scopadulcic-acid-b and scopadulciol

In interviews on the traditional herbal medicines of Tupi-Guarany Indians at the herbal market of Asuncion and questionnaire from their users, it was clarified that various useful medicinal plants are available in Paraguay and most of them are generally used without drying. In the search for bioactive substances from those plants, a β-glucuronidase-inhibitory diterpene called scoparic acid A (SA) was isolated from Scoparia dulcis L. together with scoparic acid B, scoparic acid C, and the aphidicolin-like tetracyclic diterpenes scopadulcic acid A (SDA) and scopadulcic acid B (SDB). HPLC analysis of diterpenes in the individual plants of Paraguayan and Asian S. dulcis revealed the presence of three chemotypes based on major component, i.e., SA type, SDB type, and SDX type containing mainly scopadiol and scopadulciol (SDC). SA and SDB were elucidated to be mainly biosynthesized in the leaves via 2-C-methyl-D-erythritol- 4-phosphate pathway, and a leaf organ culture system containing methyl jasmonate 10 µM was found to enhance the production of diterpenes by activation of Ca-signal transduction systems such as calmodulin and protein kinase C. On the other hand, SDB and SDC were found to show multifaceted pharmacological effects such as inhibitory effects on gastric acid excretion, bone resorption, replication of herpes simplex virus type 1 (HSV-1), etc. In addition, SDC was suggested to be applicable to cancer gene therapy using ganciclovir or acyclovir and the HSV-1 thymidine kinase gene called the suicide gene.

Topics: Abietanes; Animals; Bone Resorption; Chromatography, High Pressure Liquid; Diterpenes; Gastric Acid; Genes, Transgenic, Suicide; Genetic Therapy; Herpesvirus 1, Human; Humans; Medicine, Traditional; Neoplasms; Paraguay; Phytotherapy; Rats; Scoparia; Surveys and Questionnaires; Thymidine Kinase; Virus Replication

Six new diterpenoids, 4-epi-7α-O-acetylscoparic acid A (1), 7α-hydroxyscopadiol (2), 7α-O-acetyl-8,17β-epoxyscoparic acid A (3), neo-dulcinol (4), dulcinodal-13-one (5), and 4-epi-7α-hydroxydulcinodal-13-one (6), and a new flavonoid, dillenetin 3-O-(6″-O-p-coumaroyl)-β-D-glucopyranoside (10), along with 12 known compounds, were isolated from the aerial parts of Scoparia dulcis. The 7S absolute configuration of the new diterpenoids 1-4 and 6 was deduced by comparing their NOESY spectra with that of a known compound, (7S)-4-epi-7-hydroxyscoparic acid A (7), which was determined by the modified Mosher's method. The flavonoids scutellarein (11), hispidulin (12), apigenin (15), and luteolin (16) and the terpenoids 4-epi-scopadulcic acid B (9) and betulinic acid (19) showed more potent α-glucosidase inhibitory effects (with IC50 values in the range 13.7-132.5 μM) than the positive control, acarbose. In addition, compounds 1, 11, 12, 15, 16, and acerosin (17) exhibited peroxisome proliferator-activated receptor gamma (PPAR-γ) agonistic activity, with EC50 values ranging from 0.9 to 24.9 μM.

Topics: Abietanes; Acarbose; Apigenin; Diterpenes; Flavonoids; Glucosides; Glycoside Hydrolase Inhibitors; Luteolin; Molecular Structure; Plant Components, Aerial; PPAR gamma; Scoparia