Iridoid aglycones from Deutzia scabra

A New Eremophilane Sesquiterpenoid and a New Iridoid fromPedicularis striatasubsp.arachnoides

“…The 13C-NMR spectrum of 2 showed the presence of eighteen carbon signals, which were very similar to those reported for the aglycone unit of dihydrocatalpol. The above evidence indicated that compound 2 was the diyhdrocatalpol aglycone and was present as a mixture of J3 and a epimers at C-I in a ratio of about 10: 7, as shown by the integral trace of corresponding signal multiplicites in their 1H-NMR spectrum (15). The ElMS of 2 gave molecular ion peaks at m/z = 202, which supported the above deduction.…”

Effect on capillary permeability in rabbits of iridoids from Buddleia scordioides

“…The chemical shift values of δc 59.41, assigned as C-8 was well as δc 61.97, assigned as C-7, were characteristic for a 7,8-epoxy. From the comparison with spectra of the related iridoids deutzioside (Esposito et al, 1984) and galiridoside (Sticher, 1970) assignments of epoxide ring was determined. Further evidence for the existence of an epoxy function at this position came from the homonuclear couplings between H-7/H-6, in addition to HMBC couplings from C-7 and C-8 to H-6, H-9 and H 2 -10.…”

New Iridoids from <i>Scrophularia ningpoensis</i>

“…Compounds 3a and b were obtained as an inseparable mixture of two epimers in a 5 : 3 ratio according to of 3a and b (Table 1) were characteristic of iridoids and close resemblance to dihydrocatalpolgenin. 23) The difference between them was an additional methoxy signal presented both in 3a (δ 56.2, δ 3.36) and 3b (δ 56.3, δ 3.35). The methoxyls located at C-6 both in 3a and b were confirmed by HMBC correlations between 6-OMe (δ 3.36 in 3a)/C-6 (δ 79.8 in 3a) and 6-OMe (δ 3.35 in 3b)/C-6 (δ 81.7 in 3b).…”

“…While, a small value of J H1-H9 =4.0 Hz showed the hemiacetal hydroxyl was α configuration in 3b. 20,23) Therefore, the structures were elucidated as 1β-hydroxy-6β-methoxy-dihydrocatalpolgenin (3a) and 1α-hydroxy-6β-methoxy-dihydrocatalpolgenin (3b), respectively.…”