Chemical Constituents of Two Original Plants Used as Radix Tinosporae: Chemical Constituents of Two Original Plants Used as Radix Tinosporae

Clerodane diterpenoids with in-vitro anti-neuroinflammatory activity from the tuberous root of Tinospora sagittata (Menispermaceae)

Twenty-six clerodane diterpenoids have been isolated from T. sagittata, a plant species of traditional Chinese medicine Radix Tinosporae, also named as "Jin Guo Lan". Among them, there are eight previously undescribed clerodane diterpenoids (tinotanoids A-H: 1-8), and 18 known diterpenoids (9-26). The absolute configurations of compounds 1, 2, 5, 8, 13, 17 and 20 were determined by single-crystal X-ray diffraction. Compound 1 is the first example of rotameric clerodane diterpenoid with a γ-lactone ring which is constructed between C-11 and C-17; meanwhile, compounds 3 and 4 are two pairs of inseparable epimers. Compounds 2, 12 and 17 demonstrated excellent inhibitory activity on NO production against LPS-stimulated BV-2 cells with IC50 values of 9.56 ± 0.69, 9.11 ± 0.53 and 11.12 ± 0.70 μM, respectively. These activities were significantly higher than that of the positive control minocycline (IC50 = 23.57 ± 0.92 μM). Moreover, compounds 2, 12 and 17 dramatically reduced the LPS-induced upregulation of iNOS and COX-2 expression. Compounds 2 and 12 significantly inhibited the levels of pro-inflammatory cytokines TNF-α, IL-1β and IL-6 that were increased by LPS stimulation.

Tinosporae radix: A Review of Traditional Use, Botany, Phytochemistry, Bioactivity, and Quality Marker

BACKGROUND

Tinosporae radix is the root tuber of Tinospora capillipes Gagnep of the Menispermaceae family. It has the effects of clearing away heat and toxins, benefiting the throat, relieving pain, and treating sore throat, carbuncle and boils, and other diseases in clinical practice.

METHODS

The related references about T. radix in this review were collected by online databases, including PubMed, Elsevier, Web of Science, Willy, SciFinder, SpringLink, Google Scholar, Baidu Scholar, ACS publications, Scopus, and CNKI. The other information about T. radix was acquired from ancient books and classical works.

RESULTS

T. radix is an important medicinal plant with a variety of traditional uses according to the theory of Chinese medicine. Previous studies revealed that T. radix contained a variety of chemical components, including diterpenoids, alkaloids, steroids, cinnamic acid derivatives, and other compounds. Many pharmacological researches have exhibited that T. radix possesses various biological activities, including anti-cancer, hypoglycemic, anti-inflammatory, anti-bacterial, anti-ulcer, and anti-oxidant activities. Furthermore, the quality markers of T. radix were summarized and analyzed in this paper.

CONCLUSION

The traditional use, botany, phytochemistry, bioactivity, and quality markers of T. radix were reviewed in this paper. It will not only provide an important clue for further studying T. radix, but also supply an important theoretical basis and a valuable reference for in-depth research and exploitations of this plant in the future.

Menisperdaurines A-W, structurally diverse isoquinoline alkaloids from Menispermum dauricum and their dopamine D1 receptor activities

A total of 33 structurally diverse isoquinoline alkaloids were isolated from the rhizomes of Menispermum dauricum, including seventeen benzylisoquinoline analogues (menisperdaurines A-Q, 1-17), five protoberberine analogues (menisperdaurines R-V, 18-22), a quaternary phenanthrene alkaloid (menisperdaurine W, 23) and ten known compounds (24-33). Compound structures, including absolute configurations, were determined by extensive spectroscopic methods, quantum chemical calculations of chemical shifts, and calculated and experimental electronic circular dichroism (ECD) data. Compounds 1-5 were glycosidic benzylisoquinolines with glucose moieties attached at the C-12 position. Compound 8 was the first example that was isolated from the rhizomes of Menispermum dauricum, benzylisoquinoline and an aromatic unit connected by a sugar bridge. Compounds were evaluated for their inhibitory effects on the dopamine D1 receptor. Compounds 1, 8, 21, 24 and 29 showed potent D1 antagonistic activities, with IC₅₀ values ranging from 1.0 to 4.5 μM. Compound 1 exhibited the highest antagonistic activity with an IC₅₀ value of 1.0 ± 0.2 μM.

Bistinospinosides A and B, Dimeric Clerodane Diterpene Glycosides from Tinospora sagittata

Two dimeric clerodane diterpene glycosides, namely, bistinospinosides A (1) and B (2), were isolated from the roots of Tinospora sagittata. Their structures were elucidated by extensive spectroscopic data interpretation. The compounds feature an unusual 1,4-epoxycyclohexane ring in their structures and may be biosynthetically constructed via an intermolecular Diels-Alder [4+2] cycloaddition from the corresponding clerodane diterpene. The compounds were evaluated in a nitric oxide inhibitory assay using J774.1 macrophage-like cells.

Two New Clerodane Diterpenes from Tinospora sagittata

Two new clerodane-type diterpenes, tinosporins C (1) and tinosporins D (2) were isolated from the stems of Tinospora sagittata (Oliv.), together with three known ones, columbin (3), tinophylloloside (4), and tinospinoside D (5). The structures of these compounds were determined on the basis of spectroscopic data interpretation, with that of the absolute configuration of compound 1 was assigned by experimental and calculated ECD spectra. The cytotoxicity and α-glucosidase inhibitory activities of isolated compounds were evaluated in vitro.

Genus Tinospora: Ethnopharmacology, Phytochemistry, and Pharmacology

The genus Tinospora includes 34 species, in which several herbs were used as traditional medicines by indigenous groups throughout the tropical and subtropical parts of Asia, Africa, and Australia. The extensive literature survey revealed Tinospora species to be a group of important medicinal plants used for the ethnomedical treatment of colds, headaches, pharyngitis, fever, diarrhea, oral ulcer, diabetes, digestive disorder, and rheumatoid arthritis. Indian ethnopharmacological data points to the therapeutic potential of the T. cordifolia for the treatment of diabetic conditions. While Tinospora species are confusing in individual ingredients and their mechanisms of action, the ethnopharmacological history of those plants indicated that they exhibit antidiabetic, antioxidation, antitumor, anti-inflammation, antimicrobial, antiosteoporosis, and immunostimulation activities. While the clinical applications in modern medicine are lacking convincing evidence and support, this review is aimed at summarizing the current knowledge of the traditional uses, phytochemistry, biological activities, and toxicities of the genus Tinospora to reveal its therapeutic potentials and gaps, offering opportunities for future researches.