Lignans and fatty-acid composition of Arctium lappa seeds

Comparison of Metabolic Profiles of Fruits of Arctium lappa, Arctium minus, and Arctium tomentosum

Metabolites of the edible and medicinal plant Arctium have been shown to possess beneficial activities. The phytochemical profile of Arctium lappa is well-explored and its fruits are known to contain mainly lignans, fatty acids, and sterols. But the fruits of other Arctium species have not been thoroughly investigated. Therefore, this study compares the metabolic profiles of the fruits of A. lappa, Arctium tomentosum, and Arctium minus. Targeted metabolomics led to the putative identification of 53 metabolites in the fruit extracts, the majority of these being lignans and fatty acids. Quantification of the major lignans showed that the year of collection had a significant effect on the lignan content. Furthermore, A. lappa fruits contained lesser amounts of arctigenin but greater amounts of arctigenin glycoside than A. minus fruits. Regarding the profile of fatty acids, A. minus fruits differed from the others in the presence of linolelaidic acid.

Fatty Acids and Elements Profile of Different Parts from Congress grass (Parthenium hysterophorus L.)

Congress grass (Parthenium hysterophorus L., family Asteraceae) is found generally in agricultural and vacant lands across the globe. This study investigated the fatty acids and elemental profiles of different parts including roots, stem and leaves of P. hysterophorus in the response to seasonal variation. The elemental analysis and fatty acid were determined in both the winter and summer seasons. The root, stem, and leaves powder were subjected to extraction with acetone, water, chloroform, diethyl ether, ethanol, methanol, and n-hexane to measure the extractive values. Among all the plant parts, leaves recorded the highest extractive value of 29%, and 28% with acetone and diethyl ether, respectively, while the root recorded the lowest (10.3%) extractive value with chloroform. Higher concentrations of saturated and unsaturated fatty acids were detected in all the plant parts in the winter collection than in the summer season. Parthenium hysterophorus is multi medicinal applications such as used for rheumatic pain, urinary tract infections, inflammation, diarrhea, neuralgia, and malaria. The study highlights the importance of collection time (seasons) of different parts of P. hysterophorus for the maximum extraction of both elements and fatty acids either saturated or unsaturated from the pharmacogenetic point of view.

Identification and characterization of human UDP-glucuronosyltransferases responsible for the in-vitro glucuronidation of arctigenin

Objectives

This study aimed to characterize the glucuronidation pathway of arctigenin (AR) in human liver microsomes (HLM) and human intestine microsomes (HIM).

Methods

HLM and HIM incubation systems were employed to catalyse the formation of AR glucuronide. The glucuronidation activity of commercially recombinant UGT isoforms towards AR was screened. A combination of chemical inhibition assay and kinetic analysis was used to determine the UGT isoforms involved in the glucuronidation of AR in HLM and HIM.

Key findings

AR could be extensively metabolized to one mono-glucuronide in HLM and HIM. The mono-glucuronide was biosynthesized and characterized as 4′-O-glucuronide. UGT1A1, 1A3, 1A7, 1A8, 1A9, 1A10, 2B4, 2B7 and 2B17 participated in the formation of 4′-O-G, while UGT2B17 demonstrated the highest catalytic activity in this biotransformation. Both kinetic analysis and chemical inhibition assays demonstrated that UGT1A9, UGT2B7 and UGT2B17 played important roles in AR-4′-O-glucuronidation in HLM. Furthermore, HIM demonstrated moderate efficiency for AR-4′-O-glucuronidation, implying that AR may undergo a first-pass metabolism during the absorption process.

Conclusion

UGT1A9, UGT2B7 and UGT2B17 were the major isoforms responsible for the 4′-O-glucuronidation of AR in HLM, while UGT2B7 and UGT2B17 were the major contributors to this biotransformation in HIM.

New Butyrolactone Type Lignans from Arctii Fructus and Their Anti-inflammatory Activities

Arctiidilactone (1), a novel rare butyrolactone lignan with a 6-carboxyl-2-pyrone moiety, and 11 new butyrolactone lignans (2-12) were isolated from the fruits of Arctium lappa L., together with 5 known compounds (13-17). Their structures were elucidated by interpretation of their spectroscopic data (1D and 2D NMR, UV, IR, ORD, and HRESIMS) and comparison to literature data. The absolute configurations of compounds 1-12 were determined by a combination of rotating-frame nuclear Overhauser effect spectroscopy (ROESY), circular dichroism (CD) spectroscopy, and Rh2(OCOCF3)4-induced CD spectroscopy. All of the compounds were tested for their anti-inflammatory properties in terms of suppressing the production of NO in lipopolysaccharide-induced BV2 cells. Compounds 1, 6, 8, and 10 exhibited stronger anti-inflammatory effects than the positive control curcumin, particularly 1, which exhibited 75.51, 70.72, and 61.17% inhibition at 10, 1, and 0.1 μM, respectively.

Hepatoprotective activity of twelve novel 7'-hydroxy lignan glucosides from Arctii Fructus

Twelve novel 7'-hydroxy lignan glucosides (1-12), including two benzofuran-type neolignans, two 8-O-4' neolignans, two dibenzylbutyrolactone lignans, and six tetrahydrofuranoid lignans, together with six known lignan glucosides (13-18), were isolated from the fruit of Arctium lappa L. (Asteraceae), commonly known as Arctii Fructus. Their structures were elucidated using spectroscopy (1D and 2D NMR, MS, IR, ORD, and UV) and on the basis of chemical evidence. The absolute configurations of compounds 1-12 were confirmed using rotating frame nuclear overhauser effect spectroscopy (ROESY), the circular dichroic (CD) exciton chirality method, and Rh2(OCOCF3)4-induced CD spectrum analysis. All of the isolated compounds were tested for hepatoprotective effects against D-galactosamine-induced cytotoxicity in HL-7702 hepatic cells. Compounds 1, 2, 7-12, and 17 showed significantly stronger hepatoprotective activity than the positive control bicyclol at a concentration of 1 × 10(-5) M.

Two new neolignan glucosides from Arctii Fructus

Two new neolignan glucosides named (7S, 8R)-4,7,9,9'-tetrahydroxy-3,3'-dimethoxyl-7'-oxo-8-4'-oxyneolignan-4-O-β-D-glucopyranoside and (7'S, 8'R, 8S)-4,4',9'-trihydroxy-3,3'-dimethoxy-7',9-epoxylignan-7-oxo-4-O-β-D-glucopyranosyl-4'-O-β-D-glucopyranoside, together with two small molecular peptides named 3-benzyl-6-(1-hydroxyethyl)-2,5-piperazinedione and 3-benzyl-2,5-piperazinedione, were isolated from the extract of Arctii Fructus. Their structures and absolute configurations were elucidated by various spectroscopic methods (IR, HR-ESI-MS, 1D and 2D NMR, and CD).