Crystal and molecular structure of 5α-acetoxy-6β-bromohexahydrophysalin A

Three new physalins from Physalis alkekengi var. franchetii

“…The relative configurations of H-8 and Me-28 in the physalin skeleton were established to be β-oriented by X-ray. 20,21 Thus, the NOE correlations (Figure 1) of H-4/H-6, H-6/H-7, H-7/H-8β, and H-27/Me-28 established the relative configuration of OH-4 and OH-7 to be α-oriented and Me-27 to be β-oriented. Hence, the structure of compound 1 was identified to be physalin III (1).…”

“…The relative configuration of Me-19 and H-16 in physalin skeleton were established to be β-oriented by X-ray. 20,21 So the relative configuration of 3-OMe could be determined as α-oriented by the NOE correlations of Me-19/H-3 and H-16/H-3. Hence, the structure of compound 3 was identified to be 3-O-methylphysalin X (3).…”

“…Physalins, as one of the characteristic constituents from P. alkekengi var. franchetii, is a type of steroids with 16,24-cyclo-13,14-seco-ergostane skeleton which has been established by X-ray crystallographic analysis [5][6][7] . Neophysalins, are another characteristic structure, and are transformed from physalins through an acid-induced benzilic acid-type rearrangement reaction 8 .…”

Antileishmanial Physalins fromPhysalis minima

“…The configuration at C(5) was deduced by comparing the 13 C-NMR data with literature values [21]. The basic skeleton of physalins has previously been determined by singlecrystal diffraction analysis [22] [23]. From the aforementioned data, the structure of compound 1 was deduced as 16,24-cyclo-13,14-secoergost-2-ene-18,26-dioic acid 14 : 17,14 : 27-diepoxy-5a,6b,11b,13,20,22-hexahydroxy-1,15-dioxo-g-lactone d-lactone 1 ).…”

Structure of 4,7-didehydroneophysalin B, acid-induced rearrangement product of physalin A

“…possessing a 13,14-seco-16,24-cycloergostane skeleton (Matsuura, Kawai, Nakashima & Butsugan, 1970). The structure of (I) is based on the X-ray analysis of a bromine-containing derivative of (I) (Kawai, Matsuura, Taga & Osaki, 1970). Reinvestigation of the acid-induced dehydration products of (I) using ~H and ~3C NMR spectroscopy, however, revealed that one of the products, (II), does not maintain the original carbon skeleton (Kawai, Ogura, Butsugan, Taga & Hayashi, 1991).…”