Coix lacryma-jobi chymotrypsin inhibitor displays antifungal activity.

A novel chymotrypsin inhibitor, named ClCI, was purified from coix seed (Coix lacryma-jobi L.) by aqueous two-phase extraction, chymotrypsin-Sepharose 4B affinity chromatography and centrifugal ultrafiltration. ClCI was a 7.9 kDa competitive inhibitor with pI 6.54. The inhibition constants (Ki) for bovine pancreatic chymotrypsin and bacterial subtilisin were 1.27 × 10-10 M and 1.57 × 10-9 M respectively. ClCI had no inhibitory activity against bovine trypsin and porcine elastase. ClCI had wide pH stability and good heat resistance. It can maintain >90% inhibition activity against chymotrypsin at 20-80 °C for 1 h. The primary structure of ClCI was highly similar (57%-92%) to those of several inhibitors belonging to the Gramineae crop potato protease inhibitor- I superfamily and showed the typical sequence motif of the protease inhibitor of the seed storage protein group. ClCI (12.5 mg) inhibited mycelial growth of the phytopathogenic fungi Mycosphaerella melonis, Helminthosporium turcicum, Alternaria solani, Phytophthora capsici, Isariopsis griseola, and Colletotrichum gloeosporioides, and caused 89% inhibition of the proteases from spore germination of plant-pathogenic fungi. The results of the present study indicate that ClCI had biotechnological potential as an alternative agent to combat the important phytopathogenic fungi.

Application of Fourier transform near-infrared spectroscopy combined with GC in rapid and simultaneous determination of essential components in Amomum villosum.

A method is described using rapid and sensitive Fourier transform near-infrared spectroscopy combined with Gas Chromatograpy internal standard method detection for the simultaneous identification and determination of three bioactive compounds in Amomum villosum samples. Partial least squares regression is selected as the analysis type and multiplicative scatter correction, second derivative, and SNV were adopted for the spectral pretreatment. The correlation coefficients (R) of the calibration models were above 0.95 and the root mean square error of predictions were under 0.8. The developed models were applied to unknown samples with satisfantory results. The established method was validated and can be applied to the intrinsic quality control of Amomum villosum.