积雪草总苷缓释片的处方设计研究

目的:设计积雪草总苷缓释片的处方并进行评价和优化.方法:以积雪草水溶性有效部位(积雪草总苷)为研究对象,采用拟水平的均匀设计表U6(66)设计缓释制剂处方,反相高效液相色谱(RP-HPLC)方法直接测定制剂中反映积雪草主要药效的2个指标成分--积雪草苷和羟基积雪草苷的释放度,利用指标成分的体外释放度与各辅料之间的回归方程对处方进行优化.结果:积雪草总苷为18 mg/片,处方中各辅料的组成为羟丙基甲基纤维素(HPMC)30～50 mg/片、微晶纤维素(MCC)50 mg/片、7.5%聚维酮(PVP)醇溶液时,指标成分在水中可维持12 h缓慢释放.结论:中药成分复杂,通过处方设计和优化可对积雪草指标成分的释放进行控制,这是利用现代制剂技术研究中药缓释制剂的有效途径之一.     

Field evaluation of in vitro-induced tetraploid and diploid Centella asiatica (L.) Urban

Centella asiatica—a medicinal plant that produces high-value active triterpenoids—is in increasing demand by the pharmaceutical and cosmetic industries. The aim of this study was to field-test one induced tetraploid and three diploid C. asiatica lines for the selection of high-quality plants with high phytomass and triterpenoid content and to determine their optimal harvesting time. All tested C. asiatica were micropropagated using an established protocol. One-month-old plantlets were acclimatized for the field experiment. The plants were grown in a randomized complete block design (RCBD) with three replications, ten plantlets per replication, and the experimental bed site was 0.6 × 1.0 m. Growth parameters, phytomass and the amounts of four active triterpenoids were evaluated. All lines exhibited the highest growth, yields and triterpenoids at 4 months after cultivation. The tetraploid line showed significantly better characteristics, i.e., larger leaf area, leaf width, petiole length, and greater yields, than diploid lines. Dry weight per cultivated area (77.53 ± 3.07 g/m²) and total triterpenoids (15.38 ± 0.76 % dry weight) were increased significantly in tetraploid plants of C. asiatica. Furthermore, the harvesting time had an effect on the yield and triterpenoid content (P < 0.001). In all tetraploid and diploid lines, the yields and triterpenoid content per cultivated area reached their maximum at 4 months after planting. Our results demonstrated that polyploidy induction is a beneficial tool that can be used to improve the medicinal value of C. asiatica.     

Two new flavonoids from Centella asiatica (Linn.)

Two new flavonoids named castilliferol 1 and castillicetin 2, as well as a known compound, isochlorogenic acid 3, were isolated from the whole plant of Centella asiatica. Isolates 1 and 2 exhibited good antioxidant activity using 2,2-diphenyl-1-picryl hydrazyl radical solution with IC₅₀ values of 23.10 and 13.30, respectively. The structures of these isolates were determined by analytical and spectral data, including 1-D and 2-D NMR spectra.     

积雪草挥发油的GC指纹图谱研究

目的 建立积雪草挥发油的气相色谱指纹图谱.方法 采用GC法,以石竹烯为参照物,对10批积雪草挥发油指纹图谱进行研究.结果 GC指纹图谱中共有33个共有峰,10批积雪草药材的指纹图谱相似度均大于0.90,符合指纹图谱的技术要求.结论 所建立积雪草挥发油指纹图谱,可作为积雪草药材以及正在研制的抗抑郁新药雪抑乐的质量控制依据.     

Chemical constituents of Centella asiatica

Studies on the chemical constituents of the aerial part of Centella asiatica have led to the isolation of three new compounds, named centellin (1), asiaticin (2), and centellicin (3). Their structures have been elucidated through spectral studies including 2D NMR experiments (HMQC, HMBC, (1)H-(1)H COSY, NOESY and J resolved).     

The anti-thrombotic active constituents from Centella asiatica

The in vitro effects of a methanol extract from the aerial parts of Centella asiatica on shear-induced platelet activation and coagulation were assessed after oral administration to rats, by subjecting non-anticoagulated blood to haemostatometry. 3,5-Di-O-caffeoyl quinic acid, 1,5-di-O-caffeoyl quinic acid, 3,4-di-O-caffeoyl quinic acid, 4,5-di-O-caffeoyl quinic acid, and chlorogenic acid, together with asiaticoside, kaempferol, quercetine, kaempferol-3-O-beta-D-glucoside and quercetin-3-O-beta-D-glucoside were all isolated from the methanol extract. Amongst these, only 3,5-di-O-caffeoylquinic acid showed significant inhibition of shear-induced platelet activation and dynamic coagulation. The reactive curve of the inhibitory effect on the platelet reaction and the dynamic coagulation showed a bell-shape.     

Chemical constituents of Centella asiatica

Studies on the chemical constituents of the aerial part of Centella asiatica have led to the isolation of three new compounds, named centellin (1), asiaticin (2), and centellicin (3). Their structures have been elucidated through spectral studies including 2D NMR experiments (HMQC, HMBC, ¹H–¹H COSY, NOESY and J resolved).     

Chemical constituents of Centella asiatica

Studies on the chemical constituents of the aerial part of Centella asiatica have led to the isolation of three new compounds, named centellin (1), asiaticin (2), and centellicin (3). Their structures have been elucidated through spectral studies including 2D NMR experiments (HMQC, HMBC, ¹H-¹H COSY, NOESY and J resolved).     

Two new dammarane monodesmosides from Centella asiatica

Two new dammarane monodesmosides centellosides A (1) and B (2), and two new natural products ginsenosides Mc (10) and Y (11), together with 11 known compounds (3-9 and 12-15) reported for the first time from this genus, were isolated from the whole plants of Centella asiatica. All structures were elucidated by spectroscopic techniques and chemical methods, and compared with literature values. All the isolated compounds were evaluated in vitro for cytotoxicity.     

Two new dammarane monodesmosides from Centella asiatica

Two new dammarane monodesmosides centellosides A (1) and B (2), and two new natural products ginsenosides Mc (10) and Y (11), together with 11 known compounds (3–9 and 12–15) reported for the first time from this genus, were isolated from the whole plants of Centella asiatica. All structures were elucidated by spectroscopic techniques and chemical methods, and compared with literature values. All the isolated compounds were evaluated in vitro for cytotoxicity.     

高效液相法测定积雪草配方颗粒中积雪草苷的含量

目的:建立测定积雪草配方颗粒剂中积雪草苷的HPLC含量分析方法。方法:采用C18柱,RP-HPLC法,水-乙腈为流动相,梯度洗脱,检测波长205 nm。结果:积雪草苷在0.02-0.51 mg·mL-1范围内,峰面积与浓度呈线性关系,r=0.9999,高、中、低浓度的平均回收率分别为99.6％,101.7％,102.2％;RSD分别为2.9％,1.7％,4.9％(n=3)。结论:该方法简便,结果准确,适用于积雪草配方颗粒剂的质量控制。