Boswellic acids: a group of medicinally important compounds

This review, containing over 276 references, covers the progress made in the chemistry and bioactivity of this important group of triterpenoids. Though initially known for their anti-inflammatory and antiarthritic activities through a unique 5-LO inhibition mechanism, boswellic acids have recently attained significance due to their anti-cancer properties. The phytochemistry and chemical modifications, including mechanism of action, are discussed

Domino Transformation of d‑Glucal to Racemic α‑Substituted α‑Hydroxymethyl Furfuryl Derivatives

Domino Transformation of d‑Glucal to Racemic α‑Substituted α‑Hydroxymethyl Furfuryl Derivative

A facile approach towards enantiomerically pure masked β-amino alcohols

b-Amino alcohols are bioactive molecules, used also as catalysts in asymmetric C–C bond formation. While asymmetric synthesis has been the preferred route for their preparation, there was always been a need to develop a facile methodology involving environmentally friendly transformations. Masked amines in the form of phthalimide alcohols, prepared via a fast coupling reaction in an ionic liquid as a reusable reaction media together with reduction and an efficient biocatalytic resolution, offer a green methodology for enantiomerically pure products(ee . 99%, 50 g L21)

New isoflavones from Iris kashmiriana

Phytochemical investigation of the rhizomes of Iris kashmiriana (Iridaceae) led to the isolation of three isoflavones characterized by 1D and 2D NMR, IR, UV, and MS as 4 0 -hydroxy-8-methoxy-6,7-methylenedioxyisoflavone (isonigricin, 1), 5,6-dihydroxy-4 0 ,7-dimethoxyisoflavone (isoirisolidone, 2), and 5,7-dihydroxy-4 0 ,6-dimethoxyisoflavone (irisolidone, 3). Compound 1 is a new isoflavone, while 2 is reported for the first time from a natural source

Reaction of carbohydrates with Vilsmeier reagent: a tandem selective chloro O-formylation of sugars

A convenient and efficient method for selective replacement of the primary hydroxyl groups of sugars by chlorine with concomitant O-formylation, compatible with the presence of a variety of functional groups, has been developed using the Vilsmeier–Haack reaction. Sugars having free primary hydroxyl groups mostly afforded the chloro-O-formylated product while sugars devoid of primary hydroxyl groups yielded only O-formylated products

Boswellic acids and glucosamine show synergistic effect in preclinical anti-inflammatory study in rats

The present study revealed the synergistic effect of boswellic acid mixture (BA) and glucosamine for anti-inflammatory and anti-arthritic activities in rats. Two studies were conducted, that is, acute anti-inflammatory by carrageenan edema and chronic anti-arthritic by Mycobacterium-induced developing arthritis. Five groups of animals were included in each of the study: the vehicle control, positive control (ibuprofen 100 mg/kg), boswellic acids (250 mg/kg), glucosamine (250 mg/kg) and a combination of boswellic acids (125 mg/kg) and glucosamine (125 mg/kg). BA when administered at 250 mg/kg in rats, carrageenan-induced paw edema and Mycobacterium-induced developing arthritis were significantly inhibited. In comparison to boswellic acids, glucosamine when administered at 250 mg/kg showed a mild effect in carrageenan-induced edema and moderate inhibition of paw swelling against developing arthritis. Although the combination of boswellic acids and glucosamine did not affect the acute inflammation to a greater extent yet a significant anti-arthritic activity was observed in rats. In conclusion, a synergistic effect was observed in chronic inflammatory conditions when two chemical entities were administered in combination in preclinical study

A comparative study of proapoptotic potential of cyano analogues of boswellic acid and 11-keto-boswellic acid

Semi-synthetic analogues of b-boswellic acid (BA) and 11-keto-b-boswellic acid (KBA) were comparatively evaluated for in vitro cytotoxicity against human myeloid leukaemia (HL-60) and human cervical carcinoma (HeLa) cells. 2-Cyano analogues of both the triterpenes were observed to have significant cytotoxicity against both the cells, displaying cytotoxicity in HL-60 cells at low concentrations. Further investigations suggested the proapoptotic potential associated with the two molecules to induce cytotoxicity in HL-60 cells, where one of them showed early proapoptotic effect as evidenced by several biological end-points of the apoptosis such as annexinV binding, DNA fragmentation and increase in sub-G0 DNA fraction and apoptotic bodies formation (Hoechst 33258 staining and SEM studies)

Ring A structural modified derivatives of withaferin A and the evaluation of their cytotoxic potential

Regio-/stereoselective Michael addition to ring A of withaferin-A was performed using an optimized reaction procedure to synthesise a library of 2,3-dihydro,3-�-substituted withaferin-A derivatives. The analogues thus obtained were evaluated for in vitro cytotoxicity against various human cancer cell lines.3-Azido analogue exhibited 35-fold increase (IC50 = 0.02–1.9 �M) in cytotoxicity against almost the entire cell lines tested when compared to the parent molecule. However, further modifications of 3-azido analogue with various alkynes under Husigen’s cycloaddition conditions generated a variety of triazole derivatives with reduced cytotoxicity

A triterpenediol from Boswellia serrata induces apoptosis through both the intrinsic and extrinsic apoptotic pathways in human leukemia HL-60 cells

A triterpenediol (TPD) comprising of isomeric mixture of 3a, 24-dihydroxyurs-12-ene and 3a, 24-dihydroxyolean-12-ene from Boswellia serrata induces apoptosis in cancer cells. An attempt was made in this study to investigate the mechanism of cell death by TPD in human leukemia HL-60 cells. It inhibited cell proliferation with IC50 ~ 12 lg/ml and produced apoptosis as measured by various biological end points e.g. increased sub-G0 DNA fraction, DNA ladder formation, enhanced AnnexinV-FITC binding of the cells. Further, initial events involved massive reactive oxygen species (ROS) and nitric oxide (NO) formation, which were significantly inhibited by their respective inhibitors. Persistent high levels of NO and ROS caused Bcl-2 cleavage and translocation of Bax to mitochondria, which lead to loss of mitochondrial membrane potential (Dwm) and release of cytochrome c, AIF,Smac/DIABLO to the cytosol. These events were associated with decreased expression of survivin and ICAD with attendant activation of caspases leading to PARP cleavage.Furthermore, TPD up regulated the expression of cell death receptors DR4 and TNF-R1 level, leading to caspase-8 activation. These studies thus demonstrate that TPD produces oxidative stress in cancer cells that triggers selfdemise by ROS and NO regulated activation of both the intrinsic and extrinsic signaling cascades

Structure–activity relationship (SAR) of parthenin analogues with pro-apoptotic activity: Development of novel anti-cancer leads

Analogues of parthenin were synthesized by substitutions at different reaction centres to establish a structure–activity relationship (SAR). Some of the molecules have displayed significant cytotoxicity in human cervical carcinoma (HeLa) and human myeloid leukemia (HL-60) cells. A few of the compounds also induced apoptosis in HL-60 cells measured in terms of sub-Go/G1 DNA fraction. Also one of the lead molecules has been shown to be the inhibitor of both telomerase and topoisomerase-II