污泥堆肥农用中重金属在海桐中的积累效应

采用小区试验的方法,研究了金华污水厂污泥堆肥土地利用过程中海桐根部对重金属的吸收及富集作用。结果表明,海桐对Cu均表现出比Zn更强的富集能力,而对Cd、Pb的富集能力很弱,其须根对重金属的吸收能力显著高于主根;就不同重金属的绝对吸收量而言,对Zn的吸收总量是最高的;须根中的Zn含量总体呈现随土壤中Zn含量增加而上升的趋势。     

Triterpenoid Saponins from the Cultivar “Green Elf” of Pittosporum tenuifolium

Four oleanane-type glycosides were isolated from a horticultural cultivar “Green Elf” of the endemic Pittosporum tenuifolium (Pittosporaceae) from New Zealand: three acylated barringtogenol C glycosides from the leaves, with two previously undescribed 3-O-β-d-glucopyranosyl-(1→2)-[α-l-arabinopyranosyl-(1→3)]-β-d-glucuronopyranosyl-21-O-angeloyl-28-O-acetylbarringtogenol C, 3-O-β-d-galactopyranosyl-(1→2)-[α-l-arabinopyranosyl-(1→3)]-β-d-glucuronopyranosyl-21-O-angeloyl-28-O-acetylbarringtogenol C, and the known 3-O-β-d-glucopyranosyl-(1→2)-[α-l-arabinopyranosyl-(1→3)]-β-d-glucuronopyranosyl-21-O-angeloyl-28-O-acetylbarringtogenol C (Eryngioside L). From the roots, the known 3-O-β-d-glucopyranosyl-(1→2)-β-d-galactopyranosyl-(1→2)-β-d-glucuronopyranosyloleanolic acid (Sandrosaponin X) was identified. Their structures were elucidated by spectroscopic methods including 1D- and 2D-NMR experiments and mass spectrometry (ESI-MS). According to their structural similarities with gymnemic acids, the inhibitory activities on the sweet taste TAS1R2/TAS1R3 receptor of an aqueous ethanolic extract of the leaves and roots, a crude saponin mixture, 3-O-β-d-glucopyranosyl-(1→2)-[α-l-arabinopyranosyl-(1→3)]-β-d-glucuronopyranosyl-21-O-angeloyl-28-O-acetylbarringtogenol C, and Eryngioside L were evaluated.     

Two new triterpenoid saponins from Pittosporum senacia Putterlick (Pittosporaceae)

From the branches of Pittosporum senacia Putterlick (Pittosporaceae), two new triterpenoid saponins, senaciapittosides A and B (1, 2), were isolated. Their structures were elucidated by extensive analysis of one‐ and two‐dimensional nuclear magnetic resonance spectroscopy, high‐resolution electrospray ionization mass spectrometry (HR‐ESIMS) and chemical evidence as 3‐O‐[β‐d ‐glucopyranosyl‐(1 → 2)]‐[α‐l ‐arabinopyranosyl‐(1 → 3)]‐[α‐l ‐arabinofuranosyl‐(1 → 4)]‐β‐d ‐glucuronopyranosyl oleanolic acid 28‐O‐β‐d ‐glucopyranosyl ester (1) and 3‐O‐[β‐d ‐glucopyranosyl‐(1 → 2)]‐[α‐l ‐arabinopyranosyl‐(1 → 3)]‐[α‐l ‐arabinofuranosyl‐(1 → 4)]‐β‐d ‐glucuronopyranosyl‐22‐O‐α‐l ‐arabinopyranosyl‐21‐acetoxy R1‐barrigenol (2). Compound 2 presents an unusual glycosylation at C‐22 of its aglycone. Copyright © 2012 John Wiley & Sons, Ltd.