The journey of boswellic acids from synthesis to pharmacological activities.

There has been a lot of interest in using naturally occurring substances to treat a wide variety of chronic disorders in recent years. From the gum resin of Boswellia serrata and Boswellia carteri, the pentacyclic triterpene molecules known as boswellic acid (BA) are extracted. We aimed to provide a detailed overview of the origins, chemistry, synthetic derivatives, pharmacokinetic, and biological activity of numerous Boswellia species and their derivatives. The literature searched for reports of B. serrata and isolated BAs having anti-cancer, anti-microbial, anti-inflammatory, anti-arthritic, hypolipidemic, immunomodulatory, anti-diabetic, hepatoprotective, anti-asthmatic, and clastogenic activities. Our results revealed that the cytotoxic and anticancer effects of B. serrata refer to its triterpenoid component, including BAs. Three-O-acetyl-11-keto-BA was the most promising cytotoxic molecule among tested substances. Activation of caspases, upregulation of Bax expression, downregulation of nuclear factor-kappa B (NF-kB), and stimulation of poly (ADP)-ribose polymerase (PARP) cleavage are the primary mechanisms responsible for cytotoxic and antitumor effects. Evidence suggests that BAs have shown promise in combating a wide range of debilitating disease conditions, including cancer, hepatic, inflammatory, and neurological disorders.

Phytoconstituents of two Gleditsia L. species and cytotoxic activity of the isolated curcumin analogues.

Methanolic extracts of Gleditsia triacanthos L. fruits and Gleditsia caspica Desf. leaves yielded two mono-carbonyl curcumin analogues; (1E,4E)-1,5-bis(4-hydroxy-3-methoxyphenyl)penta-1,4-dien-3-one [1], (1E,4E)-1,5-bis(4-hydroxyphenyl)penta-1,4-dien-3-one [2], in addition to ß-sitosterol [3], apigenin [4], quercetin-3`-O-methyl ether [5], rutin [6], quercetin [7], naringenin [8], eriodictyol [9], vitexin [10], isovitexin [11], gleditsin A [12]. The isolation of these compounds was reported here for the first time from the named plants. The separation and identification of curcumin analogues from genus Gleditsia in addition to 13C NMR data of compound 2 were reported here for the first time. Compounds 1 and 2 were assayed in two hepatic cancer cells; HepG-2 and Huh-7. Compound 1 showed high cytotoxic activity against HepG-2 with an IC50 value of 14.39 µM, compared with the standard, IC50 = 12.44 µM.

Isolation, Characterization, Complete Structural Assignment, and Anticancer Activities of the Methoxylated Flavonoids from Rhamnus disperma Roots.

Different chromatographic methods including reversed-phase HPLC led to the isolation and purification of three O-methylated flavonoids; 5,4'-dihydroxy-3,6,7-tri-O-methyl flavone (penduletin) (1), 5,3'-dihydroxy-3,6,7,4',5'-penta-O-methyl flavone (2), and 5-hydroxy-3,6,7,3',4',5'-hexa-O-methyl flavone (3) from Rhamnus disperma roots. Additionlly, four flavonoid glycosides; kampferol 7-O-α-L-rhamnopyranoside (4), isorhamnetin-3-O-ß-D-glucopyranoside (5), quercetin 7-O-α-L-rhamnopyranoside (6), and kampferol 3, 7-di-O-α-L-rhamnopyranoside (7) along with benzyl-O-ß-D-glucopyranoside (8) were successfully isolated. Complete structure characterization of these compounds was assigned based on NMR spectroscopic data, MS analyses, and comparison with the literature. The O-methyl protons and carbons of the three O-methylated flavonoids (1-3) were unambiguously assigned based on 2D NMR data. The occurrence of compounds 1, 4, 5, and 8 in Rhamnus disperma is was reported here for the first time. Compound 3 was acetylated at 5-OH position to give 5-O-acetyl-3,6,7,3',4',5'-hexa-O-methyl flavone (9). Compound 1 exhibited the highest cytotoxic activity against MCF 7, A2780, and HT29 cancer cell lines with IC50 values at 2.17 µM, 0.53 µM, and 2.16 µM, respectively, and was 2-9 folds more selective against tested cancer cell lines compared to the normal human fetal lung fibroblasts (MRC5). It also doubled MCF 7 apoptotic populations and caused G1 cell cycle arrest. The acetylated compound 9 exhibited cytotoxic activity against MCF 7 and HT29 cancer cell lines with IC50 values at 2.19 µM and 3.18 µM, respectively, and was 6-8 folds more cytotoxic to tested cancer cell lines compared to the MRC5 cells.