广东石豆兰中的噁庚英和联苄类化合物

从兰科植物广东石豆兰(Bulbophyllum kwangtungense Schlecht.)的乙酸乙酯部分分离得到了2个新的茋类化合物5-(2,3-二甲氧苯乙基)-6-甲基苯并[d][1,3]二氧戊环(1)和10,11-二氢-2,7-二甲氧基-3,4-亚甲二氧基二苯并[b,f]噁庚英(2). 药理活性实验结果证明, 化合物2对体外培养的Hela细胞有较强的抑制作用.     

A new flavone C-glycoside and a new bibenzyl from Bulbophyllum retusiusculum

A new flavone C-glycoside, apigenin 6-C-α-arabinofuranosyl 8-C-α-arabinopyranoside (1) and a new bibenzyl, bulbotetusine (2), were isolated from the tubers of Bulbophyllum retusiusculum. Their structures were established on the basis of extensive spectroscopic analyses. The absolute configuration of 2 was determined by the comparison of experimental and calculated electronic circular dichroism. Compounds 1 and 2 showed no obvious cytotoxic activity against any five human tumour cell lines with IC₅₀ values >40 μM.     

A new phenanthrene and a new 9,10-dihydrophenanthren from Bulbophyllum retusiusculum

A new phenanthrene, bobulretin A (1), and a new 9,10-dihydrophenanthrene, bobulretin B (2) along with four known bibenzyls (3–6) were isolated from the whole plants of Bulbophyllum retusiusculum. Their structures were elucidated by means of extensive spectroscopic analysis. Bobulretin B (2), isolated as enantiomer mixture with unequal proportions, was verified by analysis on a chiral OD-H HPLC column. Compounds 1, 3 and 4 were evaluated for their α-glucosidase inhibitory activity. Neither of them showed obvious activity.     

Total Synthesis of Three New Dihydrostilbenes from Bulbophllum odoratissimum

Natural stilbenoids are presently well known by their various kinds of bioactivity, such as antitumor, anti-inflammatory and platelet antiaggregation1. In our previous studies of naturally-occurring cytotoxic agents present in traditional Chinese medicine…