Achanta Venkata Narasimha Appa Rao

Antihyperglycemic activity of Caralluma attenuata

Extracts of Caralluma attenuata are screened for their antihyperglycemic activity. Ethanol, chloroform and butanol extracts were tested on glucose loaded and alloxan-induced diabetic rats. In both tests, the butanol extract, at the oral dose of 250 mg/kg, has shown statistically significant and considerable antihyperglycemic activity.

Acylated C-21 steroidal bisdesmosidic glycosides from Caraluma umbellata

From the whole plant of Caraluma umbellata, three new C-21 steroidal glycosides, named as carumbellosides III-V, were isolated and their structures elucidated by extensive spectroscopic experiments, devoid of any derivatisation, as caralumagenin 3-O-beta-D-glucopyranosyl(1-->4)-beta-D-digitalopyranoside-20-O-be ta- D-glucopyranoside, caralumagenin 3-O-beta-D-glucopyranosy(1-->4)- beta-D-digitalopyranoside-20-O-(2-O- benzoyl)-beta-D-glucopyranoside and caralumagenin 3-O-[6-O-benzoyl-beta-D-glucopyranosyl(1-->4)]-beta-D- digitalopyranoside-20-O-(2-O-benzoyl)-beta-D-glucopyranoside. The determination of the absolute configuration of the aglycone as (20 R), the conformations of the sugars and the unambiguous assignments of their NMR spectroscopic signals were achieved by a combination of 2D-NMR techniques. The isolates were devoid of significant cytotoxity in the UIC human cancer cell panel.

Bisdesmosidic pregnane glycosides from Caralluma lasiantha

Abstract From the whole plant of Caralluma lasiantha , two new bisdesmosidic C-21 steroidal (pregnane) glycosides, named as lasianthoside-A and -B, were isolated and their structures elucidated solely based on extensive 2D-NMR and MS/MS spectral analysis as caralasigenin 3- O -β- d -glucopyranosyl(1→4)-β- d -digitalopyranoside-20- O -α- l -rhamnosyl(1→6)-β- d -glucopyranoside and caralumagenin 3- O -β- d -glucopyranosyl(1→4)-β- d -digitalopyranoside-20- O -α- l -rhamnosyl(1→6)-β- d -glucopyranoside. In addition, a known flavonoid glycoside, luteolin neohesperidoside, was also isolated.

Antinociceptive and anti-inflammatory activity of carumbelloside-I isolated from Caralluma umbellata.

The phytochemical study using Caralluma umbellata (Asclepiadaceae) whole plant allowed the isolation of a novel pregnane glycoside named carumbelloside-I (3-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl-3beta,14beta -dihydroxypregn-5-en-20-one). Carumbelloside-I was evaluated for both antinociceptive activity and anti-inflammatory activity. The antinociceptive activity was evaluated in mice using the writhing test method, while the anti-inflammatory activity was evaluated in rats using the paw edema test with carrageenin. Carumbelloside-I has significant antinociceptive action. It has no anti-inflammatory activity.

Pregnane Glycosides from Caralluma adscendens var. fimbriata

Eleven novel pregnane glycosides, 2–7 and 9–13, of which four, i.e., 10–13, comprised a new pregnane‐type genin exhibiting a hydroxymethylene instead of a Me group at C(19), and the known pregnane glycoside stalagmoside V (8) were isolated from whole plants of Caralluma adscendens var. fimbriata, a native Indian succulent plant. Their structures were elucidated by extensive 2D‐NMR spectroscopic studies.

Rapid identification of cytotoxic alkenyl catechols in Semecarpus anacardium using bioassay-linked high performance liquid chromatography–electrospray/mass spectrometric analysis

Two alkenyl catechols were rapidly identified as probable cytotoxic constituents from the petroleum ether extract of Semecarpus anacardium using HPLC–electrospray/MS analysis linked to bioassay. These compounds were then isolated from the same extract using semi-prep HPLC and were proven to be 1,2-dihydroxy-3-pentadeca-7′,10′-dienylbenzene and 1,2-dihydroxy-3-pentadec-8′-enylbenzene, respectively, by comparison with physico-chemical data in the literature. Both isolates showed cytotoxic activities against a panel of human cancer cell lines. Copyright

Cycloartane triterpenes from dikamali, the gum resin of Gardenia gummifera and Gardenia lucida.

We report on the chemical investigation of dikamali gum, which is the resin of Gardenia gummifera and G. lucida (Rubiaceae). Six new cycloartane triterpenes, dikamaliartanes A–F (1–6, resp.), together with a known flavonoid (7), were isolated and identified by NMR spectroscopy. All six cycloartanes are characterized by an open A‐ring with a free COOH group at C(3). In four of them, the C‐atoms C(23)–C(27) form a 4‐methylfuran‐2‐yl moiety. Bacterial assays using Staphylococcus aureus, Candida albicans, and Mycobacteria have been carried out but did not reveal significant activity.

Chemical Investigation of the Fruits of Terminalia chebula

AbstractArjungenin and arjunglucoside-I have been isolated and characterised from an alcohol extract of the fruits of Terminalia chebula Retz. (Combretaceae); their 13C NMR data are reported for the first time.

Minor pregnanes from Caralluma adscendens var. gracilis and Caralluma pauciflora.

Phytochemical investigation of Caralluma adscendens var. gracilis and Caralluma pauciflora (Asclepiadaceae) whole plant extracts allowed to isolate one pregnane glycoside and two pregnanes characterized as 12β,20-O-dibenzoyl-5α,6-dihydrosarcostin β-oleandropyranosyl-(1→4)-β-cymaropyranosyl-(1→4)-β-digitoxypyranosyl-(1→4)-β-cymaropyranosyl-(1→4)-β-cymaropyranoside (1), 12β-O-benzoyl-3β,11α,14β,20R-pentahydroxy-pregn-5-ene (2), and 11α-O-benzoyl-3β,12β,14β,20R-pentahydroxy-pregn-5-ene (3), respectively. Their structural characterization was obtained on the basis of extensive NMR spectral studies. Three known pregnane glycosides along with lupeol and β-sitosterol were also isolated and characterized.

Flavonoids of Dikamali: A phytochemical reinvestigation.

Eleven known flavonoids (1–11) were isolated from Dikamali, the gum resin of Gardenia lucida. Three of them, desmethylnobiletin, pectolinarigenin and xanthomicrol, are a new report from this source. Nuclear magnetic resonance (NMR) data are being given for all the isolates. For two of them, viz., 3′,4′-dimethoxywogonin and 4′-hydroxywogonin, such data have not been reported in literature. Furthermore, correct NMR data are being provided for gardenin C as the data reported in literature were found to be incorrect.