Studies On Chemical Constituents And Bio-activities Of Degradation Products Of Aconitines

Aconitum L. is a large genus of the Ranunculaceae family, which consists of over 300 species distributed all over the world. Most of them grow naturally in high altitudes in the northern hemisphere. The genus Aconitum consist of more than 200 species in China, and is widely distributed in all the provinces of China except Hai nan province. As widely used Chinese herbal medicine,76 Aconitum species in China have been medicinally used. The tubers and roots of Aconitum L (Ranunculaceae) are commonly used for various diseases, such as collapse, syncope, rheumatic fever, painful joints, gastroenteritis, diarrhea, oedema, bronchial asthma, various tumors, and some endocrinal disorders like irregular menstruation.A literature survey revealed that about 400 alkaloids, some flavonoids and polyglycosides have been isolated and identified from Aconitum L. Mesaconitine, aconitine and hypaconitine are not only toxic, but also analgesic and anti-inflammatory constituents in Aconitum L. The acetyl group at the 8-postion in the diestertype alkaloids is easily hydrolyzed into benzoylmesaconine, benzoylaconine and benzoylhypaconine. Those monoester aconitines showed a much lower toxicity than that of the diester-type aconitines. However, the pharmacological studies showed that they also have significant anti-inflammatory and analgesic actions.There are few reports about the pharmacological effects of the monoester aconitines. In order to further study the bioactivities of the monoester aconitines, the extraction, separation and determination of active constituents in Radix Aconiti lateralis praeparata were preformed. Four compounds including mesaconitine, aconitine, hypaconitine and deoxyaconitine were separated and identified by]H NMR and 13C NMR. Eleven compounds were separated from the hydrolysates of the four diester-type alkaloids and identified by 1D NMR,2D NMR, IR and MS. The compounds are benzoyldeoxyaconine, benzoylhypaconine, benzoylaconine, benzoylmesaconine, aconine, mesaconine, hypaconine, pyrodeoxyaconitine, pyrohypaconitine, pyromesaconitine and pyroaconitine. The chemical shift assignment of 1H and 13C were made.To determine the six alkaloids, including mesaconitine,aconitine, hypaconitine, benzoylmesaconine, benzoylhypaconine and benzoylaconine in Aconitum kusnezoffii Reichb., the chromato graphic separation of the compounds was achieved with an Agilent Zorbax Eclipse plus-C18 column(5μm,250 mm×4.60 mm). The elution was carried out using methanol (A) and water containing 5mmol L-1 ammonium acetate and 0.2% acetic acid (B) (A:B=40:60) as mobile phase at a flow rate of 1.0 mL min-1. UV absorption was measured at 235 nm. The column temperature was maintained at 35℃and the sample injection volume was 5μL.The results revealed that the linearity of the six compounds was in the range of 0.01-10.0μg, with the correlation coefficients from 0.9995 to 0.9999 (n=8). The RSD for determining the six compounds ranged from 1.84% to 3.17%. The stability of the analytes were satisfactory. Mean recoveries ranged from 96.83% to 104.73%, with relative standard deviations less than 2.61%. This method is accurate,reliable and sensitive for determination of six alkaloids in Aconitum kusnezoffii Reichb. and provide a standard for quality control of Aconitum kusnezoffii Reichb..The matrix solid-phase dispersion (MSPD) was developed for the extraction of four alkaloids, including aconitine, mesaconitine, hypaconitine and deoxyaconitine, from the roots of Aconitum kusnezoffii Reichb.. The effects of several extraction parameters such as dispersion sorbent, ratio of sample to dispersion sorbent, elution solvent, the volume of elution solvent and clean-up sorbent were examined and optimized. When alkaline alumina was used as dispersion sorbent, acetonitrile-water (80:20, v/v pH=12) was used as elution solvent, the ratio of sample to dispersion sorbent was 1:2 and the volume of elution solvent was 10 mL, the extraction yields of mesaconitine, hypaconitine, aconitine and deoxyaconitine obtained by MSPD were 2214.44,1769.55,1299.28 and 275.40μg g-1, respectively. The RSDS of extraction yields for the compounds were all less than 1.20%. Whereas, those obtained by reflux extraction were 1949.08,1239.75,1152.61,149.03μg g-1, respectively. Mean recoveries ranged from 93.16% to 102.73%, with relative standard deviations from 0.27% to 4.17%. Compared with reflux extraction, the MSPD extraction has the advantages in extraction time, and consumption solvent.This paper also studied the effect of benzoylaconine,benzoylmesaconine and benzoylhypaconine on the adjuvant arthritis profile of rats. The results showed that these alkaloids can inhibited the hind paw edema in rats, decreased erthrocyte sedimentation rate,content of leucocyte and MDA(malon dialdehyde), and increased the activity of SOD(superoxide dismutase).