Development of a chemical fingerprint as a tool to distinguish closely related Tinospora species and quantitation of marker compounds

Tinospora species are morphologically similar. Several cases of human toxicity have been reported in association with T. crispa. A chemical fingerprint was developed to differentiate T. crispa from its closely related species and to quantitate its major furanoditerpenes namely as borapetosides B, C and F. The rapid, sensitive and repeatable method was established using ultra-high performance liquid chromatography coupled with photodiode array and single quadrupole electrospray mass spectrometry detectors using a flavonoid, two alkaloids, an amide and six diterpenoids. Qualitative and quantitative determination was performed by UHPLC-UV and confirmed by MS. The intra-day RSD for replicates was between 0.9 and 6.8% and inter-day RSD was between 1.2 and 9.1%. Recovery was 97-103 %. The method is useful to achieve decisiveness in not only identifying but also differentiating T. crispa from T. sinensis and other closely related Tinospora species. Seventeen Tinospora plant samples and seventeen dietary supplements claiming T. crispa, T. sinensis and T. cordifolia were analyzed. The newly developed and validated method successfully resulted in the conclusive identification of two dietary supplements to be mislabeled.

Rearranged clerodane diterpenoid from Tinospora crispa

A new rearranged clerodane diterpenoid, tinocrispide was isolated from the stems of Tinospora crispa along with thirteen known compounds including eight clerodane diterpenoids. Among the known compounds baenzigeride A, (6S, 9 R)-vomifoliol and steponine are being reported for the first time from T. crispa. Their structures were elucidated by 1 D and 2 D NMR and confirmed by HRESIMS. The ¹³C NMR data of borapetol A has been revised.

Undescribed phenylpropanoid and a dimeric sesquiterpenoid possessing a rare cyclobutane ring from Tinospora sinensis

A rare dimeric sesquiterpenoid (tinosposinoside, 1) and a phenylpropanoid (cordifolioside C, 2), two undescribed metabolites, were isolated from the methanolic extract of the stems of Tinospora sinensis together with thirteen known compounds. This is the second example of a sesquiterpene dimer where two monomers linked together through a cyclobutane ring, possibly generated through [2 + 2] cycloaddition. The structures of 1 and 2 were elucidated by NMR and mass techniques.

Glycosides of ursane-type triterpenoid, benzophenone, and iridoid from Vangueria agrestis (Fadogia agrestis) and their anti-infective activities

Four ursane-type triterpenoid glycosides (1-4), two benzophenone glycosides (5 and 6), and one iridoid glucoside (7) were isolated and characterized from the dried roots of Vangueria agrestis. Compounds 1 (3-O-[α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranosyl]pomolic acid 28-O-β-D-glucopyranosyl ester) and 5 (2-O-[β-D-apiofuranosyl-(1→6)-β-D-glucopyranosyl]-6,4'-dihydroxy-4-methoxy benzophenone) were found to be new metabolites. The identity of all compounds has been accomplished, primarily, based on 1 D and 2 D NMR and HRESMS analysis. Compounds 6 and 2, showed inhibitory effect against Trypanosoma brucei with IC₅₀ 22.3 µM for 6 and IC₅₀ 11.1 µM, IC₉₀ 12.3 µM for 2.

Three undescribed monoterpene rhamnosides from the aerial parts of Vangueria agrestis

Phytochemical investigation of the methanolic extract of Vangueria agrestis aerial parts led to the isolation and characterization of four monoterpene rhamnosides, two ursane saponins, and six flavonoid glycosides. Of these constituents, are three undescribed monoterpene glycosides, vangagrestosides A-C. The reported constituents comprise the monoterpene glycoside [(2E,6Z)-2,6-dimethyl-8-[O-α-L-rhamnopyranosyl-(1→3)-α-L-rhamnopyranosyl)-oxy]-octadien-1-yl α-L-rhamnopyranoside], the saponins [3-O-[α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl]pomolic acid, and 3-O-[α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranosyl]pomolic acid], and the flavonoids [narcissoside, rutin, hyperoside, guajavarin, biorobin, and nicotifloroside].