Synthesis and antimicrobial evaluation of piperic acid amides and their lower homologues.

Seven piperic acid amides along with their lower homologs (12) were synthesized using HATU-DIPEA coupling reagent. All the synthesized derivatives were evaluated for their antibacterial activities against Staphylococcus aureus, Pseudomonas aeruginosa, and vancomycin-resistant P. aeruginosa. They were found to be more active on P. aeruginosa than on S. aureus. However, they did not exhibit potent activity on Vancomycin resistant P. aeruginosa. Among the tested compounds, methylenedioxycinnamic acid amide of anthranilic acid (MDCA-AA, 2a) was found to be most active against S. aureus with MIC of 3.125 µg/ml. The PAS and INH amides of piperic acid were screened against Mycobacterium tuberculosis H37Ra strain. They were found to be most active among all the tested compounds but were found to be less active than the standard drug, isoniazid.

Differentiating the gum resins of two closely related Indian Gardenia species, G. gummifera and G. lucida, and establishing the source of dikamali gum resin using high-performance thin-layer chromatography and ultra-performance liquid chromatography-UV/MS.

Dikamali is a gum resin obtained from the leaf buds of Gardenia lucida or G. gummifera. There is controversy regarding the botanical source of this gum resin with some stating it to be from G. lucida while others claim it to be from G. gummifera. Analytical methods including UPLC and HPTLC were developed for the qualitative analysis of Gardenia species and various commercial samples. The separation using a UPLC method was achieved within 12.0 min by using C18 column material, a water/acetonitrile mobile phase, both containing formic acid, a gradient system, and a temperature of 40 degrees C. Extensive studies of dikamali collected from various parts of India in comparison with the gum resins collected from G. lucida and G. gummifera clearly indicated that the botanical source of commercially available dikamali is G. lucida, not G. gummifera. The marker compounds isolated from a market sample of dikamali were present only in the gum resin of G. lucida and the compounds isolated from G. gummifera were not present in any of the dikamali samples, confirming the botanical source of dikamali. This work is of utmost importance, given the ambiguity regarding the botanical source of the gum resin dikamali. LC/MS coupled with electrospray ionization is described for the identification and confirmation of nine compounds from various samples of the gum resin. An HPTLC method was also developed for the fast chemical fingerprint analysis of Gardenia samples.

Flavone C-glycosides from Trichuriella monsoniae (L.f.) Bennet.

In the first phytochemical investigation of Trichuriella monsoniae, three known flavonoidal C-glycosides, isoswertisin 1, 2″-O-ß-d-galactosyl isoswertisin 2 and 2″-O-ß-d-xylosyl isoswertisin 3 were isolated from the methanolic extract of the whole plant. Their structures were elucidated by extensive NMR spectroscopic studies including 2D NMR and HRMS, and the structure of 2 was supported by single crystal X-ray data studies. Further, NMR assignments for 3 are being reported for the first time.

New malabaricane triterpenes from the oleoresin of Ailanthus malabarica.

Ten malabaricane type triterpenes were isolated from the oleoresin of Ailanthus malabarica, out of which six (1-6) were new. For three of the known compounds (7-9), NMR assignments are being reported for the first time. Compound 10, a known one, is a new report from this source. The structures were established by extensive 1D and 2D NMR spectroscopy. The oleoresin and some of the isolates did not possess antimicrobial activity and did not lyse RBCs.