广东紫珠中的萜类化合物及其抗炎活性

对岭南药材广东紫珠(Callicarpa kwangtungensis)地上部分进行化学成分研究,得到11个萜类化合物,分别鉴定为sambucunlin A(1)、2α-羟基羽扇豆醇(2)、swinhoeic acid(3)、3β-羟基-乌苏烷-11-烯-13β,28-内酯(4)、蔷薇酸(5)、2α,3β,6β,18β,23-pentahydroxy-olean-12-en-28-oic acid(6)、rel-5-(3 S,8 S-dihydroxy-1 R,5 S-dimethyl-7-oxa-6-oxobicyclo-oct-8-yl)-3-methyl-2 Z,4 E-pentadienoic acid(7)、salvionoside B(8)、齐墩果酸(9)、白桦脂酸(10)和α-香树脂醇(11)。其中,化合物1~4和6~8为首次从该属植物中分离得到。在化学成分分离基础上,进一步选择脂多糖(LPS)诱导的RAW 264.7小鼠巨噬细胞炎症模型进行萜类化合物抗炎活性测试。结果表明:化合物3和9具有显著的抗炎活性,对比结构发现,三萜类化合物(3~6、9和11)抗炎活性优于倍半萜类化合物(7和8)。研究结果广东紫珠萜类成分在抗炎方面的临床应用提供了实验依据。     

不同采收期裸花紫珠的HPLC指纹图谱研究

为建立裸花紫珠药材高效液相指纹图谱研究方法,该研究采用0．4％磷酸水溶液(A)-乙腈(B);梯度洗脱为0~15 min,16％~25％ B,15~25 min,25％~39．7％ B;Agilent ZORBAX SB-C18色谱柱(4．6 mm×250 mm,5μm);柱温为30℃;流速为1 mL??min-1;进样量为10μL;检测波长327 nm;检测时间25 min 等色谱条件,研究了不同采集时间共25批裸花紫珠药材的指纹图谱,获取14个共有特征色谱峰,确定了其中的3个成分,利用相似度分析、主成分分析及对应分析对它们进行了分析.结果表明：HPLC 指纹图谱结合计量分析法可有效评价裸花紫珠的质量,该方法可有效应用到裸花紫珠原料及其制品的质量控制中.     

裸花紫珠提取物及其主要成分抗氧化活性研究

裸花紫珠是海南一种道地药材,具有消炎止血的功效。裸花紫珠富含黄酮类和苯乙醇苷类化学成分,它们已经被证实是天然抗氧化剂的主要来源之一。为了考察裸花紫珠药材的抗氧化活性,该研究采用DPPH.自由基清除法测定裸花紫珠醇提物、4个不同极性部位(石油醚、乙酸乙酯、正丁醇、水)及其7个主要成分的抗氧化作用。结果表明：裸花紫珠醇提物、醇提物的水部位、正丁醇部位、乙酸乙酯部位和化合物木犀草素、木犀草苷、毛蕊花糖苷具有较强的抗氧化活性,而5-羟基-3,7,3′,4′-四甲氧基黄酮的抗氧化活性则较弱。该研究结果为裸花紫珠的保健功能开发提供了依据。     

Naphthoquinone spiroketal with allelochemical activity from the newly discovered endophytic fungus Edenia gomezpompae

Chemical investigation of the mycelium of Edenia gomezpompae, a newly discovered endophytic fungus isolated from the leaves of Callicarpa acuminata (Verbenaceae) collected from the ecological reserve El Eden, Quintana Roo, Mexico, resulted in the isolation of four naphthoquinone spiroketals, including three new compounds and palmarumycin CP2 (4). We elucidated the structures of the metabolites by extensive NMR spectroscopy studies, including DEPT, COSY, NOESY, HSQC, HMBC, and chiroptical methods. The trivial names proposed for these compounds are preussomerin EG1 (1), preussomerin EG2 (2) and preussomerin EG3 (3). In addition, the X-ray data for 4 were obtained. The bioactivity of the mycelial organic extracts and the pure compounds was tested against three endophytic fungi (Colletotrichum sp., Phomopsis sp., and Guignardia manguifera) isolated from the same plant species (C. acuminata, Verbenaceae) and against four economically important phytopathogenic microorganisms (two fungoid oomycetes, Phythophtora capsici and Phythophtora parasitica, and the fungi Fusarium oxysporum and Alternaria solani). Spiroketals 1-3 displayed significant growth inhibition against all the phytopathogens. IC50 values for the four phytopathogens were from 20 to 170 microg/ml. Palmarumycin CP2 (4) was not bioactive against any of the fungi tested. Compound 1 showed the strongest bioactivity. The acetylated derivatives of preussomerin EG1 (1), 1a and 1b, were obtained and their biological activity was tested on endophytes and phytopathogens. Preussomerin EG1 1, 1a and 1b exhibited significant bioactivity against all microorganisms tested with the exception of Alternaria solani. This is the first report of allelochemicals with antifungal activity from the newly discovered endophytic fungus E. gomezpompae.     

Phytotoxicity and volatile constituents from leaves of Callicarpa japonica Thunb

The essential oil from the leaves of Callicarpa japonica was analyzed by GC-MS, and 84 compounds were identified. The main constituents of the essential oil were spathulenol (18.1%), germacrene B (13.0%), bicyclogermacrene (11.0%), globulol (3.3%), viridiflorol (2.6%), alpha-guaiene (2.3%), and gamma-elemene (2.0%). The essential oil constituents of C. japonica were significantly different from those found in our previous work on Callicarpa americana. The oil of C. japonica was selectively phytotoxic to bentgrass compared to lettuce seeds, with 80-100% growth reduction observed at 0.3 mg/ml.     

Environmentally-Friendly Pesticidal Activities of Callicarpa and Karomia Essential Oils from Vietnam and Their Microemulsions

There is an ongoing interest to identify alternative pesticidal agents to avoid the chronic problems associated with synthetic pesticides. Essential oils have shown promise as botanical pest control agents. In the present study, the essential oils of four members of the Lamiaceae (Callicarpa candicans, C. erioclona, C. macrophylla, and Karomia fragrans; Vietnamese names: Nàng nàng, Tu châu lông mem, Tu châu lá to and Cà diện, respectively), obtained from wild populations in Vietnam, have been obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry. The essential oils were formulated into microemulsions and the essential oils and their microemulsions were screened for mosquito larvicidal activity against Aedes aegypti, Aedes albopictus, Culex quinquefasciatus, and for molluscicidal activity against Pomacea canaliculata. Atractylone and (E)-caryophyllene dominated the volatiles of C. candicans (CCEO) and C. erioclona (CEEO), while the major component in C. macrophylla (CMEO) and K. fragrans (KFEO) was (E)-caryophyllene. The essential oils and microemulsions of both C. candicans and C. erioclona exhibited excellent larvicidal activity against all three mosquito species (Ae. aegypti, Ae. albopictus, and Cx. quinquefasciatus) with LC₅₀ values <10 μg/mL. Additionally, the larvicidal activity of the microemulsions were significantly improved compared with their free essential oils, especially for C. candicans and C. erioclona. All four essential oils and their microemulsions showed excellent molluscicidal activity with LC₅₀ <10 μg/mL. In most cases, the essential oils and microemulsions showed greater pesticidal activity against target organisms than the non-target freshwater fish, Oreochromis niloticus. The in silico studies on physicochemical and ADMET properties of the major components in the studied essential oils were also investigated and most of the compounds possessed a favorable ADMET profile. Computational modeling studies of the studied compounds demonstrated a favorable binding interaction with the mosquito odorant-binding protein target and support atractylone, β-selinene, and caryophyllene oxide as potential inhibitors. Based on the observed pesticidal activities of the essential oils and their microemulsions, the Callicarpa species and K. fragrans should be considered for potential cultivation and further exploration as botanical pesticidal agents.     

紫珠耐热抗旱性初步研究

针对武汉地区夏季高温干旱的气候特点,分别在室内人工模拟高温和干旱的条件下,对紫珠的耐热性和抗旱性进行了初步研究。结果表明:紫珠有一定的耐高温干旱能力,能忍受45℃高温连续9天和持续9天的干旱,是一种较好的新型园林节水耐旱观果灌木。     

遮荫对裸花紫珠苗期光合特性及总黄酮含量的影响

为了解遮荫对裸花紫珠(Callicarpa nudiflora)幼苗生长和药材质量的影响,研究了遮荫处理(遮荫30%、50%、70%和对照0%)下2年生裸花紫珠苗的光合气体交换参数、叶绿素荧光参数、光合色素和总黄酮含量的变化。结果表明,无遮荫或遮荫30%下,裸花紫珠的叶片净光合速率(Pn)日变化曲线呈典型的双峰型,而随遮荫程度的增加,Pn日变化曲线逐渐转变为单峰型。蒸腾速率(Tr)和气孔导度(Gs)日变化曲线呈单峰型,且峰值随着遮荫程度的增加而降低。PSII最大光化学效率(Fv/Fm)和潜在活性(Fv/Fo)的日变化曲线呈"V"型,且两者均随遮荫程度的增加而升高。幼苗叶片的叶绿素a(Chl a)、叶绿素b(Chl b)、类胡萝卜素(Car)含量随遮荫程度的增加而显著增加(P0.05),而Chl a/b和Car/Chl却随遮荫程度的增加而下降。随遮荫程度的增加,叶片中总黄酮含量呈先上升后下降的趋势,以遮荫30%为最大。因此,裸花紫珠幼苗最适宜生长在无遮荫条件下,但为获得更高的总黄酮含量,可以选择30%遮荫处理。