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The limited supply of Chinese officinal rhubarbs (Rheum palmatum L., R. tanguticum Maxim. ex Balf., and R. officinale Baill.) has resulted in the use of other Rheum species in many places. Therefore, investigating the metabolite profile of unofficinal rhubarbs, and an analytical comparison of their metabolite profile with the officinal ones is crucial. Rheum turkestanicum Janisch. and R. ribes L. are two Rheum species distributed in Iran and are widely being traded in traditional markets as substitutes for R. palmatum. Herein, we isolated different phenolic compounds in the roots and rhizomes of R. turkestanicum and R. ribes by chromatographic techniques and identified them by nuclear magnetic resonance spectroscopy (NMR), electronic circular dichroism (ECD), electrospray ionization-mass spectrometry (ESI-MS), and high-resolution mass spectrometry (HRMS). In addition, the metabolite profile of the two above-mentioned species were compared with that of R. palmatum by liquid chromatography-electrospray ionization-quadrupole time-of-flight mass spectrometry (LC-ESI-QqTOF MS). The obtained MS data were statistically compared by non-metric multidimensional scaling (NMDS) and analysis of similarities (ANOSIM) and a heatmap was plotted for comparing the tested samples. The isolated compounds were catechins, anthraquinones, naphthoquinones, chromones and rhododendrol glycosides, among which (-) 3′,4′′-di-O-methyl-catechin-3-O-gallate was a new compound. The results of LC-MS/MS analysis indicated that while catechins were the most abundant compounds in R. ribes , anthraquinones and naphthalenes were the main constituents of R. palmatum and R. turkestanicum. Interestingly, the substitution in the hexosyl residue of anthraquinone and naphthalene hexosides was a malonyl or an acetyl group in R. palmatum , while this substitution was a 3-hydroxy-3-methylglutaryl group in R. turkestanicum. This may be considered as a potential marker for the differentiation of R. palmatum and R. turkestanicum. The statistical analysis showed that R. palmatum , R. turkestanicum , and R. ribes are distinct species, however, R. turkestanicum had some similarities to R. palmatum. In conclusion, R. turkestanicum can be a subject for future phytochemical, pharmacological, and clinical research regarding its ability to be used as a potential substitute for R. palmatum in pharmaceutical industries. [Display omitted] • Rheum palmatum is one of the three species considered as officinal Chinese rhubarbs. • One new and six known compounds were isolated from R. turkestanicum. • In the LC-MS/MS spectrum of R. ribes , catechins were the major compounds. • In R. palmatum and R. turkestanicum , anthraquinones and naphthalenes were abundant. • Rheum palmatum and R. turkestanicum had some similarities in their metabolite profiles. [ABSTRACT FROM AUTHOR]

Two new triterpenoids, urmiensolide B ( 1 ) and urmiensic acid ( 2 ), with rare carbon skeletons together with three known compounds were isolated from the aerial parts of Salvia urmiensis Bunge, an endemic species of Iran. The structures were established by a combination of 1D and 2D NMR, and HRESIMS, and in the case of 2 and 3 , their structures were confirmed by single-crystal X-ray analysis. The absolute configuration of 2 was established by electronic circular dichroism (ECD) spectra. The new compounds were evaluated for their anti-proliferative activities against A549 and MCF-7 human cancer cell lines. Compounds 1 and 2 showed IC 50 values of 2.8 and 1.6 μM against MCF-7 cells, respectively. [ABSTRACT FROM AUTHOR]

Purpose: Zhumeria majdae, a unique species of the Zhumeria genus, is an endemic Iranian plant in the Lamiaceae family. Phytochemical investigation and biological activity of this plant are rarely reported. The current study aimed to find new antiprotozoal compounds from the roots of Z. majdae and to determine the absolute configuration of isolated compounds by circular dichroism., Methods: The extraction process from roots and aerial parts of Z. majdae was carried out by hexane, ethyl acetate and methanol followed by testing their antiprotozoal effects against Leishmania donovani, Trypanosoma brucei rhodesiense, T. cruzi, and Plasmodium falciparum, respectively. Structure elucidation was done using 1D and 2D NMR spectroscopy and HREIMS spectrometry. In addition, experimental and theoretical circular dichroism spectroscopy was used to establish absolute configuration., Results: In comparison with aerial parts, the hexane extract from roots showed superior activity against T. b. rhodesiense, L. donovani and P. falciparum with IC 50 values of 5.4, 1.6 and 2.1 μg/ml, respectively. From eight abietane-type diterpenoids identified in roots, six were reported for the first time in the genus Zhumeria. 11,14-dihydroxy-8,11,13-abietatrien-7-one (6) exhibited a promising biological activity against P. falciparum (IC 50 8.65 μM), with a selectivity index (SI) of 4.6, and lanugon Q (8) showed an IC 50 value of 0.13 μM and SI of 15.4 against T. b. rhodesiense., Conclusion: Altogether, according to the results, of 8 isolated compounds, dihydroxy-8,11,13-abietatrien-7-one (6) and lanugon Q (8) exhibited a promising activity against T. b. rhodesiense and P. falciparum. In conclusion, these compounds could be potential candidates for further analysis and may serve as lead compounds for the synthesis of antiprotozoal agents. Graphical abstract.

In a screening of Iranian plants for antiprotozoal activity a dichlomethane extract from the aerial parts of Helichrysum oocephalum showed in vitro antiprotozoal activity against Plasmodium falciparum and Leishmania donovani, with IC 50 values of 4.01 ± 0.50 and 5.08 ± 0.07 μg/mL, respectively. The activity in the extract was tracked by HPLC-based activity profiling, and subsequent targeted preparative isolation afforded 24 compounds, including pyrones 22-24, phloroglucinol derivatives 12-19, and compounds containing both structural motifs (1-11, 20, and 21). Of these, 15 compounds were new natural products. The in vitro antiprotozoal activity of isolates was determined. Compound 3 showed good potency and selectivity in vitro against L. donovani (IC 50 1.79 ± 0.17 μM; SI 53).

Five new manoyloxide-type sesterterpenes were isolated from aerial parts of Salvia mirzayanii, a species endemic to Iran. The planar structures were established by means of 1D and 2D NMR and HRESIMS. Compounds 1-3 differed only in their configurations at C-13 and C-14. Assignment of relative and absolute configurations was achieved by NOESY experiments and by comparison of experimental and simulated ECD spectra of possible stereoisomers. The absolute configurations of 4 and 5 were established in a similar manner.

A new triterpenoid, urmiensolide (1), was isolated from Salvia urmiensis. The structure was elucidated by a combination of 1D and 2D NMR, HRESIMS, and X-ray crystallographic analyses. The absolute configuration was established by comparison of experimental and simulated ECD spectra. Urmiensolide is the first pentacyclic triterpenoid bearing a ε-lactone E-ring. The compound showed in vitro antitrypanosoal activity with an IC₅₀ value of 5.6 μM against the Trypanosoma brucei rhodesiense STIB 900 strain and a selectivity index of 33. A possible biosynthetic pathway of 1 from α-amyrin is proposed.

Salvadione C (1) and perovskone B (2), two new triterpenoids with rare carbon skeletons, were isolated from an antiplasmodial n-hexane extract of Salvia hydrangea. The absolute configuration was determined by comparison of experimental and calculated electronic circular dichroism (ECD) spectra. In vitro activity against Plasmodium falciparum K1 strain, Trypanosoma brucei rhodesiense STIB 900 strain, and cytotoxicity in rat myoblast (L6) cells were determined. Compounds 1 and 2 showed in vitro antiplasmodial activity, with IC50 values of 1.43 and 0.18 μM and selectivity indices (SI) of 86.2 and 69.6, respectively. IC50 values against T. brucei rhodesiense were found to be 4.33 and 15.92 μM, respectively.