparasitic (antiprotozoal and anthelminthic), antinociceptive and anti-inflammatory, brine shrimp lethality, hepatoprotective, anti-hemagglutinin, anti-constipation and diuretic, and radioprotective activities as well as acute toxicity studies. Research articles were acquired by the accessing three scientific databases comprising PubMed, Scopus, and Google Scholar. For this review, specific information was obtained using the general search term "Alocasia", followed by the "plant species names" and "phytochemical" or "bioactivity" or "pharmacological activity". The accepted authority of the plant species was referred from theplantlist.org. Scientific studies have revealed that the genus is mainly scattered throughout Asia. It has broad traditional benefits, which have been associated with various biological properties such as cytotoxic, antihyperglycaemic, antimicrobial, and anti-inflammatory. Alocasia species exhibit diverse biological activities that are very useful for medical treatment. The genus Alocasia was reported to be able to produce a strong and high-quality anti-cancer compound, namely alocasgenoside B, although information on this compound is currently limited. Therefore, it is strongly recommended to further explore the relevant use of natural compounds present in the genus Alocasia, particularly as an anti-cancer agent. With only a few Alocasia species that have been scientifically studied so far, more attention and effort is required to establish the link between traditional uses, active compounds, and pharmacological activities of various species of this genus.

Toward a Systematic Nomenclature for (Neo)Lignanamides

Phenylalkenoic acid amides, often referred to as phenol amides or hydroxycinnamic acid amides, are bioactive phytochemicals, whose bioactivity can be enhanced by coupling to form dimers or oligomers. Phenylalkenoic acid amides consist of a (hydroxy)cinnamic acid derivative (i.e., the phenylalkenoic acid subunit) linked to an amine-containing compound (i.e., the amine subunit) via an amide bond. The phenylalkenoic acid moiety can undergo oxidative coupling, either catalyzed by oxidative enzymes or due to autoxidation, which leads to the formation of (neo)lignanamides. Dimers described in the literature are often named after the species in which the compound was first discovered; however, the naming of these compounds lacks a systematic approach. We propose a new nomenclature, inspired by the existing system used for hydroxycinnamic acid dimers and lignin. In the proposed systematic nomenclature for (neo)lignanamides, compound names will be composed of three-letter codes and prefixes denoting the subunits, and numbers that indicate the carbon atoms involved in the linkage between the monomeric precursors. The proposed nomenclature is consistent, future-proof, and systematic.

Lignanamides: sources, biosynthesis and potential health benefits - a minireview

Lignanamides are natural plant secondary metabolites derived from oxidative coupling mechanism with hydroxycinnamic acid amides as intermediates. These compounds display powerful anti-inflammatory, antioxidant, anti-cancer and anti-hyperlipidemic capacities in vitro, cell culture and in vivo studies. With strong potential to be utilized as protective agents against human chronic diseases, these compounds have attracted the interest of researchers. This review aims to discuss current understanding on the sources, classification, biosynthesis of lignanamides in plants, and importantly their biological activity and potential health benefits. The general biosynthesis pathway for lignanamides is comprehensively summarized, though some details in molecular regulation of the coupling process have yet to be elucidated. Lignanamides deserves additional clinical studies involving animal and human subjects, to prove its health benefits.

Effects of landscape plant species and concentration of sewage sludge compost on plant growth, nutrient uptake, and heavy metal removal

Landscape plants have great potentials in heavy metals (HMs) removal as sewage sludge compost (SSC) is increasingly used in urban forestry. We hypothesize that woody plants might perform better in HMs phytoremediation because they have greater biomass and deeper roots than herbaceous plants. We tested the differences in growth responses and HMs phytoremediation among several herbaceous and woody species growing under different SSC concentrations through pot experiments. The mixing percentage of SSC with soil at 0%, 15%, 30%, 60, and 100% were used as growth substrate for three woody (Ficus altissima Bl., Neolamarckia cadamba (Roxb.) Bosser, and Bischofia javanica Bl.) and two herbaceous (Alocasia macrorrhiza (L.) G. Don and Dianella ensifolia (L.) DC) plants. Results showed that the biomass, relative growth rate, and nutrient uptake for all plants increased significantly at each SSC concentration compared to the control; woody plants had higher biomass and nutrient use efficiency than herbaceous plants. All plants growing in SSC-amended soils accumulated appreciable amounts of HMs and reduced the contents of HMs present in the substrates. The woody plants were generally more effective than herbaceous plants in potentials of HMs phytoextraction, but A. macrorrhiza showed higher bioconcentration and translocation of Cu and Zn and D. ensifolia had higher bioconcentration and translocation of Cd than woody plants. The optimal application concentrations were 30% or less for woody plants and 15% for herbaceous plants for plant growth and ecological risk control, respectively. Intercropping suitable woody and herbaceous landscape plants in urban forestry might have promising potentials to minimize the ecological risks in the phytoremediation of SSC.

Piperidine alkaloids from Alocasia macrorrhiza

Six previously undescribed piperidine alkaloids were isolated from the rhizomes of Alocasia macrorrhiza (L.) Schott. Their structures were elucidated based on 1D and 2D NMR, IR, HR-ESI-MS spectroscopic analysis and the application of a modified Mosher method. All isolated alkaloids were evaluated for cytotoxicity against five human cancer cell lines (CNE-1, Detroit 562, Fadu, MGC-803, and MCF-7) using the MTT method. Only one compound exhibited cytotoxic effects against Detroit 562, Fadu, and MCF-7 cell lines with IC₅₀ values less than 10 μM.