Methyl 3-acet­oxy-3-dehydroxy­ursolate

Four of the five six-membered rings of the title penta­cyclic triterpene, C33H52O4, adopt chair conformations; the fifth, which has a C=C double bond, adopts an approximate envelope conformation

Methyl 3-dehydr­oxy-3-oxoursolate

Four of the five six-membered rings of the title penta­cylic triterpene, C31H48O3, adopt chair conformations; the fifth, which has a C=C double bond, adopts an approximate envelope conformation

[1R-(1α,2α,4α,5β,6α,7α)]-4-Benzoyl­oxymethyl-5,6-dihy­droxy-3,8-dioxa­tricyclo­[5.1.0.02,4]octan-5-yl acetate (3-deacetyl­crotepoxide) from Kaempferia rotunda Val.

The title compound, C16H16O7, isolated from Kaempferia rotunda rhizomes, features a six-membered cyclo­hexane ring that adopts a twisted-boat conformation owing to the presence of two adjacent epoxide attachments that lock in four of the six axial positions. The CH3CO2– and HO– substituents occupy equatorial positions. However, the bond angles at the ring carbon connected to the C6H5CO2CH2– substituent deviate signifcantly from the idealized tetra­hedral angles as the carbon atom is part of an epoxide ring. In the crystal, the molecules are linked into chains by O—H⋯O hydrogen bonds

(E)-3-(2H-1,3-Benzodioxol-5-yl)-1-(7-hy­droxy-5-meth­oxy-2,2-dimethyl­chroman-8-yl)prop-2-en-1-one

The reaction of 5,6-(2,2-dimethyl­chromane)-2-hy­droxy-4-meth­oxy­acetophenone and 3,4-methlene­dioxy­benzaldehyde affords the title chalcone derivative, C22H22O6. The two benzene rings are connected through a —C(=O)—CH=CH— (propenone) unit, which is in an E conformation; the ring with the hy­droxy substitutent is aligned at 6.2 (1)° with respect to this unit, whereas the ring with the methyl­enedi­oxy substituent is aligned at 8.2 (1)°. The dihdral angle between the rings is 14.32 (7)°. The hy­droxy group engages in an intra­molecular hydrogen bond with the carbonyl O atom of the propenone unit, generating an S(5) ring

(E)-1-(2-Hy­droxy-4,6-dimeth­oxy­phen­yl)-3-(4-meth­oxy­phen­yl)prop-2-en-1-one from Kaempferia rotunda Val.

The planar –CH=CHC(=O)– fragment (r.m.s. deviation = 0.074 Å) in the title compound, C18H18O5, connects the planar hy­droxy­dimeth­oxy­phenyl (r.m.s. deviation = 0.039 Å) and meth­oxy­lphenyl (r.m.s. deviation = 0.021 Å) parts. The central fragment forms a dihedral angle of 13.7 (1)° with the hy­droxy­dimeth­oxy­phenyl part and 32.0 (1)° with the meth­oxy­phenyl part. The hy­droxy group forms an intra­molecular hydrogen bond to the carbonyl O atom

1,3-Dihydr­oxy-9,10-dioxo-9,10-di­hydro­anthracene-2-carbaldehyde

The title compound, C15H8O5, also known as nordamnacanthal, was isolated from the Malaysian Morinda citrifolia L. The 20 non-H atoms are coplanar. The structure is stabilized by intra­molecular O—H⋯O hydrogen bonds and inter­molecular O—H⋯O and C—H⋯O hydrogen bonds, forming bilayers of mol­ecular tapes with alternating stacking directions along the a axis

Cardiovascular Activity of Labdane Diterpenes from Andrographis paniculata in Isolated Rat Hearts

The dichloromethane (DCM) extract of Andrographis paniculata Nees was tested for cardiovascular activity. The extract significantly reduced coronary perfusion pressure by up to 24.5 ± 3.0 mm Hg at a 3 mg dose and also reduced heart rate by up to 49.5 ± 11.4 beats/minute at this dose. Five labdane diterpenes, 14-deoxy-12-hydroxyandrographolide (1), 14-deoxy-11,12-didehydroandrographolide (2), 14-deoxyandrographolide (3), andrographolide (4), and neoandrographolide (5), were isolated from the aerial parts of this medicinal plant. Bioassay-guided studies using animal model showed that compounds, (2) and (3) were responsible for the coronary vasodilatation. This study also showed that andrographolide (4), the major labdane diterpene in this plant, has minimal effects on the heart

Flavokavain B from the rhizome of Alpinia mutica Roxb

The title compound [systematic name: (E)-1-(2-hydroxy-4,6-dimethoxyphenyl)-3-phenylprop-2-en-1-one], C17H16O4, has an aromatic ring at both ends of the –CH= CH–C(=O)– fragment with the –CH=CH– bond in a trans configuration. The phenyl ring is nearly coplanar with this fragment [dihedral angle 4.8 (3) °] as is the hy­droxy­ldimeth­oxy­lphenyl unit [dihedral angle 6.3 (3) °]. The hy­droxy group is the donor in an intra­molecular hydrogen bond to the double-bonded O atom

Cabraleahy­droxy­lactone from the leaves of Aglaia exima

Cabraleahy­droxy­lactone, C27H44O3, isolated from the leaves of Aglaia exima, has three six-membered rings fused together that adopt chair conformations. Its two five-membered rings are enveloped shaped. The hy­droxy group is in an axial position. It is a hydrogen-bond donor to the carbonyl O atom of an adjacent mol­ecule; the O—H⋯O inter­actions lead to the formation of a helical chain that runs along the b axis. There are two independent mol­ecules in the asymmetric unit