Alkaloids,coumarins, triterpenes and a flavanone from the root of Zanthoxylum dipetalum

The root bark of Zanthoxylum dipetalum contained the alkaloids canthin-6-one, chelerythrine, nitidine and tembetarine, the pyranocoumarins avicennol and xanthoxyletin, the triterpene lupeol and the flavanoid hesperidin. The MS fragmentation pattern for avicennol is discussed and a tentative structure is proposed for a third coumarin, designated ZD/1. The root wood of the type species and the stem bark of the γ variety contained most of the above compounds plus sitosterol and, in the root wood only, magnoflorine. The chemotaxonomic implications of these findings are briefly discussed.     

Biosynthesis of sterols and triterpenes in Pelargonium hortorum

Although all parts of the geranium plant (Pelargonium hortorum) are capable of synthesizing sterols and triterpenes and their esters in vitro from mevalonic acid-[2-¹⁴C], the aerial portions are more active than other tissues. All plant parts were shown to incorporate mevalonic acid-[2-¹⁴C] into isoprenoids for at least 3 days. The leaves and petioles had the greatest incorporation on a wet weight basis. Chopped preparations showed comparable incorporations of mevalonate whereby rootlets incorporated about one half as much as most parts; the flower petals incorporated five times the average amount. In leaves the principal sterol synthesized was sitosterol. Metabolic studies with isolated leaves indicated a fairly rapid conversion of free tetracyclic triterpenes to 4-desmethyl-sterols, while β-amyrin was synthesized at a different rate than α-amyrin. Esterified tetracyclic triterpenes exhibited only a slight amount of conversion to 4-desmethylsterols.     

Swertane triterpenoids from Swertia chirata

Two novel triterpenes belonging to swertane skeleton, besides gammacer-16-en-3β-ol and 21αH-hop- 22(29)-en-3β-ol, of rare occurrence have been isolated from Swertia chirata, along with some common triterpenoids. Their structures were established on the basis of spectral and chemical evidence.     

西洋梨枝化学成分的研究

从西洋梨的枝中分离鉴定了8个化合物,它们分别是正二十九烷(Ⅰ)、羽扇豆醇(Ⅲ)、β-谷甾醇(Ⅳ)、白桦脂醇(Ⅴ)、白桦脂酸(Ⅵ)、胡萝卜甙(Ⅶ)、氢醌(Ⅷ)、和熊果甙(Ⅸ)。初步药理实验表明,化合物Ⅲ、Ⅳ、Ⅴ、Ⅵ、Ⅷ和Ⅸ有一定的抑菌作用,Ⅷ对S-180有一定抑瘤活性。     

Translocation of sitosterol and related compounds in Pelargonium hortorum and helianthus annuus

The translocation of several plant sterols and a triterpene was studied in geranium and sunflower plants. Upward translocation of sitosterol-[¹⁴C] and β-amyrin-[¹⁴C] was shown within 48 hr to the upper parts of a geranium plant sectioned previously above the roots. Downward translocation of sitosterol-[¹⁴C] from the leaf of application was evident in intact plants after 48 hr. In addition to free sitosterol-[¹⁴C] considerable amounts of sitosteryl-[¹⁴C] glycoside and traces of sitosteryl-[^14C] ester were found in most parts examined. Very slow downward translocation of cholesterol-[¹⁴C] but not of desmosterol-[¹⁴C], sitosteryl-[¹⁴C] palmitate or β-amyrin-[¹⁴C] was shown in geranium. In sunflower no downward translocation of cholesterol-[³H], sitosteryl-[³H] acetate or palmitate could be detected. In geranium, sitosteryl-[¹⁴C] glycoside translocated downward from the leaf of application to all other plant parts, except other leaves, and was found in these parts after 10 days as the unchanged glycoside, free sterol and steryl ester. The effect of drying the plant parts on the recovery of radioactive steroidal material is discussed. Traces of a water soluble, dialyzable form of sterol-[¹⁴C] were also detected in dried geranium roots after treatment with strong acid or alkali.     

水分、氮肥及MeJA处理对白桦三萜积累特性的影响

以一年半生白桦幼树为试材,研究水分、氮肥和茉莉酸甲酯(MeJA)处理对白桦三萜物质积累的影响,并对白桦植株中三萜积累规律进行了探讨。结果表明:(1)白桦幼树植株中总三萜主要分布在茎皮和叶片,根皮中最低,平均含量分别为71.94、81.60和25.45mg.g-1;叶片中总三萜积累高峰出现在6、7月份,茎皮和根皮中总三萜积累高峰分别出现在8月份和7月份。(2)干旱胁迫早期(6月)中度和重度干旱胁迫显著促进了叶中总三萜积累,分别是对照的1.24和1.27倍。茎皮中,除7月水分胁迫处理显著高于对照外,其它各月份水分胁迫不利于茎皮中总三萜含量积累,干旱胁迫不利根皮中三萜积累。(3)施氮早期(6月)不利于三萜在叶片和根皮中积累,中后期(7～10月),氮肥处理对三萜积累有显著促进作用;而施氮早期(6～7月)促进茎皮中三萜积累作用。(4)MeJA喷施处理对叶片和根皮中三萜积累(7月～10月)均具有显著的促进作用,在积累高峰期分别是对照的1.42倍和1.52倍。(5)轻度干旱、氮肥均促进了白桦幼树株高的增长和生物量的积累,而MeJA处理对整株生物量的积累不利。     

小果南烛三萜类化学成分研究

羊毛甾烷三萜是南烛属植物主要活性成分之一.为进一步研究南烛属植物功效物质基础,结合民族民间对小果南烛的应用实际,该文利用硅胶、MCI、Sephadex LH-20、半制备高效液相色谱等植物化学技术手段对该植物95％乙醇提取物进行分离、纯化,综合理化性质和波谱数据对其化合物进行鉴定.结果表明:从小果南烛的茎、叶提取物中分...