New Pregnane Glycosides from Sinomarsdenia incisa

Abstract

Five new pregnane glycosides, sinomarinosides A (1), B (2), C (3), D (4), and E (5), have been isolated from Sinomarsdenia incisa (Asclepiadaceae). The structures of these compounds were elucidated by NMR and mass spectroscopic methods and chemical evidence.

New Oxypregnane Glycosides from Caralluma penicillata

“…The 1 H-and 13 C-NMR spectra of 1 showed the presence of isovaleroyl and benzoyl moieties (see Table 2 and experimental). This finding was further confirmed by comparing the spectral data of 1 with those reported in literature [7], [8], [9], [10]. [8], [9], [10].…”

“…This finding was further confirmed by comparing the spectral data of 1 with those reported in literature [7], [8], [9], [10]. [8], [9], [10]. By the analyses of the 1 H-1 H COSY and HMQC experiments, hydroxylation at C-3, C-14, C-15 and C-16 of the pregnane unit was inferred.…”

“…The acid hydrolysis of 3 showed the presence of two sugar units, one of them was identified as cymarose by TLC against authentic sample. The terminal sugar unit was determined as 6deoxy-3-O-methyl-b-allopyranose, while inner sugars were determined as two cymarose units by the interpretation of 1 H-NMR, 1 H-1 H COSY, TOCSY spectra, and confirmed by comparison with data reported in the literature [7], [8], [10]. The sequence of the three sugar units was established from the long-range correlation between H-1¢ and C-3 of the aglycone, and H-1¢¢ and C-4¢, and H-1¢¢¢ and C-4¢¢ (HMBC).…”

“…This finding confirmed that C-3 is the only site of glycosylation in 1. [8], [10], [14]. The configuration of the side chain at C-17 was determined as b-form, in the same way as in 1.…”

Two novel steroidal derivatives from chloroform-soluble extract of Hoya longifolia

“…Plant family Asclepiadaceae has been a rich source of biologically active steroids and their derivatives are mostly pregnane (Deepak et al 1989;Ketwaru et al 1993;Khare et al 1986Khare et al , 1987, cardenolides (Reichstein 1967) and glycosides Chen et al 1999). Plants of this family have been traditionally used for their anti-inflammatory, anti-tumours (Chopra et al 1956;Ahmad, Usmaghani, et al 1983, 1988Ahmad, Noorwala, et al 1993;Masoodi et al 2008;Mahmood et al 2010), immunostimulant (Pan et al 2003(Pan et al , 2013, antidiabetic (Noor et al 2013), anti-oxidant, antimicrobial, anti-complementary, antiepileptic and antineoplastic activities (Piacente et al 1998;Sethi et al 2008Sethi et al , 2012Sethi et al , 2013MacLeod et al 1997).…”