Lignans: Quantitative Analysis of the Research Literature

The current study provides a comprehensive overview and analysis of the lignan literature. Data for the current study were extracted from the electronic Web of Science Core Collection database via the search string TOPIC = ("lignan*") and processed by the VOSviewer software. The search yielded 10,742 publications. The ratio of original articles to reviews was 14.6:1. Over 80% of the analyzed papers have been published since the year 2000 and nearly 50% since the year 2010. Many of the publications were focused on pharmacology, chemistry, and plant sciences. The United States and Asian countries, such as China, Japan, South Korea, and India, were the most productive producers of lignan publications. Among the 5 most productive institutions was the University of Helsinki in Finland, the country that ranked 9^th. Nineteen journals collectively published 3,607 lignan publications and were considered as core journals. Their impact factor did not correlate with the proportion of uncited papers. Highly cited publications usually mentioned phytoestrogen, isoflavone, daidzein, enterodiol, enterolactone, equol, genistein, and isoflavonoid. Cancer (e.g., breast cancer), cardiovascular disease, and antioxidation were the major themes. Clinical trials were estimated to contribute to 0.2-1.1% of the analyzed body of literature, so more of them should be conducted in the future to substantiate the beneficial effects and optimal dose of lignan intake in humans. Moreover, researchers can refer to these findings for future research directions and collaborations.

Dasymaschalolactams A-E, Aristolactams from a Twig Extract of Dasymaschalon dasymaschalum

Five new aristolactam alkaloids (1-5), dasymaschalolactams A-E, and the first isolation of dasymaschalolactone (17) as a natural product, together with 19 known compounds (6-16 and 18-25) were isolated from the twig extract of Dasymaschalon dasymaschalum. Their structures were elucidated by spectroscopic methods as well as comparisons made from the literature. Compounds 20 and 21 showed α-glucosidase inhibitory activities with IC₅₀ values of 4.5 and 24.7 μM, respectively.

A New Oxoaporphine Alkaloid from the Root of Dasymaschalon glaucum

The first phytochemical investigation of the root of Dasymaschalon glaucum led to the isolation of a new oxoaporphine alkaloid 1 together with seven known compounds, duguevalline (2), stigmalactam (3), enterocarpam III (4), desmosdumotin B (5), spiraeamide (6), kaempferol-3- O-glucopyranoside (7) and β-sitosterol (8). The chemical structures of all isolated compounds were established on the basis of their spectroscopic data. The cytotoxic and anti-HIV 1-RT activities of isolated compounds were also evaluated.

Anti-HIV Activity of Alkaloids from Dasymaschalon echinatum

Bioassay-guided fractionation of the aerial parts of Dasymaschalon echinatum led to the isolation of five known aristolactams; aristolactam AII (1), aristolactam BII (2), piperolactam A (3), piperolactam C (4), and goniopedaline (5), together with two aphorphine alkaloids; duguevalline (6) and noraristolodione (7) and two amide derivatives; asperphenamate (8), and N -benzoyl-L-phenylalaninol (9). Alkaloids 2 and 7 were isolated for the first time from the Dasymaschalon genus. The anti-HIV 1 reverse transcriptase (RT) activity of all isolated compounds was determined. Except for aristolactam BII (2), this is the first report of the anti-HIV 1-RT activity of compounds 1 and 3-9. Compounds 1, 3, 5, 6 and 8 showed weak anti-HIV 1-RT inhibitory activity with IC50 ranging from 112.74 to 225.55μM.