Two new polyhydroxylated triterpenoids from Salvia urmiensis and their cytotoxic activity

Recent progress on triterpenoid derivatives and their anticancer potential

Cancer poses a significant global public health challenge, with commonly used adjuvant or neoadjuvant chemotherapy often leading to adverse side effects and drug resistance. Therefore, advancing cancer treatment necessitates the ongoing development of novel anticancer agents with diverse structures and mechanisms of action. Natural products remain crucial in the process of drug discovery, serving as a primary source for pharmaceutical leads and therapeutic advancements. Triterpenoids are particularly compelling due to their complex structures and wide array of biological activities. Recent research has demonstrated that naturally occurring triterpenes and their derivatives have the potential to serve as promising candidates for new drug development. This review aims to comprehensively explore the anticancer properties of triterpenoids and their synthetic analogs, with a focus on recent advancements. Various aspects, such as synthesis, phytochemistry, and molecular simulation for structure-activity relationship analyses, are summarized. It is anticipated that triterpenoid derivatives will emerge as notable anticancer agents following further investigation into their mechanisms of action and in vivo studies.

Purification, Molecular Docking and Cytotoxicity Evaluation of Bioactive Pentacyclic Polyhydroxylated Triterpenoids from Salvia urmiensis

Triterpenoids, as one of the largest classes of naturally occurring secondary metabolites in higher plants, are of interest due to their high structural diversity and wide range of biological activities. In addition to several promising pharmacological activities such as antimicrobial, antiviral, antioxidant, anti-inflammatory and hepatoprotective effects, a large number of triterpenoids have revealed high potential for cancer therapy through their strong cytotoxicity on cancer cell lines and, also, low toxicity in normal cells. So, this study was aimed at discovering novel and potentially bioactive triterpenoids from the Salvia urmiensis species. For this, an ethyl acetate fraction of the acetone extract of the aerial parts of the plant was chromatographed to yield five novel polyhydroxylated triterpenoids (1: -5: ). Their structure was elucidated by extensive spectroscopic methods including 1D (1H, 13C, DEPT-Q) and 2D NMR (COSY, HSQC, HMBC, NOESY) experiments, as well as HRESIMS analysis. Cytotoxic activity of the purified compounds was also investigated by MTT assay against the MCF-7 cancer cell line. Furthermore, a molecular docking analysis was applied to evaluate the inhibition potential of the ligands against the nuclear factor kappa B (NF-κB) protein, which promotes tumor metastasis or affects gene expression in cancer disease. The 1β,11β,22α-trihydroxy-olean-12-ene-3-one (compound 4: ) indicated the best activity in both in vitro and in silico assays, with an IC50 value of 32 µM and a docking score value of - 3.976 kcal/mol, respectively.

Eupatorin 3'-O-glucopyranoside, a trimethoxyflavonoid glucoside from the aerial parts of Salvia mellifera

Salvia mellifera, native to California, Baja California, and Mexico, is a medicinal herb traditionally used to relieve pain, body aches, including chronic pain. A detailed phytochemical investigation of aerial parts of S. mellifera was accomplished to find species-specific markers and to differentiate the closely related, often (un)intentionally substituted with S. apiana. A total of 22 metabolites, including flavonoids (1-14), triterpenoids (15-18), diterpenoids (19-21), and phenylpropanoid (22), were isolated and characterized thoroughly. Among the isolates, eupatorin 3'-O-glucopyranoside (1) was identified as undescribed phytochemical and detailed structure elucidation was achieved through extensive NMR and mass spectral data analysis.

Two new cytotoxic ursane triterpenoids from the aerial parts of Salvia urmiensis Bunge

Bioassay-guided fractionation of a dichloromethane extract of the aerial parts of Salvia urmiensis, an endemic plant species of Iran, led to the isolation of two new cytotoxic ursane triterpenoids, Salvurmin A and Salvurmin B. Their structures were elucidated by a combination of 1D and 2D NMR, HR-ESI-MS, IR and UV analysis. Cytotoxicity of the above-mentioned compounds were evaluated against two human cancerous cell lines (SW1116, MCF-7). IC₅₀ values for Salvurmin A and Salvurmin B on colon cancer cell line (SW1116) were 41.6 ± 2.6 and 23.2 ± 0.4 μM respectively, in comparison to cisplatin as control positive. In addition, these two compounds exhibited cytotoxic activity on breast cancer cell line (MCF-7) with an IC₅₀ of 54.2 ± 5.3 and 40.2 ± 3.1 μM for Salvurmin A and Salvurmin B, respectively. The cytotoxic activities of these two compounds present a promising potential for the future investigation on this endemic species of Salvia.

Iranian Salvia species: A phytochemical and pharmacological update

Salvia is the largest genus of the Lamiaceae family, with over 900 species in the world which about 60 species are distributed in Iran, 17 of them are endemic. In Iran, Salvia species have been used to treat various diseases with a wide spectrum of pharmacological activity in vitro and in vivo. The present review summarizes the phytochemistry and pharmacology of medicinal Iranian Salvia species in order to describe their therapeutic potential for a range of diseases. . Phytochemical investigations reveal that the Iranian Salvia has a varied range of metabolites including terpenoids, flavonoids and phenolic acids. The most important pharmacological activities are antidiabetic, antioxidant, antimicrobial, cytotoxic and anti-inflammatory. Iranian Salvia traditionally used as carminatives, analgesics, digestive aids, antiseptics, sedative, anxiolytic, hypnotic, pain reduction and antidiabetic. Among the endemic species, the most interesting for human health are treating a variety of diseases.

Perovskanol, a new sesquiterpenoid with an unprecedented skeleton from Perovskia Abrotanoides

Phytochemical investigation of the aerial parts of Perovskia abrotanoides (Lamiaceae) by normal phase column chromatography resulted in the isolation of perovskanol (1), a novel sesquiterpenoid possessing a 5/7/5 fused carbon ring skeleton. The structure of 1 was established by comprehensive spectroscopic data analysis including 1 D and 2 D NMR and HRESIMS. The antiprotozoal activity of compound 1 was evaluated against Trypanosoma brucei rhodesiense, T. cruzi, Leishmania donovani, Plasmodium falciparum and no promising activities were shown against all parasite tested.

Triterpenic Acid Content and Cytotoxicity of Some Salvia Species From Iran

For prosperous domestication, breeding, and cultivation of a herbal species, it is important to screen its medicinally valuable compounds as well as its referred biological activity. Salvia L. species (Lamiaceae), distributed throughout the world, contain a wide range of secondary metabolites including terpenoids and phenolic derivatives. Betulinic acid (BA), oleanolic acid (OA), and ursolic acid (UA) are highly valuable triterpenic acids (TAs) because of their wide range of biological activities. The objective of the present work was to evaluate the BA, OA, and UA contents among 22 Salvia species native to Iran. TA content in the studied Salvia species was compared with that in Salvia officinalis as a commercial species. High-performance liquid chromatography with photodiode array detector results showed that the maximum content of BA (3.12 ± 0.03 mg/g dry weight [DW]) and OA (1.96 ± 0.05 mg/g DW) was determined in Salvia multicaulis. The highest content of UA (4.34 ± 0.1 mg/g DW) was quantified in S. officinalis L. followed by S. multicaulis (3.71 ± 0.08 mg/g DW). Salvia multicaulis exhibited significantly higher agro-morphological values than S. officinalis in traits related to plant width, leaf length, internode length, and inflorescence length. The cytotoxicities of both species were determined against human cancer cell lines using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The methanolic extract of S. multicaulis and S. officinalis showed cytotoxic effects against SH-SY5Y and MCF-7 cell lines, respectively. Both species were equally cytotoxic against the HL-60 cell line. This study provides scope for the selection of high-yielding species and genetic improvement through breeding and biotechnological programs in the future.

Terpenoids and phenolics of Micromeria persica

Phytochemical investigation of the aerial parts of Micromeria persica led to the isolation of a new oleane type triterpenoid ester (1), together with six known compounds 2-7), comprising one phenyl ethanoid ester, one glycosylated flavonoid, two triterpenoids, and two steroids. Their structures were elucidated by interpretation of their one-dimensional and two-dimensional NMR spectra and completed by the analysis of the HRESIMS data. Compounds 1 and 3 were evaluated for their cytotoxic feature against human breast adenocarcinoma cell line (MDA-MB231) and human prostate cancer cell line (DU145). However, they did not show positive effect (IC₅₀ > 75µM).[Figure: see text].

Antiprotozoal Isoprenoids from Salvia hydrangea

Fractionation of the n-hexane extract of Salvia hydrangea afforded seven isoprenoids including six new compounds (1-6) and salvadione A (7). Their structures were established by comprehensive spectroscopic and spectrometric data analysis (1D and 2D NMR, HRMS). The absolute configuration of salvadione A (7) was established by single-crystal X-ray diffraction analysis with Cu/Kα radiation. In addition, the absolute configuration of all compounds was determined by electronic circular dichroism spectroscopy. A biosynthetic pathway for the formation of the scaffold of 1 is proposed. The antiprotozoal activity of the compounds against Trypanosoma brucei rhodesiense, Trypanosoma cruzi, Leishmania donovani, and Plasmodium falciparum was determined, and cytotoxicity was assessed in rat myoblast L6 cells. Perovskone C (2) exhibited good activity against P. falciparum (IC₅₀ 0.6 μM) and a selectivity index of 62.2.

New tetranorlabdanoic acid from aerial parts of Salvia aethiopis

Salvia aethiopis is a perennial plant native to Eurasia and known by the common names Mediterranean sage or African sage. This plant has been used in Iranian medicine as a carminative and tonic. The ethanolic extract of aerial part of S. aethiopis exhibited moderate to weak activity towards delta and kappa opioid receptors (46.3 and 45.3% displacement, respectively). Chromatographic purification of the ethanolic extract on silica gel column led to isolation of one new: 3α-hydroxy-8α-acetoxy-13,14,15,16-tetranorlabdan-12-oic acid (I) and three known compounds: sesquiterpene spathulenol (II), β-sitosterol (III) and β-sitosterol-3-O-glucoside (IV). The structures of all isolated compounds were elucidated by their NMR (1D and 2D) and MS spectral data. All the fractions and isolated compounds were tested for cannabinoid and opioid receptor binding assays.

Phytochemical and biological evaluation of Salvia apiana

Salvia apiana (white sage, Lamiaceae family) plant is native to southern California and parts of Mexico. Some Native American tribes local to this region consider S. apiana to be sacred and burn the leaves as incense for purification ceremonies. The plant has been used to treat sore throats, coughs, chest colds, upper respiratory infections and poison oak rashes. The aqueous ethanolic extract of S. apiana showed moderate CB1 activity (58.3% displacement). Chromatographic purification of the ethanolic extract on silica gel column led to isolation of nine compounds: rosmadial (I), carnosol (II), 16-hydroxycarnosol (III), sageone (IV), cirsimaritin (V), salvigenin (VI), oleanolic acid (VII), 3β,28-dihydroxy-urs-12-ene (VIII), and ursolic acid (IX). The structures of the isolated compounds were determined by their 1D, 2D NMR and MS spectral data. All the fractions and isolated compounds were tested for cannabinoid and opioid receptor binding.

Anti-influenza effect of the major flavonoids from Salvia plebeia R.Br. via inhibition of influenza H1N1 virus neuraminidase

To determine the compounds responsible for its anti-influenza activities, we isolated the three flavonoids, 6-hydroxyluteolin 7-O-β-d-glucoside (1), nepitrin (2), homoplantaginin (3) from the MeOH extract of Salvia plebeia R.Br. and identified them by comparing the spectroscopic data with that reported in the literature. The contents of the three flavonoids in the whole extract were 108.74 ± 0.95, 46.26 ± 2.19, and 69.35 ± 1.22 mg/g for 6-hydroxyluteolin 7-O-β-d-glucoside, nepitrin, and homoplantaginin, respectively, which demonstrates that they are the major constituents of this plant. The three flavonoids were evaluated for their inhibitory activities against influenza virus H1N1 A/PR/9/34 neuraminidase and H1N1-induced cytopathic effect (CPE) on Madin-Darby canine kidney (MDCK) cells. Our results demonstrated the following arrangement for their anti-influenza activities: nepitrin (2) > 6-hydroxyluteolin 7-O-β-d-glucoside (1) > homoplantaginin (3). The potent inhibitory activities of these flavonoids against influenza suggested their potential to be developed as novel anti-influenza drugs in the future.

A novel Salvialactomine from the callus culture of Salvia santolinifolia Boiss

A novel compound Salvialactomine (1) along with two other unusual occurring natural products Pentatriacontanoic acid 1, 3-dihydroxypropyl ester (2) and 5-Methylflavone (3) were isolated from the callus of Salvia santolinifolia Boiss. Callus was initiated on MS medium containing NAA (0.5 mg/L) and further sub-cultured on MS medium supplemented with NAA with BA (0.5 + 1.5 mg/L). The structures of isolated compounds were determined by using mass spectrometry, 1D, and 2D-NMR techniques. Compounds 1, and 3 were tested for two different cancer cell lines, i.e. Hela (Cervical cancer cell) and PC-3 (Prostate cancer cells). IC₅₀ was found as > 30 using Doxorobicin (0.912 ± 0.12 μmol L^-1) as a standard.

A nor-diterpene from Salvia sahendica leaves

Phytochemical investigation of n-hexane extract of Salvia sahendica by normal phase column chromatography resulted in the isolation of six compounds. Structures were established by 1D and 2D NMR spectroscopy, and HRMS, as a new norditerpene 1, and known terpenoids, sclareol (2), oleanolic acid (3), β-sitosterol (4), salvigenin (5) and 3α-hydroxy-11α,12α-epoxyoleanan-28,13β-olide (6). The absolute configuration of 1 was confirmed by a combination of X-ray single crystal analysis and electronic circular dichroism spectroscopy. In vitro cytotoxic activity on breast cancer cell line (MDA-MB-231) and also the antimicrobial activity of the pure compounds were tested against Staphylococcus aureus, Bacilus cereus and Escherichia coli.