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Eight Thai edible plants were tested for their inhibitory activity against an angiotensin-converting enzyme (ACE) using an in vitro assay. The methanol extract of Apium graveolens exhibited significant ACE inhibitory activity with an IC50 value of 1.7mg/ml, and was then subjected to an isolation procedure that resulted in identification of a pure active constituent, junipediol A 8-O-&H#x03b2;-D-glucoside (1-β-D-glucosyloxy-2-(3-methoxy-4-hydroxyphenyl)-propane-1,3-diol) (1), which had good ACE inhibitory activity with an IC50 value of 76μg/ml. Another eight known compounds, isofraxidin-β-D-glucoside (2), roseoside (3), apigenin-7-O-β-D-glucoside (4), luteolin-7-O-β-D-glucoside (5), icariside D2 (6), apiin (7), chrysoeriol-7-O-β-D-apiosylglucoside (8), and 11,21-dioxo-3 β,15α,24-trihydroxyurs-12-ene-24-O-β-D-glucopyranoside (9) were also identified. Although each of these five constituents (2-6) isolated from the same fraction as 1 showed no activity at concentrations of 500μM, together, when each was present at 300μg/ml, they enhanced the inhibitory activity of 500μM of 1 from 64% to 81%. [ABSTRACT FROM AUTHOR]

The antioxidant activities of 24 isoflavonoids that were previously isolated as pure compounds from Dalbergia parviflora were evaluated using three different in vitro antioxidant-based assay systems: xanthine/xanthine oxidase (X/XO), ORAC, and DPPH. The isolates consisted of three subgroups, namely isoflavones, isoflavanones, and isoflavans, each of which appeared to have diversified substituents, and were thus ideal for the study of their structure-activity relationships (SARs). The SAR analysis was performed using the results obtained from both the inter-subgroup isoflavonoids with the same substitution pattern and the intra-subgroup compounds with different substitution patterns. The inter-subgroup comparison showed that the isoflavones exhibited the highest antioxidant activities based on all three assays. The intra-subgroup analysis showed that the additional presence of an OH group in Ring B at either R3' or R5' from the basic common structure of the R7-OH of Ring A and the R4'-OH (or -OMe) of Ring B greatly increased the antioxidant activities of all of the isoflavonoid subgroups and that other positions of OH and OMe substitutions exerted different effects on the activities depending on the subgroup and assay type. Therefore, based on the structural diversity of the isoflavonoids in D. parviflora, the present study provides the first clarification of the detailed antioxidant SARs of isoflavonoids. [ABSTRACT FROM AUTHOR]

Reports on the production of coumarin-type stress compounds by CuSo4-treated Pharbitis nil hairy roots, their release into the medium and their uptake as glucosides into the hairy roots. Glucosylation of umbelliferone, scopoletin and aesculetin in hairy roots; Umbelliferone and scopoletin production and change in skimmin level after adding of CuSo4.