Structural analysis of 3‐α‐acetyl‐20(29)‐lupene‐24‐oic acid, a novel pentacyclic triterpene isolated from the gum resin of Boswellia serrata, by NMR spectroscopy

Abstract

3a-Acetyl-20(29)-lupene-24-oic acid (1) was isolated from the gum resin of Boswellia serrata. Its presence evidently suggests, that the oxidosqualene triterpene pathway of Boswellia serrata closely resembles the biosynthetic route already found in other plants. Complete 1 H and 13 C spectral assignments were derived from 1D and 2D NMR spectra. This is the first compound with the lupene backbone combining a 3a-hydroxy or 3a-acetyl group with the 24-carboxyl group, a configuration which is typical of the classical boswellic acids.

Acetyl-lupeolic acid inhibits Akt signaling and induces apoptosis in chemoresistant prostate cancer cells in vitro and in vivo

“…3α-acetyl-lup-20(29)-en-24-oic acid (acetyl- lupeolic acid, ac-LA) was isolated from African frankincense oleogum resin obtained from Boswellia carterii and purified to chemical homogeneity (> 99% purity) using reverse-phase HPLC. Ac-LA was characterized by mass spectrometry and nuclear magnetic resonance spectroscopy [ 15 , 16 , 22 ]. Lupeol (purity > 99%) was purchased from Carl Roth (Karlsruhe, Germany), docetaxel was from Fluka (Buchs, Switzerland), and Akt inhibitor VIII (Akt Inh.)…”

“…Oleogum resins of Boswellia species, commonly named frankincense, contain a plethora of various pentacyclic triterpenes with anti-inflammatory and anticancer properties [ 5 , 7 , 13 – 21 ]. In addition to lupeol, we have isolated the novel pentacyclic triterpenoid, acetyl-lupeolic acid (3α-acetyl-lup-20(29)-en-24-oic acid; ac-LA) from the oleogum resin of Boswellia carterii [ 16 , 22 ]. In order to analyze the efficacy of this new triterpenoid in the treatment of chemoresistant tumors, we compared the pharmacological properties of ac-LA to lupeol in vitro by using a panel of human cancer cell lines and in vivo by using pre-established prostate cancers xenografted onto the chick chorioallantoic membrane (CAM) and in mice.…”

Anti-inflammatory activities of the triterpene acids from the resin of Boswellia carteri

“…Further chromatography on silica gel of fraction B yielded five fractions, fractions B1 (107 mg), B2 (649 mg), B3 (296 mg), B4 (216 mg), and B5 (378 mg), as arranged with the increasing order of polarity. HPLC (HPLC I) of fractions B1 and B2 gave acetyl ␣-boswellic acid (Badria et al, 2003;Belsner et al, 2003a) (9, t R 19.7 min; 9.9 mg); and elemonic acid (Pardhy and Bhattacharyya, 1978) (13, t R 11.2 min; 147.9 mg), acetyl lupeolic acid (Belsner et al, 2003b;Culioli et al, 2003) (11, t R 16.4 min; 25.7 mg), 9 (53.6 mg), and acetyl ␤-boswellic acid (Badria et al, 2003;Belsner et al, 2003a) (2, t R 21.4 min; 157.0 mg), respectively. HPLC (HPLC II) of fractions B3 and B4 yielded ␣-elemolic acid (Pardhy and Bhattacharyya, 1978) (12, t R 20.4 min; 14.8 mg), lupeolic acid (Belsner et al, 2003b;Culioli et al, 2003) (10, t R 25.2 min; 14.6 mg), ␣-boswellic acid (Culioli et al, 2003) (8, t R 30.8 min; 15.9 mg), and ␤-boswellic acid (Badria et al, 2003;Culioli et al, 2003) (1, t R 33.6 min; 74.3 mg); and acetyl 11-keto-␤-boswellic acid (Badria et al, 2003;Belsner et al, 2003a) (4, t R 17.2 min; 44.4 mg) and 12 (9.7 mg), respectively.…”

Boswellic Acids in Chronic Inflammatory Diseases

“…Interestingly, as discussed later, in pharmacokinetic studies with extracts from Boswellia serrata oleogum resin only little AKBA was found in the plasma if compared to KBA. A new pentacyclic triterpene from BS, i. e., 3a-acetyl-20(29)-lupene-24-oic acid was recently identified by Beisner et al [4]. Employing a commercial extract from BS (H 15 Ayurmedica TM ),~2.6 mg/100 mg KBA and 2.8 mg/100 mg AKBA were detected on average in 11 different lots [5].…”

“…However, these compounds are not effective in the treatment of inflammatory bowel diseases such as ulcerative colitis and Crohn's disease. It is known that the mucosa of patients with chronic inflammatory bowel diseases is synthesising considerable amounts of leukotrienes LTB 4 , LTD 4 and LTE 4 that increase the production of mucus and stimulate contraction of the smooth muscle of the gastrointestinal tract. This effect can be inhibited by sulfasalazine and 5-aminosalicylic acid in a dose-dependent manner [53].…”