Godavarin K: a New Limonoid with an Oxygen Bridge between C(1) and C(29) from the Godavari Mangrove Xylocarpus moluccensis

Godavarin K ( 1 ), a new limonoid with an oxygen bridge between C(1) and C(29), was obtained from seeds of an Indian mangrove, Xylocarpus moluccensis, together with a known tetranortriterpene, 6‐de(acetyloxy)‐7‐deacetylchisocheton compound E (=(5α,7α,13α,17α)‐7‐hydroxy‐4,4,8‐trimethyl‐3‐oxocarda‐1,14‐dienolide; 2 ). The structure of godavarin K was established on the basis of spectroscopic data. In addition, the confusion of ¹H‐ and ¹³C‐NMR data for compound 2 in previous literature was clarified.     

Andhraxylocarpins A–E: Structurally Intriguing Limonoids from the True Mangroves Xylocarpus granatum and Xylocarpus moluccensis

Five new limonoids, including andhraxylocarpins A and B ( 1 and 2 ) which contain a 9‐oxa‐tricyclo[3.3.2.1^{7, 10}]undecane‐2‐ene motif, andhraxylocarpins C and D ( 3 and 4 ), which contain a (Z)‐bicyclo[5.2.1]dec‐3‐en‐8‐one substructure, and andhraxylocarpin E ( 5 ), which contains a tricyclo[3.3.1.1^{3, 6}]decane‐9‐one scaffold, were isolated from the seeds of two true mangroves, Xylocarpus granatum and Xylocarpus moluccensis, that were collected in the estuaries of Andhra Pradesh, India. The absolute configurations of these compounds were determined by extensive NMR investigations, single‐crystal X‐ray diffraction analysis, and by circular dichroism and optical rotatory dispersion spectroscopy, in combination with quantum‐chemical calculations. The pronounced structural diversity of limonoids from these mangroves might originate from environmental factors.     

Delaying of cataract through intervention of Hemidesmus indicus in STZ induced diabetic rats

Hemidesmus indicus (L.) R. Br. was extensively used as hypoglycaemic agent and significance of this plant on secondary complications of diabetes remained unknown. The present study was to investigate the anti-cataractous activity of H. indicus against streptozotocin (STZ)-induced diabetic cataract in rodent model. Root extracts have been prepared and tested for inhibition of rat lens aldose reductase (AR) activity. In addition, its pharmacological potential has been investigated in STZ-induced diabetic cataract. Methanol extract of H. indicus-inhibited AR activity in vitro decreased the blood glucose levels, inhibited the AR activity and delayed the onset and progression of cataract in a dose-dependent manner in in vivo and the antioxidant markers have been normalised. Our results demonstrate that H. indicus has decrease the osmotic stress by inhibiting the AR activity and prevented the loss of antioxidants and delayed the progression of diabetic cataract in STZ-induced diabetic rats.